Bump Tokio to v0.1.15. (#869)

Also bumps:

- tokio-sync (0.1.0)
- tokio-threadpool (0.1.11)
- tokio-timer (0.2.9)

.appveyor.yml

@@ -1,3 +1,4 @@
+image: Visual Studio 2017
 environment:
   matrix:
   - TARGET: x86_64-pc-windows-msvc
@@ -9,6 +10,8 @@ install:
   - appveyor-retry appveyor DownloadFile https://win.rustup.rs/ -FileName rustup-init.exe
   - rustup-init.exe -y --default-host %TARGET%
   - set PATH=%PATH%;C:\Users\appveyor\.cargo\bin
+  - set RUST_BACKTRACE=1
+  - set LOOM_MAX_DURATION=10
 
   - rustc -V
   - cargo -V
@@ -16,4 +19,4 @@ install:
 build: false
 
 test_script:
-  - cargo test --all --target %TARGET%
+  - cargo test --all --no-fail-fast --target %TARGET%

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,51 @@
+<!--
+Thank you for reporting an issue.
+
+Please fill in as much of the template below as you're able.
+-->
+
+## Version
+
+<!--
+List the versions of all `tokio` crates you are using. The easiest way to get
+this information is using `cargo-tree`.
+
+`cargo install cargo-tree`
+(see install here: https://github.com/sfackler/cargo-tree)
+
+Then:
+
+`cargo tree | grep tokio`
+-->
+
+## Platform
+
+<!---
+Output of `uname -a` (UNIX), or version and 32 or 64-bit (Windows)
+-->
+
+## Subcrates
+
+<!--
+If known, please specify the affected Tokio sub crates. Otherwise, delete this
+section.
+-->
+
+## Description
+
+<!--
+
+Enter your issue details below this comment.
+
+One way to structure the description:
+
+<short summary of the bug>
+
+I tried this code:
+
+<code sample that causes the bug>
+
+I expected to see this happen: <explanation>
+
+Instead, this happened: <explanation>
+-->

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,23 @@
+<!--
+Thank you for your Pull Request. Please provide a description above and review
+the requirements below.
+
+Bug fixes and new features should include tests.
+
+Contributors guide: https://github.com/tokio-rs/tokio/blob/master/CONTRIBUTING.md
+-->
+
+## Motivation
+
+<!--
+Explain the context and why you're making that change. What is the problem
+you're trying to solve? In some cases there is not a problem and this can be
+thought of as being the motivation for your change.
+-->
+
+## Solution
+
+<!--
+Summarize the solution and provide any necessary context needed to understand
+the code change.
+-->

.travis.yml

@@ -1,9 +1,6 @@
 ---
 language: rust
 sudo: false
-cache:
-  - apt
-  - cargo
 addons:
   apt:
     packages:
@@ -12,23 +9,53 @@ addons:
 
 matrix:
   include:
-  # This represents the minimum Rust version supported by Tokio. Updating this
-  # should be done in a dedicated PR and cannot be greater than two 0.x
-  # releases prior to the current stable.
-  - rust: 1.25.0
   - rust: stable
   - rust: beta
   - rust: nightly
+    env: ALLOW_FAILURES=true
   - os: osx
   - env: TARGET=x86_64-unknown-freebsd
   - env: TARGET=i686-unknown-freebsd
   - env: TARGET=i686-unknown-linux-gnu
 
-script:
-  - |
-    set -e
-    if [[ "$TRAVIS_RUST_VERSION" == nightly ]]
-    then
+  # This represents the minimum Rust version supported by Tokio. Updating this
+  # should be done in a dedicated PR and cannot be greater than two 0.x
+  # releases prior to the current stable.
+  #
+  # Tests are not run as tests may require newer versions of rust.
+  - rust: 1.26.0
+    script: |
+      cargo check --all
+
+  # Test combinations of enabled features.
+  - rust: stable
+    script: |
+      shopt -s expand_aliases
+      alias check="cargo check --no-default-features"
+      check
+      check --features codec
+      check --features fs
+      check --features io
+      check --features reactor
+      check --features rt-full
+      check --features tcp
+      check --features timer
+      check --features udp
+      check --features uds
+
+  # Test the async / await preview. We don't want to block PRs on this failing
+  # though.
+  - rust: nightly
+    env: ALLOW_FAILURES=true
+    script: |
+      cd tokio-async-await
+      cargo check --all
+
+  # This runs TSAN against nightly and allows failures to propagate up.
+  - rust: nightly-2018-11-18
+    env: TSAN=yes
+    script: |
+        set -e
         # Make sure the benchmarks compile
         cargo build --benches --all
 
@@ -55,22 +82,30 @@ script:
         # Run thread sanitizer
         RUSTFLAGS="-Z sanitizer=thread" \
         cargo test -p tokio-threadpool --tests --target x86_64-unknown-linux-gnu
-    fi
-  - |
-    set -e
-    if [[ "$TARGET" ]]
-    then
-        rustup target add $TARGET
-        cargo check --all --exclude tokio-tls --target $TARGET
-        cargo check --tests --all --exclude tokio-tls --target $TARGET
-    else
-        cargo test --all
-        # Disable these tests for now as they are buggy
-        #
-        # cargo test --features unstable-futures
-        # cargo test --manifest-path tokio-threadpool/Cargo.toml --features unstable-futures
-        # cargo test --manifest-path tokio-reactor/Cargo.toml --features unstable-futures
-    fi
+
+  # This runs cargo +nightly doc
+  - name: nightly_docs
+    rust: nightly
+    env: ALLOW_FAILURES=true
+    script: cargo doc
+
+  allow_failures:
+    - rust: nightly
+      env: ALLOW_FAILURES=true
+
+script: |
+  set -e
+  if [[ "$TARGET" ]]
+  then
+      rustup target add $TARGET
+      cargo check --all --exclude tokio-tls --target $TARGET
+      cargo check --tests --all --exclude tokio-tls --target $TARGET
+  else
+      # Limit the execution time of loom tests.
+      export LOOM_MAX_DURATION=10
+      cargo test --all --no-fail-fast
+      cargo doc --all
+  fi
 
 before_deploy:
   - cargo doc --all --no-deps
@@ -85,7 +120,7 @@ deploy:
     branch: master
     repo: tokio-rs/tokio
     rust: stable
-    condition: $TRAVIS_OS_NAME = linux
+    condition: $TRAVIS_OS_NAME = "linux" && $TARGET = ""
 
 env:
   global:

CHANGELOG.md

@@ -1,6 +1,55 @@
 This changelog only applies to the `tokio` crate proper. Each sub crate
 maintains its own changelog tracking changes made in each respective sub crate.
 
+# 0.1.15 (January 24, 2019)
+
+### Added
+- Re-export tokio-sync APIs (#839).
+- Stream enumerate combinator (#832).
+
+# 0.1.14 (January 6, 2019)
+
+* Use feature flags to break up the crate, allowing users to pick & choose
+  components (#808).
+* Export `UnixDatagram` and `UnixDatagramFramed` (#772).
+
+# 0.1.13 (November 21, 2018)
+
+* Fix `Runtime::reactor()` when no tasks are spawned (#721).
+* `runtime::Builder` no longer uses deprecated methods (#749).
+* Provide `after_start` and `before_stop` configuration settings for
+  `Runtime` (#756).
+* Implement throttle stream combinator (#736).
+
+# 0.1.12 (October 23, 2018)
+
+* runtime: expose `keep_alive` on runtime builder (#676).
+* runtime: create a reactor per worker thread (#660).
+* codec: fix panic in `LengthDelimitedCodec` (#682).
+* io: re-export `tokio_io::io::read` function (#689).
+* runtime: check for executor re-entry in more places (#708).
+
+# 0.1.11 (September 28, 2018)
+
+* Fix `tokio-async-await` dependency (#675).
+
+# 0.1.10 (September 27, 2018)
+
+* Fix minimal versions
+
+# 0.1.9 (September 27, 2018)
+
+* Experimental async/await improvements (#661).
+* Re-export `TaskExecutor` from `tokio-current-thread` (#652).
+* Improve `Runtime` builder API (#645).
+* `tokio::run` panics when called from the context of an executor
+  (#646).
+* Introduce `StreamExt` with a `timeout` helper (#573).
+* Move `length_delimited` into `tokio` (#575).
+* Re-organize `tokio::net` module (#548).
+* Re-export `tokio-current-thread::spawn` in current_thread runtime
+  (#579).
+
 # 0.1.8 (August 23, 2018)
 
 * Extract tokio::executor::current_thread to a sub crate (#370)

CONTRIBUTING.md

@@ -0,0 +1,387 @@
+# Contributing to Tokio
+
+:balloon: Thanks for your help improving the project! We are so happy to have
+you!
+
+There are opportunities to contribute to Tokio at any level. It doesn't matter if
+you are just getting started with Rust or are the most weathered expert, we can
+use your help.
+
+**No contribution is too small and all contributions are valued.**
+
+This guide will help you get started. **Do not let this guide intimidate you**.
+It should be considered a map to help you navigate the process.
+
+You may also get help with contributing in the [dev channel][dev], please join
+us!
+
+[dev]: https://gitter.im/tokio-rs/dev
+
+## Conduct
+
+The Tokio project adheres to the [Rust Code of Conduct][coc]. This describes
+the _minimum_ behavior expected from all contributors.
+
+[coc]: https://github.com/rust-lang/rust/blob/master/CODE_OF_CONDUCT.md
+
+## Contributing in Issues
+
+For any issue, there are fundamentally three ways an individual can contribute:
+
+1. By opening the issue for discussion: For instance, if you believe that you
+   have uncovered a bug in Tokio, creating a new issue in the tokio-rs/tokio
+   issue tracker is the way to report it.
+
+2. By helping to triage the issue: This can be done by providing
+   supporting details (a test case that demonstrates a bug), providing
+   suggestions on how to address the issue, or ensuring that the issue is tagged
+   correctly.
+
+3. By helping to resolve the issue: Typically this is done either in the form of
+   demonstrating that the issue reported is not a problem after all, or more
+   often, by opening a Pull Request that changes some bit of something in
+   Tokio in a concrete and reviewable manner.
+
+**Anybody can participate in any stage of contribution**. We urge you to
+participate in the discussion around bugs and participate in reviewing PRs.
+
+### Asking for General Help
+
+If you have reviewed existing documentation and still have questions or are
+having problems, you can open an issue asking for help.
+
+In exchange for receiving help, we ask that you contribute back a documentation
+PR that helps others avoid the problems that you encountered.
+
+### Submitting a Bug Report
+
+When opening a new issue in the Tokio issue tracker, users will be presented
+with a [basic template][template] that should be filled in. If you believe that you have
+uncovered a bug, please fill out this form, following the template to the best
+of your ability. Do not worry if you cannot answer every detail, just fill in
+what you can.
+
+The two most important pieces of information we need in order to properly
+evaluate the report is a description of the behavior you are seeing and a simple
+test case we can use to recreate the problem on our own. If we cannot recreate
+the issue, it becomes impossible for us to fix.
+
+In order to rule out the possibility of bugs introduced by userland code, test
+cases should be limited, as much as possible, to using only Tokio APIs.
+
+See [How to create a Minimal, Complete, and Verifiable example][mcve].
+
+[mcve]: https://stackoverflow.com/help/mcve
+[template]: .github/PULL_REQUEST_TEMPLATE.md
+
+### Triaging a Bug Report
+
+Once an issue has been opened, it is not uncommon for there to be discussion
+around it. Some contributors may have differing opinions about the issue,
+including whether the behavior being seen is a bug or a feature. This discussion
+is part of the process and should be kept focused, helpful, and professional.
+
+Short, clipped responses—that provide neither additional context nor supporting
+detail—are not helpful or professional. To many, such responses are simply
+annoying and unfriendly.
+
+Contributors are encouraged to help one another make forward progress as much as
+possible, empowering one another to solve issues collaboratively. If you choose
+to comment on an issue that you feel either is not a problem that needs to be
+fixed, or if you encounter information in an issue that you feel is incorrect,
+explain why you feel that way with additional supporting context, and be willing
+to be convinced that you may be wrong. By doing so, we can often reach the
+correct outcome much faster.
+
+### Resolving a Bug Report
+
+In the majority of cases, issues are resolved by opening a Pull Request. The
+process for opening and reviewing a Pull Request is similar to that of opening
+and triaging issues, but carries with it a necessary review and approval
+workflow that ensures that the proposed changes meet the minimal quality and
+functional guidelines of the Tokio project.
+
+## Pull Requests
+
+Pull Requests are the way concrete changes are made to the code, documentation,
+and dependencies in the Tokio repository.
+
+Even tiny pull requests (e.g., one character pull request fixing a typo in API
+documentation) are greatly appreciated. Before making a large change, it is
+usually a good idea to first open an issue describing the change to solicit
+feedback and guidance. This will increase the likelihood of the PR getting
+merged.
+
+### Tests
+
+If the change being proposed alters code (as opposed to only documentation for
+example), it is either adding new functionality to Tokio or it is fixing
+existing, broken functionality. In both of these cases, the pull request should
+include one or more tests to ensure that Tokio does not regress in the future.
+There are two ways to write tests: integration tests and documentation tests
+(Tokio avoids unit tests as much as possible).
+
+#### Integration tests
+
+Integration tests go in the same crate as the code they are testing. Each sub
+crate should have a `dev-dependency` on `tokio` itself. This makes all Tokio
+utilities available to use in tests, no matter the crate being tested.
+
+The best strategy for writing a new integration test is to look at existing
+integration tests in the crate and follow the style.
+
+#### Documentation tests
+
+Ideally, every API has at least one [documentation test] that demonstrates how to
+use the API. Documentation tests are run with `cargo test --doc`. This ensures
+that the example is correct and provides additional test coverage.
+
+The trick to documentation tests is striking a balance between being succinct
+for a reader to understand and actually testing the API.
+
+Same as with integration tests, when writing a documentation test, the full
+`tokio` crate is available. This is especially useful for getting access to the
+runtime to run the example.
+
+The documentation tests will be visible from both the crate specific
+documentation **and** the `tokio` facade documentation via the re-export. The
+example should be written from the point of view of a user that is using the
+`tokio` crate. As such, the example should use the API via the facade and not by
+directly referencing the crate.
+
+The type level example for `tokio_timer::Timeout` provides a good example of a
+documentation test:
+
+```
+/// # extern crate futures;
+/// # extern crate tokio;
+/// // import the `timeout` function, usually this is done
+/// // with `use tokio::prelude::*`
+/// use tokio::prelude::FutureExt;
+/// use futures::Stream;
+/// use futures::sync::mpsc;
+/// use std::time::Duration;
+///
+/// # fn main() {
+/// let (tx, rx) = mpsc::unbounded();
+/// # tx.unbounded_send(()).unwrap();
+/// # drop(tx);
+///
+/// let process = rx.for_each(|item| {
+///     // do something with `item`
+/// # drop(item);
+/// # Ok(())
+/// });
+///
+/// # tokio::runtime::current_thread::block_on_all(
+/// // Wrap the future with a `Timeout` set to expire in 10 milliseconds.
+/// process.timeout(Duration::from_millis(10))
+/// # ).unwrap();
+/// # }
+```
+
+Given that this is a *type* level documentation test and the primary way users
+of `tokio` will create an instance of `Timeout` is by using
+`FutureExt::timeout`, this is how the documentation test is structured.
+
+Lines that start with `/// #` are removed when the documentation is generated.
+They are only there to get the test to run. The `block_on_all` function is the
+easiest way to execute a future from a test.
+
+If this were a documentation test for the `Timeout::new` function, then the
+example would explicitly use `Timeout::new`. For example:
+
+```
+/// # extern crate futures;
+/// # extern crate tokio;
+/// use tokio::timer::Timeout;
+/// use futures::Future;
+/// use futures::sync::oneshot;
+/// use std::time::Duration;
+///
+/// # fn main() {
+/// let (tx, rx) = oneshot::channel();
+/// # tx.send(()).unwrap();
+///
+/// # tokio::runtime::current_thread::block_on_all(
+/// // Wrap the future with a `Timeout` set to expire in 10 milliseconds.
+/// Timeout::new(rx, Duration::from_millis(10))
+/// # ).unwrap();
+/// # }
+```
+
+### Commits
+
+It is a recommended best practice to keep your changes as logically grouped as
+possible within individual commits. There is no limit to the number of commits
+any single Pull Request may have, and many contributors find it easier to review
+changes that are split across multiple commits.
+
+That said, if you have a number of commits that are "checkpoints" and don't
+represent a single logical change, please squash those together.
+
+Note that multiple commits often get squashed when they are landed (see the
+notes about [commit squashing]).
+
+#### Commit message guidelines
+
+A good commit message should describe what changed and why.
+
+1. The first line should:
+
+  * contain a short description of the change (preferably 50 characters or less,
+    and no more than 72 characters)
+  * be entirely in lowercase with the exception of proper nouns, acronyms, and
+    the words that refer to code, like function/variable names
+  * be prefixed with the name of the sub crate being changed (without the `tokio-`
+    prefix) and start with an imperative verb. If modifying `tokio` proper,
+    omit the crate prefix.
+
+  Examples:
+
+  * timer: introduce `Timeout` and deprecate `Deadline`
+  * export `Encoder`, `Decoder`, `Framed*` from tokio_codec
+
+2. Keep the second line blank.
+3. Wrap all other lines at 72 columns (except for long URLs).
+4. If your patch fixes an open issue, you can add a reference to it at the end
+   of the log. Use the `Fixes: #` prefix and the issue number. For other
+   references use `Refs: #`. `Refs` may include multiple issues, separated by a
+   comma.
+
+   Examples:
+
+   - `Fixes: #1337`
+   - `Refs: #1234`
+
+Sample complete commit message:
+
+```txt
+subcrate: explain the commit in one line
+
+Body of commit message is a few lines of text, explaining things
+in more detail, possibly giving some background about the issue
+being fixed, etc.
+
+The body of the commit message can be several paragraphs, and
+please do proper word-wrap and keep columns shorter than about
+72 characters or so. That way, `git log` will show things
+nicely even when it is indented.
+
+Fixes: #1337
+Refs: #453, #154
+```
+
+### Opening the Pull Request
+
+From within GitHub, opening a new Pull Request will present you with a
+[template] that should be filled out. Please try to do your best at filling out
+the details, but feel free to skip parts if you're not sure what to put.
+
+[template]: .github/PULL_REQUEST_TEMPLATE.md
+
+### Discuss and update
+
+You will probably get feedback or requests for changes to your Pull Request.
+This is a big part of the submission process so don't be discouraged! Some
+contributors may sign off on the Pull Request right away, others may have
+more detailed comments or feedback. This is a necessary part of the process
+in order to evaluate whether the changes are correct and necessary.
+
+**Any community member can review a PR and you might get conflicting feedback**.
+Keep an eye out for comments from code owners to provide guidance on conflicting
+feedback.
+
+**Once the PR is open, do not rebase the commits**. See [Commit Squashing] for
+more details.
+
+### Commit Squashing
+
+In most cases, **do not squash commits that you add to your Pull Request during
+the review process**. When the commits in your Pull Request land, they may be
+squashed into one commit per logical change. Metadata will be added to the
+commit message (including links to the Pull Request, links to relevant issues,
+and the names of the reviewers). The commit history of your Pull Request,
+however, will stay intact on the Pull Request page.
+
+## Reviewing Pull Requests
+
+**Any Tokio community member is welcome to review any pull request**.
+
+All Tokio contributors who choose to review and provide feedback on Pull
+Requests have a responsibility to both the project and the individual making the
+contribution. Reviews and feedback must be helpful, insightful, and geared
+towards improving the contribution as opposed to simply blocking it. If there
+are reasons why you feel the PR should not land, explain what those are. Do not
+expect to be able to block a Pull Request from advancing simply because you say
+"No" without giving an explanation. Be open to having your mind changed. Be open
+to working with the contributor to make the Pull Request better.
+
+Reviews that are dismissive or disrespectful of the contributor or any other
+reviewers are strictly counter to the Code of Conduct.
+
+When reviewing a Pull Request, the primary goals are for the codebase to improve
+and for the person submitting the request to succeed. **Even if a Pull Request
+does not land, the submitters should come away from the experience feeling like
+their effort was not wasted or unappreciated**. Every Pull Request from a new
+contributor is an opportunity to grow the community.
+
+### Review a bit at a time.
+
+Do not overwhelm new contributors.
+
+It is tempting to micro-optimize and make everything about relative performance,
+perfect grammar, or exact style matches. Do not succumb to that temptation.
+
+Focus first on the most significant aspects of the change:
+
+1. Does this change make sense for Tokio?
+2. Does this change make Tokio better, even if only incrementally?
+3. Are there clear bugs or larger scale issues that need attending to?
+4. Is the commit message readable and correct? If it contains a breaking change
+   is it clear enough?
+
+Note that only **incremental** improvement is needed to land a PR. This means
+that the PR does not need to be perfect, only better than the status quo. Follow
+up PRs may be opened to continue iterating.
+
+When changes are necessary, *request* them, do not *demand* them, and **do not
+assume that the submitter already knows how to add a test or run a benchmark**.
+
+Specific performance optimization techniques, coding styles and conventions
+change over time. The first impression you give to a new contributor never does.
+
+Nits (requests for small changes that are not essential) are fine, but try to
+avoid stalling the Pull Request. Most nits can typically be fixed by the Tokio
+Collaborator landing the Pull Request but they can also be an opportunity for
+the contributor to learn a bit more about the project.
+
+It is always good to clearly indicate nits when you comment: e.g.
+`Nit: change foo() to bar(). But this is not blocking.`
+
+If your comments were addressed but were not folded automatically after new
+commits or if they proved to be mistaken, please, [hide them][hiding-a-comment]
+with the appropriate reason to keep the conversation flow concise and relevant.
+
+### Be aware of the person behind the code
+
+Be aware that *how* you communicate requests and reviews in your feedback can
+have a significant impact on the success of the Pull Request. Yes, we may land
+a particular change that makes Tokio better, but the individual might just not
+want to have anything to do with Tokio ever again. The goal is not just having
+good code.
+
+### Abandoned or Stalled Pull Requests
+
+If a Pull Request appears to be abandoned or stalled, it is polite to first
+check with the contributor to see if they intend to continue the work before
+checking if they would mind if you took it over (especially if it just has nits
+left). When doing so, it is courteous to give the original contributor credit
+for the work they started (either by preserving their name and email address in
+the commit log, or by using an `Author: ` meta-data tag in the commit.
+
+_Adapted from the [Node.js contributing guide][node]_.
+
+[node]: https://github.com/nodejs/node/blob/master/CONTRIBUTING.md
+[hiding-a-comment]: https://help.github.com/articles/managing-disruptive-comments/#hiding-a-comment
+[documentation test]: https://doc.rust-lang.org/rustdoc/documentation-tests.html

Cargo.toml

@@ -1,16 +1,17 @@
 [package]
 name = "tokio"
-
 # When releasing to crates.io:
 # - Update html_root_url.
+# - Update doc url
+#   - Cargo.toml
+#   - README.md
 # - Update CHANGELOG.md.
-# - Update doc URL.
 # - Create "v0.1.x" git tag.
-version = "0.1.8"
+version = "0.1.15"
 authors = ["Carl Lerche <[email protected]>"]
 license = "MIT"
 readme = "README.md"
-documentation = "https://docs.rs/tokio/0.1.8/tokio/"
+documentation = "https://docs.rs/tokio/0.1.15/tokio/"
 repository = "https://github.com/tokio-rs/tokio"
 homepage = "https://tokio.rs"
 description = """
@@ -24,12 +25,16 @@ keywords = ["io", "async", "non-blocking", "futures"]
 
 members = [
   "./",
+  "tokio-async-await",
+  "tokio-buf",
   "tokio-codec",
   "tokio-current-thread",
   "tokio-executor",
   "tokio-fs",
   "tokio-io",
   "tokio-reactor",
+  "tokio-signal",
+  "tokio-sync",
   "tokio-threadpool",
   "tokio-timer",
   "tokio-tcp",
@@ -38,32 +43,77 @@ members = [
   "tokio-uds",
 ]
 
+[features]
+default = [
+  "codec",
+  "fs",
+  "io",
+  "reactor",
+  "rt-full",
+  "sync",
+  "tcp",
+  "timer",
+  "udp",
+  "uds",
+]
+
+codec = ["tokio-codec"]
+fs = ["tokio-fs"]
+io = ["bytes", "tokio-io"]
+reactor = ["io", "mio", "tokio-reactor"]
+rt-full = [
+  "num_cpus",
+  "reactor",
+  "timer",
+  "tokio-current-thread",
+  "tokio-executor",
+  "tokio-threadpool",
+]
+sync = ["tokio-sync"]
+tcp = ["tokio-tcp"]
+timer = ["tokio-timer"]
+udp = ["tokio-udp"]
+uds = ["tokio-uds"]
+
+# This feature comes with no promise of stability. Things will
+# break with each patch release. Use at your own risk.
+async-await-preview = [
+  "tokio-async-await/async-await-preview",
+]
+
 [badges]
 travis-ci = { repository = "tokio-rs/tokio" }
 appveyor = { repository = "carllerche/tokio", id = "s83yxhy9qeb58va7" }
 
 [dependencies]
-tokio-codec = { version = "0.1.0", path = "tokio-codec" }
-tokio-current-thread = { version = "0.1.1", path = "tokio-current-thread" }
-tokio-io = { version = "0.1.6", path = "tokio-io" }
-tokio-executor = { version = "0.1.2", path = "tokio-executor" }
-tokio-reactor = { version = "0.1.1", path = "tokio-reactor" }
-tokio-threadpool = { version = "0.1.4", path = "tokio-threadpool" }
-tokio-tcp = { version = "0.1.0", path = "tokio-tcp" }
-tokio-udp = { version = "0.1.0", path = "tokio-udp" }
-tokio-timer = { version = "0.2.6", path = "tokio-timer" }
-tokio-fs = { version = "0.1.3", path = "tokio-fs" }
-
+# Only non-optional dependency...
 futures = "0.1.20"
 
+# Everything else is optional...
+bytes = { version = "0.4", optional = true }
+num_cpus = { version = "1.8.0", optional = true }
+tokio-codec = { version = "0.1.0", path = "tokio-codec", optional = true }
+tokio-current-thread = { version = "0.1.3", path = "tokio-current-thread", optional = true }
+tokio-fs = { version = "0.1.3", path = "tokio-fs", optional = true }
+tokio-io = { version = "0.1.6", path = "tokio-io", optional = true }
+tokio-executor = { version = "0.1.5", path = "tokio-executor", optional = true }
+tokio-reactor = { version = "0.1.1", path = "tokio-reactor", optional = true }
+tokio-sync = { version = "0.1.0", path = "tokio-sync", optional = true }
+tokio-threadpool = { version = "0.1.8", path = "tokio-threadpool", optional = true }
+tokio-tcp = { version = "0.1.0", path = "tokio-tcp", optional = true }
+tokio-udp = { version = "0.1.0", path = "tokio-udp", optional = true }
+tokio-timer = { version = "0.2.8", path = "tokio-timer", optional = true }
+
 # Needed until `reactor` is removed from `tokio`.
-mio = "0.6.14"
+mio = { version = "0.6.14", optional = true }
+
+# Needed for async/await preview support
+tokio-async-await = { version = "0.1.0", path = "tokio-async-await", optional = true }
 
 [target.'cfg(unix)'.dependencies]
-tokio-uds = { version = "0.2.0", path = "tokio-uds" }
+tokio-uds = { version = "0.2.1", path = "tokio-uds", optional = true }
 
 [dev-dependencies]
-bytes = "0.4"
 env_logger = { version = "0.5", default-features = false }
 flate2 = { version = "1", features = ["tokio"] }
 futures-cpupool = "0.1"
@@ -75,3 +125,20 @@ serde = "1.0"
 serde_derive = "1.0"
 serde_json = "1.0"
 time = "0.1"
+
+[patch.crates-io]
+#tokio = { path = "." }
+#tokio-async-await  = { path = "./tokio-async-await" }
+#tokio-codec = { path = "./tokio-codec" }
+#tokio-current-thread = { path = "./tokio-current-thread" }
+#tokio-executor = { path = "./tokio-executor" }
+#tokio-fs = { path = "./tokio-fs" }
+#tokio-io = { path = "./tokio-io" }
+#tokio-reactor = { path = "./tokio-reactor" }
+#tokio-signal = { path = "./tokio-signal" }
+#tokio-tcp = { path = "./tokio-tcp" }
+#tokio-threadpool = { path = "./tokio-threadpool" }
+#tokio-timer = { path = "./tokio-timer" }
+#tokio-tls = { path = "./tokio-tls" }
+#tokio-udp = { path = "./tokio-udp" }
+#tokio-uds = { path = "./tokio-uds" }

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2018 Tokio Contributors
+Copyright (c) 2019 Tokio Contributors
 
 Permission is hereby granted, free of charge, to any
 person obtaining a copy of this software and associated

README.md

@@ -31,7 +31,7 @@ the Rust programming language. It is:
 
 [Website](https://tokio.rs) |
 [Guides](https://tokio.rs/docs/getting-started/hello-world/) |
-[API Docs](https://docs.rs/tokio) |
+[API Docs](https://docs.rs/tokio/0.1.15/tokio) |
 [Chat](https://gitter.im/tokio-rs/tokio)
 
 The API docs for the master branch are published [here][master-dox].
@@ -103,6 +103,24 @@ fn main() {
 
 More examples can be found [here](examples).
 
+## Getting Help
+
+First, see if the answer to your question can be found in the [Guides] or the
+[API documentation]. If the answer is not there, there is an active community in
+the [Tokio Gitter channel][chat]. We would be happy to try to answer your
+question.  Last, if that doesn't work, try opening an [issue] with the question.
+
+[chat]: https://gitter.im/tokio-rs/tokio
+[issue]: https://github.com/tokio-rs/tokio/issues/new
+
+## Contributing
+
+:balloon: Thanks for your help improving the project! We are so happy to have
+you! We have a [contributing guide][guide] to help you get involved in the Tokio
+project.
+
+[guide]: CONTRIBUTING.md
+
 ## Project layout
 
 The `tokio` crate, found at the root, is primarily intended for use by
@@ -111,6 +129,8 @@ have greater guarantees of stability.
 
 The crates included as part of Tokio are:
 
+* [`tokio-async-await`]: Experimental `async` / `await` support.
+
 * [`tokio-codec`]: Utilities for encoding and decoding protocol frames.
 
 * [`tokio-current-thread`]: Schedule the execution of futures on the current
@@ -137,6 +157,7 @@ The crates included as part of Tokio are:
 * [`tokio-uds`]: Unix Domain Socket bindings for use with `tokio-io` and
   `tokio-reactor`.
 
+[`tokio-async-await`]: tokio-async-await
 [`tokio-codec`]: tokio-codec
 [`tokio-current-thread`]: tokio-current-thread
 [`tokio-executor`]: tokio-executor
@@ -149,6 +170,14 @@ The crates included as part of Tokio are:
 [`tokio-udp`]: tokio-udp
 [`tokio-uds`]: tokio-uds
 
+## Supported Rust Versions
+
+Tokio is built against the latest stable, nightly, and beta Rust releases. The
+minimum version supported is the stable release from three months before the
+current stable release version. For example, if the latest stable Rust is 1.29,
+the minimum version supported is 1.26. The current Tokio version is not
+guaranteed to build on Rust versions earlier than the minimum supported version.
+
 ## License
 
 This project is licensed under the [MIT license](LICENSE).

ci/tsan

@@ -21,7 +21,7 @@ race:crossbeam_epoch
 race:crossbeam_deque*push
 race:crossbeam_deque*steal
 
-# This filters out expected data race in the treiber stack implementations.
+# This filters out expected data race in the Treiber stack implementations.
 # Treiber stacks are inherently racy. The pop operation will attempt to access
 # the "next" pointer on the node it is attempting to pop. However, at this
 # point it has not gained ownership of the node and another thread might beat
@@ -29,4 +29,9 @@ race:crossbeam_deque*steal
 # original pop operation will fail due to the ABA guard, but tsan still picks
 # up the access on the next pointer.
 race:Backup::next_sleeper
+race:Backup::set_next_sleeper
 race:WorkerEntry::set_next_sleeper
+
+# This ignores a false positive caused by `thread::park()`/`thread::unpark()`.
+# See: https://github.com/rust-lang/rust/pull/54806#issuecomment-436193353
+race:pthread_cond_destroy

examples/chat-combinator-current-thread.rs

@@ -0,0 +1,167 @@
+//! A chat server that broadcasts a message to all connections.
+//!
+//! This is a line-based server which accepts connections, reads lines from
+//! those connections, and broadcasts the lines to all other connected clients.
+//!
+//! This example is similar to chat.rs, but uses combinators and a much more
+//! functional style.
+//!
+//! Because we are here running the reactor/executor on the same thread instead
+//! of a threadpool, we can avoid full synchronization with Arc + Mutex and use
+//! Rc + RefCell instead. The max performance is however limited to a CPU HW
+//! thread.
+//!
+//! You can test this out by running:
+//!
+//!     cargo run --example chat-combinator-current-thread
+//!
+//! And then in another window run:
+//!
+//!     cargo run --example connect 127.0.0.1:8080
+//!
+//! You can run the second command in multiple windows and then chat between the
+//! two, seeing the messages from the other client as they're received. For all
+//! connected clients they'll all join the same room and see everyone else's
+//! messages.
+
+#![deny(warnings)]
+
+extern crate tokio;
+extern crate futures;
+
+use tokio::io;
+use tokio::net::TcpListener;
+use tokio::prelude::*;
+use tokio::runtime::current_thread::{Runtime, TaskExecutor};
+
+use std::collections::HashMap;
+use std::iter;
+use std::env;
+use std::io::{BufReader};
+use std::rc::Rc;
+use std::cell::RefCell;
+
+
+fn main() -> Result<(), Box<std::error::Error>> {
+    let mut runtime = Runtime::new().unwrap();
+
+    // Create the TCP listener we'll accept connections on.
+    let addr = env::args().nth(1).unwrap_or("127.0.0.1:8080".to_string());
+    let addr = addr.parse()?;
+
+    let socket = TcpListener::bind(&addr)?;
+    println!("Listening on: {}", addr);
+
+    // This is running on the Tokio current_thread runtime, so it will be single-
+    // threaded. The `Rc<RefCell<...>>` allows state to be shared across the tasks.
+    let connections = Rc::new(RefCell::new(HashMap::new()));
+
+    // The server task asynchronously iterates over and processes each incoming
+    // connection.
+    let srv = socket.incoming()
+        .map_err(|e| {println!("failed to accept socket; error = {:?}", e); e})
+        .for_each(move |stream| {
+            // The client's socket address
+            let addr = stream.peer_addr()?;
+
+            println!("New Connection: {}", addr);
+
+            // Split the TcpStream into two separate handles. One handle for reading
+            // and one handle for writing. This lets us use separate tasks for
+            // reading and writing.
+            let (reader, writer) = stream.split();
+
+            // Create a channel for our stream, which other sockets will use to
+            // send us messages. Then register our address with the stream to send
+            // data to us.
+            let (tx, rx) = futures::sync::mpsc::unbounded();
+            let mut conns = connections.borrow_mut();
+            conns.insert(addr, tx);
+
+            // Define here what we do for the actual I/O. That is, read a bunch of
+            // lines from the socket and dispatch them while we also write any lines
+            // from other sockets.
+            let connections_inner = connections.clone();
+            let reader = BufReader::new(reader);
+
+            // Model the read portion of this socket by mapping an infinite
+            // iterator to each line off the socket. This "loop" is then
+            // terminated with an error once we hit EOF on the socket.
+            let iter = stream::iter_ok::<_, io::Error>(iter::repeat(()));
+
+            let socket_reader = iter.fold(reader, move |reader, _| {
+                // Read a line off the socket, failing if we're at EOF
+                let line = io::read_until(reader, b'\n', Vec::new());
+                let line = line.and_then(|(reader, vec)| {
+                    if vec.len() == 0 {
+                        Err(io::Error::new(io::ErrorKind::BrokenPipe, "broken pipe"))
+                    } else {
+                        Ok((reader, vec))
+                    }
+                });
+
+                // Convert the bytes we read into a string, and then send that
+                // string to all other connected clients.
+                let line = line.map(|(reader, vec)| {
+                    (reader, String::from_utf8(vec))
+                });
+
+                // Move the connection state into the closure below.
+                let connections = connections_inner.clone();
+
+                line.map(move |(reader, message)| {
+                    println!("{}: {:?}", addr, message);
+                    let mut conns = connections.borrow_mut();
+
+                    if let Ok(msg) = message {
+                        // For each open connection except the sender, send the
+                        // string via the channel.
+                        let iter = conns.iter_mut()
+                                        .filter(|&(&k, _)| k != addr)
+                                        .map(|(_, v)| v);
+                        for tx in iter {
+                            tx.unbounded_send(format!("{}: {}", addr, msg)).unwrap();
+                        }
+                    } else {
+                        let tx = conns.get_mut(&addr).unwrap();
+                        tx.unbounded_send("You didn't send valid UTF-8.".to_string()).unwrap();
+                    }
+
+                    reader
+                })
+            });
+
+            // Whenever we receive a string on the Receiver, we write it to
+            // `WriteHalf<TcpStream>`.
+            let socket_writer = rx.fold(writer, |writer, msg| {
+                let amt = io::write_all(writer, msg.into_bytes());
+                let amt = amt.map(|(writer, _)| writer);
+                amt.map_err(|_| ())
+            });
+
+            // Now that we've got futures representing each half of the socket, we
+            // use the `select` combinator to wait for either half to be done to
+            // tear down the other. Then we spawn off the result.
+            let connections = connections.clone();
+            let socket_reader = socket_reader.map_err(|_| ());
+            let connection = socket_reader.map(|_| ()).select(socket_writer.map(|_| ()));
+
+            // Spawn locally a task to process the connection
+            TaskExecutor::current().spawn_local(Box::new(connection.then(move |_| {
+                let mut conns = connections.borrow_mut();
+                conns.remove(&addr);
+                println!("Connection {} closed.", addr);
+                Ok(())
+            }))).unwrap();
+
+            Ok(())
+        })
+        .map_err(|err| println!("error occurred: {:?}", err));
+
+    // Spawn srv itself
+    runtime.spawn(srv);
+
+    // Execute server
+    runtime.run().unwrap();
+    Ok(())
+}

examples/chat-combinator.rs

@@ -34,12 +34,12 @@ use std::env;
 use std::io::{BufReader};
 use std::sync::{Arc, Mutex};
 
-fn main() {
+fn main() -> Result<(), Box<std::error::Error>> {
     // Create the TCP listener we'll accept connections on.
     let addr = env::args().nth(1).unwrap_or("127.0.0.1:8080".to_string());
-    let addr = addr.parse().unwrap();
+    let addr = addr.parse()?;
 
-    let socket = TcpListener::bind(&addr).unwrap();
+    let socket = TcpListener::bind(&addr)?;
     println!("Listening on: {}", addr);
 
     // This is running on the Tokio runtime, so it will be multi-threaded. The
@@ -49,10 +49,10 @@ fn main() {
     // The server task asynchronously iterates over and processes each incoming
     // connection.
     let srv = socket.incoming()
-        .map_err(|e| println!("failed to accept socket; error = {:?}", e))
+        .map_err(|e| {println!("failed to accept socket; error = {:?}", e); e})
         .for_each(move |stream| {
             // The client's socket address
-            let addr = stream.peer_addr().unwrap();
+            let addr = stream.peer_addr()?;
 
             println!("New Connection: {}", addr);
 
@@ -143,8 +143,10 @@ fn main() {
             }));
 
             Ok(())
-        });
+        })
+        .map_err(|err| println!("error occurred: {:?}", err));
 
     // execute server
     tokio::run(srv);
+    Ok(())
 }

examples/chat.rs

@@ -426,7 +426,7 @@ fn process(socket: TcpStream, state: Arc<Mutex<Shared>>) {
     tokio::spawn(connection);
 }
 
-pub fn main() {
+pub fn main() -> Result<(), Box<std::error::Error>> {
     // Create the shared state. This is how all the peers communicate.
     //
     // The server task will hold a handle to this. For every new client, the
@@ -434,12 +434,12 @@ pub fn main() {
     // client connection.
     let state = Arc::new(Mutex::new(Shared::new()));
 
-    let addr = "127.0.0.1:6142".parse().unwrap();
+    let addr = "127.0.0.1:6142".parse()?;
 
     // Bind a TCP listener to the socket address.
     //
     // Note that this is the Tokio TcpListener, which is fully async.
-    let listener = TcpListener::bind(&addr).unwrap();
+    let listener = TcpListener::bind(&addr)?;
 
     // The server task asynchronously iterates over and processes each
     // incoming connection.
@@ -471,4 +471,5 @@ pub fn main() {
     // In our example, we have not defined a shutdown strategy, so this will
     // block until `ctrl-c` is pressed at the terminal.
     tokio::run(server);
+    Ok(())
 }

examples/connect.rs

@@ -29,7 +29,7 @@ use std::thread;
 use tokio::prelude::*;
 use futures::sync::mpsc;
 
-fn main() {
+fn main() -> Result<(), Box<std::error::Error>> {
     // Determine if we're going to run in TCP or UDP mode
     let mut args = env::args().skip(1).collect::<Vec<_>>();
     let tcp = match args.iter().position(|a| a == "--udp") {
@@ -41,10 +41,11 @@ fn main() {
     };
 
     // Parse what address we're going to connect to
-    let addr = args.first().unwrap_or_else(|| {
-        panic!("this program requires at least one argument")
-    });
-    let addr = addr.parse::<SocketAddr>().unwrap();
+    let addr = match args.first() {
+        Some(addr) => addr,
+        None => Err("this program requires at least one argument")?,
+    };
+    let addr = addr.parse::<SocketAddr>()?;
 
     // Right now Tokio doesn't support a handle to stdin running on the event
     // loop, so we farm out that work to a separate thread. This thread will
@@ -52,15 +53,15 @@ fn main() {
     // loop over a standard futures channel.
     let (stdin_tx, stdin_rx) = mpsc::channel(0);
     thread::spawn(|| read_stdin(stdin_tx));
-    let stdin_rx = stdin_rx.map_err(|_| panic!()); // errors not possible on rx
+    let stdin_rx = stdin_rx.map_err(|_| panic!("errors not possible on rx"));
 
     // Now that we've got our stdin read we either set up our TCP connection or
     // our UDP connection to get a stream of bytes we're going to emit to
     // stdout.
     let stdout = if tcp {
-        tcp::connect(&addr, Box::new(stdin_rx))
+        tcp::connect(&addr, Box::new(stdin_rx))?
     } else {
-        udp::connect(&addr, Box::new(stdin_rx))
+        udp::connect(&addr, Box::new(stdin_rx))?
     };
 
     // And now with our stream of bytes to write to stdout, we execute that in
@@ -77,6 +78,7 @@ fn main() {
             })
             .map_err(|e| println!("error reading stdout; error = {:?}", e))
     });
+    Ok(())
 }
 
 mod codec {
@@ -127,12 +129,13 @@ mod tcp {
     use bytes::BytesMut;
     use codec::Bytes;
 
+    use std::error::Error;
     use std::io;
     use std::net::SocketAddr;
 
     pub fn connect(addr: &SocketAddr,
                    stdin: Box<Stream<Item = Vec<u8>, Error = io::Error> + Send>)
-        -> Box<Stream<Item = BytesMut, Error = io::Error> + Send>
+        -> Result<Box<Stream<Item = BytesMut, Error = io::Error> + Send>, Box<Error>>
     {
         let tcp = TcpStream::connect(addr);
 
@@ -151,22 +154,24 @@ mod tcp {
         // You'll also note that we *spawn* the work to read stdin and write it
         // to the TCP stream. This is done to ensure that happens concurrently
         // with us reading data from the stream.
-        Box::new(tcp.map(move |stream| {
+        let stream = Box::new(tcp.map(move |stream| {
             let (sink, stream) = Bytes.framed(stream).split();
 
             tokio::spawn(stdin.forward(sink).then(|result| {
                 if let Err(e) = result {
-                    panic!("failed to write to socket: {}", e)
+                    println!("failed to write to socket: {}", e)
                 }
                 Ok(())
             }));
 
             stream
-        }).flatten_stream())
+        }).flatten_stream());
+        Ok(stream)
     }
 }
 
 mod udp {
+    use std::error::Error;
     use std::io;
     use std::net::SocketAddr;
 
@@ -179,17 +184,19 @@ mod udp {
 
     pub fn connect(&addr: &SocketAddr,
                    stdin: Box<Stream<Item = Vec<u8>, Error = io::Error> + Send>)
-        -> Box<Stream<Item = BytesMut, Error = io::Error> + Send>
+        -> Result<Box<Stream<Item = BytesMut, Error = io::Error> + Send>, Box<Error>>
     {
         // We'll bind our UDP socket to a local IP/port, but for now we
         // basically let the OS pick both of those.
         let addr_to_bind = if addr.ip().is_ipv4() {
-            "0.0.0.0:0".parse().unwrap()
+            "0.0.0.0:0".parse()?
         } else {
-            "[::]:0".parse().unwrap()
+            "[::]:0".parse()?
+        };
+        let udp = match UdpSocket::bind(&addr_to_bind) {
+            Ok(udp) => udp,
+            Err(_) => Err("failed to bind socket")?,
         };
-        let udp = UdpSocket::bind(&addr_to_bind)
-            .expect("failed to bind socket");
 
         // Like above with TCP we use an instance of `Bytes` codec to transform
         // this UDP socket into a framed sink/stream which operates over
@@ -203,7 +210,7 @@ mod udp {
             (chunk, addr)
         }).forward(sink).then(|result| {
             if let Err(e) = result {
-                panic!("failed to write to socket: {}", e)
+                println!("failed to write to socket: {}", e)
             }
             Ok(())
         });
@@ -218,10 +225,11 @@ mod udp {
             }
         });
 
-        Box::new(future::lazy(|| {
+        let stream = Box::new(future::lazy(|| {
             tokio::spawn(forward_stdin);
             future::ok(receive)
-        }).flatten_stream())
+        }).flatten_stream());
+        Ok(stream)
     }
 }
 

examples/echo-udp.rs

@@ -1,6 +1,6 @@
 //! An UDP echo server that just sends back everything that it receives.
 //!
-//! If you're on unix you can test this out by in one terminal executing:
+//! If you're on Unix you can test this out by in one terminal executing:
 //!
 //!     cargo run --example echo-udp
 //!
@@ -50,12 +50,12 @@ impl Future for Server {
     }
 }
 
-fn main() {
+fn main() -> Result<(), Box<std::error::Error>> {
     let addr = env::args().nth(1).unwrap_or("127.0.0.1:8080".to_string());
-    let addr = addr.parse::<SocketAddr>().unwrap();
+    let addr = addr.parse::<SocketAddr>()?;
 
-    let socket = UdpSocket::bind(&addr).unwrap();
-    println!("Listening on: {}", socket.local_addr().unwrap());
+    let socket = UdpSocket::bind(&addr)?;
+    println!("Listening on: {}", socket.local_addr()?);
 
     let server = Server {
         socket: socket,
@@ -70,4 +70,5 @@ fn main() {
     //
     // `tokio::run` spawns the task on the Tokio runtime and starts running.
     tokio::run(server.map_err(|e| println!("server error = {:?}", e)));
+    Ok(())
 }

examples/echo.rs

@@ -30,19 +30,19 @@ use tokio::prelude::*;
 use std::env;
 use std::net::SocketAddr;
 
-fn main() {
+fn main() -> Result<(), Box<std::error::Error>> {
     // Allow passing an address to listen on as the first argument of this
     // program, but otherwise we'll just set up our TCP listener on
     // 127.0.0.1:8080 for connections.
     let addr = env::args().nth(1).unwrap_or("127.0.0.1:8080".to_string());
-    let addr = addr.parse::<SocketAddr>().unwrap();
+    let addr = addr.parse::<SocketAddr>()?;
 
     // Next up we create a TCP listener which will listen for incoming
     // connections. This TCP listener is bound to the address we determined
     // above and must be associated with an event loop, so we pass in a handle
     // to our event loop. After the socket's created we inform that we're ready
     // to go and start accepting connections.
-    let socket = TcpListener::bind(&addr).unwrap();
+    let socket = TcpListener::bind(&addr)?;
     println!("Listening on: {}", addr);
 
     // Here we convert the `TcpListener` to a stream of incoming connections
@@ -111,4 +111,5 @@ fn main() {
     // never completes (it just keeps accepting sockets), `tokio::run` blocks
     // forever (until ctrl-c is pressed).
     tokio::run(done);
+    Ok(())
 }

examples/hello_world.rs

@@ -1,59 +1,45 @@
 //! Hello world server.
 //!
-//! A simple server that accepts connections, writes "hello world\n", and closes
+//! A simple client that opens a TCP stream, writes "hello world\n", and closes
 //! the connection.
 //!
 //! You can test this out by running:
 //!
-//!     cargo run --example hello_world
+//!     ncat -l 6142
 //!
 //! And then in another terminal run:
 //!
-//!     telnet localhost 6142
-//!
+//!     cargo run --example hello_world
 
 #![deny(warnings)]
 
 extern crate tokio;
 
 use tokio::io;
-use tokio::net::TcpListener;
+use tokio::net::TcpStream;
 use tokio::prelude::*;
 
-pub fn main() {
-    let addr = "127.0.0.1:6142".parse().unwrap();
+pub fn main() -> Result<(), Box<std::error::Error>> {
+    let addr = "127.0.0.1:6142".parse()?;
 
-    // Bind a TCP listener to the socket address.
+    // Open a TCP stream to the socket address.
     //
-    // Note that this is the Tokio TcpListener, which is fully async.
-    let listener = TcpListener::bind(&addr).unwrap();
-
-    // The server task asynchronously iterates over and processes each
-    // incoming connection.
-    let server = listener.incoming().for_each(|socket| {
-        println!("accepted socket; addr={:?}", socket.peer_addr().unwrap());
-
-        let connection = io::write_all(socket, "hello world\n")
-            .then(|res| {
-                println!("wrote message; success={:?}", res.is_ok());
-                Ok(())
-            });
-
-        // Spawn a new task that processes the socket:
-        tokio::spawn(connection);
-
-        Ok(())
+    // Note that this is the Tokio TcpStream, which is fully async.
+    let client = TcpStream::connect(&addr).and_then(|stream| {
+        println!("created stream");
+        io::write_all(stream, "hello world\n").then(|result| {
+            println!("wrote to stream; success={:?}", result.is_ok());
+            Ok(())
+        })
     })
     .map_err(|err| {
         // All tasks must have an `Error` type of `()`. This forces error
         // handling and helps avoid silencing failures.
         //
         // In our example, we are only going to log the error to STDOUT.
-        println!("accept error = {:?}", err);
+        println!("connection error = {:?}", err);
     });
 
-    println!("server running on localhost:6142");
-
     // Start the Tokio runtime.
     //
     // The Tokio is a pre-configured "out of the box" runtime for building
@@ -63,8 +49,9 @@ pub fn main() {
     // This function blocks until the runtime reaches an idle state. Idle is
     // defined as all spawned tasks have completed and all I/O resources (TCP
     // sockets in our case) have been dropped.
-    //
-    // In our example, we have not defined a shutdown strategy, so this will
-    // block until `ctrl-c` is pressed at the terminal.
-    tokio::run(server);
+    println!("About to create the stream and write to it...");
+    tokio::run(client);
+    println!("Stream has been created and written to.");
+
+    Ok(())
 }

examples/manual-runtime.rs

@@ -60,7 +60,7 @@ fn run<F: Future<Item = (), Error = ()>>(f: F) -> Result<(), IoError> {
     Ok(())
 }
 
-fn main() {
+fn main() -> Result<(), Box<std::error::Error>> {
     run(future::lazy(|| {
         // Here comes the application logic. It can spawn further tasks by tokio_current_thread::spawn().
         // It also can use the default reactor and create timeouts.
@@ -82,5 +82,6 @@ fn main() {
         // We can spawn on the default executor, which is also the local one.
         tokio::executor::spawn(deadline);
         Ok(())
-    })).unwrap();
+    }))?;
+    Ok(())
 }

examples/print_each_packet.rs

@@ -65,19 +65,19 @@ use tokio::codec::Decoder;
 use std::env;
 use std::net::SocketAddr;
 
-fn main() {
+fn main() -> Result<(), Box<std::error::Error>> {
     // Allow passing an address to listen on as the first argument of this
     // program, but otherwise we'll just set up our TCP listener on
     // 127.0.0.1:8080 for connections.
     let addr = env::args().nth(1).unwrap_or("127.0.0.1:8080".to_string());
-    let addr = addr.parse::<SocketAddr>().unwrap();
+    let addr = addr.parse::<SocketAddr>()?;
 
     // Next up we create a TCP listener which will listen for incoming
     // connections. This TCP listener is bound to the address we determined
     // above and must be associated with an event loop, so we pass in a handle
     // to our event loop. After the socket's created we inform that we're ready
     // to go and start accepting connections.
-    let socket = TcpListener::bind(&addr).unwrap();
+    let socket = TcpListener::bind(&addr)?;
     println!("Listening on: {}", addr);
 
     // Here we convert the `TcpListener` to a stream of incoming connections
@@ -146,4 +146,5 @@ fn main() {
     // never completes (it just keeps accepting sockets), `tokio::run` blocks
     // forever (until ctrl-c is pressed).
     tokio::run(done);
+    Ok(())
 }

examples/proxy.rs

@@ -33,15 +33,15 @@ use tokio::io::{copy, shutdown};
 use tokio::net::{TcpListener, TcpStream};
 use tokio::prelude::*;
 
-fn main() {
+fn main() -> Result<(), Box<std::error::Error>> {
     let listen_addr = env::args().nth(1).unwrap_or("127.0.0.1:8081".to_string());
-    let listen_addr = listen_addr.parse::<SocketAddr>().unwrap();
+    let listen_addr = listen_addr.parse::<SocketAddr>()?;
 
     let server_addr = env::args().nth(2).unwrap_or("127.0.0.1:8080".to_string());
-    let server_addr = server_addr.parse::<SocketAddr>().unwrap();
+    let server_addr = server_addr.parse::<SocketAddr>()?;
 
     // Create a TCP listener which will listen for incoming connections.
-    let socket = TcpListener::bind(&listen_addr).unwrap();
+    let socket = TcpListener::bind(&listen_addr)?;
     println!("Listening on: {}", listen_addr);
     println!("Proxying to: {}", server_addr);
 
@@ -94,6 +94,7 @@ fn main() {
         });
 
     tokio::run(done);
+    Ok(())
 }
 
 // This is a custom type used to have a custom implementation of the

examples/tinydb.rs

@@ -56,7 +56,7 @@ use tokio::prelude::*;
 /// The in-memory database shared amongst all clients.
 ///
 /// This database will be shared via `Arc`, so to mutate the internal map we're
-/// also going to use a `RefCell` for interior mutability.
+/// going to use a `Mutex` for interior mutability.
 struct Database {
     map: Mutex<HashMap<String, String>>,
 }
@@ -74,12 +74,12 @@ enum Response {
     Error { msg: String },
 }
 
-fn main() {
+fn main() -> Result<(), Box<std::error::Error>> {
     // Parse the address we're going to run this server on
     // and set up our TCP listener to accept connections.
     let addr = env::args().nth(1).unwrap_or("127.0.0.1:8080".to_string());
-    let addr = addr.parse::<SocketAddr>().unwrap();
-    let listener = TcpListener::bind(&addr).expect("failed to bind");
+    let addr = addr.parse::<SocketAddr>()?;
+    let listener = TcpListener::bind(&addr).map_err(|_| "failed to bind")?;
     println!("Listening on: {}", addr);
 
     // Create the shared state of this server that will be shared amongst all
@@ -156,6 +156,7 @@ fn main() {
         });
 
     tokio::run(done);
+    Ok(())
 }
 
 impl Request {

examples/tinyhttp.rs

@@ -1,9 +1,9 @@
-//! A "tiny" example of HTTP request/response handling using just tokio-core
+//! A "tiny" example of HTTP request/response handling using transports.
 //!
 //! This example is intended for *learning purposes* to see how various pieces
 //! hook up together and how HTTP can get up and running. Note that this example
 //! is written with the restriction that it *can't* use any "big" library other
-//! than tokio-core, if you'd like a "real world" HTTP library you likely want a
+//! than Tokio, if you'd like a "real world" HTTP library you likely want a
 //! crate like Hyper.
 //!
 //! Code here is based on the `echo-threads` example and implements two paths,
@@ -34,13 +34,13 @@ use bytes::BytesMut;
 use http::header::HeaderValue;
 use http::{Request, Response, StatusCode};
 
-fn main() {
+fn main() -> Result<(), Box<std::error::Error>> {
     // Parse the arguments, bind the TCP socket we'll be listening to, spin up
     // our worker threads, and start shipping sockets to those worker threads.
     let addr = env::args().nth(1).unwrap_or("127.0.0.1:8080".to_string());
-    let addr = addr.parse::<SocketAddr>().unwrap();
+    let addr = addr.parse::<SocketAddr>()?;
 
-    let listener = TcpListener::bind(&addr).expect("failed to bind");
+    let listener = TcpListener::bind(&addr)?;
     println!("Listening on: {}", addr);
 
     tokio::run({
@@ -51,6 +51,7 @@ fn main() {
                 Ok(())
             })
     });
+    Ok(())
 }
 
 fn process(socket: TcpStream) {
@@ -84,28 +85,32 @@ fn process(socket: TcpStream) {
 fn respond(req: Request<()>)
     -> Box<Future<Item = Response<String>, Error = io::Error> + Send>
 {
-    let mut ret = Response::builder();
-    let body = match req.uri().path() {
-        "/plaintext" => {
-            ret.header("Content-Type", "text/plain");
-            "Hello, World!".to_string()
-        }
-        "/json" => {
-            ret.header("Content-Type", "application/json");
-
-            #[derive(Serialize)]
-            struct Message {
-                message: &'static str,
+    let f = future::lazy(move || {
+        let mut response = Response::builder();
+        let body = match req.uri().path() {
+            "/plaintext" => {
+                response.header("Content-Type", "text/plain");
+                "Hello, World!".to_string()
             }
-            serde_json::to_string(&Message { message: "Hello, World!" })
-                .unwrap()
-        }
-        _ => {
-            ret.status(StatusCode::NOT_FOUND);
-            String::new()
-        }
-    };
-    Box::new(future::ok(ret.body(body).unwrap()))
+            "/json" => {
+                response.header("Content-Type", "application/json");
+
+                #[derive(Serialize)]
+                struct Message {
+                    message: &'static str,
+                }
+                serde_json::to_string(&Message { message: "Hello, World!" })?
+            }
+            _ => {
+                response.status(StatusCode::NOT_FOUND);
+                String::new()
+            }
+        };
+        let response = response.body(body).map_err(|err| io::Error::new(io::ErrorKind::Other, err))?;
+        Ok(response)
+    });
+
+    Box::new(f)
 }
 
 struct Http;

examples/udp-client.rs

@@ -35,29 +35,27 @@ use std::net::SocketAddr;
 use tokio::net::UdpSocket;
 use tokio::prelude::*;
 
-fn get_stdin_data() -> Vec<u8> {
+fn get_stdin_data() -> Result<Vec<u8>, Box<std::error::Error>> {
     let mut buf = Vec::new();
-    stdin().read_to_end(&mut buf).unwrap();
-    buf
+    stdin().read_to_end(&mut buf)?;
+    Ok(buf)
 }
 
-fn main() {
+fn main() -> Result<(), Box<std::error::Error>> {
     let remote_addr: SocketAddr = env::args()
         .nth(1)
         .unwrap_or("127.0.0.1:8080".into())
-        .parse()
-        .unwrap();
+        .parse()?;
     // We use port 0 to let the operating system allocate an available port for us.
     let local_addr: SocketAddr = if remote_addr.is_ipv4() {
         "0.0.0.0:0"
     } else {
         "[::]:0"
-    }.parse()
-        .unwrap();
-    let socket = UdpSocket::bind(&local_addr).unwrap();
+    }.parse()?;
+    let socket = UdpSocket::bind(&local_addr)?;
     const MAX_DATAGRAM_SIZE: usize = 65_507;
-    let processing = socket
-        .send_dgram(get_stdin_data(), &remote_addr)
+    socket
+        .send_dgram(get_stdin_data()?, &remote_addr)
         .and_then(|(socket, _)| socket.recv_dgram(vec![0u8; MAX_DATAGRAM_SIZE]))
         .map(|(_, data, len, _)| {
             println!(
@@ -66,9 +64,6 @@ fn main() {
                 String::from_utf8_lossy(&data[..len])
             )
         })
-        .wait();
-    match processing {
-        Ok(_) => {}
-        Err(e) => eprintln!("Encountered an error: {}", e),
-    }
+        .wait()?;
+    Ok(())
 }

examples/udp-codec.rs

@@ -19,15 +19,15 @@ use tokio::prelude::*;
 use tokio::net::{UdpSocket, UdpFramed};
 use tokio_codec::BytesCodec;
 
-fn main() {
+fn main() -> Result<(), Box<std::error::Error>> {
     let _ = env_logger::init();
 
-    let addr: SocketAddr = "127.0.0.1:0".parse().unwrap();
+    let addr: SocketAddr = "127.0.0.1:0".parse()?;
 
     // Bind both our sockets and then figure out what ports we got.
-    let a = UdpSocket::bind(&addr).unwrap();
-    let b = UdpSocket::bind(&addr).unwrap();
-    let b_addr = b.local_addr().unwrap();
+    let a = UdpSocket::bind(&addr)?;
+    let b = UdpSocket::bind(&addr)?;
+    let b_addr = b.local_addr()?;
 
     // We're parsing each socket with the `BytesCodec` included in `tokio_io`, and then we
     // `split` each codec into the sink/stream halves.
@@ -61,4 +61,5 @@ fn main() {
             .map(|_| ())
             .map_err(|e| println!("error = {:?}", e))
     });
+    Ok(())
 }

src/async_await.rs

@@ -0,0 +1,26 @@
+use std::future::{Future as StdFuture};
+
+async fn map_ok<T: StdFuture>(future: T) -> Result<(), ()> {
+    let _ = await!(future);
+    Ok(())
+}
+
+/// Like `tokio::run`, but takes an `async` block
+pub fn run_async<F>(future: F)
+where F: StdFuture<Output = ()> + Send + 'static,
+{
+    use tokio_async_await::compat::backward;
+    let future = backward::Compat::new(map_ok(future));
+
+    ::run(future);
+}
+
+/// Like `tokio::spawn`, but takes an `async` block
+pub fn spawn_async<F>(future: F)
+where F: StdFuture<Output = ()> + Send + 'static,
+{
+    use tokio_async_await::compat::backward;
+    let future = backward::Compat::new(map_ok(future));
+
+    ::spawn(future);
+}

src/codec/length_delimited.rs

@@ -0,0 +1,977 @@
+//! Frame a stream of bytes based on a length prefix
+//!
+//! Many protocols delimit their frames by prefacing frame data with a
+//! frame head that specifies the length of the frame. The
+//! `length_delimited` module provides utilities for handling the length
+//! based framing. This allows the consumer to work with entire frames
+//! without having to worry about buffering or other framing logic.
+//!
+//! # Getting started
+//!
+//! If implementing a protocol from scratch, using length delimited framing
+//! is an easy way to get started. [`LengthDelimitedCodec::new()`] will
+//! return a length delimited codec using default configuration values.
+//! This can then be used to construct a framer to adapt a full-duplex
+//! byte stream into a stream of frames.
+//!
+//! ```
+//! # extern crate tokio;
+//! use tokio::io::{AsyncRead, AsyncWrite};
+//! use tokio::codec::*;
+//!
+//! fn bind_transport<T: AsyncRead + AsyncWrite>(io: T)
+//!     -> Framed<T, LengthDelimitedCodec>
+//! {
+//!     Framed::new(io, LengthDelimitedCodec::new())
+//! }
+//! # pub fn main() {}
+//! ```
+//!
+//! The returned transport implements `Sink + Stream` for `BytesMut`. It
+//! encodes the frame with a big-endian `u32` header denoting the frame
+//! payload length:
+//!
+//! ```text
+//! +----------+--------------------------------+
+//! | len: u32 |          frame payload         |
+//! +----------+--------------------------------+
+//! ```
+//!
+//! Specifically, given the following:
+//!
+//! ```
+//! # extern crate tokio;
+//! # extern crate bytes;
+//! # extern crate futures;
+//! #
+//! use tokio::io::{AsyncRead, AsyncWrite};
+//! use tokio::codec::*;
+//! use bytes::Bytes;
+//! use futures::{Sink, Future};
+//!
+//! fn write_frame<T: AsyncRead + AsyncWrite>(io: T) -> Result<(), Box<std::error::Error>> {
+//!     let mut transport = Framed::new(io, LengthDelimitedCodec::new());
+//!     let frame = Bytes::from("hello world");
+//!
+//!     transport.send(frame).wait()?;
+//!     Ok(())
+//! }
+//! #
+//! # pub fn main() {}
+//! ```
+//!
+//! The encoded frame will look like this:
+//!
+//! ```text
+//! +---- len: u32 ----+---- data ----+
+//! | \x00\x00\x00\x0b |  hello world |
+//! +------------------+--------------+
+//! ```
+//!
+//! # Decoding
+//!
+//! [`FramedRead`] adapts an [`AsyncRead`] into a `Stream` of [`BytesMut`],
+//! such that each yielded [`BytesMut`] value contains the contents of an
+//! entire frame. There are many configuration parameters enabling
+//! [`FramedRead`] to handle a wide range of protocols. Here are some
+//! examples that will cover the various options at a high level.
+//!
+//! ## Example 1
+//!
+//! The following will parse a `u16` length field at offset 0, including the
+//! frame head in the yielded `BytesMut`.
+//!
+//! ```
+//! # extern crate tokio;
+//! # use tokio::io::AsyncRead;
+//! # use tokio::codec::length_delimited;
+//! # fn bind_read<T: AsyncRead>(io: T) {
+//! length_delimited::Builder::new()
+//!     .length_field_offset(0) // default value
+//!     .length_field_length(2)
+//!     .length_adjustment(0)   // default value
+//!     .num_skip(0) // Do not strip frame header
+//!     .new_read(io);
+//! # }
+//! # pub fn main() {}
+//! ```
+//!
+//! The following frame will be decoded as such:
+//!
+//! ```text
+//!          INPUT                           DECODED
+//! +-- len ---+--- Payload ---+     +-- len ---+--- Payload ---+
+//! | \x00\x0B |  Hello world  | --> | \x00\x0B |  Hello world  |
+//! +----------+---------------+     +----------+---------------+
+//! ```
+//!
+//! The value of the length field is 11 (`\x0B`) which represents the length
+//! of the payload, `hello world`. By default, [`FramedRead`] assumes that
+//! the length field represents the number of bytes that **follows** the
+//! length field. Thus, the entire frame has a length of 13: 2 bytes for the
+//! frame head + 11 bytes for the payload.
+//!
+//! ## Example 2
+//!
+//! The following will parse a `u16` length field at offset 0, omitting the
+//! frame head in the yielded `BytesMut`.
+//!
+//! ```
+//! # extern crate tokio;
+//! # use tokio::io::AsyncRead;
+//! # use tokio::codec::length_delimited;
+//! # fn bind_read<T: AsyncRead>(io: T) {
+//! length_delimited::Builder::new()
+//!     .length_field_offset(0) // default value
+//!     .length_field_length(2)
+//!     .length_adjustment(0)   // default value
+//!     // `num_skip` is not needed, the default is to skip
+//!     .new_read(io);
+//! # }
+//! # pub fn main() {}
+//! ```
+//!
+//! The following frame will be decoded as such:
+//!
+//! ```text
+//!          INPUT                        DECODED
+//! +-- len ---+--- Payload ---+     +--- Payload ---+
+//! | \x00\x0B |  Hello world  | --> |  Hello world  |
+//! +----------+---------------+     +---------------+
+//! ```
+//!
+//! This is similar to the first example, the only difference is that the
+//! frame head is **not** included in the yielded `BytesMut` value.
+//!
+//! ## Example 3
+//!
+//! The following will parse a `u16` length field at offset 0, including the
+//! frame head in the yielded `BytesMut`. In this case, the length field
+//! **includes** the frame head length.
+//!
+//! ```
+//! # extern crate tokio;
+//! # use tokio::io::AsyncRead;
+//! # use tokio::codec::length_delimited;
+//! # fn bind_read<T: AsyncRead>(io: T) {
+//! length_delimited::Builder::new()
+//!     .length_field_offset(0) // default value
+//!     .length_field_length(2)
+//!     .length_adjustment(-2)  // size of head
+//!     .num_skip(0)
+//!     .new_read(io);
+//! # }
+//! # pub fn main() {}
+//! ```
+//!
+//! The following frame will be decoded as such:
+//!
+//! ```text
+//!          INPUT                           DECODED
+//! +-- len ---+--- Payload ---+     +-- len ---+--- Payload ---+
+//! | \x00\x0D |  Hello world  | --> | \x00\x0D |  Hello world  |
+//! +----------+---------------+     +----------+---------------+
+//! ```
+//!
+//! In most cases, the length field represents the length of the payload
+//! only, as shown in the previous examples. However, in some protocols the
+//! length field represents the length of the whole frame, including the
+//! head. In such cases, we specify a negative `length_adjustment` to adjust
+//! the value provided in the frame head to represent the payload length.
+//!
+//! ## Example 4
+//!
+//! The following will parse a 3 byte length field at offset 0 in a 5 byte
+//! frame head, including the frame head in the yielded `BytesMut`.
+//!
+//! ```
+//! # extern crate tokio;
+//! # use tokio::io::AsyncRead;
+//! # use tokio::codec::length_delimited;
+//! # fn bind_read<T: AsyncRead>(io: T) {
+//! length_delimited::Builder::new()
+//!     .length_field_offset(0) // default value
+//!     .length_field_length(3)
+//!     .length_adjustment(2)  // remaining head
+//!     .num_skip(0)
+//!     .new_read(io);
+//! # }
+//! # pub fn main() {}
+//! ```
+//!
+//! The following frame will be decoded as such:
+//!
+//! ```text
+//!                  INPUT
+//! +---- len -----+- head -+--- Payload ---+
+//! | \x00\x00\x0B | \xCAFE |  Hello world  |
+//! +--------------+--------+---------------+
+//!
+//!                  DECODED
+//! +---- len -----+- head -+--- Payload ---+
+//! | \x00\x00\x0B | \xCAFE |  Hello world  |
+//! +--------------+--------+---------------+
+//! ```
+//!
+//! A more advanced example that shows a case where there is extra frame
+//! head data between the length field and the payload. In such cases, it is
+//! usually desirable to include the frame head as part of the yielded
+//! `BytesMut`. This lets consumers of the length delimited framer to
+//! process the frame head as needed.
+//!
+//! The positive `length_adjustment` value lets `FramedRead` factor in the
+//! additional head into the frame length calculation.
+//!
+//! ## Example 5
+//!
+//! The following will parse a `u16` length field at offset 1 of a 4 byte
+//! frame head. The first byte and the length field will be omitted from the
+//! yielded `BytesMut`, but the trailing 2 bytes of the frame head will be
+//! included.
+//!
+//! ```
+//! # extern crate tokio;
+//! # use tokio::io::AsyncRead;
+//! # use tokio::codec::length_delimited;
+//! # fn bind_read<T: AsyncRead>(io: T) {
+//! length_delimited::Builder::new()
+//!     .length_field_offset(1) // length of hdr1
+//!     .length_field_length(2)
+//!     .length_adjustment(1)  // length of hdr2
+//!     .num_skip(3) // length of hdr1 + LEN
+//!     .new_read(io);
+//! # }
+//! # pub fn main() {}
+//! ```
+//!
+//! The following frame will be decoded as such:
+//!
+//! ```text
+//!                  INPUT
+//! +- hdr1 -+-- len ---+- hdr2 -+--- Payload ---+
+//! |  \xCA  | \x00\x0B |  \xFE  |  Hello world  |
+//! +--------+----------+--------+---------------+
+//!
+//!          DECODED
+//! +- hdr2 -+--- Payload ---+
+//! |  \xFE  |  Hello world  |
+//! +--------+---------------+
+//! ```
+//!
+//! The length field is situated in the middle of the frame head. In this
+//! case, the first byte in the frame head could be a version or some other
+//! identifier that is not needed for processing. On the other hand, the
+//! second half of the head is needed.
+//!
+//! `length_field_offset` indicates how many bytes to skip before starting
+//! to read the length field.  `length_adjustment` is the number of bytes to
+//! skip starting at the end of the length field. In this case, it is the
+//! second half of the head.
+//!
+//! ## Example 6
+//!
+//! The following will parse a `u16` length field at offset 1 of a 4 byte
+//! frame head. The first byte and the length field will be omitted from the
+//! yielded `BytesMut`, but the trailing 2 bytes of the frame head will be
+//! included. In this case, the length field **includes** the frame head
+//! length.
+//!
+//! ```
+//! # extern crate tokio;
+//! # use tokio::io::AsyncRead;
+//! # use tokio::codec::length_delimited;
+//! # fn bind_read<T: AsyncRead>(io: T) {
+//! length_delimited::Builder::new()
+//!     .length_field_offset(1) // length of hdr1
+//!     .length_field_length(2)
+//!     .length_adjustment(-3)  // length of hdr1 + LEN, negative
+//!     .num_skip(3)
+//!     .new_read(io);
+//! # }
+//! # pub fn main() {}
+//! ```
+//!
+//! The following frame will be decoded as such:
+//!
+//! ```text
+//!                  INPUT
+//! +- hdr1 -+-- len ---+- hdr2 -+--- Payload ---+
+//! |  \xCA  | \x00\x0F |  \xFE  |  Hello world  |
+//! +--------+----------+--------+---------------+
+//!
+//!          DECODED
+//! +- hdr2 -+--- Payload ---+
+//! |  \xFE  |  Hello world  |
+//! +--------+---------------+
+//! ```
+//!
+//! Similar to the example above, the difference is that the length field
+//! represents the length of the entire frame instead of just the payload.
+//! The length of `hdr1` and `len` must be counted in `length_adjustment`.
+//! Note that the length of `hdr2` does **not** need to be explicitly set
+//! anywhere because it already is factored into the total frame length that
+//! is read from the byte stream.
+//!
+//! # Encoding
+//!
+//! [`FramedWrite`] adapts an [`AsyncWrite`] into a `Sink` of [`BytesMut`],
+//! such that each submitted [`BytesMut`] is prefaced by a length field.
+//! There are fewer configuration options than [`FramedRead`]. Given
+//! protocols that have more complex frame heads, an encoder should probably
+//! be written by hand using [`Encoder`].
+//!
+//! Here is a simple example, given a `FramedWrite` with the following
+//! configuration:
+//!
+//! ```
+//! # extern crate tokio;
+//! # extern crate bytes;
+//! # use tokio::io::AsyncWrite;
+//! # use tokio::codec::length_delimited;
+//! # use bytes::BytesMut;
+//! # fn write_frame<T: AsyncWrite>(io: T) {
+//! # let _ =
+//! length_delimited::Builder::new()
+//!     .length_field_length(2)
+//!     .new_write(io);
+//! # }
+//! # pub fn main() {}
+//! ```
+//!
+//! A payload of `hello world` will be encoded as:
+//!
+//! ```text
+//! +- len: u16 -+---- data ----+
+//! |  \x00\x0b  |  hello world |
+//! +------------+--------------+
+//! ```
+//!
+//! [`LengthDelimitedCodec::new()`]: struct.LengthDelimitedCodec.html#method.new
+//! [`FramedRead`]: struct.FramedRead.html
+//! [`FramedWrite`]: struct.FramedWrite.html
+//! [`AsyncRead`]: ../../trait.AsyncRead.html
+//! [`AsyncWrite`]: ../../trait.AsyncWrite.html
+//! [`Encoder`]: ../trait.Encoder.html
+//! [`BytesMut`]: https://docs.rs/bytes/0.4/bytes/struct.BytesMut.html
+
+use {
+    codec::{
+        Decoder, Encoder, FramedRead, FramedWrite, Framed
+    },
+    io::{
+        AsyncRead, AsyncWrite
+    },
+};
+
+use bytes::{Buf, BufMut, Bytes, BytesMut, IntoBuf};
+
+use std::{cmp, fmt};
+use std::error::Error as StdError;
+use std::io::{self, Cursor};
+
+/// Configure length delimited `LengthDelimitedCodec`s.
+///
+/// `Builder` enables constructing configured length delimited codecs. Note
+/// that not all configuration settings apply to both encoding and decoding. See
+/// the documentation for specific methods for more detail.
+#[derive(Debug, Clone, Copy)]
+pub struct Builder {
+    // Maximum frame length
+    max_frame_len: usize,
+
+    // Number of bytes representing the field length
+    length_field_len: usize,
+
+    // Number of bytes in the header before the length field
+    length_field_offset: usize,
+
+    // Adjust the length specified in the header field by this amount
+    length_adjustment: isize,
+
+    // Total number of bytes to skip before reading the payload, if not set,
+    // `length_field_len + length_field_offset`
+    num_skip: Option<usize>,
+
+    // Length field byte order (little or big endian)
+    length_field_is_big_endian: bool,
+}
+
+/// An error when the number of bytes read is more than max frame length.
+pub struct FrameTooBig {
+    _priv: (),
+}
+
+/// A codec for frames delimited by a frame head specifying their lengths.
+///
+/// This allows the consumer to work with entire frames without having to worry
+/// about buffering or other framing logic.
+///
+/// See [module level] documentation for more detail.
+///
+/// [module level]: index.html
+#[derive(Debug)]
+pub struct LengthDelimitedCodec {
+    // Configuration values
+    builder: Builder,
+
+    // Read state
+    state: DecodeState,
+}
+
+#[derive(Debug, Clone, Copy)]
+enum DecodeState {
+    Head,
+    Data(usize),
+}
+
+// ===== impl LengthDelimitedCodec ======
+
+impl LengthDelimitedCodec {
+    /// Creates a new `LengthDelimitedCodec` with the default configuration values.
+    pub fn new() -> Self {
+        Self {
+            builder: Builder::new(),
+            state: DecodeState::Head,
+        }
+    }
+
+    /// Returns the current max frame setting
+    ///
+    /// This is the largest size this codec will accept from the wire. Larger
+    /// frames will be rejected.
+    pub fn max_frame_length(&self) -> usize {
+        self.builder.max_frame_len
+    }
+
+    /// Updates the max frame setting.
+    ///
+    /// The change takes effect the next time a frame is decoded. In other
+    /// words, if a frame is currently in process of being decoded with a frame
+    /// size greater than `val` but less than the max frame length in effect
+    /// before calling this function, then the frame will be allowed.
+    pub fn set_max_frame_length(&mut self, val: usize) {
+        self.builder.max_frame_length(val);
+    }
+
+    fn decode_head(&mut self, src: &mut BytesMut) -> io::Result<Option<usize>> {
+        let head_len = self.builder.num_head_bytes();
+        let field_len = self.builder.length_field_len;
+
+        if src.len() < head_len {
+            // Not enough data
+            return Ok(None);
+        }
+
+        let n = {
+            let mut src = Cursor::new(&mut *src);
+
+            // Skip the required bytes
+            src.advance(self.builder.length_field_offset);
+
+            // match endianess
+            let n = if self.builder.length_field_is_big_endian {
+                src.get_uint_be(field_len)
+            } else {
+                src.get_uint_le(field_len)
+            };
+
+            if n > self.builder.max_frame_len as u64 {
+                return Err(io::Error::new(io::ErrorKind::InvalidData, FrameTooBig {
+                    _priv: (),
+                }));
+            }
+
+            // The check above ensures there is no overflow
+            let n = n as usize;
+
+            // Adjust `n` with bounds checking
+            let n = if self.builder.length_adjustment < 0 {
+                n.checked_sub(-self.builder.length_adjustment as usize)
+            } else {
+                n.checked_add(self.builder.length_adjustment as usize)
+            };
+
+            // Error handling
+            match n {
+                Some(n) => n,
+                None => return Err(io::Error::new(io::ErrorKind::InvalidInput, "provided length would overflow after adjustment")),
+            }
+        };
+
+        let num_skip = self.builder.get_num_skip();
+
+        if num_skip > 0 {
+            let _ = src.split_to(num_skip);
+        }
+
+        // Ensure that the buffer has enough space to read the incoming
+        // payload
+        src.reserve(n);
+
+        return Ok(Some(n));
+    }
+
+    fn decode_data(&self, n: usize, src: &mut BytesMut) -> io::Result<Option<BytesMut>> {
+        // At this point, the buffer has already had the required capacity
+        // reserved. All there is to do is read.
+        if src.len() < n {
+            return Ok(None);
+        }
+
+        Ok(Some(src.split_to(n)))
+    }
+}
+
+impl Decoder for LengthDelimitedCodec {
+    type Item = BytesMut;
+    type Error = io::Error;
+
+    fn decode(&mut self, src: &mut BytesMut) -> io::Result<Option<BytesMut>> {
+        let n = match self.state {
+            DecodeState::Head => {
+                match try!(self.decode_head(src)) {
+                    Some(n) => {
+                        self.state = DecodeState::Data(n);
+                        n
+                    }
+                    None => return Ok(None),
+                }
+            }
+            DecodeState::Data(n) => n,
+        };
+
+        match try!(self.decode_data(n, src)) {
+            Some(data) => {
+                // Update the decode state
+                self.state = DecodeState::Head;
+
+                // Make sure the buffer has enough space to read the next head
+                src.reserve(self.builder.num_head_bytes());
+
+                Ok(Some(data))
+            }
+            None => Ok(None),
+        }
+    }
+}
+
+impl Encoder for LengthDelimitedCodec {
+    type Item = Bytes;
+    type Error = io::Error;
+
+    fn encode(&mut self, data: Bytes, dst: &mut BytesMut) -> Result<(), io::Error> {
+        let n = (&data).into_buf().remaining();
+
+        if n > self.builder.max_frame_len {
+            return Err(io::Error::new(io::ErrorKind::InvalidInput, FrameTooBig {
+                _priv: (),
+            }));
+        }
+
+        // Adjust `n` with bounds checking
+        let n = if self.builder.length_adjustment < 0 {
+            n.checked_add(-self.builder.length_adjustment as usize)
+        } else {
+            n.checked_sub(self.builder.length_adjustment as usize)
+        };
+
+        let n = n.ok_or_else(|| io::Error::new(
+            io::ErrorKind::InvalidInput,
+            "provided length would overflow after adjustment",
+        ))?;
+
+        // Reserve capacity in the destination buffer to fit the frame and
+        // length field (plus adjustment).
+        dst.reserve(self.builder.length_field_len + n);
+
+        if self.builder.length_field_is_big_endian {
+            dst.put_uint_be(n as u64, self.builder.length_field_len);
+        } else {
+            dst.put_uint_le(n as u64, self.builder.length_field_len);
+        }
+
+        // Write the frame to the buffer
+        dst.extend_from_slice(&data[..]);
+
+        Ok(())
+    }
+}
+
+// ===== impl Builder =====
+
+impl Builder {
+    /// Creates a new length delimited codec builder with default configuration
+    /// values.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # use tokio::io::AsyncRead;
+    /// use tokio::codec::length_delimited::Builder;
+    ///
+    /// # fn bind_read<T: AsyncRead>(io: T) {
+    /// Builder::new()
+    ///     .length_field_offset(0)
+    ///     .length_field_length(2)
+    ///     .length_adjustment(0)
+    ///     .num_skip(0)
+    ///     .new_read(io);
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    pub fn new() -> Builder {
+        Builder {
+            // Default max frame length of 8MB
+            max_frame_len: 8 * 1_024 * 1_024,
+
+            // Default byte length of 4
+            length_field_len: 4,
+
+            // Default to the header field being at the start of the header.
+            length_field_offset: 0,
+
+            length_adjustment: 0,
+
+            // Total number of bytes to skip before reading the payload, if not set,
+            // `length_field_len + length_field_offset`
+            num_skip: None,
+
+            // Default to reading the length field in network (big) endian.
+            length_field_is_big_endian: true,
+        }
+    }
+
+    /// Read the length field as a big endian integer
+    ///
+    /// This is the default setting.
+    ///
+    /// This configuration option applies to both encoding and decoding.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # use tokio::io::AsyncRead;
+    /// use tokio::codec::length_delimited::Builder;
+    ///
+    /// # fn bind_read<T: AsyncRead>(io: T) {
+    /// Builder::new()
+    ///     .big_endian()
+    ///     .new_read(io);
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    pub fn big_endian(&mut self) -> &mut Self {
+        self.length_field_is_big_endian = true;
+        self
+    }
+
+    /// Read the length field as a little endian integer
+    ///
+    /// The default setting is big endian.
+    ///
+    /// This configuration option applies to both encoding and decoding.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # use tokio::io::AsyncRead;
+    /// use tokio::codec::length_delimited::Builder;
+    ///
+    /// # fn bind_read<T: AsyncRead>(io: T) {
+    /// Builder::new()
+    ///     .little_endian()
+    ///     .new_read(io);
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    pub fn little_endian(&mut self) -> &mut Self {
+        self.length_field_is_big_endian = false;
+        self
+    }
+
+    /// Read the length field as a native endian integer
+    ///
+    /// The default setting is big endian.
+    ///
+    /// This configuration option applies to both encoding and decoding.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # use tokio::io::AsyncRead;
+    /// use tokio::codec::length_delimited::Builder;
+    ///
+    /// # fn bind_read<T: AsyncRead>(io: T) {
+    /// Builder::new()
+    ///     .native_endian()
+    ///     .new_read(io);
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    pub fn native_endian(&mut self) -> &mut Self {
+        if cfg!(target_endian = "big") {
+            self.big_endian()
+        } else {
+            self.little_endian()
+        }
+    }
+
+    /// Sets the max frame length
+    ///
+    /// This configuration option applies to both encoding and decoding. The
+    /// default value is 8MB.
+    ///
+    /// When decoding, the length field read from the byte stream is checked
+    /// against this setting **before** any adjustments are applied. When
+    /// encoding, the length of the submitted payload is checked against this
+    /// setting.
+    ///
+    /// When frames exceed the max length, an `io::Error` with the custom value
+    /// of the `FrameTooBig` type will be returned.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # use tokio::io::AsyncRead;
+    /// use tokio::codec::length_delimited::Builder;
+    ///
+    /// # fn bind_read<T: AsyncRead>(io: T) {
+    /// Builder::new()
+    ///     .max_frame_length(8 * 1024)
+    ///     .new_read(io);
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    pub fn max_frame_length(&mut self, val: usize) -> &mut Self {
+        self.max_frame_len = val;
+        self
+    }
+
+    /// Sets the number of bytes used to represent the length field
+    ///
+    /// The default value is `4`. The max value is `8`.
+    ///
+    /// This configuration option applies to both encoding and decoding.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # use tokio::io::AsyncRead;
+    /// use tokio::codec::length_delimited::Builder;
+    ///
+    /// # fn bind_read<T: AsyncRead>(io: T) {
+    /// Builder::new()
+    ///     .length_field_length(4)
+    ///     .new_read(io);
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    pub fn length_field_length(&mut self, val: usize) -> &mut Self {
+        assert!(val > 0 && val <= 8, "invalid length field length");
+        self.length_field_len = val;
+        self
+    }
+
+    /// Sets the number of bytes in the header before the length field
+    ///
+    /// This configuration option only applies to decoding.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # use tokio::io::AsyncRead;
+    /// use tokio::codec::length_delimited::Builder;
+    ///
+    /// # fn bind_read<T: AsyncRead>(io: T) {
+    /// Builder::new()
+    ///     .length_field_offset(1)
+    ///     .new_read(io);
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    pub fn length_field_offset(&mut self, val: usize) -> &mut Self {
+        self.length_field_offset = val;
+        self
+    }
+
+    /// Delta between the payload length specified in the header and the real
+    /// payload length
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # use tokio::io::AsyncRead;
+    /// use tokio::codec::length_delimited::Builder;
+    ///
+    /// # fn bind_read<T: AsyncRead>(io: T) {
+    /// Builder::new()
+    ///     .length_adjustment(-2)
+    ///     .new_read(io);
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    pub fn length_adjustment(&mut self, val: isize) -> &mut Self {
+        self.length_adjustment = val;
+        self
+    }
+
+    /// Sets the number of bytes to skip before reading the payload
+    ///
+    /// Default value is `length_field_len + length_field_offset`
+    ///
+    /// This configuration option only applies to decoding
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # use tokio::io::AsyncRead;
+    /// use tokio::codec::length_delimited::Builder;
+    ///
+    /// # fn bind_read<T: AsyncRead>(io: T) {
+    /// Builder::new()
+    ///     .num_skip(4)
+    ///     .new_read(io);
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    pub fn num_skip(&mut self, val: usize) -> &mut Self {
+        self.num_skip = Some(val);
+        self
+    }
+
+    /// Create a configured length delimited `LengthDelimitedCodec`
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # use tokio::io::AsyncRead;
+    /// use tokio::codec::length_delimited::Builder;
+    /// # pub fn main() {
+    /// Builder::new()
+    ///     .length_field_offset(0)
+    ///     .length_field_length(2)
+    ///     .length_adjustment(0)
+    ///     .num_skip(0)
+    ///     .new_codec();
+    /// # }
+    /// ```
+    pub fn new_codec(&self) -> LengthDelimitedCodec {
+        LengthDelimitedCodec {
+            builder: *self,
+            state: DecodeState::Head,
+        }
+    }
+
+    /// Create a configured length delimited `FramedRead`
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # use tokio::io::AsyncRead;
+    /// use tokio::codec::length_delimited::Builder;
+    ///
+    /// # fn bind_read<T: AsyncRead>(io: T) {
+    /// Builder::new()
+    ///     .length_field_offset(0)
+    ///     .length_field_length(2)
+    ///     .length_adjustment(0)
+    ///     .num_skip(0)
+    ///     .new_read(io);
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    pub fn new_read<T>(&self, upstream: T) -> FramedRead<T, LengthDelimitedCodec>
+        where T: AsyncRead,
+    {
+        FramedRead::new(upstream, self.new_codec())
+    }
+
+    /// Create a configured length delimited `FramedWrite`
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # extern crate bytes;
+    /// # use tokio::io::AsyncWrite;
+    /// # use tokio::codec::length_delimited;
+    /// # use bytes::BytesMut;
+    /// # fn write_frame<T: AsyncWrite>(io: T) {
+    /// length_delimited::Builder::new()
+    ///     .length_field_length(2)
+    ///     .new_write(io);
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    pub fn new_write<T>(&self, inner: T) -> FramedWrite<T, LengthDelimitedCodec>
+        where T: AsyncWrite,
+    {
+        FramedWrite::new(inner, self.new_codec())
+    }
+
+    /// Create a configured length delimited `Framed`
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # extern crate bytes;
+    /// # use tokio::io::{AsyncRead, AsyncWrite};
+    /// # use tokio::codec::length_delimited;
+    /// # use bytes::BytesMut;
+    /// # fn write_frame<T: AsyncRead + AsyncWrite>(io: T) {
+    /// # let _ =
+    /// length_delimited::Builder::new()
+    ///     .length_field_length(2)
+    ///     .new_framed(io);
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    pub fn new_framed<T>(&self, inner: T) -> Framed<T, LengthDelimitedCodec>
+        where T: AsyncRead + AsyncWrite,
+    {
+        Framed::new(inner, self.new_codec())
+    }
+
+    fn num_head_bytes(&self) -> usize {
+        let num = self.length_field_offset + self.length_field_len;
+        cmp::max(num, self.num_skip.unwrap_or(0))
+    }
+
+    fn get_num_skip(&self) -> usize {
+        self.num_skip.unwrap_or(self.length_field_offset + self.length_field_len)
+    }
+}
+
+
+// ===== impl FrameTooBig =====
+
+impl fmt::Debug for FrameTooBig {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_struct("FrameTooBig")
+            .finish()
+    }
+}
+
+impl fmt::Display for FrameTooBig {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str(self.description())
+    }
+}
+
+impl StdError for FrameTooBig {
+    fn description(&self) -> &str {
+        "frame size too big"
+    }
+}

src/codec/mod.rs

@@ -0,0 +1,26 @@
+//! Utilities for encoding and decoding frames.
+//!
+//! Contains adapters to go from streams of bytes, [`AsyncRead`] and
+//! [`AsyncWrite`], to framed streams implementing [`Sink`] and [`Stream`].
+//! Framed streams are also known as [transports].
+//!
+//! [`AsyncRead`]: ../io/trait.AsyncRead.html
+//! [`AsyncWrite`]: ../io/trait.AsyncWrite.html
+//! [`Sink`]: https://docs.rs/futures/0.1/futures/sink/trait.Sink.html
+//! [`Stream`]: https://docs.rs/futures/0.1/futures/stream/trait.Stream.html
+//! [transports]: https://tokio.rs/docs/going-deeper/frames/
+
+pub use tokio_codec::{
+    Decoder,
+    Encoder,
+    Framed,
+    FramedParts,
+    FramedRead,
+    FramedWrite,
+    BytesCodec,
+    LinesCodec,
+};
+
+pub mod length_delimited;
+
+pub use self::length_delimited::LengthDelimitedCodec;

src/executor/mod.rs

@@ -39,11 +39,15 @@
 //! [`Executor`]: trait.Executor.html
 //! [`spawn`]: fn.spawn.html
 
-#[deprecated(since = "0.1.8", note = "use tokio-current-thread crate instead")]
+#[deprecated(
+    since = "0.1.8",
+    note = "use tokio-current-thread crate or functions in tokio::runtime::current_thread instead",
+)]
 #[doc(hidden)]
 pub mod current_thread;
 
 #[deprecated(since = "0.1.8", note = "use tokio-threadpool crate instead")]
+#[doc(hidden)]
 /// Re-exports of [`tokio-threadpool`], deprecated in favor of the crate.
 ///
 /// [`tokio-threadpool`]: https://docs.rs/tokio-threadpool/0.1

src/io.rs

@@ -0,0 +1,95 @@
+//! Asynchronous I/O.
+//!
+//! This module is the asynchronous version of `std::io`. Primarily, it
+//! defines two traits, [`AsyncRead`] and [`AsyncWrite`], which extend the
+//! `Read` and `Write` traits of the standard library.
+//!
+//! # AsyncRead and AsyncWrite
+//!
+//! [`AsyncRead`] and [`AsyncWrite`] must only be implemented for
+//! non-blocking I/O types that integrate with the futures type system. In
+//! other words, these types must never block the thread, and instead the
+//! current task is notified when the I/O resource is ready.
+//!
+//! # Standard input and output
+//!
+//! Tokio provides asynchronous APIs to standard [input], [output], and [error].
+//! These APIs are very similar to the ones provided by `std`, but they also
+//! implement [`AsyncRead`] and [`AsyncWrite`].
+//!
+//! Unlike *most* other Tokio APIs, the standard input / output APIs
+//! **must** be used from the context of the Tokio runtime as they require
+//! Tokio specific features to function.
+//!
+//! [input]: fn.stdin.html
+//! [output]: fn.stdout.html
+//! [error]: fn.stderr.html
+//!
+//! # Utility functions
+//!
+//! Utilities functions are provided for working with [`AsyncRead`] /
+//! [`AsyncWrite`] types. For example, [`copy`] asynchronously copies all
+//! data from a source to a destination.
+//!
+//! # `std` re-exports
+//!
+//! Additionally, [`Read`], [`Write`], [`Error`], [`ErrorKind`], and
+//! [`Result`] are re-exported from `std::io` for ease of use.
+//!
+//! [`AsyncRead`]: trait.AsyncRead.html
+//! [`AsyncWrite`]: trait.AsyncWrite.html
+//! [`copy`]: fn.copy.html
+//! [`Read`]: trait.Read.html
+//! [`Write`]: trait.Write.html
+//! [`Error`]: struct.Error.html
+//! [`ErrorKind`]: enum.ErrorKind.html
+//! [`Result`]: type.Result.html
+
+pub use tokio_io::{
+    AsyncRead,
+    AsyncWrite,
+};
+
+// standard input, output, and error
+#[cfg(feature = "fs")]
+pub use tokio_fs::{
+    stdin,
+    Stdin,
+    stdout,
+    Stdout,
+    stderr,
+    Stderr,
+};
+
+// Utils
+pub use tokio_io::io::{
+    copy,
+    Copy,
+    flush,
+    Flush,
+    lines,
+    Lines,
+    read,
+    read_exact,
+    ReadExact,
+    read_to_end,
+    ReadToEnd,
+    read_until,
+    ReadUntil,
+    ReadHalf,
+    shutdown,
+    Shutdown,
+    write_all,
+    WriteAll,
+    WriteHalf,
+};
+
+// Re-export io::Error so that users don't have to deal
+// with conflicts when `use`ing `futures::io` and `std::io`.
+pub use ::std::io::{
+    Error,
+    ErrorKind,
+    Result,
+    Read,
+    Write,
+};

src/lib.rs

@@ -1,3 +1,11 @@
+#![doc(html_root_url = "https://docs.rs/tokio/0.1.15")]
+#![deny(missing_docs, warnings, missing_debug_implementations)]
+#![cfg_attr(feature = "async-await-preview", feature(
+        async_await,
+        await_macro,
+        futures_api,
+        ))]
+
 //! A runtime for writing reliable, asynchronous, and slim applications.
 //!
 //! Tokio is an event-driven, non-blocking I/O platform for writing asynchronous
@@ -64,196 +72,84 @@
 //! }
 //! ```
 
-#![doc(html_root_url = "https://docs.rs/tokio/0.1.5")]
-#![deny(missing_docs, warnings, missing_debug_implementations)]
+macro_rules! if_runtime {
+    ($($i:item)*) => ($(
+        #[cfg(any(feature = "rt-full"))]
+        $i
+    )*)
+}
 
 #[macro_use]
 extern crate futures;
+
+#[cfg(feature = "io")]
+extern crate bytes;
+#[cfg(feature = "reactor")]
 extern crate mio;
+#[cfg(feature = "rt-full")]
+extern crate num_cpus;
+#[cfg(feature = "rt-full")]
 extern crate tokio_current_thread;
+#[cfg(feature = "io")]
 extern crate tokio_io;
-extern crate tokio_executor;
+#[cfg(feature = "codec")]
 extern crate tokio_codec;
+#[cfg(feature = "fs")]
 extern crate tokio_fs;
+#[cfg(feature = "reactor")]
 extern crate tokio_reactor;
+#[cfg(feature = "rt-full")]
 extern crate tokio_threadpool;
+#[cfg(feature = "sync")]
+extern crate tokio_sync;
+#[cfg(feature = "timer")]
 extern crate tokio_timer;
+#[cfg(feature = "tcp")]
 extern crate tokio_tcp;
+#[cfg(feature = "udp")]
 extern crate tokio_udp;
 
-#[cfg(unix)]
+#[cfg(feature = "async-await-preview")]
+extern crate tokio_async_await;
+
+#[cfg(all(unix, feature = "uds"))]
 extern crate tokio_uds;
 
+#[cfg(feature = "timer")]
 pub mod clock;
-pub mod executor;
+#[cfg(feature = "codec")]
+pub mod codec;
+#[cfg(feature = "fs")]
 pub mod fs;
+#[cfg(feature = "io")]
+pub mod io;
+#[cfg(any(feature = "tcp", feature = "udp", feature = "uds"))]
 pub mod net;
+pub mod prelude;
+#[cfg(feature = "reactor")]
 pub mod reactor;
-pub mod runtime;
+#[cfg(feature = "sync")]
+pub mod sync;
+#[cfg(feature = "timer")]
 pub mod timer;
 pub mod util;
 
-pub use executor::spawn;
-pub use runtime::run;
+if_runtime! {
+    extern crate tokio_executor;
+    pub mod executor;
+    pub mod runtime;
 
-pub mod codec {
-    //! Utilities for encoding and decoding frames.
-    //!
-    //! Contains adapters to go from streams of bytes, [`AsyncRead`] and
-    //! [`AsyncWrite`], to framed streams implementing [`Sink`] and [`Stream`].
-    //! Framed streams are also known as [transports].
-    //!
-    //! [`AsyncRead`]: ../io/trait.AsyncRead.html
-    //! [`AsyncWrite`]: ../io/trait.AsyncWrite.html
-    //! [`Sink`]: https://docs.rs/futures/0.1/futures/sink/trait.Sink.html
-    //! [`Stream`]: https://docs.rs/futures/0.1/futures/stream/trait.Stream.html
-    //! [transports]: https://tokio.rs/docs/going-deeper/frames/
-
-    pub use tokio_codec::{
-        Decoder,
-        Encoder,
-        Framed,
-        FramedParts,
-        FramedRead,
-        FramedWrite,
-        BytesCodec,
-        LinesCodec,
-    };
+    pub use executor::spawn;
+    pub use runtime::run;
 }
 
-pub mod io {
-    //! Asynchronous I/O.
-    //!
-    //! This module is the asynchronous version of `std::io`. Primarily, it
-    //! defines two traits, [`AsyncRead`] and [`AsyncWrite`], which extend the
-    //! `Read` and `Write` traits of the standard library.
-    //!
-    //! # AsyncRead and AsyncWrite
-    //!
-    //! [`AsyncRead`] and [`AsyncWrite`] must only be implemented for
-    //! non-blocking I/O types that integrate with the futures type system. In
-    //! other words, these types must never block the thread, and instead the
-    //! current task is notified when the I/O resource is ready.
-    //!
-    //! # Standard input and output
-    //!
-    //! Tokio provides asynchronous APIs to standard [input], [output], and [error].
-    //! These APIs are very similar to the ones provided by `std`, but they also
-    //! implement [`AsyncRead`] and [`AsyncWrite`].
-    //!
-    //! Unlike *most* other Tokio APIs, the standard input / output APIs
-    //! **must** be used from the context of the Tokio runtime as they require
-    //! Tokio specific features to function.
-    //!
-    //! [input]: fn.stdin.html
-    //! [output]: fn.stdout.html
-    //! [error]: fn.stderr.html
-    //!
-    //! # Utility functions
-    //!
-    //! Utilities functions are provided for working with [`AsyncRead`] /
-    //! [`AsyncWrite`] types. For example, [`copy`] asynchronously copies all
-    //! data from a source to a destination.
-    //!
-    //! # `std` re-exports
-    //!
-    //! Additionally, [`Read`], [`Write`], [`Error`], [`ErrorKind`], and
-    //! [`Result`] are re-exported from `std::io` for ease of use.
-    //!
-    //! [`AsyncRead`]: trait.AsyncRead.html
-    //! [`AsyncWrite`]: trait.AsyncWrite.html
-    //! [`copy`]: fn.copy.html
-    //! [`Read`]: trait.Read.html
-    //! [`Write`]: trait.Write.html
-    //! [`Error`]: struct.Error.html
-    //! [`ErrorKind`]: enum.ErrorKind.html
-    //! [`Result`]: type.Result.html
+// ===== Experimental async/await support =====
 
-    pub use tokio_io::{
-        AsyncRead,
-        AsyncWrite,
-    };
+#[cfg(feature = "async-await-preview")]
+mod async_await;
 
-    // standard input, output, and error
-    pub use tokio_fs::{
-        stdin,
-        Stdin,
-        stdout,
-        Stdout,
-        stderr,
-        Stderr,
-    };
+#[cfg(feature = "async-await-preview")]
+pub use async_await::{run_async, spawn_async};
 
-    // Utils
-    pub use tokio_io::io::{
-        copy,
-        Copy,
-        flush,
-        Flush,
-        lines,
-        Lines,
-        read_exact,
-        ReadExact,
-        read_to_end,
-        ReadToEnd,
-        read_until,
-        ReadUntil,
-        ReadHalf,
-        shutdown,
-        Shutdown,
-        write_all,
-        WriteAll,
-        WriteHalf,
-    };
-
-    // Re-export io::Error so that users don't have to deal
-    // with conflicts when `use`ing `futures::io` and `std::io`.
-    pub use ::std::io::{
-        Error,
-        ErrorKind,
-        Result,
-        Read,
-        Write,
-    };
-}
-
-pub mod prelude {
-    //! A "prelude" for users of the `tokio` crate.
-    //!
-    //! This prelude is similar to the standard library's prelude in that you'll
-    //! almost always want to import its entire contents, but unlike the standard
-    //! library's prelude you'll have to do so manually:
-    //!
-    //! ```
-    //! use tokio::prelude::*;
-    //! ```
-    //!
-    //! The prelude may grow over time as additional items see ubiquitous use.
-
-    pub use tokio_io::{
-        AsyncRead,
-        AsyncWrite,
-    };
-
-    pub use util::{
-        FutureExt,
-    };
-
-    pub use ::std::io::{
-        Read,
-        Write,
-    };
-
-    pub use futures::{
-        Future,
-        future,
-        Stream,
-        stream,
-        Sink,
-        IntoFuture,
-        Async,
-        AsyncSink,
-        Poll,
-        task,
-    };
-}
+#[cfg(feature = "async-await-preview")]
+pub use tokio_async_await::await;

src/net.rs

@@ -1,54 +1,98 @@
-//! TCP/UDP bindings for `tokio`.
+//! TCP/UDP/Unix bindings for `tokio`.
 //!
-//! This module contains the TCP/UDP networking types, similar to the standard
+//! This module contains the TCP/UDP/Unix networking types, similar to the standard
 //! library, which can be used to implement networking protocols.
 //!
-//! # TCP
+//! # Organization
 //!
-//! Connecting to an address, via TCP, can be done using [`TcpStream`]'s
-//! [`connect`] method, which returns [`ConnectFuture`]. `ConnectFuture`
-//! implements a future which returns a `TcpStream`.
+//! * [`TcpListener`] and [`TcpStream`] provide functionality for communication over TCP
+//! * [`UdpSocket`] and [`UdpFramed`] provide functionality for communication over UDP
+//! * [`UnixListener`] and [`UnixStream`] provide functionality for communication over a
+//! Unix Domain Stream Socket **(available on Unix only)**
+//! * [`UnixDatagram`] and [`UnixDatagramFramed`] provide functionality for communication
+//! over Unix Domain Datagram Socket **(available on Unix only)**
+
 //!
-//! To listen on an address [`TcpListener`] can be used. `TcpListener`'s
-//! [`incoming`][incoming_method] method can be used to accept new connections.
-//! It return the [`Incoming`] struct, which implements a stream which returns
-//! `TcpStream`s.
-//!
-//! [`TcpStream`]: struct.TcpStream.html
-//! [`connect`]: struct.TcpStream.html#method.connect
-//! [`ConnectFuture`]: struct.ConnectFuture.html
 //! [`TcpListener`]: struct.TcpListener.html
-//! [incoming_method]: struct.TcpListener.html#method.incoming
-//! [`Incoming`]: struct.Incoming.html
-//!
-//! # UDP
-//!
-//! The main struct for UDP is the [`UdpSocket`], which represents a UDP socket.
-//! Reading and writing to it can be done using futures, which return the
-//! [`RecvDgram`] and [`SendDgram`] structs respectively.
-//!
-//! For convenience it's also possible to convert raw datagrams into higher-level
-//! frames.
-//!
+//! [`TcpStream`]: struct.TcpStream.html
 //! [`UdpSocket`]: struct.UdpSocket.html
-//! [`RecvDgram`]: struct.RecvDgram.html
-//! [`SendDgram`]: struct.SendDgram.html
 //! [`UdpFramed`]: struct.UdpFramed.html
-//! [`framed`]: struct.UdpSocket.html#method.framed
+//! [`UnixListener`]: struct.UnixListener.html
+//! [`UnixStream`]: struct.UnixStream.html
+//! [`UnixDatagram`]: struct.UnixDatagram.html
+//! [`UnixDatagramFramed`]: struct.UnixDatagramFramed.html
 
-pub use tokio_tcp::{TcpStream, ConnectFuture};
-pub use tokio_tcp::{TcpListener, Incoming};
-pub use tokio_udp::{UdpSocket, UdpFramed, SendDgram, RecvDgram};
+#[cfg(feature = "tcp")]
+pub mod tcp {
+    //! TCP bindings for `tokio`.
+    //!
+    //! Connecting to an address, via TCP, can be done using [`TcpStream`]'s
+    //! [`connect`] method, which returns [`ConnectFuture`]. `ConnectFuture`
+    //! implements a future which returns a `TcpStream`.
+    //!
+    //! To listen on an address [`TcpListener`] can be used. `TcpListener`'s
+    //! [`incoming`][incoming_method] method can be used to accept new connections.
+    //! It return the [`Incoming`] struct, which implements a stream which returns
+    //! `TcpStream`s.
+    //!
+    //! [`TcpStream`]: struct.TcpStream.html
+    //! [`connect`]: struct.TcpStream.html#method.connect
+    //! [`ConnectFuture`]: struct.ConnectFuture.html
+    //! [`TcpListener`]: struct.TcpListener.html
+    //! [incoming_method]: struct.TcpListener.html#method.incoming
+    //! [`Incoming`]: struct.Incoming.html
+    pub use tokio_tcp::{ConnectFuture, Incoming, TcpListener, TcpStream};
+}
+#[cfg(feature = "tcp")]
+pub use self::tcp::{TcpListener, TcpStream};
 
-#[cfg(unix)]
+#[cfg(feature = "tcp")]
+#[deprecated(note = "use `tokio::net::tcp::ConnectFuture` instead")]
+#[doc(hidden)]
+pub type ConnectFuture = self::tcp::ConnectFuture;
+#[cfg(feature = "tcp")]
+#[deprecated(note = "use `tokio::net::tcp::Incoming` instead")]
+#[doc(hidden)]
+pub type Incoming = self::tcp::Incoming;
+
+#[cfg(feature = "udp")]
+pub mod udp {
+    //! UDP bindings for `tokio`.
+    //!
+    //! The main struct for UDP is the [`UdpSocket`], which represents a UDP socket.
+    //! Reading and writing to it can be done using futures, which return the
+    //! [`RecvDgram`] and [`SendDgram`] structs respectively.
+    //!
+    //! For convenience it's also possible to convert raw datagrams into higher-level
+    //! frames.
+    //!
+    //! [`UdpSocket`]: struct.UdpSocket.html
+    //! [`RecvDgram`]: struct.RecvDgram.html
+    //! [`SendDgram`]: struct.SendDgram.html
+    //! [`UdpFramed`]: struct.UdpFramed.html
+    //! [`framed`]: struct.UdpSocket.html#method.framed
+    pub use tokio_udp::{RecvDgram, SendDgram, UdpFramed, UdpSocket};
+}
+#[cfg(feature = "udp")]
+pub use self::udp::{UdpFramed, UdpSocket};
+
+#[cfg(feature = "udp")]
+#[deprecated(note = "use `tokio::net::udp::RecvDgram` instead")]
+#[doc(hidden)]
+pub type RecvDgram<T> = self::udp::RecvDgram<T>;
+#[cfg(feature = "udp")]
+#[deprecated(note = "use `tokio::net::udp::SendDgram` instead")]
+#[doc(hidden)]
+pub type SendDgram<T> = self::udp::SendDgram<T>;
+
+#[cfg(all(unix, feature = "uds"))]
 pub mod unix {
-    //! Unix domain socket bindings for `tokio`.
+    //! Unix domain socket bindings for `tokio` (only available on unix systems).
 
     pub use tokio_uds::{
-        ConnectFuture, Incoming, RecvDgram, SendDgram, UCred, UnixDatagram, UnixListener,
-        UnixStream,
+        ConnectFuture, Incoming, RecvDgram, SendDgram, UCred, UnixDatagram, UnixDatagramFramed,
+        UnixListener, UnixStream,
     };
 }
-
-#[cfg(unix)]
-pub use self::unix::{UnixListener, UnixStream};
+#[cfg(all(unix, feature = "uds"))]
+pub use self::unix::{UnixDatagram, UnixDatagramFramed, UnixListener, UnixStream};

src/prelude.rs

@@ -0,0 +1,55 @@
+//! A "prelude" for users of the `tokio` crate.
+//!
+//! This prelude is similar to the standard library's prelude in that you'll
+//! almost always want to import its entire contents, but unlike the standard
+//! library's prelude you'll have to do so manually:
+//!
+//! ```
+//! use tokio::prelude::*;
+//! ```
+//!
+//! The prelude may grow over time as additional items see ubiquitous use.
+
+#[cfg(feature = "io")]
+pub use tokio_io::{
+    AsyncRead,
+    AsyncWrite,
+};
+
+pub use util::{
+    FutureExt,
+    StreamExt,
+};
+
+pub use ::std::io::{
+    Read,
+    Write,
+};
+
+pub use futures::{
+    Future,
+    future,
+    Stream,
+    stream,
+    Sink,
+    IntoFuture,
+    Async,
+    AsyncSink,
+    Poll,
+    task,
+};
+
+#[cfg(feature = "async-await-preview")]
+#[doc(inline)]
+pub use tokio_async_await::{
+    io::{
+        AsyncReadExt,
+        AsyncWriteExt,
+    },
+    sink::{
+        SinkExt,
+    },
+    stream::{
+        StreamExt as StreamAsyncExt,
+    },
+};

src/runtime/builder.rs

@@ -1,148 +0,0 @@
-use runtime::{Inner, Runtime};
-
-use reactor::Reactor;
-
-use std::io;
-
-use tokio_reactor;
-use tokio_threadpool::Builder as ThreadPoolBuilder;
-use tokio_threadpool::park::DefaultPark;
-use tokio_timer::clock::{self, Clock};
-use tokio_timer::timer::{self, Timer};
-
-/// Builds Tokio Runtime with custom configuration values.
-///
-/// Methods can be chained in order to set the configuration values. The
-/// Runtime is constructed by calling [`build`].
-///
-/// New instances of `Builder` are obtained via [`Builder::new`].
-///
-/// See function level documentation for details on the various configuration
-/// settings.
-///
-/// [`build`]: #method.build
-/// [`Builder::new`]: #method.new
-///
-/// # Examples
-///
-/// ```
-/// # extern crate tokio;
-/// # extern crate tokio_threadpool;
-/// # use tokio::runtime::Builder;
-///
-/// # pub fn main() {
-/// // create and configure ThreadPool
-/// let mut threadpool_builder = tokio_threadpool::Builder::new();
-/// threadpool_builder
-///     .name_prefix("my-runtime-worker-")
-///     .pool_size(4);
-///
-/// // build Runtime
-/// let runtime = Builder::new()
-///     .threadpool_builder(threadpool_builder)
-///     .build();
-/// // ... call runtime.run(...)
-/// # let _ = runtime;
-/// # }
-/// ```
-#[derive(Debug)]
-pub struct Builder {
-    /// Thread pool specific builder
-    threadpool_builder: ThreadPoolBuilder,
-
-    /// The clock to use
-    clock: Clock,
-}
-
-impl Builder {
-    /// Returns a new runtime builder initialized with default configuration
-    /// values.
-    ///
-    /// Configuration methods can be chained on the return value.
-    pub fn new() -> Builder {
-        let mut threadpool_builder = ThreadPoolBuilder::new();
-        threadpool_builder.name_prefix("tokio-runtime-worker-");
-
-        Builder {
-            threadpool_builder,
-            clock: Clock::new(),
-        }
-    }
-
-    /// Set the `Clock` instance that will be used by the runtime.
-    pub fn clock(&mut self, clock: Clock) -> &mut Self {
-        self.clock = clock;
-        self
-    }
-
-    /// Set builder to set up the thread pool instance.
-    pub fn threadpool_builder(&mut self, val: ThreadPoolBuilder) -> &mut Self {
-        self.threadpool_builder = val;
-        self
-    }
-
-    /// Create the configured `Runtime`.
-    ///
-    /// The returned `ThreadPool` instance is ready to spawn tasks.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// # extern crate tokio;
-    /// # use tokio::runtime::Builder;
-    /// # pub fn main() {
-    /// let runtime = Builder::new().build().unwrap();
-    /// // ... call runtime.run(...)
-    /// # let _ = runtime;
-    /// # }
-    /// ```
-    pub fn build(&mut self) -> io::Result<Runtime> {
-        use std::collections::HashMap;
-        use std::sync::{Arc, Mutex};
-
-        // Get a handle to the clock for the runtime.
-        let clock1 = self.clock.clone();
-        let clock2 = clock1.clone();
-
-        let timers = Arc::new(Mutex::new(HashMap::<_, timer::Handle>::new()));
-        let t1 = timers.clone();
-
-        // Spawn a reactor on a background thread.
-        let reactor = Reactor::new()?.background()?;
-
-        // Get a handle to the reactor.
-        let reactor_handle = reactor.handle().clone();
-
-        let pool = self.threadpool_builder
-            .around_worker(move |w, enter| {
-                let timer_handle = t1.lock().unwrap()
-                    .get(w.id()).unwrap()
-                    .clone();
-
-                tokio_reactor::with_default(&reactor_handle, enter, |enter| {
-                    clock::with_default(&clock1, enter, |enter| {
-                        timer::with_default(&timer_handle, enter, |_| {
-                            w.run();
-                        });
-                    })
-                });
-            })
-            .custom_park(move |worker_id| {
-                // Create a new timer
-                let timer = Timer::new_with_now(DefaultPark::new(), clock2.clone());
-
-                timers.lock().unwrap()
-                    .insert(worker_id.clone(), timer.handle());
-
-                timer
-            })
-            .build();
-
-        Ok(Runtime {
-            inner: Some(Inner {
-                reactor,
-                pool,
-            }),
-        })
-    }
-}

src/runtime/current_thread/mod.rs

@@ -71,6 +71,8 @@ mod runtime;
 
 pub use self::builder::Builder;
 pub use self::runtime::{Runtime, Handle};
+pub use tokio_current_thread::spawn;
+pub use tokio_current_thread::TaskExecutor;
 
 use futures::Future;
 
@@ -88,3 +90,18 @@ where
     r.run().expect("failed to resolve remaining futures");
     Ok(v)
 }
+
+/// Start a current-thread runtime using the supplied future to bootstrap execution.
+///
+/// # Panics
+///
+/// This function panics if called from the context of an executor.
+pub fn run<F>(future: F)
+where
+    F: Future<Item = (), Error = ()> + 'static,
+{
+
+    let mut r = Runtime::new().expect("failed to start runtime on current thread");
+    r.spawn(future);
+    r.run().expect("failed to resolve remaining futures");
+}

src/runtime/current_thread/runtime.rs

@@ -7,7 +7,7 @@ use tokio_timer::clock::{self, Clock};
 use tokio_timer::timer::{self, Timer};
 use tokio_executor;
 
-use futures::Future;
+use futures::{future, Future};
 
 use std::fmt;
 use std::error::Error;
@@ -42,6 +42,38 @@ impl Handle {
     where F: Future<Item = (), Error = ()> + Send + 'static {
         self.0.spawn(future)
     }
+
+    /// Provides a best effort **hint** to whether or not `spawn` will succeed.
+    ///
+    /// This function may return both false positives **and** false negatives.
+    /// If `status` returns `Ok`, then a call to `spawn` will *probably*
+    /// succeed, but may fail. If `status` returns `Err`, a call to `spawn` will
+    /// *probably* fail, but may succeed.
+    ///
+    /// This allows a caller to avoid creating the task if the call to `spawn`
+    /// has a high likelihood of failing.
+    pub fn status(&self) -> Result<(), tokio_executor::SpawnError> {
+        self.0.status()
+    }
+}
+
+impl<T> future::Executor<T> for Handle
+where T: Future<Item = (), Error = ()> + Send + 'static,
+{
+    fn execute(&self, future: T) -> Result<(), future::ExecuteError<T>> {
+        if let Err(e) = self.status() {
+            let kind = if e.is_at_capacity() {
+                future::ExecuteErrorKind::NoCapacity
+            } else {
+                future::ExecuteErrorKind::Shutdown
+            };
+
+            return Err(future::ExecuteError::new(kind, future));
+        }
+
+        let _ = self.spawn(future);
+        Ok(())
+    }
 }
 
 /// Error returned by the `run` function.
@@ -60,6 +92,10 @@ impl Error for RunError {
     fn description(&self) -> &str {
         self.inner.description()
     }
+
+    // FIXME(taiki-e): When the minimum support version of tokio reaches Rust 1.30,
+    // replace this with Error::source.
+    #[allow(deprecated)]
     fn cause(&self) -> Option<&Error> {
         self.inner.cause()
     }

src/runtime/mod.rs

@@ -106,388 +106,20 @@
 //! [timer]: ../timer/index.html
 //! [`Runtime`]: struct.Runtime.html
 //! [`Reactor`]: ../reactor/struct.Reactor.html
-//! [`ThreadPool`]: ../executor/thread_pool/struct.ThreadPool.html
+//! [`ThreadPool`]: https://docs.rs/tokio-threadpool/0.1/tokio_threadpool/struct.ThreadPool.html
 //! [`run`]: fn.run.html
 //! [idle]: struct.Runtime.html#method.shutdown_on_idle
 //! [`tokio::spawn`]: ../executor/fn.spawn.html
 //! [`Timer`]: https://docs.rs/tokio-timer/0.2/tokio_timer/timer/struct.Timer.html
 
-mod builder;
 pub mod current_thread;
-mod shutdown;
-mod task_executor;
+mod threadpool;
 
-pub use self::builder::Builder;
-pub use self::shutdown::Shutdown;
-pub use self::task_executor::TaskExecutor;
+pub use self::threadpool::{
+    Builder,
+    Runtime,
+    Shutdown,
+    TaskExecutor,
+    run,
+};
 
-use reactor::{Background, Handle};
-
-use std::io;
-
-use tokio_threadpool as threadpool;
-
-use futures;
-use futures::future::Future;
-
-/// Handle to the Tokio runtime.
-///
-/// The Tokio runtime includes a reactor as well as an executor for running
-/// tasks.
-///
-/// Instances of `Runtime` can be created using [`new`] or [`Builder`]. However,
-/// most users will use [`tokio::run`], which uses a `Runtime` internally.
-///
-/// See [module level][mod] documentation for more details.
-///
-/// [mod]: index.html
-/// [`new`]: #method.new
-/// [`Builder`]: struct.Builder.html
-/// [`tokio::run`]: fn.run.html
-#[derive(Debug)]
-pub struct Runtime {
-    inner: Option<Inner>,
-}
-
-#[derive(Debug)]
-struct Inner {
-    /// Reactor running on a background thread.
-    reactor: Background,
-
-    /// Task execution pool.
-    pool: threadpool::ThreadPool,
-}
-
-// ===== impl Runtime =====
-
-/// Start the Tokio runtime using the supplied future to bootstrap execution.
-///
-/// This function is used to bootstrap the execution of a Tokio application. It
-/// does the following:
-///
-/// * Start the Tokio runtime using a default configuration.
-/// * Spawn the given future onto the thread pool.
-/// * Block the current thread until the runtime shuts down.
-///
-/// Note that the function will not return immediately once `future` has
-/// completed. Instead it waits for the entire runtime to become idle.
-///
-/// See the [module level][mod] documentation for more details.
-///
-/// # Examples
-///
-/// ```rust
-/// # extern crate tokio;
-/// # extern crate futures;
-/// # use futures::{Future, Stream};
-/// use tokio::net::TcpListener;
-///
-/// # fn process<T>(_: T) -> Box<Future<Item = (), Error = ()> + Send> {
-/// # unimplemented!();
-/// # }
-/// # fn dox() {
-/// # let addr = "127.0.0.1:8080".parse().unwrap();
-/// let listener = TcpListener::bind(&addr).unwrap();
-///
-/// let server = listener.incoming()
-///     .map_err(|e| println!("error = {:?}", e))
-///     .for_each(|socket| {
-///         tokio::spawn(process(socket))
-///     });
-///
-/// tokio::run(server);
-/// # }
-/// # pub fn main() {}
-/// ```
-///
-/// # Panics
-///
-/// This function panics if called from the context of an executor.
-///
-/// [mod]: ../index.html
-pub fn run<F>(future: F)
-where F: Future<Item = (), Error = ()> + Send + 'static,
-{
-    let mut runtime = Runtime::new().unwrap();
-    runtime.spawn(future);
-    runtime.shutdown_on_idle().wait().unwrap();
-}
-
-impl Runtime {
-    /// Create a new runtime instance with default configuration values.
-    ///
-    /// This results in a reactor, thread pool, and timer being initialized. The
-    /// thread pool will not spawn any worker threads until it needs to, i.e.
-    /// tasks are scheduled to run.
-    ///
-    /// Most users will not need to call this function directly, instead they
-    /// will use [`tokio::run`](fn.run.html).
-    ///
-    /// See [module level][mod] documentation for more details.
-    ///
-    /// # Examples
-    ///
-    /// Creating a new `Runtime` with default configuration values.
-    ///
-    /// ```
-    /// use tokio::runtime::Runtime;
-    /// use tokio::prelude::*;
-    ///
-    /// let rt = Runtime::new()
-    ///     .unwrap();
-    ///
-    /// // Use the runtime...
-    ///
-    /// // Shutdown the runtime
-    /// rt.shutdown_now()
-    ///     .wait().unwrap();
-    /// ```
-    ///
-    /// [mod]: index.html
-    pub fn new() -> io::Result<Self> {
-        Builder::new().build()
-    }
-
-    #[deprecated(since = "0.1.5", note = "use `reactor` instead")]
-    #[doc(hidden)]
-    pub fn handle(&self) -> &Handle {
-        self.reactor()
-    }
-
-    /// Return a reference to the reactor handle for this runtime instance.
-    ///
-    /// The returned handle reference can be cloned in order to get an owned
-    /// value of the handle. This handle can be used to initialize I/O resources
-    /// (like TCP or UDP sockets) that will not be used on the runtime.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use tokio::runtime::Runtime;
-    ///
-    /// let rt = Runtime::new()
-    ///     .unwrap();
-    ///
-    /// let reactor_handle = rt.reactor().clone();
-    ///
-    /// // use `reactor_handle`
-    /// ```
-    pub fn reactor(&self) -> &Handle {
-        self.inner().reactor.handle()
-    }
-
-    /// Return a handle to the runtime's executor.
-    ///
-    /// The returned handle can be used to spawn tasks that run on this runtime.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use tokio::runtime::Runtime;
-    ///
-    /// let rt = Runtime::new()
-    ///     .unwrap();
-    ///
-    /// let executor_handle = rt.executor();
-    ///
-    /// // use `executor_handle`
-    /// ```
-    pub fn executor(&self) -> TaskExecutor {
-        let inner = self.inner().pool.sender().clone();
-        TaskExecutor { inner }
-    }
-
-    /// Spawn a future onto the Tokio runtime.
-    ///
-    /// This spawns the given future onto the runtime's executor, usually a
-    /// thread pool. The thread pool is then responsible for polling the future
-    /// until it completes.
-    ///
-    /// See [module level][mod] documentation for more details.
-    ///
-    /// [mod]: index.html
-    ///
-    /// # Examples
-    ///
-    /// ```rust
-    /// # extern crate tokio;
-    /// # extern crate futures;
-    /// # use futures::{future, Future, Stream};
-    /// use tokio::runtime::Runtime;
-    ///
-    /// # fn dox() {
-    /// // Create the runtime
-    /// let mut rt = Runtime::new().unwrap();
-    ///
-    /// // Spawn a future onto the runtime
-    /// rt.spawn(future::lazy(|| {
-    ///     println!("now running on a worker thread");
-    ///     Ok(())
-    /// }));
-    /// # }
-    /// # pub fn main() {}
-    /// ```
-    ///
-    /// # Panics
-    ///
-    /// This function panics if the spawn fails. Failure occurs if the executor
-    /// is currently at capacity and is unable to spawn a new future.
-    pub fn spawn<F>(&mut self, future: F) -> &mut Self
-    where F: Future<Item = (), Error = ()> + Send + 'static,
-    {
-        self.inner_mut().pool.sender().spawn(future).unwrap();
-        self
-    }
-
-    /// Run a future to completion on the Tokio runtime.
-    ///
-    /// This runs the given future on the runtime, blocking until it is
-    /// complete, and yielding its resolved result. Any tasks or timers which
-    /// the future spawns internally will be executed on the runtime.
-    ///
-    /// This method should not be called from an asynchrounous context.
-    ///
-    /// # Panics
-    ///
-    /// This function panics if the executor is at capacity, if the provided
-    /// future panics, or if called within an asynchronous execution context.
-    pub fn block_on<F, R, E>(&mut self, future: F) -> Result<R, E>
-    where
-        F: Send + 'static + Future<Item = R, Error = E>,
-        R: Send + 'static,
-        E: Send + 'static,
-    {
-        let (tx, rx) = futures::sync::oneshot::channel();
-        self.spawn(future.then(move |r| tx.send(r).map_err(|_| unreachable!())));
-        rx.wait().unwrap()
-    }
-
-    /// Run a future to completion on the Tokio runtime, then wait for all
-    /// background futures to complete too.
-    ///
-    /// This runs the given future on the runtime, blocking until it is
-    /// complete, waiting for background futures to complete, and yielding
-    /// its resolved result. Any tasks or timers which the future spawns
-    /// internally will be executed on the runtime and waited for completion.
-    ///
-    /// This method should not be called from an asynchrounous context.
-    ///
-    /// # Panics
-    ///
-    /// This function panics if the executor is at capacity, if the provided
-    /// future panics, or if called within an asynchronous execution context.
-    pub fn block_on_all<F, R, E>(mut self, future: F) -> Result<R, E>
-    where
-        F: Send + 'static + Future<Item = R, Error = E>,
-        R: Send + 'static,
-        E: Send + 'static,
-    {
-        let res = self.block_on(future);
-        self.shutdown_on_idle().wait().unwrap();
-        res
-    }
-
-    /// Signals the runtime to shutdown once it becomes idle.
-    ///
-    /// Returns a future that completes once the shutdown operation has
-    /// completed.
-    ///
-    /// This function can be used to perform a graceful shutdown of the runtime.
-    ///
-    /// The runtime enters an idle state once **all** of the following occur.
-    ///
-    /// * The thread pool has no tasks to execute, i.e., all tasks that were
-    ///   spawned have completed.
-    /// * The reactor is not managing any I/O resources.
-    ///
-    /// See [module level][mod] documentation for more details.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use tokio::runtime::Runtime;
-    /// use tokio::prelude::*;
-    ///
-    /// let rt = Runtime::new()
-    ///     .unwrap();
-    ///
-    /// // Use the runtime...
-    ///
-    /// // Shutdown the runtime
-    /// rt.shutdown_on_idle()
-    ///     .wait().unwrap();
-    /// ```
-    ///
-    /// [mod]: index.html
-    pub fn shutdown_on_idle(mut self) -> Shutdown {
-        let inner = self.inner.take().unwrap();
-
-        let inner = Box::new({
-            let pool = inner.pool;
-            let reactor = inner.reactor;
-
-            pool.shutdown_on_idle().and_then(|_| {
-                reactor.shutdown_on_idle()
-            })
-        });
-
-        Shutdown { inner }
-    }
-
-    /// Signals the runtime to shutdown immediately.
-    ///
-    /// Returns a future that completes once the shutdown operation has
-    /// completed.
-    ///
-    /// This function will forcibly shutdown the runtime, causing any
-    /// in-progress work to become canceled. The shutdown steps are:
-    ///
-    /// * Drain any scheduled work queues.
-    /// * Drop any futures that have not yet completed.
-    /// * Drop the reactor.
-    ///
-    /// Once the reactor has dropped, any outstanding I/O resources bound to
-    /// that reactor will no longer function. Calling any method on them will
-    /// result in an error.
-    ///
-    /// See [module level][mod] documentation for more details.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use tokio::runtime::Runtime;
-    /// use tokio::prelude::*;
-    ///
-    /// let rt = Runtime::new()
-    ///     .unwrap();
-    ///
-    /// // Use the runtime...
-    ///
-    /// // Shutdown the runtime
-    /// rt.shutdown_now()
-    ///     .wait().unwrap();
-    /// ```
-    ///
-    /// [mod]: index.html
-    pub fn shutdown_now(mut self) -> Shutdown {
-        let inner = self.inner.take().unwrap();
-        Shutdown::shutdown_now(inner)
-    }
-
-    fn inner(&self) -> &Inner {
-        self.inner.as_ref().unwrap()
-    }
-
-    fn inner_mut(&mut self) -> &mut Inner {
-        self.inner.as_mut().unwrap()
-    }
-}
-
-impl Drop for Runtime {
-    fn drop(&mut self) {
-        if let Some(inner) = self.inner.take() {
-            let shutdown = Shutdown::shutdown_now(inner);
-            let _ = shutdown.wait();
-        }
-    }
-}

src/runtime/threadpool/builder.rs

@@ -0,0 +1,368 @@
+use super::{Inner, Runtime};
+
+use reactor::Reactor;
+
+use std::io;
+use std::sync::Mutex;
+use std::time::Duration;
+
+use num_cpus;
+use tokio_reactor;
+use tokio_threadpool::Builder as ThreadPoolBuilder;
+use tokio_timer::clock::{self, Clock};
+use tokio_timer::timer::{self, Timer};
+
+/// Builds Tokio Runtime with custom configuration values.
+///
+/// Methods can be chained in order to set the configuration values. The
+/// Runtime is constructed by calling [`build`].
+///
+/// New instances of `Builder` are obtained via [`Builder::new`].
+///
+/// See function level documentation for details on the various configuration
+/// settings.
+///
+/// [`build`]: #method.build
+/// [`Builder::new`]: #method.new
+///
+/// # Examples
+///
+/// ```
+/// extern crate tokio;
+/// extern crate tokio_timer;
+///
+/// use std::time::Duration;
+///
+/// use tokio::runtime::Builder;
+/// use tokio_timer::clock::Clock;
+///
+/// fn main() {
+///     // build Runtime
+///     let mut runtime = Builder::new()
+///         .blocking_threads(4)
+///         .clock(Clock::system())
+///         .core_threads(4)
+///         .keep_alive(Some(Duration::from_secs(60)))
+///         .name_prefix("my-custom-name-")
+///         .stack_size(3 * 1024 * 1024)
+///         .build()
+///         .unwrap();
+///
+///     // use runtime ...
+/// }
+/// ```
+#[derive(Debug)]
+pub struct Builder {
+    /// Thread pool specific builder
+    threadpool_builder: ThreadPoolBuilder,
+
+    /// The number of worker threads
+    core_threads: usize,
+
+    /// The clock to use
+    clock: Clock,
+}
+
+impl Builder {
+    /// Returns a new runtime builder initialized with default configuration
+    /// values.
+    ///
+    /// Configuration methods can be chained on the return value.
+    pub fn new() -> Builder {
+        let core_threads = num_cpus::get().max(1);
+
+        let mut threadpool_builder = ThreadPoolBuilder::new();
+        threadpool_builder.name_prefix("tokio-runtime-worker-");
+        threadpool_builder.pool_size(core_threads);
+
+        Builder {
+            threadpool_builder,
+            core_threads,
+            clock: Clock::new(),
+        }
+    }
+
+    /// Set the `Clock` instance that will be used by the runtime.
+    pub fn clock(&mut self, clock: Clock) -> &mut Self {
+        self.clock = clock;
+        self
+    }
+
+    /// Set builder to set up the thread pool instance.
+    #[deprecated(
+        since="0.1.9",
+        note="use the `core_threads`, `blocking_threads`, `name_prefix`, \
+              `keep_alive`, and `stack_size` functions on `runtime::Builder`, \
+              instead")]
+    #[doc(hidden)]
+    pub fn threadpool_builder(&mut self, val: ThreadPoolBuilder) -> &mut Self {
+        self.threadpool_builder = val;
+        self
+    }
+
+    /// Set the maximum number of worker threads for the `Runtime`'s thread pool.
+    ///
+    /// This must be a number between 1 and 32,768 though it is advised to keep
+    /// this value on the smaller side.
+    ///
+    /// The default value is the number of cores available to the system.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # extern crate futures;
+    /// # use tokio::runtime;
+    ///
+    /// # pub fn main() {
+    /// let mut rt = runtime::Builder::new()
+    ///     .core_threads(4)
+    ///     .build()
+    ///     .unwrap();
+    /// # }
+    /// ```
+    pub fn core_threads(&mut self, val: usize) -> &mut Self {
+        self.core_threads = val;
+        self.threadpool_builder.pool_size(val);
+        self
+    }
+
+    /// Set the maximum number of concurrent blocking sections in the `Runtime`'s
+    /// thread pool.
+    ///
+    /// When the maximum concurrent `blocking` calls is reached, any further
+    /// calls to `blocking` will return `NotReady` and the task is notified once
+    /// previously in-flight calls to `blocking` return.
+    ///
+    /// This must be a number between 1 and 32,768 though it is advised to keep
+    /// this value on the smaller side.
+    ///
+    /// The default value is 100.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # extern crate futures;
+    /// # use tokio::runtime;
+    ///
+    /// # pub fn main() {
+    /// let mut rt = runtime::Builder::new()
+    ///     .blocking_threads(200)
+    ///     .build();
+    /// # }
+    /// ```
+    pub fn blocking_threads(&mut self, val: usize) -> &mut Self {
+        self.threadpool_builder.max_blocking(val);
+        self
+    }
+
+    /// Set the worker thread keep alive duration for threads in the `Runtime`'s
+    /// thread pool.
+    ///
+    /// If set, a worker thread will wait for up to the specified duration for
+    /// work, at which point the thread will shutdown. When work becomes
+    /// available, a new thread will eventually be spawned to replace the one
+    /// that shut down.
+    ///
+    /// When the value is `None`, the thread will wait for work forever.
+    ///
+    /// The default value is `None`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # extern crate futures;
+    /// # use tokio::runtime;
+    /// use std::time::Duration;
+    ///
+    /// # pub fn main() {
+    /// let mut rt = runtime::Builder::new()
+    ///     .keep_alive(Some(Duration::from_secs(30)))
+    ///     .build();
+    /// # }
+    /// ```
+    pub fn keep_alive(&mut self, val: Option<Duration>) -> &mut Self {
+        self.threadpool_builder.keep_alive(val);
+        self
+    }
+
+    /// Set name prefix of threads spawned by the `Runtime`'s thread pool.
+    ///
+    /// Thread name prefix is used for generating thread names. For example, if
+    /// prefix is `my-pool-`, then threads in the pool will get names like
+    /// `my-pool-1` etc.
+    ///
+    /// The default prefix is "tokio-runtime-worker-".
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # extern crate futures;
+    /// # use tokio::runtime;
+    ///
+    /// # pub fn main() {
+    /// let mut rt = runtime::Builder::new()
+    ///     .name_prefix("my-pool-")
+    ///     .build();
+    /// # }
+    /// ```
+    pub fn name_prefix<S: Into<String>>(&mut self, val: S) -> &mut Self {
+        self.threadpool_builder.name_prefix(val);
+        self
+    }
+
+    /// Set the stack size (in bytes) for worker threads.
+    ///
+    /// The actual stack size may be greater than this value if the platform
+    /// specifies minimal stack size.
+    ///
+    /// The default stack size for spawned threads is 2 MiB, though this
+    /// particular stack size is subject to change in the future.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # extern crate futures;
+    /// # use tokio::runtime;
+    ///
+    /// # pub fn main() {
+    /// let mut rt = runtime::Builder::new()
+    ///     .stack_size(32 * 1024)
+    ///     .build();
+    /// # }
+    /// ```
+    pub fn stack_size(&mut self, val: usize) -> &mut Self {
+        self.threadpool_builder.stack_size(val);
+        self
+    }
+
+    /// Execute function `f` after each thread is started but before it starts
+    /// doing work.
+    ///
+    /// This is intended for bookkeeping and monitoring use cases.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # extern crate futures;
+    /// # use tokio::runtime;
+    ///
+    /// # pub fn main() {
+    /// let thread_pool = runtime::Builder::new()
+    ///     .after_start(|| {
+    ///         println!("thread started");
+    ///     })
+    ///     .build();
+    /// # }
+    /// ```
+    pub fn after_start<F>(&mut self, f: F) -> &mut Self
+        where F: Fn() + Send + Sync + 'static
+    {
+        self.threadpool_builder.after_start(f);
+        self
+    }
+
+    /// Execute function `f` before each thread stops.
+    ///
+    /// This is intended for bookkeeping and monitoring use cases.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # extern crate futures;
+    /// # use tokio::runtime;
+    ///
+    /// # pub fn main() {
+    /// let thread_pool = runtime::Builder::new()
+    ///     .before_stop(|| {
+    ///         println!("thread stopping");
+    ///     })
+    ///     .build();
+    /// # }
+    /// ```
+    pub fn before_stop<F>(&mut self, f: F) -> &mut Self
+        where F: Fn() + Send + Sync + 'static
+    {
+        self.threadpool_builder.before_stop(f);
+        self
+    }
+
+    /// Create the configured `Runtime`.
+    ///
+    /// The returned `ThreadPool` instance is ready to spawn tasks.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # use tokio::runtime::Builder;
+    /// # pub fn main() {
+    /// let runtime = Builder::new().build().unwrap();
+    /// // ... call runtime.run(...)
+    /// # let _ = runtime;
+    /// # }
+    /// ```
+    pub fn build(&mut self) -> io::Result<Runtime> {
+        // TODO(stjepang): Once we remove the `threadpool_builder` method, remove this line too.
+        self.threadpool_builder.pool_size(self.core_threads);
+
+        let mut reactor_handles = Vec::new();
+        let mut timer_handles = Vec::new();
+        let mut timers = Vec::new();
+
+        for _ in 0..self.core_threads {
+            // Create a new reactor.
+            let reactor = Reactor::new()?;
+            reactor_handles.push(reactor.handle());
+
+            // Create a new timer.
+            let timer = Timer::new_with_now(reactor, self.clock.clone());
+            timer_handles.push(timer.handle());
+            timers.push(Mutex::new(Some(timer)));
+        }
+
+        // Get a handle to the clock for the runtime.
+        let clock = self.clock.clone();
+
+        let pool = self.threadpool_builder
+            .around_worker(move |w, enter| {
+                let index = w.id().to_usize();
+
+                tokio_reactor::with_default(&reactor_handles[index], enter, |enter| {
+                    clock::with_default(&clock, enter, |enter| {
+                        timer::with_default(&timer_handles[index], enter, |_| {
+                            w.run();
+                        });
+                    })
+                });
+            })
+            .custom_park(move |worker_id| {
+                let index = worker_id.to_usize();
+
+                timers[index]
+                    .lock()
+                    .unwrap()
+                    .take()
+                    .unwrap()
+            })
+            .build();
+
+        // To support deprecated `reactor()` function
+        let reactor = Reactor::new()?;
+        let reactor_handle = reactor.handle();
+
+        Ok(Runtime {
+            inner: Some(Inner {
+                reactor_handle,
+                reactor: Mutex::new(Some(reactor)),
+                pool,
+            }),
+        })
+    }
+}

src/runtime/threadpool/mod.rs

@@ -0,0 +1,395 @@
+mod builder;
+mod shutdown;
+mod task_executor;
+
+pub use self::builder::Builder;
+pub use self::shutdown::Shutdown;
+pub use self::task_executor::TaskExecutor;
+
+use reactor::{Handle, Reactor};
+
+use std::io;
+use std::sync::Mutex;
+
+use tokio_executor::enter;
+use tokio_threadpool as threadpool;
+
+use futures;
+use futures::future::Future;
+
+/// Handle to the Tokio runtime.
+///
+/// The Tokio runtime includes a reactor as well as an executor for running
+/// tasks.
+///
+/// Instances of `Runtime` can be created using [`new`] or [`Builder`]. However,
+/// most users will use [`tokio::run`], which uses a `Runtime` internally.
+///
+/// See [module level][mod] documentation for more details.
+///
+/// [mod]: index.html
+/// [`new`]: #method.new
+/// [`Builder`]: struct.Builder.html
+/// [`tokio::run`]: fn.run.html
+#[derive(Debug)]
+pub struct Runtime {
+    inner: Option<Inner>,
+}
+
+#[derive(Debug)]
+struct Inner {
+    /// A handle to the reactor in the background thread.
+    reactor_handle: Handle,
+
+    // TODO: This should go away in 0.2
+    reactor: Mutex<Option<Reactor>>,
+
+    /// Task execution pool.
+    pool: threadpool::ThreadPool,
+}
+
+// ===== impl Runtime =====
+
+/// Start the Tokio runtime using the supplied future to bootstrap execution.
+///
+/// This function is used to bootstrap the execution of a Tokio application. It
+/// does the following:
+///
+/// * Start the Tokio runtime using a default configuration.
+/// * Spawn the given future onto the thread pool.
+/// * Block the current thread until the runtime shuts down.
+///
+/// Note that the function will not return immediately once `future` has
+/// completed. Instead it waits for the entire runtime to become idle.
+///
+/// See the [module level][mod] documentation for more details.
+///
+/// # Examples
+///
+/// ```rust
+/// # extern crate tokio;
+/// # extern crate futures;
+/// # use futures::{Future, Stream};
+/// use tokio::net::TcpListener;
+///
+/// # fn process<T>(_: T) -> Box<Future<Item = (), Error = ()> + Send> {
+/// # unimplemented!();
+/// # }
+/// # fn dox() {
+/// # let addr = "127.0.0.1:8080".parse().unwrap();
+/// let listener = TcpListener::bind(&addr).unwrap();
+///
+/// let server = listener.incoming()
+///     .map_err(|e| println!("error = {:?}", e))
+///     .for_each(|socket| {
+///         tokio::spawn(process(socket))
+///     });
+///
+/// tokio::run(server);
+/// # }
+/// # pub fn main() {}
+/// ```
+///
+/// # Panics
+///
+/// This function panics if called from the context of an executor.
+///
+/// [mod]: ../index.html
+pub fn run<F>(future: F)
+where F: Future<Item = (), Error = ()> + Send + 'static,
+{
+    // Check enter before creating a new Runtime...
+    let mut entered = enter().expect("nested tokio::run");
+    let mut runtime = Runtime::new().expect("failed to start new Runtime");
+    runtime.spawn(future);
+    entered
+        .block_on(runtime.shutdown_on_idle())
+        .expect("shutdown cannot error")
+}
+
+impl Runtime {
+    /// Create a new runtime instance with default configuration values.
+    ///
+    /// This results in a reactor, thread pool, and timer being initialized. The
+    /// thread pool will not spawn any worker threads until it needs to, i.e.
+    /// tasks are scheduled to run.
+    ///
+    /// Most users will not need to call this function directly, instead they
+    /// will use [`tokio::run`](fn.run.html).
+    ///
+    /// See [module level][mod] documentation for more details.
+    ///
+    /// # Examples
+    ///
+    /// Creating a new `Runtime` with default configuration values.
+    ///
+    /// ```
+    /// use tokio::runtime::Runtime;
+    /// use tokio::prelude::*;
+    ///
+    /// let rt = Runtime::new()
+    ///     .unwrap();
+    ///
+    /// // Use the runtime...
+    ///
+    /// // Shutdown the runtime
+    /// rt.shutdown_now()
+    ///     .wait().unwrap();
+    /// ```
+    ///
+    /// [mod]: index.html
+    pub fn new() -> io::Result<Self> {
+        Builder::new().build()
+    }
+
+    #[deprecated(since = "0.1.5", note = "use `reactor` instead")]
+    #[doc(hidden)]
+    pub fn handle(&self) -> &Handle {
+        #[allow(deprecated)]
+        self.reactor()
+    }
+
+    /// Return a reference to the reactor handle for this runtime instance.
+    ///
+    /// The returned handle reference can be cloned in order to get an owned
+    /// value of the handle. This handle can be used to initialize I/O resources
+    /// (like TCP or UDP sockets) that will not be used on the runtime.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use tokio::runtime::Runtime;
+    ///
+    /// let rt = Runtime::new()
+    ///     .unwrap();
+    ///
+    /// let reactor_handle = rt.reactor().clone();
+    ///
+    /// // use `reactor_handle`
+    /// ```
+    #[deprecated(since = "0.1.11", note = "there is now a reactor per worker thread")]
+    pub fn reactor(&self) -> &Handle {
+        let mut reactor = self.inner().reactor.lock().unwrap();
+        if let Some(reactor) = reactor.take() {
+            if let Ok(background) = reactor.background() {
+                background.forget();
+            }
+        }
+
+        &self.inner().reactor_handle
+    }
+
+    /// Return a handle to the runtime's executor.
+    ///
+    /// The returned handle can be used to spawn tasks that run on this runtime.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use tokio::runtime::Runtime;
+    ///
+    /// let rt = Runtime::new()
+    ///     .unwrap();
+    ///
+    /// let executor_handle = rt.executor();
+    ///
+    /// // use `executor_handle`
+    /// ```
+    pub fn executor(&self) -> TaskExecutor {
+        let inner = self.inner().pool.sender().clone();
+        TaskExecutor { inner }
+    }
+
+    /// Spawn a future onto the Tokio runtime.
+    ///
+    /// This spawns the given future onto the runtime's executor, usually a
+    /// thread pool. The thread pool is then responsible for polling the future
+    /// until it completes.
+    ///
+    /// See [module level][mod] documentation for more details.
+    ///
+    /// [mod]: index.html
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # extern crate tokio;
+    /// # extern crate futures;
+    /// # use futures::{future, Future, Stream};
+    /// use tokio::runtime::Runtime;
+    ///
+    /// # fn dox() {
+    /// // Create the runtime
+    /// let mut rt = Runtime::new().unwrap();
+    ///
+    /// // Spawn a future onto the runtime
+    /// rt.spawn(future::lazy(|| {
+    ///     println!("now running on a worker thread");
+    ///     Ok(())
+    /// }));
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    ///
+    /// # Panics
+    ///
+    /// This function panics if the spawn fails. Failure occurs if the executor
+    /// is currently at capacity and is unable to spawn a new future.
+    pub fn spawn<F>(&mut self, future: F) -> &mut Self
+    where F: Future<Item = (), Error = ()> + Send + 'static,
+    {
+        self.inner_mut().pool.sender().spawn(future).unwrap();
+        self
+    }
+
+    /// Run a future to completion on the Tokio runtime.
+    ///
+    /// This runs the given future on the runtime, blocking until it is
+    /// complete, and yielding its resolved result. Any tasks or timers which
+    /// the future spawns internally will be executed on the runtime.
+    ///
+    /// This method should not be called from an asynchronous context.
+    ///
+    /// # Panics
+    ///
+    /// This function panics if the executor is at capacity, if the provided
+    /// future panics, or if called within an asynchronous execution context.
+    pub fn block_on<F, R, E>(&mut self, future: F) -> Result<R, E>
+    where
+        F: Send + 'static + Future<Item = R, Error = E>,
+        R: Send + 'static,
+        E: Send + 'static,
+    {
+        let mut entered = enter().expect("nested block_on");
+        let (tx, rx) = futures::sync::oneshot::channel();
+        self.spawn(future.then(move |r| tx.send(r).map_err(|_| unreachable!())));
+        entered.block_on(rx).unwrap()
+    }
+
+    /// Run a future to completion on the Tokio runtime, then wait for all
+    /// background futures to complete too.
+    ///
+    /// This runs the given future on the runtime, blocking until it is
+    /// complete, waiting for background futures to complete, and yielding
+    /// its resolved result. Any tasks or timers which the future spawns
+    /// internally will be executed on the runtime and waited for completion.
+    ///
+    /// This method should not be called from an asynchronous context.
+    ///
+    /// # Panics
+    ///
+    /// This function panics if the executor is at capacity, if the provided
+    /// future panics, or if called within an asynchronous execution context.
+    pub fn block_on_all<F, R, E>(mut self, future: F) -> Result<R, E>
+    where
+        F: Send + 'static + Future<Item = R, Error = E>,
+        R: Send + 'static,
+        E: Send + 'static,
+    {
+        let mut entered = enter().expect("nested block_on_all");
+        let (tx, rx) = futures::sync::oneshot::channel();
+        self.spawn(future.then(move |r| tx.send(r).map_err(|_| unreachable!())));
+        let block = rx
+            .map_err(|_| unreachable!())
+            .and_then(move |r| {
+                self.shutdown_on_idle()
+                    .map(move |()| r)
+            });
+        entered.block_on(block).unwrap()
+    }
+
+    /// Signals the runtime to shutdown once it becomes idle.
+    ///
+    /// Returns a future that completes once the shutdown operation has
+    /// completed.
+    ///
+    /// This function can be used to perform a graceful shutdown of the runtime.
+    ///
+    /// The runtime enters an idle state once **all** of the following occur.
+    ///
+    /// * The thread pool has no tasks to execute, i.e., all tasks that were
+    ///   spawned have completed.
+    /// * The reactor is not managing any I/O resources.
+    ///
+    /// See [module level][mod] documentation for more details.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use tokio::runtime::Runtime;
+    /// use tokio::prelude::*;
+    ///
+    /// let rt = Runtime::new()
+    ///     .unwrap();
+    ///
+    /// // Use the runtime...
+    ///
+    /// // Shutdown the runtime
+    /// rt.shutdown_on_idle()
+    ///     .wait().unwrap();
+    /// ```
+    ///
+    /// [mod]: index.html
+    pub fn shutdown_on_idle(mut self) -> Shutdown {
+        let inner = self.inner.take().unwrap();
+        let inner = inner.pool.shutdown_on_idle();
+        Shutdown { inner }
+    }
+
+    /// Signals the runtime to shutdown immediately.
+    ///
+    /// Returns a future that completes once the shutdown operation has
+    /// completed.
+    ///
+    /// This function will forcibly shutdown the runtime, causing any
+    /// in-progress work to become canceled. The shutdown steps are:
+    ///
+    /// * Drain any scheduled work queues.
+    /// * Drop any futures that have not yet completed.
+    /// * Drop the reactor.
+    ///
+    /// Once the reactor has dropped, any outstanding I/O resources bound to
+    /// that reactor will no longer function. Calling any method on them will
+    /// result in an error.
+    ///
+    /// See [module level][mod] documentation for more details.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use tokio::runtime::Runtime;
+    /// use tokio::prelude::*;
+    ///
+    /// let rt = Runtime::new()
+    ///     .unwrap();
+    ///
+    /// // Use the runtime...
+    ///
+    /// // Shutdown the runtime
+    /// rt.shutdown_now()
+    ///     .wait().unwrap();
+    /// ```
+    ///
+    /// [mod]: index.html
+    pub fn shutdown_now(mut self) -> Shutdown {
+        let inner = self.inner.take().unwrap();
+        Shutdown::shutdown_now(inner)
+    }
+
+    fn inner(&self) -> &Inner {
+        self.inner.as_ref().unwrap()
+    }
+
+    fn inner_mut(&mut self) -> &mut Inner {
+        self.inner.as_mut().unwrap()
+    }
+}
+
+impl Drop for Runtime {
+    fn drop(&mut self) {
+        if let Some(inner) = self.inner.take() {
+            let shutdown = Shutdown::shutdown_now(inner);
+            let _ = shutdown.wait();
+        }
+    }
+}

src/runtime/threadpool/shutdown.rs

@@ -1,4 +1,5 @@
-use runtime::Inner;
+use super::Inner;
+use tokio_threadpool as threadpool;
 
 use std::fmt;
 
@@ -6,23 +7,12 @@ use futures::{Future, Poll};
 
 /// A future that resolves when the Tokio `Runtime` is shut down.
 pub struct Shutdown {
-    pub(super) inner: Box<Future<Item = (), Error = ()> + Send>,
+    pub(super) inner: threadpool::Shutdown,
 }
 
 impl Shutdown {
     pub(super) fn shutdown_now(inner: Inner) -> Self {
-        let inner = Box::new({
-            let pool = inner.pool;
-            let reactor = inner.reactor;
-
-            pool.shutdown_now().and_then(|_| {
-                reactor.shutdown_now()
-                    .then(|_| {
-                        Ok(())
-                    })
-            })
-        });
-
+        let inner = inner.pool.shutdown_now();
         Shutdown { inner }
     }
 }

src/sync.rs

@@ -0,0 +1,16 @@
+//! Future-aware synchronization
+//!
+//! This module is enabled with the **`sync`** feature flag.
+//!
+//! Tasks sometimes need to communicate with each other. This module contains
+//! two basic abstractions for doing so:
+//!
+//! - [oneshot](oneshot/index.html), a way of sending a single value
+//!   from one task to another.
+//! - [mpsc](mpsc/index.html), a multi-producer, single-consumer channel for
+//!   sending values between tasks.
+
+pub use tokio_sync::{
+    mpsc,
+    oneshot,
+};

src/timer.rs

@@ -10,9 +10,9 @@
 //!   is initialized with a `Duration` and repeatedly yields each time the
 //!   duration elapses.
 //!
-//! * [`Timeout`][Timeeout]: Wraps a future or stream, setting an upper bound to the
+//! * [`Timeout`][Timeout]: Wraps a future or stream, setting an upper bound to the
 //!   amount of time it is allowed to execute. If the future or stream does not
-//!   completee in time, then it is canceled and an error is returned.
+//!   complete in time, then it is canceled and an error is returned.
 //!
 //! * [`DelayQueue`]: A queue where items are returned once the requested delay
 //!   has expired.

src/util/enumerate.rs

@@ -0,0 +1,80 @@
+use futures::{Async, Poll, Stream, Sink, StartSend};
+
+/// A stream combinator which combines the yields the current item
+/// plus its count starting from 0.
+///
+/// This structure is produced by the `Stream::enumerate` method.
+#[derive(Debug)]
+#[must_use = "Does nothing unless polled"]
+pub struct Enumerate<T> {
+    inner: T,
+    count: usize,
+}
+
+impl<T> Enumerate<T> {
+    pub(crate) fn new(stream: T) -> Self {
+        Self { inner: stream, count: 0 }
+    }
+
+    /// Acquires a reference to the underlying stream that this combinator is
+    /// pulling from.
+    pub fn get_ref(&self) -> &T {
+        &self.inner
+    }
+
+    /// Acquires a mutable reference to the underlying stream that this
+    /// combinator is pulling from.
+    ///
+    /// Note that care must be taken to avoid tampering with the state of the
+    /// stream which may otherwise confuse this combinator.
+    pub fn get_mut(&mut self) -> &mut T {
+        &mut self.inner
+    }
+
+    /// Consumes this combinator, returning the underlying stream.
+    ///
+    /// Note that this may discard intermediate state of this combinator, so
+    /// care should be taken to avoid losing resources when this is called.
+    pub fn into_inner(self) -> T {
+        self.inner
+    }
+}
+
+impl<T> Stream for Enumerate<T>
+where
+    T: Stream,
+{
+    type Item = (usize, T::Item);
+    type Error = T::Error;
+
+    fn poll(&mut self) -> Poll<Option<Self::Item>, T::Error> {
+        match try_ready!(self.inner.poll()) {
+            Some(item) => {
+                let ret = Some((self.count, item));
+                self.count += 1;
+                Ok(Async::Ready(ret))
+            }
+            None => return Ok(Async::Ready(None)),
+        }
+    }
+}
+
+// Forwarding impl of Sink from the underlying stream
+impl<T> Sink for Enumerate<T>
+    where T: Sink
+{
+    type SinkItem = T::SinkItem;
+    type SinkError = T::SinkError;
+
+    fn start_send(&mut self, item: T::SinkItem) -> StartSend<T::SinkItem, T::SinkError> {
+        self.inner.start_send(item)
+    }
+
+    fn poll_complete(&mut self) -> Poll<(), T::SinkError> {
+        self.inner.poll_complete()
+    }
+
+    fn close(&mut self) -> Poll<(), T::SinkError> {
+        self.inner.close()
+    }
+}

src/util/future.rs

@@ -1,9 +1,12 @@
+#[cfg(feature = "timer")]
 #[allow(deprecated)]
 use tokio_timer::Deadline;
+#[cfg(feature = "timer")]
 use tokio_timer::Timeout;
 
 use futures::Future;
 
+#[cfg(feature = "timer")]
 use std::time::{Instant, Duration};
 
 
@@ -31,6 +34,9 @@ pub trait FutureExt: Future {
     /// If the future completes before `timeout` then the future will resolve
     /// with that item. Otherwise the future will resolve to an error.
     ///
+    /// The future is guaranteed to be polled at least once, even if `timeout`
+    /// is set to zero.
+    ///
     /// # Examples
     ///
     /// ```
@@ -52,12 +58,14 @@ pub trait FutureExt: Future {
     /// tokio::run(future);
     /// # }
     /// ```
+    #[cfg(feature = "timer")]
     fn timeout(self, timeout: Duration) -> Timeout<Self>
     where Self: Sized,
     {
         Timeout::new(self, timeout)
     }
 
+    #[cfg(feature = "timer")]
     #[deprecated(since = "0.1.8", note = "use `timeout` instead")]
     #[allow(deprecated)]
     #[doc(hidden)]
@@ -69,3 +77,17 @@ pub trait FutureExt: Future {
 }
 
 impl<T: ?Sized> FutureExt for T where T: Future {}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use prelude::future;
+
+    #[cfg(feature = "timer")]
+    #[test]
+    fn timeout_polls_at_least_once() {
+        let base_future = future::result::<(), ()>(Ok(()));
+        let timeouted_future = base_future.timeout(Duration::new(0, 0));
+        assert!(timeouted_future.wait().is_ok());
+    }
+}

src/util/mod.rs

@@ -1,10 +1,15 @@
 //! Utilities for working with Tokio.
 //!
 //! This module contains utilities that are useful for working with Tokio.
-//! Currently, this only includes [`FutureExt`], but this may grow over time.
+//! Currently, this only includes [`FutureExt`] and [`StreamExt`], but this
+//! may grow over time.
 //!
 //! [`FutureExt`]: trait.FutureExt.html
+//! [`StreamExt`]: trait.StreamExt.html
 
 mod future;
+mod stream;
+mod enumerate;
 
 pub use self::future::FutureExt;
+pub use self::stream::StreamExt;

src/util/stream.rs

@@ -0,0 +1,95 @@
+#[cfg(feature = "timer")]
+use tokio_timer::{
+    throttle::Throttle,
+    Timeout,
+};
+
+use futures::Stream;
+
+#[cfg(feature = "timer")]
+use std::time::Duration;
+pub use util::enumerate::Enumerate;
+
+/// An extension trait for `Stream` that provides a variety of convenient
+/// combinator functions.
+///
+/// Currently, there only is a [`timeout`] function, but this will increase
+/// over time.
+///
+/// Users are not expected to implement this trait. All types that implement
+/// `Stream` already implement `StreamExt`.
+///
+/// This trait can be imported directly or via the Tokio prelude: `use
+/// tokio::prelude::*`.
+///
+/// [`timeout`]: #method.timeout
+pub trait StreamExt: Stream {
+    /// Throttle down the stream by enforcing a fixed delay between items.
+    ///
+    /// Errors are also delayed.
+    #[cfg(feature = "timer")]
+    fn throttle(self, duration: Duration) -> Throttle<Self>
+    where Self: Sized
+    {
+        Throttle::new(self, duration)
+    }
+
+    /// Creates a new stream which gives the current iteration count as well
+    /// as the next value.
+    ///
+    /// The stream returned yields pairs `(i, val)`, where `i` is the
+    /// current index of iteration and `val` is the value returned by the
+    /// iterator.
+    ///
+    /// # Overflow Behavior
+    ///
+    /// The method does no guarding against overflows, so counting elements of
+    /// an iterator with more than [`std::usize::MAX`] elements either produces the
+    /// wrong result or panics.
+    fn enumerate(self) -> Enumerate<Self>
+    where Self: Sized,
+    {
+        Enumerate::new(self)
+    }
+
+    /// Creates a new stream which allows `self` until `timeout`.
+    ///
+    /// This combinator creates a new stream which wraps the receiving stream
+    /// with a timeout. For each item, the returned stream is allowed to execute
+    /// until it completes or `timeout` has elapsed, whichever happens first.
+    ///
+    /// If an item completes before `timeout` then the stream will yield
+    /// with that item. Otherwise the stream will yield to an error.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate tokio;
+    /// # extern crate futures;
+    /// use tokio::prelude::*;
+    /// use std::time::Duration;
+    /// # use futures::future::{self, FutureResult};
+    ///
+    /// # fn long_future() -> FutureResult<(), ()> {
+    /// #   future::ok(())
+    /// # }
+    /// #
+    /// # fn main() {
+    /// let stream = long_future()
+    ///     .into_stream()
+    ///     .timeout(Duration::from_secs(1))
+    ///     .for_each(|i| future::ok(println!("item = {:?}", i)))
+    ///     .map_err(|e| println!("error = {:?}", e));
+    ///
+    /// tokio::run(stream);
+    /// # }
+    /// ```
+    #[cfg(feature = "timer")]
+    fn timeout(self, timeout: Duration) -> Timeout<Self>
+    where Self: Sized,
+    {
+        Timeout::new(self, timeout)
+    }
+}
+
+impl<T: ?Sized> StreamExt for T where T: Stream {}

tests/enumerate.rs

@@ -0,0 +1,27 @@
+extern crate futures;
+extern crate tokio;
+extern crate tokio_executor;
+extern crate tokio_timer;
+
+use futures::sync::mpsc;
+use tokio::util::StreamExt;
+
+#[test]
+fn enumerate() {
+    use futures::*;
+
+    let (mut tx, rx) = mpsc::channel(1);
+
+    std::thread::spawn(|| {
+        for i in 0..5 {
+            tx = tx.send(i * 2).wait().unwrap();
+        }
+    });
+
+    let result = rx.enumerate().collect();
+    assert_eq!(
+        result.wait(),
+        Ok(vec![(0, 0), (1, 2), (2, 4), (3, 6), (4, 8)])
+    );
+
+}

tests/length_delimited.rs

@@ -0,0 +1,580 @@
+extern crate tokio;
+extern crate futures;
+extern crate bytes;
+
+use tokio::io::{AsyncRead, AsyncWrite};
+use tokio::codec::*;
+
+use bytes::{Bytes, BytesMut, BufMut};
+use futures::{Stream, Sink, Poll};
+use futures::Async::*;
+
+use std::io;
+use std::collections::VecDeque;
+
+macro_rules! mock {
+    ($($x:expr,)*) => {{
+        let mut v = VecDeque::new();
+        v.extend(vec![$($x),*]);
+        Mock { calls: v }
+    }};
+}
+
+
+#[test]
+fn read_empty_io_yields_nothing() {
+    let mut io = FramedRead::new(mock!(), LengthDelimitedCodec::new());
+
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn read_single_frame_one_packet() {
+    let mut io = FramedRead::new(mock! {
+        Ok(b"\x00\x00\x00\x09abcdefghi"[..].into()),
+    }, LengthDelimitedCodec::new());
+
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn read_single_frame_one_packet_little_endian() {
+    let mut io = length_delimited::Builder::new()
+        .little_endian()
+        .new_read(mock! {
+            Ok(b"\x09\x00\x00\x00abcdefghi"[..].into()),
+        });
+
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn read_single_frame_one_packet_native_endian() {
+    let data = if cfg!(target_endian = "big") {
+        b"\x00\x00\x00\x09abcdefghi"
+    } else {
+        b"\x09\x00\x00\x00abcdefghi"
+    };
+    let mut io = length_delimited::Builder::new()
+        .native_endian()
+        .new_read(mock! {
+            Ok(data[..].into()),
+        });
+
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn read_single_multi_frame_one_packet() {
+    let mut data: Vec<u8> = vec![];
+    data.extend_from_slice(b"\x00\x00\x00\x09abcdefghi");
+    data.extend_from_slice(b"\x00\x00\x00\x03123");
+    data.extend_from_slice(b"\x00\x00\x00\x0bhello world");
+
+    let mut io = FramedRead::new(mock! {
+        Ok(data.into()),
+    }, LengthDelimitedCodec::new());
+
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"123"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"hello world"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn read_single_frame_multi_packet() {
+    let mut io = FramedRead::new(mock! {
+        Ok(b"\x00\x00"[..].into()),
+        Ok(b"\x00\x09abc"[..].into()),
+        Ok(b"defghi"[..].into()),
+    }, LengthDelimitedCodec::new());
+
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn read_multi_frame_multi_packet() {
+    let mut io = FramedRead::new(mock! {
+        Ok(b"\x00\x00"[..].into()),
+        Ok(b"\x00\x09abc"[..].into()),
+        Ok(b"defghi"[..].into()),
+        Ok(b"\x00\x00\x00\x0312"[..].into()),
+        Ok(b"3\x00\x00\x00\x0bhello world"[..].into()),
+    }, LengthDelimitedCodec::new());
+
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"123"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"hello world"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn read_single_frame_multi_packet_wait() {
+    let mut io = FramedRead::new(mock! {
+        Ok(b"\x00\x00"[..].into()),
+        Err(would_block()),
+        Ok(b"\x00\x09abc"[..].into()),
+        Err(would_block()),
+        Ok(b"defghi"[..].into()),
+        Err(would_block()),
+    }, LengthDelimitedCodec::new());
+
+    assert_eq!(io.poll().unwrap(), NotReady);
+    assert_eq!(io.poll().unwrap(), NotReady);
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap(), NotReady);
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn read_multi_frame_multi_packet_wait() {
+    let mut io = FramedRead::new(mock! {
+        Ok(b"\x00\x00"[..].into()),
+        Err(would_block()),
+        Ok(b"\x00\x09abc"[..].into()),
+        Err(would_block()),
+        Ok(b"defghi"[..].into()),
+        Err(would_block()),
+        Ok(b"\x00\x00\x00\x0312"[..].into()),
+        Err(would_block()),
+        Ok(b"3\x00\x00\x00\x0bhello world"[..].into()),
+        Err(would_block()),
+    }, LengthDelimitedCodec::new());
+
+
+    assert_eq!(io.poll().unwrap(), NotReady);
+    assert_eq!(io.poll().unwrap(), NotReady);
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap(), NotReady);
+    assert_eq!(io.poll().unwrap(), NotReady);
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"123"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"hello world"[..].into())));
+    assert_eq!(io.poll().unwrap(), NotReady);
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn read_incomplete_head() {
+    let mut io = FramedRead::new(mock! {
+        Ok(b"\x00\x00"[..].into()),
+    }, LengthDelimitedCodec::new());
+
+    assert!(io.poll().is_err());
+}
+
+#[test]
+fn read_incomplete_head_multi() {
+    let mut io = FramedRead::new(mock! {
+        Err(would_block()),
+        Ok(b"\x00"[..].into()),
+        Err(would_block()),
+    }, LengthDelimitedCodec::new());
+
+    assert_eq!(io.poll().unwrap(), NotReady);
+    assert_eq!(io.poll().unwrap(), NotReady);
+    assert!(io.poll().is_err());
+}
+
+#[test]
+fn read_incomplete_payload() {
+    let mut io = FramedRead::new(mock! {
+        Ok(b"\x00\x00\x00\x09ab"[..].into()),
+        Err(would_block()),
+        Ok(b"cd"[..].into()),
+        Err(would_block()),
+    }, LengthDelimitedCodec::new());
+
+    assert_eq!(io.poll().unwrap(), NotReady);
+    assert_eq!(io.poll().unwrap(), NotReady);
+    assert!(io.poll().is_err());
+}
+
+#[test]
+fn read_max_frame_len() {
+    let mut io = length_delimited::Builder::new()
+        .max_frame_length(5)
+        .new_read(mock! {
+            Ok(b"\x00\x00\x00\x09abcdefghi"[..].into()),
+        });
+
+    assert_eq!(io.poll().unwrap_err().kind(), io::ErrorKind::InvalidData);
+}
+
+#[test]
+fn read_update_max_frame_len_at_rest() {
+    let mut io = length_delimited::Builder::new()
+        .new_read(mock! {
+            Ok(b"\x00\x00\x00\x09abcdefghi"[..].into()),
+            Ok(b"\x00\x00\x00\x09abcdefghi"[..].into()),
+        });
+
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    io.decoder_mut().set_max_frame_length(5);
+    assert_eq!(io.poll().unwrap_err().kind(), io::ErrorKind::InvalidData);
+}
+
+#[test]
+fn read_update_max_frame_len_in_flight() {
+    let mut io = length_delimited::Builder::new()
+        .new_read(mock! {
+            Ok(b"\x00\x00\x00\x09abcd"[..].into()),
+            Err(would_block()),
+            Ok(b"efghi"[..].into()),
+            Ok(b"\x00\x00\x00\x09abcdefghi"[..].into()),
+        });
+
+    assert_eq!(io.poll().unwrap(), NotReady);
+    io.decoder_mut().set_max_frame_length(5);
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap_err().kind(), io::ErrorKind::InvalidData);
+}
+
+#[test]
+fn read_one_byte_length_field() {
+    let mut io = length_delimited::Builder::new()
+        .length_field_length(1)
+        .new_read(mock! {
+            Ok(b"\x09abcdefghi"[..].into()),
+        });
+
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn read_header_offset() {
+    let mut io = length_delimited::Builder::new()
+        .length_field_length(2)
+        .length_field_offset(4)
+        .new_read(mock! {
+            Ok(b"zzzz\x00\x09abcdefghi"[..].into()),
+        });
+
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn read_single_multi_frame_one_packet_skip_none_adjusted() {
+    let mut data: Vec<u8> = vec![];
+    data.extend_from_slice(b"xx\x00\x09abcdefghi");
+    data.extend_from_slice(b"yy\x00\x03123");
+    data.extend_from_slice(b"zz\x00\x0bhello world");
+
+    let mut io = length_delimited::Builder::new()
+        .length_field_length(2)
+        .length_field_offset(2)
+        .num_skip(0)
+        .length_adjustment(4)
+        .new_read(mock! {
+            Ok(data.into()),
+        });
+
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"xx\x00\x09abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"yy\x00\x03123"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"zz\x00\x0bhello world"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn read_single_multi_frame_one_packet_length_includes_head() {
+    let mut data: Vec<u8> = vec![];
+    data.extend_from_slice(b"\x00\x0babcdefghi");
+    data.extend_from_slice(b"\x00\x05123");
+    data.extend_from_slice(b"\x00\x0dhello world");
+
+    let mut io = length_delimited::Builder::new()
+        .length_field_length(2)
+        .length_adjustment(-2)
+        .new_read(mock! {
+            Ok(data.into()),
+        });
+
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"abcdefghi"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"123"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(Some(b"hello world"[..].into())));
+    assert_eq!(io.poll().unwrap(), Ready(None));
+}
+
+#[test]
+fn write_single_frame_length_adjusted() {
+    let mut io = length_delimited::Builder::new()
+        .length_adjustment(-2)
+        .new_write(mock! {
+            Ok(b"\x00\x00\x00\x0b"[..].into()),
+            Ok(b"abcdefghi"[..].into()),
+            Ok(Flush),
+        });
+    assert!(io.start_send(Bytes::from("abcdefghi")).unwrap().is_ready());
+    assert!(io.poll_complete().unwrap().is_ready());
+    assert!(io.get_ref().calls.is_empty());
+}
+
+#[test]
+fn write_nothing_yields_nothing() {
+    let mut io = FramedWrite::new(
+        mock!(),
+        LengthDelimitedCodec::new()
+    );
+    assert!(io.poll_complete().unwrap().is_ready());
+}
+
+#[test]
+fn write_single_frame_one_packet() {
+    let mut io = FramedWrite::new(mock! {
+        Ok(b"\x00\x00\x00\x09"[..].into()),
+        Ok(b"abcdefghi"[..].into()),
+        Ok(Flush),
+    }, LengthDelimitedCodec::new());
+
+    assert!(io.start_send(Bytes::from("abcdefghi")).unwrap().is_ready());
+    assert!(io.poll_complete().unwrap().is_ready());
+    assert!(io.get_ref().calls.is_empty());
+}
+
+#[test]
+fn write_single_multi_frame_one_packet() {
+    let mut io = FramedWrite::new(mock! {
+        Ok(b"\x00\x00\x00\x09"[..].into()),
+        Ok(b"abcdefghi"[..].into()),
+        Ok(b"\x00\x00\x00\x03"[..].into()),
+        Ok(b"123"[..].into()),
+        Ok(b"\x00\x00\x00\x0b"[..].into()),
+        Ok(b"hello world"[..].into()),
+        Ok(Flush),
+    }, LengthDelimitedCodec::new());
+
+    assert!(io.start_send(Bytes::from("abcdefghi")).unwrap().is_ready());
+    assert!(io.start_send(Bytes::from("123")).unwrap().is_ready());
+    assert!(io.start_send(Bytes::from("hello world")).unwrap().is_ready());
+    assert!(io.poll_complete().unwrap().is_ready());
+    assert!(io.get_ref().calls.is_empty());
+}
+
+#[test]
+fn write_single_multi_frame_multi_packet() {
+    let mut io = FramedWrite::new(mock! {
+        Ok(b"\x00\x00\x00\x09"[..].into()),
+        Ok(b"abcdefghi"[..].into()),
+        Ok(Flush),
+        Ok(b"\x00\x00\x00\x03"[..].into()),
+        Ok(b"123"[..].into()),
+        Ok(Flush),
+        Ok(b"\x00\x00\x00\x0b"[..].into()),
+        Ok(b"hello world"[..].into()),
+        Ok(Flush),
+    }, LengthDelimitedCodec::new());
+
+    assert!(io.start_send(Bytes::from("abcdefghi")).unwrap().is_ready());
+    assert!(io.poll_complete().unwrap().is_ready());
+    assert!(io.start_send(Bytes::from("123")).unwrap().is_ready());
+    assert!(io.poll_complete().unwrap().is_ready());
+    assert!(io.start_send(Bytes::from("hello world")).unwrap().is_ready());
+    assert!(io.poll_complete().unwrap().is_ready());
+    assert!(io.get_ref().calls.is_empty());
+}
+
+#[test]
+fn write_single_frame_would_block() {
+    let mut io = FramedWrite::new(mock! {
+        Err(would_block()),
+        Ok(b"\x00\x00"[..].into()),
+        Err(would_block()),
+        Ok(b"\x00\x09"[..].into()),
+        Ok(b"abcdefghi"[..].into()),
+        Ok(Flush),
+    }, LengthDelimitedCodec::new());
+
+    assert!(io.start_send(Bytes::from("abcdefghi")).unwrap().is_ready());
+    assert!(!io.poll_complete().unwrap().is_ready());
+    assert!(!io.poll_complete().unwrap().is_ready());
+    assert!(io.poll_complete().unwrap().is_ready());
+
+    assert!(io.get_ref().calls.is_empty());
+}
+
+#[test]
+fn write_single_frame_little_endian() {
+    let mut io = length_delimited::Builder::new()
+        .little_endian()
+        .new_write(mock! {
+            Ok(b"\x09\x00\x00\x00"[..].into()),
+            Ok(b"abcdefghi"[..].into()),
+            Ok(Flush),
+        });
+
+    assert!(io.start_send(Bytes::from("abcdefghi")).unwrap().is_ready());
+    assert!(io.poll_complete().unwrap().is_ready());
+    assert!(io.get_ref().calls.is_empty());
+}
+
+
+#[test]
+fn write_single_frame_with_short_length_field() {
+    let mut io = length_delimited::Builder::new()
+        .length_field_length(1)
+        .new_write(mock! {
+            Ok(b"\x09"[..].into()),
+            Ok(b"abcdefghi"[..].into()),
+            Ok(Flush),
+        });
+
+    assert!(io.start_send(Bytes::from("abcdefghi")).unwrap().is_ready());
+    assert!(io.poll_complete().unwrap().is_ready());
+    assert!(io.get_ref().calls.is_empty());
+}
+
+#[test]
+fn write_max_frame_len() {
+    let mut io = length_delimited::Builder::new()
+        .max_frame_length(5)
+        .new_write(mock! { });
+
+    assert_eq!(io.start_send(Bytes::from("abcdef")).unwrap_err().kind(), io::ErrorKind::InvalidInput);
+    assert!(io.get_ref().calls.is_empty());
+}
+
+#[test]
+fn write_update_max_frame_len_at_rest() {
+    let mut io = length_delimited::Builder::new()
+        .new_write(mock! {
+            Ok(b"\x00\x00\x00\x06"[..].into()),
+            Ok(b"abcdef"[..].into()),
+            Ok(Flush),
+        });
+
+    assert!(io.start_send(Bytes::from("abcdef")).unwrap().is_ready());
+    assert!(io.poll_complete().unwrap().is_ready());
+    io.encoder_mut().set_max_frame_length(5);
+    assert_eq!(io.start_send(Bytes::from("abcdef")).unwrap_err().kind(), io::ErrorKind::InvalidInput);
+    assert!(io.get_ref().calls.is_empty());
+}
+
+#[test]
+fn write_update_max_frame_len_in_flight() {
+    let mut io = length_delimited::Builder::new()
+        .new_write(mock! {
+            Ok(b"\x00\x00\x00\x06"[..].into()),
+            Ok(b"ab"[..].into()),
+            Err(would_block()),
+            Ok(b"cdef"[..].into()),
+            Ok(Flush),
+        });
+
+    assert!(io.start_send(Bytes::from("abcdef")).unwrap().is_ready());
+    assert!(!io.poll_complete().unwrap().is_ready());
+    io.encoder_mut().set_max_frame_length(5);
+    assert!(io.poll_complete().unwrap().is_ready());
+    assert_eq!(io.start_send(Bytes::from("abcdef")).unwrap_err().kind(), io::ErrorKind::InvalidInput);
+    assert!(io.get_ref().calls.is_empty());
+}
+
+#[test]
+fn write_zero() {
+    let mut io = length_delimited::Builder::new()
+        .new_write(mock! { });
+
+    assert!(io.start_send(Bytes::from("abcdef")).unwrap().is_ready());
+    assert_eq!(io.poll_complete().unwrap_err().kind(), io::ErrorKind::WriteZero);
+    assert!(io.get_ref().calls.is_empty());
+}
+
+#[test]
+fn encode_overflow() {
+    // Test reproducing tokio-rs/tokio#681.
+    let mut codec = length_delimited::Builder::new().new_codec();
+    let mut buf = BytesMut::with_capacity(1024);
+
+    // Put some data into the buffer without resizing it to hold more.
+    let some_as = std::iter::repeat(b'a')
+        .take(1024)
+        .collect::<Vec<_>>();
+    buf.put_slice(&some_as[..]);
+
+    // Trying to encode the length header should resize the buffer if it won't fit.
+    codec.encode(Bytes::from("hello"), &mut buf).unwrap();
+}
+
+// ===== Test utils =====
+
+fn would_block() -> io::Error {
+    io::Error::new(io::ErrorKind::WouldBlock, "would block")
+}
+
+struct Mock {
+    calls: VecDeque<io::Result<Op>>,
+}
+
+enum Op {
+    Data(Vec<u8>),
+    Flush,
+}
+
+use self::Op::*;
+
+impl io::Read for Mock {
+    fn read(&mut self, dst: &mut [u8]) -> io::Result<usize> {
+        match self.calls.pop_front() {
+            Some(Ok(Op::Data(data))) => {
+                debug_assert!(dst.len() >= data.len());
+                dst[..data.len()].copy_from_slice(&data[..]);
+                Ok(data.len())
+            }
+            Some(Ok(_)) => panic!(),
+            Some(Err(e)) => Err(e),
+            None => Ok(0),
+        }
+    }
+}
+
+impl AsyncRead for Mock {
+}
+
+impl io::Write for Mock {
+    fn write(&mut self, src: &[u8]) -> io::Result<usize> {
+        match self.calls.pop_front() {
+            Some(Ok(Op::Data(data))) => {
+                let len = data.len();
+                assert!(src.len() >= len, "expect={:?}; actual={:?}", data, src);
+                assert_eq!(&data[..], &src[..len]);
+                Ok(len)
+            }
+            Some(Ok(_)) => panic!(),
+            Some(Err(e)) => Err(e),
+            None => Ok(0),
+        }
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        match self.calls.pop_front() {
+            Some(Ok(Op::Flush)) => {
+                Ok(())
+            }
+            Some(Ok(_)) => panic!(),
+            Some(Err(e)) => Err(e),
+            None => Ok(()),
+        }
+    }
+}
+
+impl AsyncWrite for Mock {
+    fn shutdown(&mut self) -> Poll<(), io::Error> {
+        Ok(Ready(()))
+    }
+}
+
+impl<'a> From<&'a [u8]> for Op {
+    fn from(src: &'a [u8]) -> Op {
+        Op::Data(src.into())
+    }
+}
+
+impl From<Vec<u8>> for Op {
+    fn from(src: Vec<u8>) -> Op {
+        Op::Data(src)
+    }
+}

tests/runtime.rs

@@ -3,7 +3,7 @@ extern crate env_logger;
 extern crate futures;
 
 use futures::sync::oneshot;
-use std::sync::{Arc, Mutex};
+use std::sync::{Arc, Mutex, atomic};
 use std::thread;
 use tokio::io;
 use tokio::net::{TcpStream, TcpListener};
@@ -11,6 +11,11 @@ use tokio::prelude::future::lazy;
 use tokio::prelude::*;
 use tokio::runtime::Runtime;
 
+// this import is used in all child modules that have it in scope
+// from importing super::*, but the compiler doesn't realise that
+// and warns about it.
+pub use futures::future::Executor;
+
 macro_rules! t {
     ($e:expr) => (match $e {
         Ok(e) => e,
@@ -72,78 +77,130 @@ fn runtime_single_threaded_block_on() {
     tokio::runtime::current_thread::block_on_all(create_client_server_future()).unwrap();
 }
 
-#[test]
-fn runtime_single_threaded_block_on_all() {
-    let cnt = Arc::new(Mutex::new(0));
-    let c = cnt.clone();
+mod runtime_single_threaded_block_on_all {
+    use super::*;
 
-    let msg = tokio::runtime::current_thread::block_on_all(lazy(move || {
-        {
-            let mut x = c.lock().unwrap();
-            *x = 1 + *x;
-        }
+    fn test<F>(spawn: F)
+    where
+        F: Fn(Box<Future<Item=(), Error=()> + Send>),
+    {
+        let cnt = Arc::new(Mutex::new(0));
+        let c = cnt.clone();
 
-        // Spawn!
-        tokio::spawn(lazy(move || {
+        let msg = tokio::runtime::current_thread::block_on_all(lazy(move || {
             {
                 let mut x = c.lock().unwrap();
                 *x = 1 + *x;
             }
-            Ok::<(), ()>(())
-        }));
 
-        Ok::<_, ()>("hello")
-    })).unwrap();
+            // Spawn!
+            spawn(Box::new(lazy(move || {
+                {
+                    let mut x = c.lock().unwrap();
+                    *x = 1 + *x;
+                }
+                Ok::<(), ()>(())
+            })));
 
-    assert_eq!(2, *cnt.lock().unwrap());
-    assert_eq!(msg, "hello");
+            Ok::<_, ()>("hello")
+        })).unwrap();
+
+        assert_eq!(2, *cnt.lock().unwrap());
+        assert_eq!(msg, "hello");
+    }
+
+    #[test]
+    fn spawn() {
+       test(|f| { tokio::spawn(f); })
+    }
+
+    #[test]
+    fn execute() {
+        test(|f| {
+            tokio::executor::DefaultExecutor::current()
+                .execute(f)
+                .unwrap();
+        })
+    }
 }
 
-#[test]
-fn runtime_single_threaded_racy_spawn() {
-    let (trigger, exit) = futures::sync::oneshot::channel();
-    let (handle_tx, handle_rx) = ::std::sync::mpsc::channel();
-    let jh = ::std::thread::spawn(move || {
-        let mut rt = tokio::runtime::current_thread::Runtime::new().unwrap();
-        handle_tx.send(rt.handle()).unwrap();
+mod runtime_single_threaded_racy {
+    use super::*;
+    fn test<F>(spawn: F)
+    where
+        F: Fn(
+            tokio::runtime::current_thread::Handle,
+            Box<Future<Item=(), Error=()> + Send>,
+        ),
+    {
+        let (trigger, exit) = futures::sync::oneshot::channel();
+        let (handle_tx, handle_rx) = ::std::sync::mpsc::channel();
+        let jh = ::std::thread::spawn(move || {
+            let mut rt = tokio::runtime::current_thread::Runtime::new().unwrap();
+            handle_tx.send(rt.handle()).unwrap();
 
-        // don't exit until we are told to
-        rt.block_on(exit.map_err(|_| ())).unwrap();
+            // don't exit until we are told to
+            rt.block_on(exit.map_err(|_| ())).unwrap();
 
-        // run until all spawned futures (incl. the "exit" signal future) have completed.
-        rt.run().unwrap();
-    });
+            // run until all spawned futures (incl. the "exit" signal future) have completed.
+            rt.run().unwrap();
+        });
 
-    let (tx, rx) = futures::sync::oneshot::channel();
+        let (tx, rx) = futures::sync::oneshot::channel();
 
-    let handle = handle_rx.recv().unwrap();
-    handle
-        .spawn(futures::future::lazy(move || {
+        let handle = handle_rx.recv().unwrap();
+        spawn(handle, Box::new(futures::future::lazy(move || {
             tx.send(()).unwrap();
             Ok(())
-        }))
-        .unwrap();
+        })));
 
-    // signal runtime thread to exit
-    trigger.send(()).unwrap();
+        // signal runtime thread to exit
+        trigger.send(()).unwrap();
 
-    // wait for runtime thread to exit
-    jh.join().unwrap();
+        // wait for runtime thread to exit
+        jh.join().unwrap();
 
-    assert_eq!(rx.wait().unwrap(), ());
+        assert_eq!(rx.wait().unwrap(), ());
+    }
+
+    #[test]
+    fn spawn() {
+        test(|handle, f| { handle.spawn(f).unwrap(); })
+    }
+
+    #[test]
+    fn execute() {
+        test(|handle, f| { handle.execute(f).unwrap(); })
+    }
 }
 
-#[test]
-fn runtime_multi_threaded() {
-    let _ = env_logger::try_init();
+mod runtime_multi_threaded {
+    use super::*;
+    fn test<F>(spawn: F)
+    where
+        F: Fn(&mut Runtime) + Send + 'static,
+    {
+        let _ = env_logger::try_init();
 
-    let mut runtime = tokio::runtime::Builder::new()
-        .build()
-        .unwrap();
-    runtime.spawn(create_client_server_future());
-    runtime.shutdown_on_idle().wait().unwrap();
+        let mut runtime = tokio::runtime::Builder::new()
+            .build()
+            .unwrap();
+        spawn(&mut runtime);
+        runtime.shutdown_on_idle().wait().unwrap();
+    }
+
+    #[test]
+    fn spawn() {
+        test(|rt| { rt.spawn(create_client_server_future()); });
+    }
+
+    #[test]
+    fn execute() {
+        test(|rt| { rt.executor().execute(create_client_server_future()).unwrap(); });
+    }
 }
 
+
 #[test]
 fn block_on_timer() {
     use std::time::{Duration, Instant};
@@ -161,35 +218,57 @@ fn block_on_timer() {
     runtime.shutdown_on_idle().wait().unwrap();
 }
 
-#[test]
-fn spawn_from_block_on() {
-    let cnt = Arc::new(Mutex::new(0));
-    let c = cnt.clone();
+mod from_block_on {
+    use super::*;
 
-    let mut runtime = Runtime::new().unwrap();
-    let msg = runtime
-        .block_on(lazy(move || {
-            {
-                let mut x = c.lock().unwrap();
-                *x = 1 + *x;
-            }
+    fn test<F>(spawn: F)
+    where
+        F: Fn(Box<Future<Item=(), Error=()> + Send>) + Send + 'static,
+    {
+        let cnt = Arc::new(Mutex::new(0));
+        let c = cnt.clone();
 
-            // Spawn!
-            tokio::spawn(lazy(move || {
+        let mut runtime = Runtime::new().unwrap();
+        let msg = runtime
+            .block_on(lazy(move || {
                 {
                     let mut x = c.lock().unwrap();
                     *x = 1 + *x;
                 }
-                Ok::<(), ()>(())
-            }));
 
-            Ok::<_, ()>("hello")
-        }))
-        .unwrap();
+                // Spawn!
+                spawn(Box::new(lazy(move || {
+                    {
+                        let mut x = c.lock().unwrap();
+                        *x = 1 + *x;
+                    }
+                    Ok::<(), ()>(())
+                })));
 
-    runtime.shutdown_on_idle().wait().unwrap();
-    assert_eq!(2, *cnt.lock().unwrap());
-    assert_eq!(msg, "hello");
+                Ok::<_, ()>("hello")
+            }))
+            .unwrap();
+
+        runtime.shutdown_on_idle().wait().unwrap();
+        assert_eq!(2, *cnt.lock().unwrap());
+        assert_eq!(msg, "hello");
+    }
+
+    #[test]
+    fn execute() {
+        test(|f| {
+            tokio::executor::DefaultExecutor::current()
+                .execute(f)
+                .unwrap();
+        })
+    }
+
+    #[test]
+    fn spawn() {
+        test(|f| {
+            tokio::spawn(f);
+        })
+    }
 }
 
 #[test]
@@ -220,54 +299,218 @@ fn block_waits() {
     runtime.shutdown_on_idle().wait().unwrap();
 }
 
-#[test]
-fn spawn_many() {
+mod many {
+    use super::*;
+
     const ITER: usize = 200;
+    fn test<F>(spawn: F)
+    where
+        F: Fn(&mut Runtime, Box<Future<Item=(), Error=()> + Send>),
+    {
+        let cnt = Arc::new(Mutex::new(0));
+        let mut runtime = Runtime::new().unwrap();
 
-    let cnt = Arc::new(Mutex::new(0));
-    let mut runtime = Runtime::new().unwrap();
-
-    for _ in 0..ITER {
-        let c = cnt.clone();
-        runtime.spawn(lazy(move || {
-            {
-                let mut x = c.lock().unwrap();
-                *x = 1 + *x;
-            }
-            Ok::<(), ()>(())
-        }));
-    }
-
-    runtime.shutdown_on_idle().wait().unwrap();
-    assert_eq!(ITER, *cnt.lock().unwrap());
-}
-
-#[test]
-fn spawn_from_block_on_all() {
-    let cnt = Arc::new(Mutex::new(0));
-    let c = cnt.clone();
-
-    let runtime = Runtime::new().unwrap();
-    let msg = runtime
-        .block_on_all(lazy(move || {
-            {
-                let mut x = c.lock().unwrap();
-                *x = 1 + *x;
-            }
-
-            // Spawn!
-            tokio::spawn(lazy(move || {
+        for _ in 0..ITER {
+            let c = cnt.clone();
+            spawn(&mut runtime, Box::new(lazy(move || {
                 {
                     let mut x = c.lock().unwrap();
                     *x = 1 + *x;
                 }
                 Ok::<(), ()>(())
-            }));
+            })));
+        }
 
-            Ok::<_, ()>("hello")
-        }))
-        .unwrap();
+        runtime.shutdown_on_idle().wait().unwrap();
+        assert_eq!(ITER, *cnt.lock().unwrap());
+    }
 
-    assert_eq!(2, *cnt.lock().unwrap());
-    assert_eq!(msg, "hello");
+    #[test]
+    fn spawn() {
+        test(|rt, f| { rt.spawn(f); })
+    }
+
+    #[test]
+    fn execute() {
+        test(|rt, f| {
+            rt.executor()
+                .execute(f)
+                .unwrap();
+        })
+    }
+}
+
+
+mod from_block_on_all {
+    use super::*;
+
+    fn test<F>(spawn: F)
+    where
+        F: Fn(Box<Future<Item=(), Error=()> + Send>) + Send + 'static,
+    {
+        let cnt = Arc::new(Mutex::new(0));
+        let c = cnt.clone();
+
+        let runtime = Runtime::new().unwrap();
+        let msg = runtime
+            .block_on_all(lazy(move || {
+                {
+                    let mut x = c.lock().unwrap();
+                    *x = 1 + *x;
+                }
+
+                // Spawn!
+                spawn(Box::new(lazy(move || {
+                    {
+                        let mut x = c.lock().unwrap();
+                        *x = 1 + *x;
+                    }
+                    Ok::<(), ()>(())
+                })));
+
+                Ok::<_, ()>("hello")
+            }))
+            .unwrap();
+
+        assert_eq!(2, *cnt.lock().unwrap());
+        assert_eq!(msg, "hello");
+    }
+
+    #[test]
+    fn execute() {
+        test(|f| {
+            tokio::executor::DefaultExecutor::current()
+                .execute(f)
+                .unwrap();
+        })
+    }
+
+    #[test]
+    fn spawn() {
+        test(|f| { tokio::spawn(f); })
+    }
+}
+
+mod nested_enter {
+    use super::*;
+    use tokio::runtime::current_thread;
+    use std::panic;
+
+    fn test<F1, F2>(first: F1, nested: F2)
+    where
+        F1: Fn(Box<Future<Item=(), Error=()> + Send>) + Send + 'static,
+        F2: Fn(Box<Future<Item=(), Error=()> + Send>) + panic::UnwindSafe + Send + 'static,
+    {
+        let panicked = Arc::new(Mutex::new(false));
+        let panicked2 = panicked.clone();
+
+        // Since this is testing panics in other threads, printing about panics
+        // is noisy and can give the impression that the test is ignoring panics.
+        //
+        // It *is* ignoring them, but on purpose.
+        let prev_hook = panic::take_hook();
+        panic::set_hook(Box::new(|info| {
+            let s = info.to_string();
+            if s.starts_with("panicked at 'nested ")
+                || s.starts_with("panicked at 'Multiple executors at once")
+            {
+                // expected, noop
+            } else {
+                println!("{}", s);
+            }
+        }));
+
+        first(Box::new(lazy(move || {
+            panic::catch_unwind(move || {
+                nested(Box::new(lazy(|| { Ok::<(), ()>(()) })))
+            }).expect_err("nested should panic");
+            *panicked2.lock().unwrap() = true;
+            Ok::<(), ()>(())
+        })));
+
+        panic::set_hook(prev_hook);
+
+        assert!(*panicked.lock().unwrap(), "nested call should have panicked");
+    }
+
+    fn threadpool_new() -> Runtime {
+        Runtime::new().expect("rt new")
+    }
+
+    #[test]
+    fn run_in_run() {
+        test(tokio::run, tokio::run);
+    }
+
+    #[test]
+    fn threadpool_block_on_in_run() {
+        test(tokio::run, |fut| {
+            let mut rt = threadpool_new();
+            rt.block_on(fut).unwrap();
+        });
+    }
+
+    #[test]
+    fn threadpool_block_on_all_in_run() {
+        test(tokio::run, |fut| {
+            let rt = threadpool_new();
+            rt.block_on_all(fut).unwrap();
+        });
+    }
+
+    #[test]
+    fn current_thread_block_on_all_in_run() {
+        test(tokio::run, |fut| {
+            current_thread::block_on_all(fut).unwrap();
+        });
+    }
+}
+
+#[test]
+fn runtime_reactor_handle() {
+    #![allow(deprecated)]
+
+    use futures::Stream;
+    use std::net::{
+        TcpListener as StdListener,
+        TcpStream as StdStream,
+    };
+
+    let rt = Runtime::new().unwrap();
+
+    let std_listener = StdListener::bind("127.0.0.1:0").unwrap();
+    let tk_listener = TcpListener::from_std(std_listener, rt.handle()).unwrap();
+
+    let addr = tk_listener.local_addr().unwrap();
+
+    // Spawn a thread since we are avoiding the runtime
+    let th = thread::spawn(|| {
+        for _ in tk_listener.incoming().take(1).wait() {
+        }
+    });
+
+    let _ = StdStream::connect(&addr).unwrap();
+
+    th.join().unwrap();
+}
+
+#[test]
+fn after_start_and_before_stop_is_called() {
+    let _ = env_logger::try_init();
+
+    let after_start = Arc::new(atomic::AtomicUsize::new(0));
+    let before_stop = Arc::new(atomic::AtomicUsize::new(0));
+
+    let after_inner = after_start.clone();
+    let before_inner = before_stop.clone();
+    let runtime = tokio::runtime::Builder::new()
+            .after_start(move || { after_inner.clone().fetch_add(1, atomic::Ordering::Relaxed); })
+            .before_stop(move || { before_inner.clone().fetch_add(1, atomic::Ordering::Relaxed); })
+            .build()
+            .unwrap();
+
+    runtime.block_on_all(create_client_server_future()).unwrap();
+
+    assert!(after_start.load(atomic::Ordering::Relaxed) > 0);
+    assert!(before_stop.load(atomic::Ordering::Relaxed) > 0);
 }

tests/timer.rs

@@ -80,6 +80,7 @@ fn deadline() {
     let when = Instant::now() + Duration::from_millis(20);
     let (tx, rx) = mpsc::channel();
 
+    #[allow(deprecated)]
     tokio::run({
         future::empty::<(), ()>()
             .deadline(when)
@@ -92,3 +93,24 @@ fn deadline() {
 
     rx.recv().unwrap();
 }
+
+#[test]
+fn timeout() {
+    use futures::future;
+
+    let _ = env_logger::try_init();
+
+    let (tx, rx) = mpsc::channel();
+
+    tokio::run({
+        future::empty::<(), ()>()
+            .timeout(Duration::from_millis(20))
+            .then(move |res| {
+                assert!(res.is_err());
+                tx.send(()).unwrap();
+                Ok(())
+            })
+    });
+
+    rx.recv().unwrap();
+}

tokio-async-await/Cargo.toml

@@ -0,0 +1,29 @@
+[package]
+name = "tokio-async-await"
+
+# When releasing to crates.io:
+# - Update html_root_url.
+version = "0.1.5"
+authors = ["Carl Lerche <[email protected]>"]
+license = "MIT"
+repository = "https://github.com/tokio-rs/tokio"
+homepage = "https://tokio.rs"
+documentation = "https://docs.rs/tokio-async-await/0.1.3"
+description = """
+Experimental async/await support for Tokio
+"""
+categories = ["asynchronous"]
+
+[features]
+# This feature comes with no promise of stability. Things will
+# break with each patch release. Use at your own risk.
+async-await-preview = ["futures/nightly"]
+
+[dependencies]
+futures = "0.1.23"
+tokio-io = { version = "0.1.7", path = "../tokio-io" }
+
+[dev-dependencies]
+bytes = "0.4.9"
+tokio = { version = "0.1.8", path = ".." }
+hyper = "0.12.8"

tokio-async-await/LICENSE

@@ -0,0 +1,52 @@
+Copyright (c) 2019 Tokio Contributors
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+
+Copyright (c) 2016 futures-rs authors
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+

tokio-async-await/README.md

@@ -0,0 +1,55 @@
+# Tokio async/await preview
+
+This crate provides a preview of Tokio with async / await support. It is a shim
+layer on top of `tokio`.
+
+**This crate requires Rust nightly and does not provide API stability
+guarantees. You are living on the edge here.**
+
+## Usage
+
+To use this crate, you need to start with a Rust 2018 edition crate, with rustc
+1.33.0-nightly or later.
+
+Add this to your `Cargo.toml`:
+
+```toml
+# In the `[packages]` section
+edition = "2018"
+
+# In the `[dependencies]` section
+tokio = {version = "0.1.0", features = ["async-await-preview"]}
+```
+
+Then, get started. In your application, add:
+
+```rust
+// The nightly features that are commonly needed with async / await
+#![feature(await_macro, async_await, futures_api)]
+
+// This pulls in the `tokio-async-await` crate. While Rust 2018 doesn't require
+// `extern crate`, we need to pull in the macros.
+#[macro_use]
+extern crate tokio;
+
+fn main() {
+    // And we are async...
+    tokio::run_async(async {
+        println!("Hello");
+    });
+}
+```
+
+Because nightly is required, run the app with `cargo +nightly run`
+
+Check the [examples](examples) directory for more.
+
+## License
+
+This project is licensed under the [MIT license](LICENSE).
+
+### Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in Tokio by you, shall be licensed as MIT, without any additional
+terms or conditions.

tokio-async-await/examples/.cargo/config

@@ -0,0 +1,2 @@
+[build]
+target-dir = "../../target"

tokio-async-await/examples/Cargo.toml

@@ -0,0 +1,49 @@
+[package]
+name = "examples"
+edition = "2018"
+version = "0.1.0"
+authors = ["Carl Lerche <[email protected]>"]
+license = "MIT"
+
+# Break out of the parent workspace
+[workspace]
+
+[[bin]]
+name = "chat"
+path = "src/chat.rs"
+
+[[bin]]
+name = "echo_client"
+path = "src/echo_client.rs"
+
+[[bin]]
+name = "echo_server"
+path = "src/echo_server.rs"
+
+[[bin]]
+name = "hyper"
+path = "src/hyper.rs"
+
+[dependencies]
+tokio = { version = "0.1.0", path = "../..", features = ["async-await-preview"] }
+futures = "0.1.23"
+bytes = "0.4.9"
+hyper = "0.12.8"
+
+# Avoid using crates.io for Tokio dependencies
+[patch.crates-io]
+tokio = { path = "../.." }
+tokio-async-await  = { path = "../" }
+tokio-codec = { path = "../../tokio-codec" }
+tokio-current-thread = { path = "../../tokio-current-thread" }
+tokio-executor = { path = "../../tokio-executor" }
+tokio-fs = { path = "../../tokio-fs" }
+tokio-io = { path = "../../tokio-io" }
+tokio-reactor = { path = "../../tokio-reactor" }
+tokio-signal = { path = "../../tokio-signal" }
+tokio-tcp = { path = "../../tokio-tcp" }
+tokio-threadpool = { path = "../../tokio-threadpool" }
+tokio-timer = { path = "../../tokio-timer" }
+tokio-tls = { path = "../../tokio-tls" }
+tokio-udp = { path = "../../tokio-udp" }
+tokio-uds = { path = "../../tokio-uds" }

tokio-async-await/examples/README.md

@@ -0,0 +1,5 @@
+# Tokio async/await examples
+
+These are a separate crate in order to work around some cargo bugs. It also
+allows `[patch]` to be used in `Cargo.toml` to ensure the correct lib versions
+are being pulled in.

tokio-async-await/examples/src/chat.rs

@@ -0,0 +1,135 @@
+#![feature(await_macro, async_await, futures_api)]
+
+#[macro_use]
+extern crate tokio;
+extern crate futures; // v0.1
+
+use tokio::codec::{LinesCodec, Decoder};
+use tokio::net::{TcpListener, TcpStream};
+use tokio::prelude::*;
+
+use futures::sync::mpsc;
+
+use std::collections::HashMap;
+use std::io;
+use std::net::SocketAddr;
+use std::sync::{Arc, Mutex};
+
+/// Shorthand for the transmit half of the message channel.
+type Tx = mpsc::UnboundedSender<String>;
+
+struct Shared {
+    peers: HashMap<SocketAddr, Tx>,
+}
+
+impl Shared {
+    /// Create a new, empty, instance of `Shared`.
+    fn new() -> Self {
+        Shared {
+            peers: HashMap::new(),
+        }
+    }
+}
+
+async fn process(stream: TcpStream, state: Arc<Mutex<Shared>>) -> io::Result<()> {
+    let addr = stream.peer_addr().unwrap();
+    let mut lines = LinesCodec::new().framed(stream);
+
+    // Extract the peer's name
+    let name = match await!(lines.next()) {
+        Some(name) => name?,
+        None => {
+            // Disconnected early
+            return Ok(());
+        }
+    };
+
+    println!("`{}` is joining the chat", name);
+
+    let (tx, mut rx) = mpsc::unbounded();
+
+    // Register the socket
+    state.lock().unwrap()
+        .peers.insert(addr, tx);
+
+    // Split the `lines` handle into send and recv handles. This allows spawning
+    // separate tasks.
+    let (mut lines_tx, mut lines_rx) = lines.split();
+
+    // Spawn a task that receives all lines broadcasted to us from other peers
+    // and writes it to the client.
+    tokio::spawn_async(async move {
+        while let Some(line) = await!(rx.next()) {
+            let line = line.unwrap();
+            await!(lines_tx.send_async(line));
+        }
+    });
+
+    // Use the current task to read lines from the socket and broadcast them to
+    // other peers.
+    while let Some(message) = await!(lines_rx.next()) {
+        // TODO: Error handling
+        let message = message.unwrap();
+
+        let mut line = name.clone();
+        line.push_str(": ");
+        line.push_str(&message);
+        line.push_str("\r\n");
+
+        let state = state.lock().unwrap();
+
+        for (peer_addr, tx) in &state.peers {
+            if *peer_addr != addr {
+                // TODO: Error handling
+                tx.unbounded_send(line.clone()).unwrap();
+            }
+        }
+    }
+
+    // Remove the client from the shared state. Doing so will also result in the
+    // tx task to terminate.
+    state.lock().unwrap()
+        .peers.remove(&addr)
+        .expect("bug");
+
+    Ok(())
+}
+
+fn main() {
+    // Create the shared state. This is how all the peers communicate.
+    //
+    // The server task will hold a handle to this. For every new client, the
+    // `state` handle is cloned and passed into the task that processes the
+    // client connection.
+    let state = Arc::new(Mutex::new(Shared::new()));
+
+    let addr = "127.0.0.1:6142".parse().unwrap();
+
+    // Bind a TCP listener to the socket address.
+    //
+    // Note that this is the Tokio TcpListener, which is fully async.
+    let listener = TcpListener::bind(&addr).unwrap();
+
+    println!("server running on localhost:6142");
+
+    // Start the Tokio runtime.
+    tokio::run_async(async move {
+        let mut incoming = listener.incoming();
+
+        while let Some(stream) = await!(incoming.next()) {
+            let stream = match stream {
+                Ok(stream) => stream,
+                Err(_) => continue,
+            };
+
+            let state = state.clone();
+
+            tokio::spawn_async(async move {
+                if let Err(_) = await!(process(stream, state)) {
+                    eprintln!("failed to process connection");
+                }
+            });
+        }
+    });
+}
+

tokio-async-await/examples/src/echo_client.rs

@@ -0,0 +1,53 @@
+#![feature(await_macro, async_await, futures_api)]
+
+#[macro_use]
+extern crate tokio;
+
+use tokio::net::TcpStream;
+use tokio::prelude::*;
+
+use std::io;
+use std::net::SocketAddr;
+
+const MESSAGES: &[&str] = &[
+    "hello",
+    "world",
+    "one two three",
+];
+
+async fn run_client(addr: &SocketAddr) -> io::Result<()> {
+    let mut stream = await!(TcpStream::connect(addr))?;
+
+    // Buffer to read into
+    let mut buf = [0; 128];
+
+    for msg in MESSAGES {
+        println!(" > write = {:?}", msg);
+
+        // Write the message to the server
+        await!(stream.write_all_async(msg.as_bytes()))?;
+
+        // Read the message back from the server
+        await!(stream.read_exact_async(&mut buf[..msg.len()]))?;
+
+        assert_eq!(&buf[..msg.len()], msg.as_bytes());
+    }
+
+    Ok(())
+}
+
+fn main() {
+    use std::env;
+
+    let addr = env::args().nth(1).unwrap_or("127.0.0.1:8080".to_string());
+    let addr = addr.parse::<SocketAddr>().unwrap();
+
+    // Connect to the echo serveer
+
+    tokio::run_async(async move {
+        match await!(run_client(&addr)) {
+            Ok(_) => println!("done."),
+            Err(e) => eprintln!("echo client failed; error = {:?}", e),
+        }
+    });
+}

tokio-async-await/examples/src/echo_server.rs

@@ -0,0 +1,45 @@
+#![feature(await_macro, async_await)]
+
+#[macro_use]
+extern crate tokio;
+
+use tokio::net::{TcpListener, TcpStream};
+use tokio::prelude::*;
+
+use std::net::SocketAddr;
+
+fn handle(mut stream: TcpStream) {
+    tokio::spawn_async(async move {
+        let mut buf = [0; 1024];
+
+        loop {
+            match await!(stream.read_async(&mut buf)).unwrap() {
+                0 => break, // Socket closed
+                n => {
+                    // Send the data back
+                    await!(stream.write_all_async(&buf[0..n])).unwrap();
+                }
+            }
+        }
+    });
+}
+
+fn main() {
+    use std::env;
+
+    let addr = env::args().nth(1).unwrap_or("127.0.0.1:8080".to_string());
+    let addr = addr.parse::<SocketAddr>().unwrap();
+
+    // Bind the TCP listener
+    let listener = TcpListener::bind(&addr).unwrap();
+    println!("Listening on: {}", addr);
+
+    tokio::run_async(async {
+        let mut incoming = listener.incoming();
+
+        while let Some(stream) = await!(incoming.next()) {
+            let stream = stream.unwrap();
+            handle(stream);
+        }
+    });
+}

tokio-async-await/examples/src/hyper.rs

@@ -0,0 +1,33 @@
+#![feature(await_macro, async_await, futures_api)]
+
+#[macro_use]
+extern crate tokio;
+extern crate hyper;
+
+use tokio::prelude::*;
+use hyper::Client;
+
+use std::time::Duration;
+use std::str;
+
+pub fn main() {
+    tokio::run_async(async {
+        let client = Client::new();
+
+        let uri = "http://httpbin.org/ip".parse().unwrap();
+
+        let response = await!({
+            client.get(uri)
+                .timeout(Duration::from_secs(10))
+        }).unwrap();
+
+        println!("Response: {}", response.status());
+
+        let mut body = response.into_body();
+
+        while let Some(chunk) = await!(body.next()) {
+            let chunk = chunk.unwrap();
+            println!("chunk = {}", str::from_utf8(&chunk[..]).unwrap());
+        }
+    });
+}

tokio-async-await/src/await.rs

@@ -0,0 +1,16 @@
+/// Wait for a future to complete.
+#[macro_export]
+macro_rules! await {
+    ($e:expr) => {{
+        use $crate::std_await;
+        #[allow(unused_imports)]
+        use $crate::compat::forward::IntoAwaitable as IntoAwaitableForward;
+        #[allow(unused_imports)]
+        use $crate::compat::backward::IntoAwaitable as IntoAwaitableBackward;
+
+        #[allow(unused_mut)]
+        let mut e = $e;
+        let e = e.into_awaitable();
+        std_await!(e)
+    }}
+}

tokio-async-await/src/compat/backward.rs

@@ -0,0 +1,89 @@
+use futures::{Future, Poll};
+
+use std::pin::Pin;
+use std::future::{
+    Future as StdFuture,
+};
+use std::ptr::NonNull;
+use std::task::{
+    LocalWaker,
+    Poll as StdPoll,
+    UnsafeWake,
+    Waker,
+};
+
+/// Convert an 0.3 `Future` to an 0.1 `Future`.
+#[derive(Debug)]
+pub struct Compat<T>(Pin<Box<T>>);
+
+impl<T> Compat<T> {
+    /// Create a new `Compat` backed by `future`.
+    pub fn new(future: T) -> Compat<T> {
+        Compat(Box::pin(future))
+    }
+}
+
+/// Convert a value into one that can be used with `await!`.
+pub trait IntoAwaitable {
+    type Awaitable;
+
+    fn into_awaitable(self) -> Self::Awaitable;
+}
+
+impl<T> IntoAwaitable for T
+where T: StdFuture,
+{
+    type Awaitable = Self;
+
+    fn into_awaitable(self) -> Self {
+        self
+    }
+}
+
+impl<T, Item, Error> Future for Compat<T>
+where T: StdFuture<Output = Result<Item, Error>>,
+{
+    type Item = Item;
+    type Error = Error;
+
+    fn poll(&mut self) -> Poll<Item, Error> {
+        use futures::Async::*;
+
+        let local_waker = noop_local_waker();
+
+        let res = self.0.as_mut().poll(&local_waker);
+
+        match res {
+            StdPoll::Ready(Ok(val)) => Ok(Ready(val)),
+            StdPoll::Ready(Err(err)) => Err(err),
+            StdPoll::Pending => Ok(NotReady),
+        }
+    }
+}
+
+// ===== NoopWaker =====
+
+struct NoopWaker;
+
+fn noop_local_waker() -> LocalWaker {
+    let w: NonNull<NoopWaker> = NonNull::dangling();
+    unsafe { LocalWaker::new(w) }
+}
+
+fn noop_waker() -> Waker {
+    let w: NonNull<NoopWaker> = NonNull::dangling();
+    unsafe { Waker::new(w) }
+}
+
+unsafe impl UnsafeWake for NoopWaker {
+    unsafe fn clone_raw(&self) -> Waker {
+        noop_waker()
+    }
+
+    unsafe fn drop_raw(&self) {
+    }
+
+    unsafe fn wake(&self) {
+        unimplemented!("async-await-preview currently only supports futures 0.1. Use the compatibility layer of futures 0.3 instead, if you want to use futures 0.3.");
+    }
+}

tokio-async-await/src/compat/forward.rs

@@ -0,0 +1,68 @@
+
+use futures::{Future, Async};
+
+use std::marker::Unpin;
+use std::future::Future as StdFuture;
+use std::pin::Pin;
+use std::task::{LocalWaker, Poll as StdPoll};
+
+/// Converts an 0.1 `Future` into an 0.3 `Future`.
+#[derive(Debug)]
+pub struct Compat<T>(T);
+
+pub(crate) fn convert_poll<T, E>(poll: Result<Async<T>, E>) -> StdPoll<Result<T, E>> {
+    use futures::Async::{Ready, NotReady};
+
+    match poll {
+        Ok(Ready(val)) => StdPoll::Ready(Ok(val)),
+        Ok(NotReady) => StdPoll::Pending,
+        Err(err) => StdPoll::Ready(Err(err)),
+    }
+}
+
+pub(crate) fn convert_poll_stream<T, E>(
+    poll: Result<Async<Option<T>>, E>) -> StdPoll<Option<Result<T, E>>>
+{
+    use futures::Async::{Ready, NotReady};
+
+    match poll {
+        Ok(Ready(Some(val))) => StdPoll::Ready(Some(Ok(val))),
+        Ok(Ready(None)) => StdPoll::Ready(None),
+        Ok(NotReady) => StdPoll::Pending,
+        Err(err) => StdPoll::Ready(Some(Err(err))),
+    }
+}
+
+/// Convert a value into one that can be used with `await!`.
+pub trait IntoAwaitable {
+    type Awaitable;
+
+    /// Convert `self` into a value that can be used with `await!`.
+    fn into_awaitable(self) -> Self::Awaitable;
+}
+
+impl<T: Future + Unpin> IntoAwaitable for T {
+    type Awaitable = Compat<T>;
+
+    fn into_awaitable(self) -> Self::Awaitable {
+        Compat(self)
+    }
+}
+
+impl<T> StdFuture for Compat<T>
+where T: Future + Unpin
+{
+    type Output = Result<T::Item, T::Error>;
+
+    fn poll(mut self: Pin<&mut Self>, _lw: &LocalWaker) -> StdPoll<Self::Output> {
+        use futures::Async::{Ready, NotReady};
+
+        // TODO: wire in cx
+
+        match self.0.poll() {
+            Ok(Ready(val)) => StdPoll::Ready(Ok(val)),
+            Ok(NotReady) => StdPoll::Pending,
+            Err(e) => StdPoll::Ready(Err(e)),
+        }
+    }
+}

tokio-async-await/src/compat/mod.rs

@@ -0,0 +1,4 @@
+#![doc(hidden)]
+
+pub mod forward;
+pub mod backward;

tokio-async-await/src/io/flush.rs

@@ -0,0 +1,32 @@
+use tokio_io::AsyncWrite;
+
+
+use std::io;
+use std::future::Future;
+use std::marker::Unpin;
+use std::pin::Pin;
+use std::task::{LocalWaker, Poll};
+
+/// A future used to fully flush an I/O object.
+#[derive(Debug)]
+pub struct Flush<'a, T: ?Sized + 'a> {
+    writer: &'a mut T,
+}
+
+// Pin is never projected to fields
+impl<'a, T: ?Sized> Unpin for Flush<'a, T> {}
+
+impl<'a, T: AsyncWrite + ?Sized> Flush<'a, T> {
+    pub(super) fn new(writer: &'a mut T) -> Flush<'a, T> {
+        Flush { writer }
+    }
+}
+
+impl<'a, T: AsyncWrite + ?Sized> Future for Flush<'a, T> {
+    type Output = io::Result<()>;
+
+    fn poll(mut self: Pin<&mut Self>, _wx: &LocalWaker) -> Poll<Self::Output> {
+        use crate::compat::forward::convert_poll;
+        convert_poll(self.writer.poll_flush())
+    }
+}

tokio-async-await/src/io/mod.rs

@@ -0,0 +1,192 @@
+//! Use I/O with `async` / `await`.
+
+mod flush;
+mod read;
+mod read_exact;
+mod write;
+mod write_all;
+
+pub use self::flush::Flush;
+pub use self::read::Read;
+pub use self::read_exact::ReadExact;
+pub use self::write::Write;
+pub use self::write_all::WriteAll;
+
+use tokio_io::{AsyncRead, AsyncWrite};
+
+/// An extension trait which adds utility methods to `AsyncRead` types.
+pub trait AsyncReadExt: AsyncRead {
+    /// Tries to read some bytes directly into the given `buf` in an
+    /// asynchronous manner, returning a future.
+    ///
+    /// The returned future will resolve to the number of bytes read once the read
+    /// operation is completed.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(async_await, await_macro, futures_api)]
+    /// tokio::run_async(async {
+    /// // The extension trait can also be imported with
+    /// // `use tokio::prelude::*`.
+    /// use tokio::prelude::AsyncReadExt;
+    /// use std::io::Cursor;
+    ///
+    /// let mut reader = Cursor::new([1, 2, 3, 4]);
+    /// let mut output = [0u8; 5];
+    ///
+    /// let bytes = await!(reader.read_async(&mut output[..])).unwrap();
+    ///
+    /// // This is only guaranteed to be 4 because `&[u8]` is a synchronous
+    /// // reader. In a real system you could get anywhere from 1 to
+    /// // `output.len()` bytes in a single read.
+    /// assert_eq!(bytes, 4);
+    /// assert_eq!(output, [1, 2, 3, 4, 0]);
+    /// });
+    /// ```
+    fn read_async<'a>(&'a mut self, buf: &'a mut [u8]) -> Read<'a, Self> {
+        Read::new(self, buf)
+    }
+
+    /// Creates a future which will read exactly enough bytes to fill `buf`,
+    /// returning an error if end of file (EOF) is hit sooner.
+    ///
+    /// The returned future will resolve once the read operation is completed.
+    ///
+    /// In the case of an error the buffer and the object will be discarded, with
+    /// the error yielded.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(async_await, await_macro, futures_api)]
+    /// tokio::run_async(async {
+    /// // The extension trait can also be imported with
+    /// // `use tokio::prelude::*`.
+    /// use tokio::prelude::AsyncReadExt;
+    /// use std::io::Cursor;
+    ///
+    /// let mut reader = Cursor::new([1, 2, 3, 4]);
+    /// let mut output = [0u8; 4];
+    ///
+    /// await!(reader.read_exact_async(&mut output)).unwrap();
+    ///
+    /// assert_eq!(output, [1, 2, 3, 4]);
+    /// });
+    /// ```
+    ///
+    /// ## EOF is hit before `buf` is filled
+    ///
+    /// ```
+    /// #![feature(async_await, await_macro, futures_api)]
+    /// tokio::run_async(async {
+    /// // The extension trait can also be imported with
+    /// // `use tokio::prelude::*`.
+    /// use tokio::prelude::AsyncReadExt;
+    /// use std::io::{self, Cursor};
+    ///
+    /// let mut reader = Cursor::new([1, 2, 3, 4]);
+    /// let mut output = [0u8; 5];
+    ///
+    /// let result = await!(reader.read_exact_async(&mut output));
+    ///
+    /// assert_eq!(result.unwrap_err().kind(), io::ErrorKind::UnexpectedEof);
+    /// });
+    /// ```
+    fn read_exact_async<'a>(&'a mut self, buf: &'a mut [u8]) -> ReadExact<'a, Self> {
+        ReadExact::new(self, buf)
+    }
+}
+
+/// An extension trait which adds utility methods to `AsyncWrite` types.
+pub trait AsyncWriteExt: AsyncWrite {
+    /// Write data into this object.
+    ///
+    /// Creates a future that will write the entire contents of the buffer `buf` into
+    /// this `AsyncWrite`.
+    ///
+    /// The returned future will not complete until all the data has been written.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(async_await, await_macro, futures_api)]
+    /// tokio::run_async(async {
+    /// // The extension trait can also be imported with
+    /// // `use tokio::prelude::*`.
+    /// use tokio::prelude::AsyncWriteExt;
+    /// use std::io::Cursor;
+    ///
+    /// let mut buf = [0u8; 5];
+    /// let mut writer = Cursor::new(&mut buf[..]);
+    ///
+    /// let n = await!(writer.write_async(&[1, 2, 3, 4])).unwrap();
+    ///
+    /// assert_eq!(writer.into_inner()[..n], [1, 2, 3, 4, 0][..n]);
+    /// });
+    /// ```
+    fn write_async<'a>(&'a mut self, buf: &'a [u8]) -> Write<'a, Self> {
+        Write::new(self, buf)
+    }
+
+    /// Write an entire buffer into this object.
+    ///
+    /// Creates a future that will write the entire contents of the buffer `buf` into
+    /// this `AsyncWrite`.
+    ///
+    /// The returned future will not complete until all the data has been written.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(async_await, await_macro, futures_api)]
+    /// tokio::run_async(async {
+    /// // The extension trait can also be imported with
+    /// // `use tokio::prelude::*`.
+    /// use tokio::prelude::AsyncWriteExt;
+    /// use std::io::Cursor;
+    ///
+    /// let mut buf = [0u8; 5];
+    /// let mut writer = Cursor::new(&mut buf[..]);
+    ///
+    /// await!(writer.write_all_async(&[1, 2, 3, 4])).unwrap();
+    ///
+    /// assert_eq!(writer.into_inner(), [1, 2, 3, 4, 0]);
+    /// });
+    /// ```
+    fn write_all_async<'a>(&'a mut self, buf: &'a [u8]) -> WriteAll<'a, Self> {
+        WriteAll::new(self, buf)
+    }
+
+    /// Creates a future which will entirely flush this `AsyncWrite`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(async_await, await_macro, futures_api)]
+    /// tokio::run_async(async {
+    /// // The extension trait can also be imported with
+    /// // `use tokio::prelude::*`.
+    /// use tokio::prelude::AsyncWriteExt;
+    /// use std::io::{BufWriter, Cursor};
+    ///
+    /// let mut output = [0u8; 5];
+    ///
+    /// {
+    ///     let mut writer = Cursor::new(&mut output[..]);
+    ///     let mut buffered = BufWriter::new(writer);
+    ///     await!(buffered.write_all_async(&[1, 2])).unwrap();
+    ///     await!(buffered.write_all_async(&[3, 4])).unwrap();
+    ///     await!(buffered.flush_async()).unwrap();
+    /// }
+    ///
+    /// assert_eq!(output, [1, 2, 3, 4, 0]);
+    /// });
+    /// ```
+    fn flush_async<'a>(&mut self) -> Flush<Self> {
+        Flush::new(self)
+    }
+}
+
+impl<T: AsyncRead + ?Sized> AsyncReadExt for T {}
+impl<T: AsyncWrite + ?Sized> AsyncWriteExt for T {}

tokio-async-await/src/io/read.rs

@@ -0,0 +1,38 @@
+use tokio_io::AsyncRead;
+
+use std::future::Future;
+use std::task::{self, Poll};
+
+use std::io;
+use std::marker::Unpin;
+use std::pin::Pin;
+
+/// A future which can be used to read bytes.
+#[derive(Debug)]
+pub struct Read<'a, T: ?Sized + 'a> {
+    reader: &'a mut T,
+    buf: &'a mut [u8],
+}
+
+// Pinning is never projected to fields
+impl<'a, T: ?Sized> Unpin for Read<'a, T> {}
+
+impl<'a, T: AsyncRead + ?Sized> Read<'a, T> {
+    pub(super) fn new(reader: &'a mut T, buf: &'a mut [u8]) -> Read<'a, T> {
+        Read {
+            reader,
+            buf,
+        }
+    }
+}
+
+impl<'a, T: AsyncRead + ?Sized> Future for Read<'a, T> {
+    type Output = io::Result<usize>;
+
+    fn poll(mut self: Pin<&mut Self>, _lw: &task::LocalWaker) -> Poll<Self::Output> {
+        use crate::compat::forward::convert_poll;
+
+        let this = &mut *self;
+        convert_poll(this.reader.poll_read(this.buf))
+    }
+}

tokio-async-await/src/io/read_exact.rs

@@ -0,0 +1,56 @@
+use tokio_io::AsyncRead;
+
+use std::future::Future;
+use std::task::{self, Poll};
+
+use std::io;
+use std::marker::Unpin;
+use std::mem;
+use std::pin::Pin;
+
+/// A future which can be used to read exactly enough bytes to fill a buffer.
+#[derive(Debug)]
+pub struct ReadExact<'a, T: ?Sized + 'a> {
+    reader: &'a mut T,
+    buf: &'a mut [u8],
+}
+
+// Pinning is never projected to fields
+impl<'a, T: ?Sized> Unpin for ReadExact<'a, T> {}
+
+impl<'a, T: AsyncRead + ?Sized> ReadExact<'a, T> {
+    pub(super) fn new(reader: &'a mut T, buf: &'a mut [u8]) -> ReadExact<'a, T> {
+        ReadExact {
+            reader,
+            buf,
+        }
+    }
+}
+
+fn eof() -> io::Error {
+    io::Error::new(io::ErrorKind::UnexpectedEof, "early eof")
+}
+
+impl<'a, T: AsyncRead + ?Sized> Future for ReadExact<'a, T> {
+    type Output = io::Result<()>;
+
+    fn poll(mut self: Pin<&mut Self>, _lw: &task::LocalWaker) -> Poll<Self::Output> {
+        use crate::compat::forward::convert_poll;
+
+        let this = &mut *self;
+
+        while !this.buf.is_empty() {
+            let n = try_ready!(convert_poll(this.reader.poll_read(this.buf)));
+
+            {
+                let (_, rest) = mem::replace(&mut this.buf, &mut []).split_at_mut(n);
+                this.buf = rest;
+            }
+            if n == 0 {
+                return Poll::Ready(Err(eof()))
+            }
+        }
+
+        Poll::Ready(Ok(()))
+    }
+}

tokio-async-await/src/io/write.rs

@@ -0,0 +1,38 @@
+use tokio_io::AsyncWrite;
+
+use std::future::Future;
+use std::task::{self, Poll};
+
+use std::io;
+use std::marker::Unpin;
+use std::pin::Pin;
+
+/// A future used to write data.
+#[derive(Debug)]
+pub struct Write<'a, T: 'a + ?Sized> {
+    writer: &'a mut T,
+    buf: &'a [u8],
+}
+
+// Pinning is never projected to fields
+impl<'a, T: ?Sized> Unpin for Write<'a, T> {}
+
+impl<'a, T: AsyncWrite + ?Sized> Write<'a, T> {
+    pub(super) fn new(writer: &'a mut T, buf: &'a [u8]) -> Write<'a, T> {
+        Write {
+            writer,
+            buf,
+        }
+    }
+}
+
+impl<'a, T: AsyncWrite + ?Sized> Future for Write<'a, T> {
+    type Output = io::Result<usize>;
+
+    fn poll(mut self: Pin<&mut Self>, _lw: &task::LocalWaker) -> Poll<io::Result<usize>> {
+        use crate::compat::forward::convert_poll;
+
+        let this = &mut *self;
+        convert_poll(this.writer.poll_write(this.buf))
+    }
+}

tokio-async-await/src/io/write_all.rs

@@ -0,0 +1,57 @@
+use tokio_io::AsyncWrite;
+
+use std::future::Future;
+use std::task::{self, Poll};
+
+use std::io;
+use std::marker::Unpin;
+use std::mem;
+use std::pin::Pin;
+
+/// A future used to write the entire contents of a buffer.
+#[derive(Debug)]
+pub struct WriteAll<'a, T: ?Sized + 'a> {
+    writer: &'a mut T,
+    buf: &'a [u8],
+}
+
+// Pinning is never projected to fields
+impl<'a, T: ?Sized> Unpin for WriteAll<'a, T> {}
+
+impl<'a, T: AsyncWrite + ?Sized> WriteAll<'a, T> {
+    pub(super) fn new(writer: &'a mut T, buf: &'a [u8]) -> WriteAll<'a, T> {
+        WriteAll {
+            writer,
+            buf,
+        }
+    }
+}
+
+fn zero_write() -> io::Error {
+    io::Error::new(io::ErrorKind::WriteZero, "zero-length write")
+}
+
+impl<'a, T: AsyncWrite + ?Sized> Future for WriteAll<'a, T> {
+    type Output = io::Result<()>;
+
+    fn poll(mut self: Pin<&mut Self>, _lw: &task::LocalWaker) -> Poll<io::Result<()>> {
+        use crate::compat::forward::convert_poll;
+
+        let this = &mut *self;
+
+        while !this.buf.is_empty() {
+            let n = try_ready!(convert_poll(this.writer.poll_write(this.buf)));
+
+            {
+                let (_, rest) = mem::replace(&mut this.buf, &[]).split_at(n);
+                this.buf = rest;
+            }
+
+            if n == 0 {
+                return Poll::Ready(Err(zero_write()))
+            }
+        }
+
+        Poll::Ready(Ok(()))
+    }
+}

tokio-async-await/src/lib.rs

@@ -0,0 +1,114 @@
+#![cfg(feature = "async-await-preview")]
+#![feature(
+    rust_2018_preview,
+    arbitrary_self_types,
+    async_await,
+    await_macro,
+    futures_api,
+    )]
+
+#![doc(html_root_url = "https://docs.rs/tokio-async-await/0.1.5")]
+#![deny(missing_docs, missing_debug_implementations)]
+#![cfg_attr(test, deny(warnings))]
+
+//! A preview of Tokio w/ `async` / `await` support.
+
+extern crate futures;
+extern crate tokio_io;
+
+/// Extracts the successful type of a `Poll<Result<T, E>>`.
+///
+/// This macro bakes in propagation of `Pending` and `Err` signals by returning early.
+macro_rules! try_ready {
+    ($x:expr) => {
+        match $x {
+            std::task::Poll::Ready(Ok(x)) => x,
+            std::task::Poll::Ready(Err(e)) =>
+                return std::task::Poll::Ready(Err(e.into())),
+            std::task::Poll::Pending =>
+                return std::task::Poll::Pending,
+        }
+    }
+}
+
+#[macro_use]
+mod await;
+pub mod compat;
+pub mod io;
+pub mod sink;
+pub mod stream;
+
+/*
+pub mod prelude {
+    //! A "prelude" for users of the `tokio` crate.
+    //!
+    //! This prelude is similar to the standard library's prelude in that you'll
+    //! almost always want to import its entire contents, but unlike the standard
+    //! library's prelude you'll have to do so manually:
+    //!
+    //! ```
+    //! use tokio::prelude::*;
+    //! ```
+    //!
+    //! The prelude may grow over time as additional items see ubiquitous use.
+
+    pub use tokio_main::prelude::*;
+
+    #[doc(inline)]
+    pub use crate::async_await::{
+        io::{
+            AsyncReadExt,
+            AsyncWriteExt,
+        },
+        sink::{
+            SinkExt,
+        },
+        stream::{
+            StreamExt,
+        },
+    };
+}
+*/
+
+// Rename the `await` macro in `std`. This is used by the redefined
+// `await` macro in this crate.
+#[doc(hidden)]
+pub use std::await as std_await;
+
+/*
+use std::future::{Future as StdFuture};
+
+fn run<T: futures::Future<Item = (), Error = ()>>(t: T) {
+    drop(t);
+}
+
+async fn map_ok<T: StdFuture>(future: T) -> Result<(), ()> {
+    let _ = await!(future);
+    Ok(())
+}
+
+/// Like `tokio::run`, but takes an `async` block
+pub fn run_async<F>(future: F)
+where F: StdFuture<Output = ()> + Send + 'static,
+{
+    use async_await::compat::backward;
+    let future = backward::Compat::new(map_ok(future));
+
+    run(future);
+    unimplemented!();
+}
+*/
+
+/*
+/// Like `tokio::spawn`, but takes an `async` block
+pub fn spawn_async<F>(future: F)
+where F: StdFuture<Output = ()> + Send + 'static,
+{
+    use crate::async_await::compat::backward;
+
+    spawn(backward::Compat::new(async || {
+        let _ = await!(future);
+        Ok(())
+    }));
+}
+*/

tokio-async-await/src/sink/mod.rs

@@ -0,0 +1,26 @@
+//! Use sinks with `async` / `await`.
+
+mod send;
+
+pub use self::send::Send;
+
+use futures::Sink;
+
+use std::marker::Unpin;
+
+/// An extension trait which adds utility methods to `Sink` types.
+pub trait SinkExt: Sink {
+    /// Send an item into the sink.
+    ///
+    /// Note that, **because of the flushing requirement, it is usually better
+    /// to batch together items to send via `send_all`, rather than flushing
+    /// between each item.**
+    fn send_async(&mut self, item: Self::SinkItem) -> Send<Self>
+    where
+        Self: Sized + Unpin,
+    {
+        Send::new(self, item)
+    }
+}
+
+impl<T: Sink> SinkExt for T {}

tokio-async-await/src/sink/send.rs

@@ -0,0 +1,54 @@
+use futures::Sink;
+
+use std::future::Future;
+use std::task::{self, Poll};
+
+use std::marker::Unpin;
+use std::pin::Pin;
+
+/// Future for the `SinkExt::send_async` combinator, which sends a value to a
+/// sink and then waits until the sink has fully flushed.
+#[derive(Debug)]
+pub struct Send<'a, T: Sink + 'a + ?Sized> {
+    sink: &'a mut T,
+    item: Option<T::SinkItem>,
+}
+
+impl<T: Sink + Unpin + ?Sized> Unpin for Send<'_, T> {}
+
+impl<'a, T: Sink + Unpin + ?Sized> Send<'a, T> {
+    pub(super) fn new(sink: &'a mut T, item: T::SinkItem) -> Self {
+        Send {
+            sink,
+            item: Some(item),
+        }
+    }
+}
+
+impl<T: Sink + Unpin + ?Sized> Future for Send<'_, T> {
+    type Output = Result<(), T::SinkError>;
+
+    fn poll(mut self: Pin<&mut Self>, _lw: &task::LocalWaker) -> Poll<Self::Output> {
+        use crate::compat::forward::convert_poll;
+        use futures::AsyncSink::{Ready, NotReady};
+
+        if let Some(item) = self.item.take() {
+            match self.sink.start_send(item) {
+                Ok(Ready) => {}
+                Ok(NotReady(val)) => {
+                    self.item = Some(val);
+                    return Poll::Pending;
+                }
+                Err(err) => {
+                    return Poll::Ready(Err(err));
+                }
+            }
+        }
+
+        // we're done sending the item, but want to block on flushing the
+        // sink
+        try_ready!(convert_poll(self.sink.poll_complete()));
+
+        Poll::Ready(Ok(()))
+    }
+}

tokio-async-await/src/stream/mod.rs

@@ -0,0 +1,40 @@
+//! Use streams with `async` / `await`.
+
+mod next;
+
+pub use self::next::Next;
+
+use futures::Stream;
+
+use std::marker::Unpin;
+
+/// An extension trait which adds utility methods to `Stream` types.
+pub trait StreamExt: Stream {
+    /// Creates a future that resolves to the next item in the stream.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(await_macro, async_await)]
+    /// tokio::run_async(async {
+    /// // The extension trait can also be imported with
+    /// // `use tokio::prelude::*`.
+    /// use tokio::prelude::{stream, StreamExt};
+    ///
+    /// let mut stream = stream::iter_ok::<_, ()>(1..3);
+    ///
+    /// assert_eq!(await!(stream.next()), Some(Ok(1)));
+    /// assert_eq!(await!(stream.next()), Some(Ok(2)));
+    /// assert_eq!(await!(stream.next()), Some(Ok(3)));
+    /// assert_eq!(await!(stream.next()), None);
+    /// });
+    /// ```
+    fn next(&mut self) -> Next<Self>
+    where
+        Self: Sized + Unpin,
+    {
+        Next::new(self)
+    }
+}
+
+impl<T: Stream> StreamExt for T {}

tokio-async-await/src/stream/next.rs

@@ -0,0 +1,30 @@
+use futures::Stream;
+
+use std::future::Future;
+use std::marker::Unpin;
+use std::pin::Pin;
+use std::task::{LocalWaker, Poll};
+
+/// A future of the next element of a stream.
+#[derive(Debug)]
+pub struct Next<'a, T: 'a> {
+    stream: &'a mut T,
+}
+
+impl<'a, T: Stream + Unpin> Unpin for Next<'a, T> {}
+
+impl<'a, T: Stream + Unpin> Next<'a, T> {
+    pub(super) fn new(stream: &'a mut T) -> Next<'a, T> {
+        Next { stream }
+    }
+}
+
+impl<'a, T: Stream + Unpin> Future for Next<'a, T> {
+    type Output = Option<Result<T::Item, T::Error>>;
+
+    fn poll(mut self: Pin<&mut Self>, _lw: &LocalWaker) -> Poll<Self::Output> {
+        use crate::compat::forward::convert_poll_stream;
+
+        convert_poll_stream(self.stream.poll())
+    }
+}

tokio-buf/CHANGELOG.md

@@ -0,0 +1,3 @@
+# 0.1.0 (unreleased)
+
+* Initial release

tokio-buf/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "tokio-buf"
+
+# When releasing to crates.io:
+# - Update html_root_url.
+# - Update CHANGELOG.md.
+# - Create "v0.1.x" git tag.
+version = "0.1.0"
+authors = ["Carl Lerche <[email protected]>"]
+license = "MIT"
+repository = "https://github.com/tokio-rs/tokio"
+homepage = "https://tokio.rs"
+documentation = "https://docs.rs/tokio-buf/0.1.0"
+description = """
+Asynchronous stream of byte buffers
+"""
+categories = ["asynchronous"]
+
+[dependencies]
+bytes = { version = "0.4.10", features = [ "either" ] }
+either = "1.5"
+futures = "0.1.23"

tokio-buf/LICENSE

@@ -0,0 +1,25 @@
+Copyright (c) 2019 Tokio Contributors
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

tokio-buf/src/buf_stream/bytes.rs

@@ -0,0 +1,70 @@
+use BufStream;
+use buf_stream::errors::internal::Never;
+
+use bytes::{Bytes, BytesMut};
+use futures::Poll;
+
+use std::io;
+
+impl BufStream for Vec<u8> {
+    type Item = io::Cursor<Vec<u8>>;
+    type Error = Never;
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        if self.is_empty() {
+            return Ok(None.into());
+        }
+
+        poll_bytes(self)
+    }
+}
+
+impl BufStream for &'static [u8] {
+    type Item = io::Cursor<&'static [u8]>;
+    type Error = Never;
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        if self.is_empty() {
+            return Ok(None.into());
+        }
+
+        poll_bytes(self)
+    }
+}
+
+impl BufStream for Bytes {
+    type Item = io::Cursor<Bytes>;
+    type Error = Never;
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        if self.is_empty() {
+            return Ok(None.into());
+        }
+
+        poll_bytes(self)
+    }
+}
+
+impl BufStream for BytesMut {
+    type Item = io::Cursor<BytesMut>;
+    type Error = Never;
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        if self.is_empty() {
+            return Ok(None.into());
+        }
+
+        poll_bytes(self)
+    }
+}
+
+fn poll_bytes<T: Default>(buf: &mut T)
+    -> Poll<Option<io::Cursor<T>>, Never>
+{
+    use std::mem;
+
+    let bytes = mem::replace(buf, Default::default());
+    let buf = io::Cursor::new(bytes);
+
+    Ok(Some(buf).into())
+}

tokio-buf/src/buf_stream/chain.rs

@@ -0,0 +1,51 @@
+use super::{BufStream, SizeHint};
+
+use either::Either;
+use futures::Poll;
+
+/// A buf stream that sequences two buf streams together.
+///
+/// `Chain` values are produced by the `chain` function on `BufStream`.
+#[derive(Debug)]
+pub struct Chain<T, U> {
+    left: Option<T>,
+    right: U,
+}
+
+impl<T, U> Chain<T, U> {
+    pub(crate) fn new(left: T, right: U) -> Chain<T, U> {
+        Chain {
+            left: Some(left),
+            right,
+        }
+    }
+}
+
+impl<T, U> BufStream for Chain<T, U>
+where
+    T: BufStream,
+    U: BufStream<Error = T::Error>,
+{
+    type Item = Either<T::Item, U::Item>;
+    type Error = T::Error;
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        if let Some(ref mut stream) = self.left {
+            let res = try_ready!(stream.poll_buf());
+
+            if res.is_some() {
+                return Ok(res.map(Either::Left).into());
+            }
+        }
+
+        self.left = None;
+
+        let res = try_ready!(self.right.poll_buf());
+        Ok(res.map(Either::Right).into())
+    }
+
+    fn size_hint(&self) -> SizeHint {
+        // TODO: Implement
+        SizeHint::default()
+    }
+}

tokio-buf/src/buf_stream/collect.rs

@@ -0,0 +1,103 @@
+use super::{BufStream, FromBufStream};
+
+use futures::{Future, Poll};
+
+/// Consumes a buf stream, collecting the data into a single byte container.
+///
+/// `Collect` values are produced by `BufStream::collect`.
+#[derive(Debug)]
+pub struct Collect<T, U>
+where
+    T: BufStream,
+    U: FromBufStream<T::Item>,
+{
+    stream: T,
+    builder: Option<U::Builder>,
+}
+
+/// Errors returned from `Collect` future.
+#[derive(Debug)]
+pub struct CollectError<T, U> {
+    inner: Error<T, U>,
+}
+
+#[derive(Debug)]
+enum Error<T, U> {
+    Stream(T),
+    Collect(U),
+}
+
+impl<T, U> Collect<T, U>
+where
+    T: BufStream,
+    U: FromBufStream<T::Item>,
+{
+    pub(crate) fn new(stream: T) -> Collect<T, U> {
+        let builder = U::builder(&stream.size_hint());
+
+        Collect {
+            stream,
+            builder: Some(builder),
+        }
+    }
+}
+
+impl<T, U> Future for Collect<T, U>
+where
+    T: BufStream,
+    U: FromBufStream<T::Item>,
+{
+    type Item = U;
+    type Error = CollectError<T::Error, U::Error>;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        loop {
+            let res = self.stream.poll_buf()
+                .map_err(|err| {
+                    let inner = Error::Stream(err);
+                    CollectError { inner }
+                });
+
+            match try_ready!(res) {
+                Some(mut buf) => {
+                    let builder = self.builder.as_mut().expect("cannot poll after done");
+
+                    U::extend(builder, &mut buf, &self.stream.size_hint())
+                        .map_err(|err| {
+                            let inner = Error::Collect(err);
+                            CollectError { inner }
+                        })?;
+                }
+                None => {
+                    let builder = self.builder.take().expect("cannot poll after done");
+                    let value = U::build(builder)
+                        .map_err(|err| {
+                            let inner = Error::Collect(err);
+                            CollectError { inner }
+                        })?;
+                    return Ok(value.into());
+                }
+            }
+        }
+    }
+}
+
+// ===== impl CollectError =====
+
+impl<T, U> CollectError<T, U> {
+    /// Returns `true` if the error was caused by polling the stream.
+    pub fn is_stream_err(&self) -> bool {
+        match self.inner {
+            Error::Stream(_) => true,
+            _ => false,
+        }
+    }
+
+    /// Returns `true` if the error happened while collecting the data.
+    pub fn is_collect_err(&self) -> bool {
+        match self.inner {
+            Error::Collect(_) => true,
+            _ => false,
+        }
+    }
+}

tokio-buf/src/buf_stream/errors.rs

@@ -0,0 +1,32 @@
+//! Error types
+
+pub use super::collect::CollectError;
+pub use super::from::CollectVecError;
+pub use super::limit::LimitError;
+
+// Being crate-private, we should be able to swap the type out in a
+// backwards compatible way.
+pub(crate) mod internal {
+    use std::{error, fmt};
+
+    /// An error that can never occur
+    pub enum Never {}
+
+    impl fmt::Debug for Never {
+        fn fmt(&self, _f: &mut fmt::Formatter) -> fmt::Result {
+            match *self {}
+        }
+    }
+
+    impl fmt::Display for Never {
+        fn fmt(&self, _f: &mut fmt::Formatter) -> fmt::Result {
+            match *self {}
+        }
+    }
+
+    impl error::Error for Never {
+        fn description(&self) -> &str {
+            match *self {}
+        }
+    }
+}

tokio-buf/src/buf_stream/from.rs

@@ -0,0 +1,110 @@
+use super::SizeHint;
+
+use bytes::{Buf, BufMut};
+
+use std::usize;
+
+/// Conversion from a `BufStream`.
+///
+/// By implementing `FromBufStream` for a type, you define how it will be
+/// created from a buf stream. This is common for types which describe byte
+/// storage of some kind.
+///
+/// `FromBufStream` is rarely called explicitly, and it is instead used through
+/// `BufStream`'s `collect` method.
+pub trait FromBufStream<T: Buf>: Sized {
+    /// Type that is used to build `Self` while the `BufStream` is being
+    /// consumed.
+    type Builder;
+
+    /// Error that might happen on conversion.
+    type Error;
+
+    /// Create a new, empty, builder. The provided `hint` can be used to inform
+    /// reserving capacity.
+    fn builder(hint: &SizeHint) -> Self::Builder;
+
+    /// Extend the builder with the `Buf`.
+    ///
+    /// This method is called whenever a new `Buf` value is obtained from the
+    /// buf stream.
+    ///
+    /// The provided size hint represents the state of the stream **after**
+    /// `buf` has been yielded. The lower bound represents the minimum amount of
+    /// data that will be provided after this call to `extend` returns.
+    fn extend(builder: &mut Self::Builder, buf: &mut T, hint: &SizeHint)
+        -> Result<(), Self::Error>;
+
+    /// Finalize the building of `Self`.
+    ///
+    /// Called once the buf stream is fully consumed.
+    fn build(builder: Self::Builder) -> Result<Self, Self::Error>;
+}
+
+/// Error returned from collecting into a `Vec<u8>`
+#[derive(Debug)]
+pub struct CollectVecError { _p: () }
+
+impl<T: Buf> FromBufStream<T> for Vec<u8> {
+    type Builder = Vec<u8>;
+    type Error = CollectVecError;
+
+    fn builder(_hint: &SizeHint) -> Vec<u8> {
+        Vec::new()
+    }
+
+    fn extend(builder: &mut Self, buf: &mut T, hint: &SizeHint) -> Result<(), Self::Error> {
+        let lower = hint.lower();
+
+        // If the lower bound is greater than `usize::MAX` then we have a
+        // problem
+        if lower > usize::MAX as u64 {
+            return Err(CollectVecError { _p: () });
+        }
+
+        let mut reserve = lower as usize;
+
+        // If `upper` is set, use this value if it is less than or equal to 64.
+        // This only really impacts the first iteration.
+        match hint.upper() {
+            Some(upper) if upper <= 64 => {
+                reserve = upper as usize;
+            }
+            _ => {},
+        }
+
+        // hint.lower() represents the minimum amount of data that will be
+        // received *after* this function call. We reserve this amount on top of
+        // the amount of data in `buf`.
+        reserve = match reserve.checked_add(buf.remaining()) {
+            Some(n) => n,
+            None => return Err(CollectVecError { _p: () }),
+        };
+
+        // Always reserve 64 bytes the first time, unless `upper` is set and is
+        // less than 64.
+        if builder.is_empty() {
+            reserve = reserve.max(match hint.upper() {
+                Some(upper) if upper < 64 => upper as usize,
+                _ => 64,
+            });
+        }
+
+        // Make sure overflow won't happen when reserving
+        if reserve.checked_add(builder.len()).is_none() {
+            return Err(CollectVecError { _p: () });
+        }
+
+        // Reserve space
+        builder.reserve(reserve);
+
+        // Copy the data
+        builder.put(buf);
+
+        Ok(())
+    }
+
+    fn build(builder: Self) -> Result<Self, Self::Error> {
+        Ok(builder)
+    }
+}

tokio-buf/src/buf_stream/limit.rs

@@ -0,0 +1,92 @@
+use super::{BufStream, SizeHint};
+
+use bytes::Buf;
+use futures::Poll;
+
+/// Limits the stream to a maximum amount of data.
+#[derive(Debug)]
+pub struct Limit<T> {
+    stream: T,
+    remaining: u64,
+}
+
+/// Errors returned from `Limit`.
+#[derive(Debug)]
+pub struct LimitError<T> {
+    /// When `None`, limit was reached
+    inner: Option<T>,
+}
+
+impl<T> Limit<T> {
+    pub(crate) fn new(stream: T, amount: u64) -> Limit<T> {
+        Limit {
+            stream,
+            remaining: amount,
+        }
+    }
+}
+
+impl<T> BufStream for Limit<T>
+where
+    T: BufStream,
+{
+    type Item = T::Item;
+    type Error = LimitError<T::Error>;
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        use futures::Async::Ready;
+
+        if self.stream.size_hint().lower() > self.remaining {
+            return Err(LimitError { inner: None });
+        }
+
+        let res = self.stream.poll_buf()
+            .map_err(|err| {
+                LimitError { inner: Some(err) }
+            });
+
+        match res {
+            Ok(Ready(Some(ref buf))) => {
+                if buf.remaining() as u64 > self.remaining {
+                    self.remaining = 0;
+                    return Err(LimitError { inner: None });
+                }
+
+                self.remaining -= buf.remaining() as u64;
+            }
+            _ => {}
+        }
+
+        res
+    }
+
+    fn size_hint(&self) -> SizeHint {
+        let mut hint = self.stream.size_hint();
+
+        let upper = hint.upper()
+            .map(|upper| upper.min(self.remaining))
+            .unwrap_or(self.remaining);
+
+        hint.set_upper(upper);
+        hint
+    }
+
+    fn consume_hint(&mut self, amount: usize) {
+        // TODO: Should this be capped by `self.remaining`?
+        self.stream.consume_hint(amount)
+    }
+}
+
+// ===== impl LimitError =====
+
+impl<T> LimitError<T> {
+    /// Returns `true` if the error was caused by polling the stream.
+    pub fn is_stream_err(&self) -> bool {
+        self.inner.is_some()
+    }
+
+    /// Returns `true` if the stream reached its limit.
+    pub fn is_limit_err(&self) -> bool {
+        self.inner.is_none()
+    }
+}

tokio-buf/src/buf_stream/mod.rs

@@ -0,0 +1,163 @@
+//! Types and utilities for working with `BufStream`.
+
+mod bytes;
+mod chain;
+mod collect;
+pub mod errors;
+mod from;
+mod limit;
+mod size_hint;
+mod str;
+
+pub use self::chain::Chain;
+pub use self::collect::Collect;
+pub use self::from::FromBufStream;
+pub use self::limit::Limit;
+pub use self::size_hint::SizeHint;
+
+use bytes::Buf;
+use futures::Poll;
+
+/// An asynchronous stream of bytes.
+///
+/// `BufStream` asynchronously yields values implementing `Buf`, i.e. byte
+/// buffers.
+pub trait BufStream {
+    /// Values yielded by the `BufStream`.
+    ///
+    /// Each item is a sequence of bytes representing a chunk of the total
+    /// `ByteStream`.
+    type Item: Buf;
+
+    /// The error type this `BufStream` might generate.
+    type Error;
+
+    /// Attempt to pull out the next buffer of this stream, registering the
+    /// current task for wakeup if the value is not yet available, and returning
+    /// `None` if the stream is exhausted.
+    ///
+    /// # Return value
+    ///
+    /// There are several possible return values, each indicating a distinct
+    /// stream state:
+    ///
+    /// - `Ok(Async::NotReady)` means that this stream's next value is not ready
+    /// yet. Implementations will ensure that the current task will be notified
+    /// when the next value may be ready.
+    ///
+    /// - `Ok(Async::Ready(Some(buf)))` means that the stream has successfully
+    /// produced a value, `buf`, and may produce further values on subsequent
+    /// `poll_buf` calls.
+    ///
+    /// - `Ok(Async::Ready(None))` means that the stream has terminated, and
+    /// `poll_buf` should not be invoked again.
+    ///
+    /// # Panics
+    ///
+    /// Once a stream is finished, i.e. `Ready(None)` has been returned, further
+    /// calls to `poll_buf` may result in a panic or other "bad behavior".
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error>;
+
+    /// Returns the bounds on the remaining length of the stream.
+    ///
+    /// The size hint allows the caller to perform certain optimizations that
+    /// are dependent on the byte stream size. For example, `collect` uses the
+    /// size hint to pre-allocate enough capacity to store the entirety of the
+    /// data received from the byte stream.
+    ///
+    /// When `SizeHint::upper()` returns `Some` with a value equal to
+    /// `SizeHint::lower()`, this represents the exact number of bytes that will
+    /// be yielded by the `BufStream`.
+    ///
+    /// # Implementation notes
+    ///
+    /// While not enforced, implementations are expected to respect the values
+    /// returned from `SizeHint`. Any deviation is considered an implementation
+    /// bug. Consumers may rely on correctness in order to use the value as part
+    /// of protocol impelmentations. For example, an HTTP library may use the
+    /// size hint to set the `content-length` header.
+    ///
+    /// However, `size_hint` must not be trusted to omit bounds checks in unsafe
+    /// code. An incorrect implementation of `size_hint()` must not lead to
+    /// memory safety violations.
+    fn size_hint(&self) -> SizeHint {
+        SizeHint::default()
+    }
+
+    /// Indicates to the `BufStream` how much data the consumer is currently
+    /// able to process.
+    ///
+    /// The consume hint allows the stream to perform certain optimizations that
+    /// are dependent on the consumer's readiness. For example, the consume hint
+    /// may be used to request a remote peer to start sending up to `amount`
+    /// data.
+    ///
+    /// Calling `consume_hint` is not a requirement. If `consume_hint` is never
+    /// called, the stream should assume a default behavior. When `consume_hint`
+    /// is called, the stream should make a best effort to honor by the request.
+    ///
+    /// `amount` represents the number of bytes that the caller would like to
+    /// receive at the time the function is called. For example, if
+    /// `consume_hint` is called with 20, the consumer requests 20 bytes. The
+    /// stream may yield less than that. If the next call to `poll_buf` returns
+    /// 5 bytes, the consumer still has 15 bytes requested. At this point,
+    /// invoking `consume_hint` again with 20 resets the amount requested back
+    /// to 20 bytes.
+    ///
+    /// Calling `consume_hint` with 0 as the argument informs the stream that
+    /// the caller does not intend to call `poll_buf`. If `poll_buf` **is**
+    /// called, the stream may, but is not obligated to, return `NotReady` even
+    /// if it could produce data at that point. If it chooses to return
+    /// `NotReady`, when `consume_hint` is called with a non-zero argument, the
+    /// task must be notified in order to respect the `poll_buf` contract.
+    fn consume_hint(&mut self, amount: usize) {
+        // By default, this function does nothing
+        drop(amount);
+    }
+
+    /// Takes two buf streams and creates a new buf stream over both in
+    /// sequence.
+    ///
+    /// `chain()` returns a new `BufStream` value which will first yield all
+    /// data from `self` then all data from `other`.
+    ///
+    /// In other words, it links two buf streams together, in a chain.
+    fn chain<T>(self, other: T) -> Chain<Self, T>
+    where
+        Self: Sized,
+        T: BufStream<Error = Self::Error>,
+    {
+        Chain::new(self, other)
+    }
+
+    /// Consumes all data from `self`, storing it in byte storage of type `T`.
+    ///
+    /// `collect()` returns a future that buffers all data yielded from `self`
+    /// into storage of type of `T`. The future completes once `self` yield
+    /// `None`, returning the buffered data.
+    ///
+    /// The collect future will yield an error if `self` yields an error or if
+    /// the collect operation errors. The collect error cases are dependent on
+    /// the target storage type.
+    fn collect<T>(self) -> Collect<Self, T>
+    where
+        Self: Sized,
+        T: FromBufStream<Self::Item>,
+    {
+        Collect::new(self)
+    }
+
+    /// Limit the number of bytes that the stream can yield.
+    ///
+    /// `limit()` returns a new `BufStream` value which yields all the data from
+    /// `self` while ensuring that at most `amount` bytes are yielded.
+    ///
+    /// If `self` can yield greater than `amount` bytes, the returned stream
+    /// will yield an error.
+    fn limit(self, amount: u64) -> Limit<Self>
+    where
+        Self: Sized,
+    {
+        Limit::new(self, amount)
+    }
+}

tokio-buf/src/buf_stream/size_hint.rs

@@ -0,0 +1,56 @@
+use std::u64;
+
+/// A `BufStream` size hint
+///
+/// The default implementation returns:
+///
+/// * 0 for `available`
+/// * 0 for `lower`
+/// * `None` for `upper`.
+#[derive(Debug, Default, Clone)]
+pub struct SizeHint {
+    lower: u64,
+    upper: Option<u64>,
+}
+
+impl SizeHint {
+    /// Returns a new `SizeHint` with default values
+    pub fn new() -> SizeHint {
+        SizeHint::default()
+    }
+
+    /// Returns the lower bound of data that the `BufStream` will yield before
+    /// completing.
+    pub fn lower(&self) -> u64 {
+        self.lower
+    }
+
+    /// Set the value of the `lower` hint.
+    ///
+    /// # Panics
+    ///
+    /// The function panics if `value` is less than `upper`.
+    pub fn set_lower(&mut self, value: u64) {
+        assert!(value <= self.upper.unwrap_or(u64::MAX));
+        self.lower = value;
+    }
+
+    /// Returns the upper bound of data the `BufStream` will yield before
+    /// completing, or `None` if the value is unknown.
+    pub fn upper(&self) -> Option<u64> {
+        self.upper
+    }
+
+    /// Set the value of the `upper` hint value.
+    ///
+    /// # Panics
+    ///
+    /// This function panics if `value` is less than `lower`.
+    pub fn set_upper(&mut self, value: u64) {
+        // There is no need to check `available` as that is guaranteed to be
+        // less than or equal to `lower`.
+        assert!(value >= self.lower, "`value` is less than than `lower`");
+
+        self.upper = Some(value);
+    }
+}

tokio-buf/src/buf_stream/str.rs

@@ -0,0 +1,39 @@
+use BufStream;
+use buf_stream::errors::internal::Never;
+
+use futures::Poll;
+
+use std::io;
+use std::mem;
+
+impl BufStream for String {
+    type Item = io::Cursor<Vec<u8>>;
+    type Error = Never;
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        if self.is_empty() {
+            return Ok(None.into());
+        }
+
+        let bytes = mem::replace(self, Default::default()).into_bytes();
+        let buf = io::Cursor::new(bytes);
+
+        Ok(Some(buf).into())
+    }
+}
+
+impl BufStream for &'static str {
+    type Item = io::Cursor<&'static [u8]>;
+    type Error = Never;
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        if self.is_empty() {
+            return Ok(None.into());
+        }
+
+        let bytes = mem::replace(self, Default::default()).as_bytes();
+        let buf = io::Cursor::new(bytes);
+
+        Ok(Some(buf).into())
+    }
+}

tokio-buf/src/lib.rs

@@ -0,0 +1,20 @@
+#![doc(html_root_url = "https://docs.rs/tokio-buf/0.1.0")]
+#![deny(missing_docs, missing_debug_implementations)]
+#![cfg_attr(test, deny(warnings))]
+
+//! Asynchronous stream of bytes.
+//!
+//! This crate contains the `BufStream` trait and a number of combinators for
+//! this trait. The trait is similar to `Stream` in the `futures` library, but
+//! instead of yielding arbitrary values, it only yields types that implement
+//! `Buf` (i.e, byte collections).
+
+extern crate bytes;
+extern crate either;
+#[macro_use]
+extern crate futures;
+
+pub mod buf_stream;
+
+#[doc(inline)]
+pub use buf_stream::BufStream;

tokio-buf/tests/buf_stream.rs

@@ -0,0 +1,329 @@
+extern crate tokio_buf;
+extern crate bytes;
+extern crate futures;
+
+use tokio_buf::buf_stream::{BufStream, SizeHint};
+use bytes::Buf;
+use futures::{Future, Poll};
+use futures::Async::*;
+
+use std::collections::VecDeque;
+use std::io::Cursor;
+
+macro_rules! assert_buf_eq {
+    ($actual:expr, $expect:expr) => {{
+        match $actual {
+            Ok(Ready(Some(val))) => {
+                assert_eq!(val.remaining(), val.bytes().len());
+                assert_eq!(val.bytes(), $expect.as_bytes());
+            }
+            Ok(Ready(None)) => panic!("expected value; BufStream yielded None"),
+            Ok(NotReady) => panic!("expected value; BufStream is not ready"),
+            Err(e) => panic!("expected value; got error = {:?}", e),
+        }
+    }};
+}
+
+macro_rules! assert_none {
+    ($actual:expr) => {
+        match $actual {
+            Ok(Ready(None)) => {}
+            actual => panic!("expected None; actual = {:?}", actual),
+        }
+    }
+}
+
+macro_rules! assert_not_ready {
+    ($actual:expr) => {
+        match $actual {
+            Ok(NotReady) => {}
+            actual => panic!("expected NotReady; actual = {:?}", actual),
+        }
+    }
+}
+
+// ===== test `SizeHint` =====
+
+#[test]
+fn size_hint() {
+    let hint = SizeHint::new();
+    assert_eq!(hint.lower(), 0);
+    assert!(hint.upper().is_none());
+
+    let mut hint = SizeHint::new();
+    hint.set_lower(100);
+    assert_eq!(hint.lower(), 100);
+    assert!(hint.upper().is_none());
+
+    let mut hint = SizeHint::new();
+    hint.set_upper(200);
+    assert_eq!(hint.lower(), 0);
+    assert_eq!(hint.upper(), Some(200));
+
+    let mut hint = SizeHint::new();
+    hint.set_lower(100);
+    hint.set_upper(100);
+    assert_eq!(hint.lower(), 100);
+    assert_eq!(hint.upper(), Some(100));
+}
+
+#[test]
+#[should_panic]
+fn size_hint_lower_bigger_than_upper() {
+    let mut hint = SizeHint::new();
+    hint.set_upper(100);
+    hint.set_lower(200);
+}
+
+#[test]
+#[should_panic]
+fn size_hint_upper_less_than_lower() {
+    let mut hint = SizeHint::new();
+    hint.set_lower(200);
+    hint.set_upper(100);
+}
+
+// ===== test `chain()` =====
+
+#[test]
+fn chain() {
+    // Chain one with one
+    //
+    let mut bs = one("hello").chain(one("world"));
+
+    assert_buf_eq!(bs.poll_buf(), "hello");
+    assert_buf_eq!(bs.poll_buf(), "world");
+    assert_none!(bs.poll_buf());
+
+    // Chain multi with multi
+    let mut bs = list(&["foo", "bar"])
+        .chain(list(&["baz", "bok"]));
+
+    assert_buf_eq!(bs.poll_buf(), "foo");
+    assert_buf_eq!(bs.poll_buf(), "bar");
+    assert_buf_eq!(bs.poll_buf(), "baz");
+    assert_buf_eq!(bs.poll_buf(), "bok");
+    assert_none!(bs.poll_buf());
+
+    // Chain includes a not ready call
+    //
+    let mut bs = new_mock(&[
+        Ok(Ready("foo")),
+        Ok(NotReady),
+        Ok(Ready("bar"))
+    ]).chain(one("baz"));
+
+    assert_buf_eq!(bs.poll_buf(), "foo");
+    assert_not_ready!(bs.poll_buf());
+    assert_buf_eq!(bs.poll_buf(), "bar");
+    assert_buf_eq!(bs.poll_buf(), "baz");
+    assert_none!(bs.poll_buf());
+}
+
+// ===== Test `collect()` =====
+
+#[test]
+fn collect_vec() {
+    // While unfortunate, this test makes some assumptions on vec's resizing
+    // behavior.
+    //
+    // Collect one
+    //
+    let bs = one("hello world");
+
+    let vec: Vec<u8> = bs.collect()
+        .wait().unwrap();
+
+    assert_eq!(vec, b"hello world");
+    assert_eq!(vec.capacity(), 64);
+
+    // Collect one, with size hint
+    //
+    let mut bs = one("hello world");
+    bs.size_hint.set_lower(11);
+
+    let vec: Vec<u8> = bs.collect()
+        .wait().unwrap();
+
+    assert_eq!(vec, b"hello world");
+    assert_eq!(vec.capacity(), 64);
+
+    // Collect one, with size hint
+    //
+    let mut bs = one("hello world");
+    bs.size_hint.set_lower(10);
+
+    let vec: Vec<u8> = bs.collect()
+        .wait().unwrap();
+
+    assert_eq!(vec, b"hello world");
+    assert_eq!(vec.capacity(), 64);
+
+    // Collect many
+    //
+    let bs = list(&["hello", " ", "world", ", one two three"]);
+
+    let vec: Vec<u8> = bs.collect()
+        .wait().unwrap();
+
+    assert_eq!(vec, b"hello world, one two three");
+}
+
+// ===== Test limit() =====
+
+#[test]
+fn limit() {
+    // Not limited
+
+    let res = one("hello world")
+        .limit(100)
+        .collect::<Vec<_>>()
+        .wait().unwrap();
+
+    assert_eq!(res, b"hello world");
+
+    let res = list(&["hello", " ", "world"])
+        .limit(100)
+        .collect::<Vec<_>>()
+        .wait().unwrap();
+
+    assert_eq!(res, b"hello world");
+
+    let res = list(&["hello", " ", "world"])
+        .limit(11)
+        .collect::<Vec<_>>()
+        .wait().unwrap();
+
+    assert_eq!(res, b"hello world");
+
+    // Limited
+
+    let res = one("hello world")
+        .limit(5)
+        .collect::<Vec<_>>()
+        .wait();
+
+    assert!(res.is_err());
+
+    let res = one("hello world")
+        .limit(10)
+        .collect::<Vec<_>>()
+        .wait();
+
+    assert!(res.is_err());
+
+    let mut bs = list(&["hello", " ", "world"])
+        .limit(9);
+
+    assert_buf_eq!(bs.poll_buf(), "hello");
+    assert_buf_eq!(bs.poll_buf(), " ");
+    assert!(bs.poll_buf().is_err());
+
+    let mut bs = list(&["hello", " ", "world"]);
+    bs.size_hint.set_lower(11);
+    let mut bs = bs.limit(9);
+
+    assert!(bs.poll_buf().is_err());
+}
+
+// ===== BufStream impelmentations for misc types =====
+
+#[test]
+fn str_buf_stream() {
+    let mut bs = "hello world".to_string();
+    assert_buf_eq!(bs.poll_buf(), "hello world");
+    assert!(bs.is_empty());
+    assert_none!(bs.poll_buf());
+
+    let mut bs = "hello world";
+    assert_buf_eq!(bs.poll_buf(), "hello world");
+    assert!(bs.is_empty());
+    assert_none!(bs.poll_buf());
+}
+
+// ===== Test utils =====
+
+fn one(buf: &'static str) -> Mock {
+    list(&[buf])
+}
+
+fn list(bufs: &[&'static str]) -> Mock {
+    let mut polls = VecDeque::new();
+
+    for &buf in bufs {
+        polls.push_back(Ok(Ready(buf.as_bytes())));
+    }
+
+    Mock {
+        polls,
+        size_hint: SizeHint::default(),
+    }
+}
+
+fn new_mock(values: &[Poll<&'static str, ()>]) -> Mock {
+    let mut polls = VecDeque::new();
+
+    for &v in values {
+        polls.push_back(match v {
+            Ok(Ready(v)) => Ok(Ready(v.as_bytes())),
+            Ok(NotReady) => Ok(NotReady),
+            Err(e) => Err(e),
+        });
+    }
+
+    Mock {
+        polls,
+        size_hint: SizeHint::default(),
+    }
+}
+
+#[derive(Debug)]
+struct Mock {
+    polls: VecDeque<Poll<&'static [u8], ()>>,
+    size_hint: SizeHint,
+}
+
+#[derive(Debug)]
+struct MockBuf {
+    data: Cursor<&'static [u8]>,
+}
+
+impl BufStream for Mock {
+    type Item = MockBuf;
+    type Error = ();
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        match self.polls.pop_front() {
+            Some(Ok(Ready(value))) => Ok(Ready(Some(MockBuf::new(value)))),
+            Some(Ok(NotReady)) => Ok(NotReady),
+            Some(Err(e)) => Err(e),
+            None => Ok(Ready(None)),
+        }
+    }
+
+    fn size_hint(&self) -> SizeHint {
+        self.size_hint.clone()
+    }
+}
+
+impl MockBuf {
+    fn new(data: &'static [u8]) -> MockBuf {
+        MockBuf {
+            data: Cursor::new(data),
+        }
+    }
+}
+
+impl Buf for MockBuf {
+    fn remaining(&self) -> usize {
+        self.data.remaining()
+    }
+
+    fn bytes(&self) -> &[u8] {
+        self.data.bytes()
+    }
+
+    fn advance(&mut self, cnt: usize) {
+        self.data.advance(cnt)
+    }
+}

tokio-codec/CHANGELOG.md

@@ -1,3 +1,7 @@
-# # 0.1.0 (June 13, 2018)
+# 0.1.1 (September 26, 2018)
+
+* Allow setting max line length with `LinesCodec` (#632)
+
+# 0.1.0 (June 13, 2018)
 
 * Initial release (#353)

tokio-codec/Cargo.toml

@@ -3,14 +3,15 @@ name = "tokio-codec"
 
 # When releasing to crates.io:
 # - Update html_root_url.
+# - Update doc URL.
 # - Update CHANGELOG.md.
 # - Create "v0.1.x" git tag.
-version = "0.1.0"
+version = "0.1.1"
 authors = ["Carl Lerche <[email protected]>", "Bryan Burgers <[email protected]>"]
 license = "MIT"
 repository = "https://github.com/tokio-rs/tokio"
 homepage = "https://tokio.rs"
-documentation = "https://docs.rs/tokio-codec/0.1"
+documentation = "https://docs.rs/tokio-codec/0.1.1/tokio_codec"
 description = """
 Utilities for encoding and decoding frames.
 """

tokio-codec/LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2018 Tokio Contributors
+Copyright (c) 2019 Tokio Contributors
 
 Permission is hereby granted, free of charge, to any
 person obtaining a copy of this software and associated

tokio-codec/src/lib.rs

@@ -1,3 +1,6 @@
+#![deny(missing_docs, missing_debug_implementations, warnings)]
+#![doc(html_root_url = "https://docs.rs/tokio-codec/0.1.1")]
+
 //! Utilities for encoding and decoding frames.
 //!
 //! Contains adapters to go from streams of bytes, [`AsyncRead`] and
@@ -10,9 +13,6 @@
 //! [`Stream`]: #
 //! [transports]: #
 
-#![deny(missing_docs, missing_debug_implementations, warnings)]
-#![doc(html_root_url = "https://docs.rs/tokio-codec/0.1.0")]
-
 extern crate bytes;
 extern crate tokio_io;
 

tokio-codec/src/lines_codec.rs

@@ -1,6 +1,6 @@
 use bytes::{BufMut, BytesMut};
 use tokio_io::_tokio_codec::{Encoder, Decoder};
-use std::{io, str};
+use std::{cmp, io, str, usize};
 
 /// A simple `Codec` implementation that splits up data into lines.
 #[derive(Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
@@ -12,12 +12,93 @@ pub struct LinesCodec {
     // The next time `decode` is called with `abcde\n`, the method will
     // only look at `de\n` before returning.
     next_index: usize,
+
+    /// The maximum length for a given line. If `usize::MAX`, lines will be
+    /// read until a `\n` character is reached.
+    max_length: usize,
+
+    /// Are we currently discarding the remainder of a line which was over
+    /// the length limit?
+    is_discarding: bool,
 }
 
 impl LinesCodec {
     /// Returns a `LinesCodec` for splitting up data into lines.
+    ///
+    /// # Note
+    ///
+    /// The returned `LinesCodec` will not have an upper bound on the length
+    /// of a buffered line. See the documentation for [`new_with_max_length`]
+    /// for information on why this could be a potential security risk.
+    ///
+    /// [`new_with_max_length`]: #method.new_with_max_length
     pub fn new() -> LinesCodec {
-        LinesCodec { next_index: 0 }
+        LinesCodec {
+            next_index: 0,
+            max_length: usize::MAX,
+            is_discarding: false,
+        }
+    }
+
+    /// Returns a `LinesCodec` with a maximum line length limit.
+    ///
+    /// If this is set, calls to `LinesCodec::decode` will return a
+    /// [`LengthError`] when a line exceeds the length limit. Subsequent calls
+    /// will discard up to `limit` bytes from that line until a newline
+    /// character is reached, returning `None` until the line over the limit
+    /// has been fully discarded. After that point, calls to `decode` will
+    /// function as normal.
+    ///
+    /// # Note
+    ///
+    /// Setting a length limit is highly recommended for any `LinesCodec` which
+    /// will be exposed to untrusted input. Otherwise, the size of the buffer
+    /// that holds the line currently being read is unbounded. An attacker could
+    /// exploit this unbounded buffer by sending an unbounded amount of input
+    /// without any `\n` characters, causing unbounded memory consumption.
+    ///
+    /// [`LengthError`]: ../struct.LengthError
+    pub fn new_with_max_length(max_length: usize) -> Self {
+        LinesCodec {
+            max_length,
+            ..LinesCodec::new()
+        }
+    }
+
+    /// Returns the maximum line length when decoding.
+    ///
+    /// ```
+    /// use std::usize;
+    /// use tokio_codec::LinesCodec;
+    ///
+    /// let codec = LinesCodec::new();
+    /// assert_eq!(codec.max_length(), usize::MAX);
+    /// ```
+    /// ```
+    /// use tokio_codec::LinesCodec;
+    ///
+    /// let codec = LinesCodec::new_with_max_length(256);
+    /// assert_eq!(codec.max_length(), 256);
+    /// ```
+    pub fn max_length(&self) -> usize {
+        self.max_length
+    }
+
+    fn discard(&mut self, newline_offset: Option<usize>, read_to: usize, buf: &mut BytesMut) {
+        let discard_to = if let Some(offset) = newline_offset {
+            // If we found a newline, discard up to that offset and
+            // then stop discarding. On the next iteration, we'll try
+            // to read a line normally.
+            self.is_discarding = false;
+            offset + self.next_index + 1
+        } else {
+            // Otherwise, we didn't find a newline, so we'll discard
+            // everything we read. On the next iteration, we'll continue
+            // discarding up to max_len bytes unless we find a newline.
+            read_to
+        };
+        buf.advance(discard_to);
+        self.next_index = 0;
     }
 }
 
@@ -38,22 +119,49 @@ fn without_carriage_return(s: &[u8]) -> &[u8] {
 
 impl Decoder for LinesCodec {
     type Item = String;
+    // TODO: in the next breaking change, this should be changed to a custom
+    // error type that indicates the "max length exceeded" condition better.
     type Error = io::Error;
 
     fn decode(&mut self, buf: &mut BytesMut) -> Result<Option<String>, io::Error> {
-        if let Some(newline_offset) =
-            buf[self.next_index..].iter().position(|b| *b == b'\n')
-        {
-            let newline_index = newline_offset + self.next_index;
-            let line = buf.split_to(newline_index + 1);
-            let line = &line[..line.len()-1];
-            let line = without_carriage_return(line);
-            let line = utf8(line)?;
-            self.next_index = 0;
-            Ok(Some(line.to_string()))
-        } else {
-            self.next_index = buf.len();
-            Ok(None)
+        loop {
+            // Determine how far into the buffer we'll search for a newline. If
+            // there's no max_length set, we'll read to the end of the buffer.
+            let read_to = cmp::min(self.max_length.saturating_add(1), buf.len());
+
+            let newline_offset = buf[self.next_index..read_to]
+                .iter()
+                .position(|b| *b == b'\n');
+
+            if self.is_discarding {
+                self.discard(newline_offset, read_to, buf);
+            } else {
+                return if let Some(offset) = newline_offset {
+                    // Found a line!
+                    let newline_index = offset + self.next_index;
+                    self.next_index = 0;
+                    let line = buf.split_to(newline_index + 1);
+                    let line = &line[..line.len() - 1];
+                    let line = without_carriage_return(line);
+                    let line = utf8(line)?;
+
+                    Ok(Some(line.to_string()))
+                } else if buf.len() > self.max_length {
+                    // Reached the maximum length without finding a
+                    // newline, return an error and start discarding on the
+                    // next call.
+                    self.is_discarding = true;
+                    Err(io::Error::new(
+                        io::ErrorKind::Other,
+                        "line length limit exceeded"
+                    ))
+                } else {
+                    // We didn't find a line or reach the length limit, so the next
+                    // call will resume searching at the current offset.
+                    self.next_index = read_to;
+                    Ok(None)
+                };
+            }
         }
     }
 

tokio-codec/tests/codecs.rs

@@ -55,6 +55,116 @@ fn lines_decoder() {
     assert_eq!(None, codec.decode_eof(buf).unwrap());
 }
 
+#[test]
+fn lines_decoder_max_length() {
+    const MAX_LENGTH: usize = 6;
+
+    let mut codec = LinesCodec::new_with_max_length(MAX_LENGTH);
+    let buf = &mut BytesMut::new();
+
+    buf.reserve(200);
+    buf.put("line 1 is too long\nline 2\nline 3\r\nline 4\n\r\n\r");
+
+    assert!(codec.decode(buf).is_err());
+
+    let line = codec.decode(buf).unwrap().unwrap();
+    assert!(line.len() <= MAX_LENGTH, "{:?}.len() <= {:?}", line, MAX_LENGTH);
+    assert_eq!("line 2", line);
+
+    assert!(codec.decode(buf).is_err());
+
+    let line = codec.decode(buf).unwrap().unwrap();
+    assert!(line.len() <= MAX_LENGTH, "{:?}.len() <= {:?}", line, MAX_LENGTH);
+    assert_eq!("line 4", line);
+
+    let line = codec.decode(buf).unwrap().unwrap();
+    assert!(line.len() <= MAX_LENGTH, "{:?}.len() <= {:?}", line, MAX_LENGTH);
+    assert_eq!("", line);
+
+    assert_eq!(None, codec.decode(buf).unwrap());
+    assert_eq!(None, codec.decode_eof(buf).unwrap());
+    buf.put("k");
+    assert_eq!(None, codec.decode(buf).unwrap());
+
+    let line = codec.decode_eof(buf).unwrap().unwrap();
+    assert!(line.len() <= MAX_LENGTH, "{:?}.len() <= {:?}", line, MAX_LENGTH);
+    assert_eq!("\rk", line);
+
+    assert_eq!(None, codec.decode(buf).unwrap());
+    assert_eq!(None, codec.decode_eof(buf).unwrap());
+
+    // Line that's one character too long. This could cause an out of bounds
+    // error if we peek at the next characters using slice indexing.
+    // buf.put("aaabbbc");
+    // assert!(codec.decode(buf).is_err());
+}
+
+#[test]
+fn lines_decoder_max_length_underrun() {
+    const MAX_LENGTH: usize = 6;
+
+    let mut codec = LinesCodec::new_with_max_length(MAX_LENGTH);
+    let buf = &mut BytesMut::new();
+
+    buf.reserve(200);
+    buf.put("line ");
+    assert_eq!(None, codec.decode(buf).unwrap());
+    buf.put("too l");
+    assert!(codec.decode(buf).is_err());
+    buf.put("ong\n");
+    assert_eq!(None, codec.decode(buf).unwrap());
+
+    buf.put("line 2");
+    assert_eq!(None, codec.decode(buf).unwrap());
+    buf.put("\n");
+    assert_eq!("line 2", codec.decode(buf).unwrap().unwrap());
+}
+
+#[test]
+fn lines_decoder_max_length_bursts() {
+    const MAX_LENGTH: usize = 10;
+
+    let mut codec = LinesCodec::new_with_max_length(MAX_LENGTH);
+    let buf = &mut BytesMut::new();
+
+    buf.reserve(200);
+    buf.put("line ");
+    assert_eq!(None, codec.decode(buf).unwrap());
+    buf.put("too l");
+    assert_eq!(None, codec.decode(buf).unwrap());
+    buf.put("ong\n");
+    assert!(codec.decode(buf).is_err());
+}
+
+#[test]
+fn lines_decoder_max_length_big_burst() {
+    const MAX_LENGTH: usize = 10;
+
+    let mut codec = LinesCodec::new_with_max_length(MAX_LENGTH);
+    let buf = &mut BytesMut::new();
+
+    buf.reserve(200);
+    buf.put("line ");
+    assert_eq!(None, codec.decode(buf).unwrap());
+    buf.put("too long!\n");
+    assert!(codec.decode(buf).is_err());
+}
+
+#[test]
+fn lines_decoder_max_length_newline_between_decodes() {
+    const MAX_LENGTH: usize = 5;
+
+    let mut codec = LinesCodec::new_with_max_length(MAX_LENGTH);
+    let buf = &mut BytesMut::new();
+
+    buf.reserve(200);
+    buf.put("hello");
+    assert_eq!(None, codec.decode(buf).unwrap());
+
+    buf.put("\nworld");
+    assert_eq!("hello", codec.decode(buf).unwrap().unwrap());
+}
+
 #[test]
 fn lines_encoder() {
     let mut codec = LinesCodec::new();

tokio-current-thread/CHANGELOG.md

@@ -1,3 +1,16 @@
+# 0.1.4 (November 21, 2018)
+
+* Fix shutdown on idle (#763).
+
+# 0.1.3 (September 27, 2018)
+
+* Fix minimal versions
+
+# 0.1.2 (September 26, 2018)
+
+* Implement `futures::Executor` for executor types (#563)
+* Spawning performance improvements (#565)
+
 # 0.1.1 (August 6, 2018)
 
 * Implement `std::Error` for misc error types (#501)

tokio-current-thread/Cargo.toml

@@ -3,10 +3,11 @@ name = "tokio-current-thread"
 
 # When releasing to crates.io:
 # - Update html_root_url.
+# - Update doc URL
 # - Update CHANGELOG.md.
 # - Create "v0.1.x" git tag.
-version = "0.1.1"
-documentation = "https://docs.rs/tokio-current-thread"
+version = "0.1.4"
+documentation = "https://docs.rs/tokio-current-thread/0.1.4/tokio_current_thread"
 repository = "https://github.com/tokio-rs/tokio"
 homepage = "https://github.com/tokio-rs/tokio"
 license = "MIT"
@@ -18,5 +19,5 @@ keywords = ["futures", "tokio"]
 categories = ["concurrency", "asynchronous"]
 
 [dependencies]
-tokio-executor = { version = "0.1.2", path = "../tokio-executor" }
+tokio-executor = { version = "0.1.5", path = "../tokio-executor" }
 futures = "0.1.19"

tokio-current-thread/LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2018 Tokio Contributors
+Copyright (c) 2019 Tokio Contributors
 
 Permission is hereby granted, free of charge, to any
 person obtaining a copy of this software and associated

tokio-current-thread/src/lib.rs

@@ -1,3 +1,6 @@
+#![doc(html_root_url = "https://docs.rs/tokio-current-thread/0.1.4")]
+#![deny(warnings, missing_docs, missing_debug_implementations)]
+
 //! A single-threaded executor which executes tasks on the same thread from which
 //! they are spawned.
 //!
@@ -22,9 +25,6 @@
 //! [`block_on_all`]: fn.block_on_all.html
 //! [executor module]: https://docs.rs/tokio/0.1/tokio/executor/index.html
 
-#![doc(html_root_url = "https://docs.rs/tokio-current-thread/0.1.1")]
-#![deny(warnings, missing_docs, missing_debug_implementations)]
-
 extern crate futures;
 extern crate tokio_executor;
 
@@ -44,6 +44,7 @@ use std::error::Error;
 use std::rc::Rc;
 use std::sync::{atomic, mpsc, Arc};
 use std::time::{Duration, Instant};
+use std::thread;
 
 /// Executes tasks on the current thread
 pub struct CurrentThread<P: Park = ParkThread> {
@@ -64,6 +65,9 @@ pub struct CurrentThread<P: Park = ParkThread> {
 
     /// Receiver for futures spawned from other threads
     spawn_receiver: mpsc::Receiver<Box<Future<Item = (), Error = ()> + Send + 'static>>,
+
+    /// The thread-local ID assigned to this executor.
+    id: u64,
 }
 
 /// Executes futures on the current thread.
@@ -176,6 +180,7 @@ impl<T: fmt::Debug> Error for BlockError<T> {
 
 /// This is mostly split out to make the borrow checker happy.
 struct Borrow<'a, U: 'a> {
+    id: u64,
     scheduler: &'a mut Scheduler<U>,
     num_futures: &'a atomic::AtomicUsize,
 }
@@ -186,13 +191,21 @@ trait SpawnLocal {
 
 struct CurrentRunner {
     spawn: Cell<Option<*mut SpawnLocal>>,
+    id: Cell<Option<u64>>,
 }
 
 /// Current thread's task runner. This is set in `TaskRunner::with`
 thread_local!(static CURRENT: CurrentRunner = CurrentRunner {
     spawn: Cell::new(None),
+    id: Cell::new(None),
 });
 
+/// Unique ID to assign to each new executor launched on this thread.
+///
+/// The unique ID is used to determine if the currently running executor matches the one referred
+/// to by a `Handle` so that direct task dispatch can be used.
+thread_local!(static EXECUTOR_ID: Cell<u64> = Cell::new(0));
+
 /// Run the executor bootstrapping the execution with the provided future.
 ///
 /// This creates a new [`CurrentThread`] executor, spawns the provided future,
@@ -256,6 +269,12 @@ impl<P: Park> CurrentThread<P> {
         let unpark = park.unpark();
 
         let (spawn_sender, spawn_receiver) = mpsc::channel();
+        let thread = thread::current().id();
+        let id = EXECUTOR_ID.with(|idc| {
+            let id = idc.get();
+            idc.set(id + 1);
+            id
+        });
 
         let scheduler = Scheduler::new(unpark);
         let notify = scheduler.notify();
@@ -266,11 +285,14 @@ impl<P: Park> CurrentThread<P> {
             scheduler: scheduler,
             num_futures: num_futures.clone(),
             park,
+            id,
             spawn_handle: Handle {
                 sender: spawn_sender,
                 num_futures: num_futures,
                 notify: notify,
                 shut_down: Cell::new(false),
+                thread: thread,
+                id,
             },
             spawn_receiver: spawn_receiver,
         }
@@ -367,6 +389,7 @@ impl<P: Park> CurrentThread<P> {
 
     fn borrow(&mut self) -> Borrow<P::Unpark> {
         Borrow {
+            id: self.id,
             scheduler: &mut self.scheduler,
             num_futures: &*self.num_futures,
         }
@@ -567,6 +590,7 @@ impl<'a, P: Park> Entered<'a, P> {
         // FIXME: Slightly ugly but needed to make the borrow checker happy
         let (mut borrow, spawn_receiver) = (
             Borrow {
+                id: self.executor.id,
                 scheduler: &mut self.executor.scheduler,
                 num_futures: &*self.executor.num_futures,
             },
@@ -579,6 +603,7 @@ impl<'a, P: Park> Entered<'a, P> {
 
         // After any pending futures were scheduled, do the actual tick
         borrow.scheduler.tick(
+            borrow.id,
             &mut *self.enter,
             borrow.num_futures)
     }
@@ -602,6 +627,10 @@ pub struct Handle {
     num_futures: Arc<atomic::AtomicUsize>,
     shut_down: Cell<bool>,
     notify: executor::NotifyHandle,
+    thread: thread::ThreadId,
+
+    /// The thread-local ID assigned to this Handle's executor.
+    id: u64,
 }
 
 // Manual implementation because the Sender does not implement Debug
@@ -624,6 +653,13 @@ impl Handle {
     where
         F: Future<Item = (), Error = ()> + Send + 'static,
     {
+        if thread::current().id() == self.thread {
+            let mut e = TaskExecutor::current();
+            if e.id() == Some(self.id) {
+                return e.spawn_local(Box::new(future));
+            }
+        }
+
         if self.shut_down.get() {
             return Err(SpawnError::shutdown());
         }
@@ -640,11 +676,26 @@ impl Handle {
             return Err(SpawnError::shutdown());
         }
 
-        self.sender
-            .send(Box::new(future))
+        self.sender.send(Box::new(future))
             .expect("CurrentThread does not exist anymore");
         // use 0 for the id, CurrentThread does not make use of it
         self.notify.notify(0);
+        Ok(())
+    }
+
+    /// Provides a best effort **hint** to whether or not `spawn` will succeed.
+    ///
+    /// This function may return both false positives **and** false negatives.
+    /// If `status` returns `Ok`, then a call to `spawn` will *probably*
+    /// succeed, but may fail. If `status` returns `Err`, a call to `spawn` will
+    /// *probably* fail, but may succeed.
+    ///
+    /// This allows a caller to avoid creating the task if the call to `spawn`
+    /// has a high likelihood of failing.
+    pub fn status(&self) -> Result<(), SpawnError> {
+        if self.shut_down.get() {
+            return Err(SpawnError::shutdown());
+        }
 
         Ok(())
     }
@@ -665,6 +716,13 @@ impl TaskExecutor {
         }
     }
 
+    /// Get the current executor's thread-local ID.
+    fn id(&self) -> Option<u64> {
+        CURRENT.with(|current| {
+            current.id.get()
+        })
+    }
+
     /// Spawn a future onto the current `CurrentThread` instance.
     pub fn spawn_local(&mut self, future: Box<Future<Item = (), Error = ()>>)
         -> Result<(), SpawnError>
@@ -716,6 +774,7 @@ impl<'a, U: Unpark> Borrow<'a, U> {
     where F: FnOnce() -> R,
     {
         CURRENT.with(|current| {
+            current.id.set(Some(self.id));
             current.set_spawn(self, || {
                 f()
             })
@@ -745,6 +804,7 @@ impl CurrentRunner {
         impl<'a> Drop for Reset<'a> {
             fn drop(&mut self) {
                 self.0.spawn.set(None);
+                self.0.id.set(None);
             }
         }