Introduce a tokio-sync crate containing useful synchronization primitives for programs
written using Tokio.
The initial release contains:
* An mpsc channel
* A oneshot channel
* A semaphore implementation
* An `AtomicTask` primitive.
The `oneshot` and `mpsc` channels are new implementations providing improved
performance characteristics. In some benchmarks, the new mpsc channel shows
up to 7x improvement over the version provided by the `futures` crate. Unfortunately,
the `oneshot` implementation only provides a slight performance improvement as it
is mostly limited by the `futures` 0.1 task system. Once updated to the `std` version
of `Future` (currently nightly only), much greater performance improvements should
be achievable by `oneshot`.
Additionally, he implementations provided here are checked using
[Loom](http://github.com/carllerche/loom/), which provides greater confidence of
correctness.
Should hopefully fix the underlying bug that was causing tokio-tls tests to occasionally fail on Windows.
Signed-off-by: Toby Lawrence <[email protected]>
## Motivation
Currently, the `RUST_BACKTRACE` environment variable is set to `1` on
Travis CI builds:
https://github.com/tokio-rs/tokio/blob/0ca973a7ebc5b8a29beac1ccb6c73ef26ddcbf22/.travis.yml#L49
However, it's not set on AppVeyor. This can make debugging
Windows-specific CI failures challenging for developers on other
operating systems.
## Solution
This branch sets `RUST_BACKTRACE=1` on AppVeyor.
Signed-off-by: Eliza Weisman <[email protected]>
Since the CI runs all tests for all tokio crates, it is possible that a
sporadic failure in one crate can mask failures/successes of other
crates' tests.
Using the `--no-fail-fast` flag instructs cargo to run *all* tests
before failing the build. This will allow checking to see if any
relevant test cases still pass even if an unrelated test has failed.
Carl Lerche