diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index be5d1e9b5..6e948b034 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -11,13 +11,14 @@ jobs:
 #     name: rustfmt
 
 # Test top level crate
-# - template: ci/azure-test-stable.yml
-#   parameters:
-#     name: test_tokio
-#     displayName: Test tokio
-#     cross: true
-#     crates:
-#       - tokio
+- template: ci/azure-test-stable.yml
+  parameters:
+    name: test_tokio
+    rust: $(nightly)
+    displayName: Test tokio
+    cross: true
+    crates:
+      - tokio
 
 # Test crates that are platform specific
 - template: ci/azure-test-stable.yml
diff --git a/tokio/Cargo.toml b/tokio/Cargo.toml
index 742e70805..79d8dca8c 100644
--- a/tokio/Cargo.toml
+++ b/tokio/Cargo.toml
@@ -85,6 +85,8 @@ tokio-tcp = { version = "0.2.0", optional = true, path = "../tokio-tcp" }
 tokio-uds = { version = "0.2.1", optional = true }
 
 [dev-dependencies]
+tokio-test = { path = "../tokio-test" }
+pin-utils = "0.1.0-alpha.4"
 env_logger = { version = "0.5", default-features = false }
 flate2 = { version = "1", features = ["tokio"] }
 futures-cpupool = "0.1"
diff --git a/tokio/examples/README.md b/tokio/examples_old/README.md
similarity index 100%
rename from tokio/examples/README.md
rename to tokio/examples_old/README.md
diff --git a/tokio/examples/blocking.rs b/tokio/examples_old/blocking.rs
similarity index 100%
rename from tokio/examples/blocking.rs
rename to tokio/examples_old/blocking.rs
diff --git a/tokio/examples/chat-combinator-current-thread.rs b/tokio/examples_old/chat-combinator-current-thread.rs
similarity index 100%
rename from tokio/examples/chat-combinator-current-thread.rs
rename to tokio/examples_old/chat-combinator-current-thread.rs
diff --git a/tokio/examples/chat-combinator.rs b/tokio/examples_old/chat-combinator.rs
similarity index 100%
rename from tokio/examples/chat-combinator.rs
rename to tokio/examples_old/chat-combinator.rs
diff --git a/tokio/examples/chat.rs b/tokio/examples_old/chat.rs
similarity index 100%
rename from tokio/examples/chat.rs
rename to tokio/examples_old/chat.rs
diff --git a/tokio/examples/connect.rs b/tokio/examples_old/connect.rs
similarity index 100%
rename from tokio/examples/connect.rs
rename to tokio/examples_old/connect.rs
diff --git a/tokio/examples/echo-udp.rs b/tokio/examples_old/echo-udp.rs
similarity index 100%
rename from tokio/examples/echo-udp.rs
rename to tokio/examples_old/echo-udp.rs
diff --git a/tokio/examples/echo.rs b/tokio/examples_old/echo.rs
similarity index 100%
rename from tokio/examples/echo.rs
rename to tokio/examples_old/echo.rs
diff --git a/tokio/examples/hello_world.rs b/tokio/examples_old/hello_world.rs
similarity index 100%
rename from tokio/examples/hello_world.rs
rename to tokio/examples_old/hello_world.rs
diff --git a/tokio/examples/manual-runtime.rs b/tokio/examples_old/manual-runtime.rs
similarity index 100%
rename from tokio/examples/manual-runtime.rs
rename to tokio/examples_old/manual-runtime.rs
diff --git a/tokio/examples/print_each_packet.rs b/tokio/examples_old/print_each_packet.rs
similarity index 100%
rename from tokio/examples/print_each_packet.rs
rename to tokio/examples_old/print_each_packet.rs
diff --git a/tokio/examples/proxy.rs b/tokio/examples_old/proxy.rs
similarity index 100%
rename from tokio/examples/proxy.rs
rename to tokio/examples_old/proxy.rs
diff --git a/tokio/examples/tinydb.rs b/tokio/examples_old/tinydb.rs
similarity index 100%
rename from tokio/examples/tinydb.rs
rename to tokio/examples_old/tinydb.rs
diff --git a/tokio/examples/tinyhttp.rs b/tokio/examples_old/tinyhttp.rs
similarity index 100%
rename from tokio/examples/tinyhttp.rs
rename to tokio/examples_old/tinyhttp.rs
diff --git a/tokio/examples/udp-client.rs b/tokio/examples_old/udp-client.rs
similarity index 100%
rename from tokio/examples/udp-client.rs
rename to tokio/examples_old/udp-client.rs
diff --git a/tokio/examples/udp-codec.rs b/tokio/examples_old/udp-codec.rs
similarity index 100%
rename from tokio/examples/udp-codec.rs
rename to tokio/examples_old/udp-codec.rs
diff --git a/tokio/src/executor.rs b/tokio/src/executor.rs
index 266da320c..347531316 100644
--- a/tokio/src/executor.rs
+++ b/tokio/src/executor.rs
@@ -40,7 +40,7 @@
 //! [`spawn`]: fn.spawn.html
 
 use std::future::Future;
-pub use tokio_executor::{Executor, TypedExecutor, DefaultExecutor, SpawnError};
+pub use tokio_executor::{DefaultExecutor, Executor, SpawnError, TypedExecutor};
 
 /// Return value from the `spawn` function.
 ///
@@ -68,7 +68,7 @@ pub struct Spawn(());
 /// In this example, a server is started and `spawn` is used to start a new task
 /// that processes each received connection.
 ///
-/// ```rust
+/// ```rust,ignore
 /// # use futures::{Future, Stream};
 /// use tokio::net::TcpListener;
 ///
@@ -100,7 +100,8 @@ pub struct Spawn(());
 ///
 /// [`DefaultExecutor`]: struct.DefaultExecutor.html
 pub fn spawn<F>(f: F) -> Spawn
-where F: Future<Output = ()> + 'static + Send
+where
+    F: Future<Output = ()> + 'static + Send,
 {
     ::tokio_executor::spawn(f);
     Spawn(())
diff --git a/tokio/src/io/copy.rs b/tokio/src/io/copy.rs
new file mode 100644
index 000000000..b407c193b
--- /dev/null
+++ b/tokio/src/io/copy.rs
@@ -0,0 +1,107 @@
+use std::future::Future;
+use std::io;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+use tokio_io::{AsyncRead, AsyncWrite};
+
+macro_rules! ready {
+    ($e:expr) => {
+        match $e {
+            ::std::task::Poll::Ready(t) => t,
+            ::std::task::Poll::Pending => return ::std::task::Poll::Pending,
+        }
+    };
+}
+
+/// A future which will copy all data from a reader into a writer.
+///
+/// Created by the [`copy`] function, this future will resolve to the number of
+/// bytes copied or an error if one happens.
+///
+/// [`copy`]: fn.copy.html
+#[derive(Debug)]
+pub struct Copy<'a, R, W> {
+    reader: &'a mut R,
+    read_done: bool,
+    writer: &'a mut W,
+    pos: usize,
+    cap: usize,
+    amt: u64,
+    buf: Box<[u8]>,
+}
+
+/// Creates a future which represents copying all the bytes from one object to
+/// another.
+///
+/// The returned future will copy all the bytes read from `reader` into the
+/// `writer` specified. This future will only complete once the `reader` has hit
+/// EOF and all bytes have been written to and flushed from the `writer`
+/// provided.
+///
+/// On success the number of bytes is returned and the `reader` and `writer` are
+/// consumed. On error the error is returned and the I/O objects are consumed as
+/// well.
+pub fn copy<'a, R, W>(reader: &'a mut R, writer: &'a mut W) -> Copy<'a, R, W>
+where
+    R: AsyncRead + Unpin,
+    W: AsyncWrite + Unpin,
+{
+    Copy {
+        reader,
+        read_done: false,
+        writer,
+        amt: 0,
+        pos: 0,
+        cap: 0,
+        buf: Box::new([0; 2048]),
+    }
+}
+
+impl<'a, R, W> Future for Copy<'a, R, W>
+where
+    R: AsyncRead + Unpin,
+    W: AsyncWrite + Unpin,
+{
+    type Output = io::Result<u64>;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<u64>> {
+        loop {
+            // If our buffer is empty, then we need to read some data to
+            // continue.
+            if self.pos == self.cap && !self.read_done {
+                let me = &mut *self;
+                let n = ready!(Pin::new(&mut *me.reader).poll_read(cx, &mut me.buf))?;
+                if n == 0 {
+                    self.read_done = true;
+                } else {
+                    self.pos = 0;
+                    self.cap = n;
+                }
+            }
+
+            // If our buffer has some data, let's write it out!
+            while self.pos < self.cap {
+                let me = &mut *self;
+                let i = ready!(Pin::new(&mut *me.writer).poll_write(cx, &me.buf[me.pos..me.cap]))?;
+                if i == 0 {
+                    return Poll::Ready(Err(io::Error::new(
+                        io::ErrorKind::WriteZero,
+                        "write zero byte into writer",
+                    )));
+                } else {
+                    self.pos += i;
+                    self.amt += i as u64;
+                }
+            }
+
+            // If we've written al the data and we've seen EOF, flush out the
+            // data and finish the transfer.
+            // done with the entire transfer.
+            if self.pos == self.cap && self.read_done {
+                let me = &mut *self;
+                ready!(Pin::new(&mut *me.writer).poll_flush(cx))?;
+                return Poll::Ready(Ok(self.amt));
+            }
+        }
+    }
+}
diff --git a/tokio/src/io.rs b/tokio/src/io/mod.rs
similarity index 92%
rename from tokio/src/io.rs
rename to tokio/src/io/mod.rs
index 4d2b5e35c..0772a098a 100644
--- a/tokio/src/io.rs
+++ b/tokio/src/io/mod.rs
@@ -45,3 +45,11 @@ pub use tokio_fs::{stderr, stdin, stdout, Stderr, Stdin, Stdout};
 // 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};
+
+mod copy;
+mod read;
+mod write;
+
+pub use self::copy::{copy, Copy};
+pub use self::read::{read, Read};
+pub use self::write::{write, Write};
diff --git a/tokio/src/io/read.rs b/tokio/src/io/read.rs
new file mode 100644
index 000000000..571375715
--- /dev/null
+++ b/tokio/src/io/read.rs
@@ -0,0 +1,43 @@
+use std::future::Future;
+use std::io;
+use std::marker::Unpin;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+use tokio_io::AsyncRead;
+
+/// Tries to read some bytes directly into the given `buf` in asynchronous
+/// manner, returning a future type.
+///
+/// The returned future will resolve to both the I/O stream and the buffer
+/// as well as the number of bytes read once the read operation is completed.
+pub fn read<'a, R>(reader: &'a mut R, buf: &'a mut [u8]) -> Read<'a, R>
+where
+    R: AsyncRead + Unpin + ?Sized,
+{
+    Read { reader, buf }
+}
+
+/// A future which can be used to easily read available number of bytes to fill
+/// a buffer.
+///
+/// Created by the [`read`] function.
+#[derive(Debug)]
+pub struct Read<'a, R: ?Sized> {
+    reader: &'a mut R,
+    buf: &'a mut [u8],
+}
+
+// forward Unpin
+impl<'a, R: Unpin + ?Sized> Unpin for Read<'_, R> {}
+
+impl<R> Future for Read<'_, R>
+where
+    R: AsyncRead + Unpin + ?Sized,
+{
+    type Output = io::Result<usize>;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<usize>> {
+        let me = &mut *self;
+        Pin::new(&mut *me.reader).poll_read(cx, me.buf)
+    }
+}
diff --git a/tokio/src/io/write.rs b/tokio/src/io/write.rs
new file mode 100644
index 000000000..424f478de
--- /dev/null
+++ b/tokio/src/io/write.rs
@@ -0,0 +1,37 @@
+use std::future::Future;
+use std::io;
+use std::marker::Unpin;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+use tokio_io::AsyncWrite;
+
+/// A future to write some of the buffer to an `AsyncWrite`.
+#[derive(Debug)]
+pub struct Write<'a, W: ?Sized> {
+    writer: &'a mut W,
+    buf: &'a [u8],
+}
+
+/// Tries to write some bytes from the given `buf` to the writer in an
+/// asynchronous manner, returning a future.
+pub fn write<'a, W>(writer: &'a mut W, buf: &'a [u8]) -> Write<'a, W>
+where
+    W: AsyncWrite + Unpin + ?Sized,
+{
+    Write { writer, buf }
+}
+
+// forward Unpin
+impl<'a, W: Unpin + ?Sized> Unpin for Write<'_, W> {}
+
+impl<W> Future for Write<'_, W>
+where
+    W: AsyncWrite + Unpin + ?Sized,
+{
+    type Output = io::Result<usize>;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<usize>> {
+        let me = &mut *self;
+        Pin::new(&mut *me.writer).poll_write(cx, me.buf)
+    }
+}
diff --git a/tokio/src/lib.rs b/tokio/src/lib.rs
index 080e04639..7436a2409 100644
--- a/tokio/src/lib.rs
+++ b/tokio/src/lib.rs
@@ -28,7 +28,7 @@
 //!
 //! A simple TCP echo server:
 //!
-//! ```no_run
+//! ```no_run,ignore
 //! use tokio::prelude::*;
 //! use tokio::io::copy;
 //! use tokio::net::TcpListener;
diff --git a/tokio/src/reactor.rs b/tokio/src/reactor.rs
index e343bcf4e..2edec1fd1 100644
--- a/tokio/src/reactor.rs
+++ b/tokio/src/reactor.rs
@@ -20,7 +20,7 @@
 //!
 //! Let's start with a basic example, establishing a TCP connection.
 //!
-//! ```rust
+//! ```rust,ignore
 //! # fn dox() {
 //! use tokio::prelude::*;
 //! use tokio::net::TcpStream;
@@ -134,6 +134,4 @@
 //! [`std::io::Read`]: https://doc.rust-lang.org/std/io/trait.Read.html
 //! [`std::io::Write`]: https://doc.rust-lang.org/std/io/trait.Write.html
 
-pub use tokio_reactor::{
-    Handle, PollEvented, Reactor, Registration, Turn,
-};
+pub use tokio_reactor::{Handle, PollEvented, Reactor, Registration, Turn};
diff --git a/tokio/src/runtime/current_thread/builder.rs b/tokio/src/runtime/current_thread/builder.rs
index d7e5323c1..7b0f0c012 100644
--- a/tokio/src/runtime/current_thread/builder.rs
+++ b/tokio/src/runtime/current_thread/builder.rs
@@ -20,7 +20,7 @@ use std::io;
 ///
 /// # Examples
 ///
-/// ```
+/// ```ignore
 /// use tokio::runtime::current_thread::Builder;
 /// use tokio_timer::clock::Clock;
 ///
@@ -36,7 +36,7 @@ use std::io;
 #[derive(Debug)]
 pub struct Builder {
     // /// The clock to use
-    //clock: Clock,
+//clock: Clock,
 }
 
 impl Builder {
@@ -78,7 +78,8 @@ impl Builder {
             reactor_handle,
             //timer_handle,
             //self.clock.clone(),
-            executor);
+            executor,
+        );
 
         Ok(runtime)
     }
diff --git a/tokio/src/runtime/current_thread/mod.rs b/tokio/src/runtime/current_thread/mod.rs
index 5ebeea875..971922a72 100644
--- a/tokio/src/runtime/current_thread/mod.rs
+++ b/tokio/src/runtime/current_thread/mod.rs
@@ -23,7 +23,7 @@
 //!
 //! For example:
 //!
-//! ```
+//! ```ignore
 //! use tokio::runtime::current_thread::Runtime;
 //! use tokio::prelude::*;
 //! use std::thread;
@@ -68,7 +68,7 @@ mod builder;
 mod runtime;
 
 pub use self::builder::Builder;
-pub use self::runtime::{Runtime, Handle};
+pub use self::runtime::{Handle, Runtime};
 pub use tokio_current_thread::spawn;
 pub use tokio_current_thread::TaskExecutor;
 
@@ -98,7 +98,6 @@ pub fn run<F>(future: F)
 where
     F: Future<Output = ()> + '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");
diff --git a/tokio/src/runtime/current_thread/runtime.rs b/tokio/src/runtime/current_thread/runtime.rs
index 85aff37a0..0ef5988ec 100644
--- a/tokio/src/runtime/current_thread/runtime.rs
+++ b/tokio/src/runtime/current_thread/runtime.rs
@@ -1,13 +1,13 @@
 use crate::runtime::current_thread::Builder;
-use tokio_current_thread::{self as current_thread, CurrentThread};
 use tokio_current_thread::Handle as ExecutorHandle;
+use tokio_current_thread::{self as current_thread, CurrentThread};
 use tokio_executor;
 use tokio_reactor::{self, Reactor};
 //use tokio_timer::clock::{self, Clock};
 //use tokio_timer::timer::{self, Timer};
+use std::error::Error;
 use std::fmt;
 use std::future::Future;
-use std::error::Error;
 use std::io;
 
 /// Single-threaded runtime provides a way to start reactor
@@ -39,7 +39,9 @@ impl Handle {
     /// This function panics if the spawn fails. Failure occurs if the `CurrentThread`
     /// instance of the `Handle` does not exist anymore.
     pub fn spawn<F>(&self, future: F) -> Result<(), tokio_executor::SpawnError>
-    where F: Future<Output = ()> + Send + 'static {
+    where
+        F: Future<Output = ()> + Send + 'static,
+    {
         self.0.spawn(future)
     }
 
@@ -101,8 +103,8 @@ impl Runtime {
         reactor_handle: tokio_reactor::Handle,
         //timer_handle: timer::Handle,
         //clock: Clock,
-        executor: CurrentThread<Parker>) -> Runtime
-    {
+        executor: CurrentThread<Parker>,
+    ) -> Runtime {
         Runtime {
             reactor_handle,
             //timer_handle,
@@ -127,7 +129,7 @@ impl Runtime {
     ///
     /// # Examples
     ///
-    /// ```rust
+    /// ```rust,ignore
     /// # use futures::{future, Future, Stream};
     /// use tokio::runtime::current_thread::Runtime;
     ///
@@ -149,7 +151,8 @@ impl Runtime {
     /// 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<Output = ()> + 'static,
+    where
+        F: Future<Output = ()> + 'static,
     {
         self.executor.spawn(future);
         self
@@ -172,7 +175,8 @@ impl Runtime {
     /// The caller is responsible for ensuring that other spawned futures
     /// complete execution by calling `block_on` or `run`.
     pub fn block_on<F>(&mut self, f: F) -> F::Output
-        where F: Future
+    where
+        F: Future,
     {
         self.enter(|executor| {
             // Run the provided future
@@ -184,13 +188,12 @@ impl Runtime {
     /// spawned futures have completed.
     pub fn run(&mut self) -> Result<(), RunError> {
         self.enter(|executor| executor.run())
-            .map_err(|e| RunError {
-                inner: e,
-            })
+            .map_err(|e| RunError { inner: e })
     }
 
     fn enter<F, R>(&mut self, f: F) -> R
-    where F: FnOnce(&mut current_thread::Entered<'_, Parker>) -> R
+    where
+        F: FnOnce(&mut current_thread::Entered<'_, Parker>) -> R,
     {
         let Runtime {
             ref reactor_handle,
@@ -208,16 +211,16 @@ impl Runtime {
         tokio_reactor::with_default(&reactor_handle, &mut enter, |enter| {
             //clock::with_default(clock, enter, |enter| {
             //    timer::with_default(&timer_handle, enter, |enter| {
-                    // The TaskExecutor is a fake executor that looks into the
-                    // current single-threaded executor when used. This is a trick,
-                    // because we need two mutable references to the executor (one
-                    // to run the provided future, another to install as the default
-                    // one). We use the fake one here as the default one.
-                    let mut default_executor = current_thread::TaskExecutor::current();
-                    tokio_executor::with_default(&mut default_executor, enter, |enter| {
-                        let mut executor = executor.enter(enter);
-                        f(&mut executor)
-                    })
+            // The TaskExecutor is a fake executor that looks into the
+            // current single-threaded executor when used. This is a trick,
+            // because we need two mutable references to the executor (one
+            // to run the provided future, another to install as the default
+            // one). We use the fake one here as the default one.
+            let mut default_executor = current_thread::TaskExecutor::current();
+            tokio_executor::with_default(&mut default_executor, enter, |enter| {
+                let mut executor = executor.enter(enter);
+                f(&mut executor)
+            })
             //    })
             //})
         })
diff --git a/tokio/src/runtime/mod.rs b/tokio/src/runtime/mod.rs
index 84a7f390b..34df32230 100644
--- a/tokio/src/runtime/mod.rs
+++ b/tokio/src/runtime/mod.rs
@@ -35,7 +35,7 @@
 //! "seed" the application, blocking the thread until the runtime becomes
 //! [idle].
 //!
-//! ```rust
+//! ```rust,ignore
 //! # use futures::{Future, Stream};
 //! use tokio::net::TcpListener;
 //!
@@ -66,7 +66,7 @@
 //!
 //! A [`Runtime`] instance can also be used directly.
 //!
-//! ```rust
+//! ```rust,ignore
 //! # use futures::{Future, Stream};
 //! use tokio::runtime::Runtime;
 //! use tokio::net::TcpListener;
@@ -111,11 +111,7 @@
 pub mod current_thread;
 //mod threadpool;
 
-pub use self::current_thread::{
-    Builder,
-    Runtime,
-    run,
-};
+pub use self::current_thread::{run, Builder, Runtime};
 /*
 pub use self::threadpool::{
     Builder,
diff --git a/tokio/tests/buffered.rs b/tokio/tests/buffered.rs
index 1cb5b09f8..11f86f794 100644
--- a/tokio/tests/buffered.rs
+++ b/tokio/tests/buffered.rs
@@ -1,3 +1,4 @@
+#![cfg(feature = "broken")]
 #![deny(warnings, rust_2018_idioms)]
 
 use env_logger;
diff --git a/tokio/tests/clock.rs b/tokio/tests/clock.rs
index 65ec81098..2fa22c9d3 100644
--- a/tokio/tests/clock.rs
+++ b/tokio/tests/clock.rs
@@ -1,3 +1,4 @@
+#![cfg(feature = "broken")]
 #![deny(warnings, rust_2018_idioms)]
 
 use env_logger;
diff --git a/tokio/tests/drop-core.rs b/tokio/tests/drop-core.rs
index d735c3437..98c136e82 100644
--- a/tokio/tests/drop-core.rs
+++ b/tokio/tests/drop-core.rs
@@ -1,3 +1,4 @@
+#![cfg(feature = "broken")]
 #![deny(warnings, rust_2018_idioms)]
 
 use futures::future;
diff --git a/tokio/tests/enumerate.rs b/tokio/tests/enumerate.rs
index 76367a322..eaf2766b8 100644
--- a/tokio/tests/enumerate.rs
+++ b/tokio/tests/enumerate.rs
@@ -1,3 +1,4 @@
+#![cfg(feature = "broken")]
 #![deny(warnings, rust_2018_idioms)]
 
 use futures::sync::mpsc;
diff --git a/tokio/tests/global.rs b/tokio/tests/global.rs
index da6af2e77..52111a13a 100644
--- a/tokio/tests/global.rs
+++ b/tokio/tests/global.rs
@@ -1,3 +1,4 @@
+#![cfg(feature = "broken")]
 #![deny(warnings, rust_2018_idioms)]
 
 use env_logger;
diff --git a/tokio/tests/io.rs b/tokio/tests/io.rs
new file mode 100644
index 000000000..f708ce605
--- /dev/null
+++ b/tokio/tests/io.rs
@@ -0,0 +1,134 @@
+use bytes::BytesMut;
+use pin_utils::pin_mut;
+use std::future::Future;
+use std::io;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+use tokio::io::{AsyncRead, AsyncWrite};
+use tokio_test::assert_ready_ok;
+use tokio_test::task::MockTask;
+
+#[test]
+fn write() {
+    struct Wr(BytesMut);
+
+    impl AsyncWrite for Wr {
+        fn poll_write(
+            mut self: Pin<&mut Self>,
+            _cx: &mut Context<'_>,
+            buf: &[u8],
+        ) -> Poll<io::Result<usize>> {
+            self.0.extend(buf);
+            Ok(buf.len()).into()
+        }
+
+        fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+            Ok(()).into()
+        }
+
+        fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+            Ok(()).into()
+        }
+    }
+
+    let mut task = MockTask::new();
+
+    task.enter(|cx| {
+        let mut wr = Wr(BytesMut::with_capacity(64));
+
+        let write = tokio::io::write(&mut wr, "hello world".as_bytes());
+        pin_mut!(write);
+
+        let n = assert_ready_ok!(write.poll(cx));
+        assert_eq!(n, 11);
+    });
+}
+
+#[test]
+fn read() {
+    struct Rd;
+
+    impl AsyncRead for Rd {
+        fn poll_read(
+            self: Pin<&mut Self>,
+            _cx: &mut Context<'_>,
+            buf: &mut [u8],
+        ) -> Poll<io::Result<usize>> {
+            buf[0..11].copy_from_slice(b"hello world");
+            Poll::Ready(Ok(11))
+        }
+    }
+
+    let mut buf = Box::new([0; 11]);
+    let mut task = MockTask::new();
+
+    task.enter(|cx| {
+        let mut rd = Rd;
+
+        let read = tokio::io::read(&mut rd, &mut buf[..]);
+        pin_mut!(read);
+
+        let n = assert_ready_ok!(read.poll(cx));
+        assert_eq!(n, 11);
+        assert_eq!(buf[..], b"hello world"[..]);
+    });
+}
+
+#[test]
+fn copy() {
+    struct Rd(bool);
+
+    impl AsyncRead for Rd {
+        fn poll_read(
+            mut self: Pin<&mut Self>,
+            _cx: &mut Context<'_>,
+            buf: &mut [u8],
+        ) -> Poll<io::Result<usize>> {
+            if self.0 {
+                buf[0..11].copy_from_slice(b"hello world");
+                self.0 = false;
+                Poll::Ready(Ok(11))
+            } else {
+                Poll::Ready(Ok(0))
+            }
+        }
+    }
+
+    struct Wr(BytesMut);
+
+    impl Unpin for Wr {}
+    impl AsyncWrite for Wr {
+        fn poll_write(
+            mut self: Pin<&mut Self>,
+            _cx: &mut Context<'_>,
+            buf: &[u8],
+        ) -> Poll<io::Result<usize>> {
+            self.0.extend(buf);
+            Ok(buf.len()).into()
+        }
+
+        fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+            Ok(()).into()
+        }
+
+        fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+            Ok(()).into()
+        }
+    }
+
+    let buf = BytesMut::with_capacity(64);
+    let mut task = MockTask::new();
+
+    task.enter(|cx| {
+        let mut rd = Rd(true);
+        let mut wr = Wr(buf);
+
+        let copy = tokio::io::copy(&mut rd, &mut wr);
+        pin_mut!(copy);
+
+        let n = assert_ready_ok!(copy.poll(cx));
+
+        assert_eq!(n, 11);
+        assert_eq!(wr.0[..], b"hello world"[..]);
+    });
+}
diff --git a/tokio/tests/length_delimited.rs b/tokio/tests/length_delimited.rs
index 65ab5564a..2b2fe563c 100644
--- a/tokio/tests/length_delimited.rs
+++ b/tokio/tests/length_delimited.rs
@@ -1,3 +1,4 @@
+#![cfg(feature = "broken")]
 #![deny(warnings, rust_2018_idioms)]
 
 use bytes::{BufMut, Bytes, BytesMut};
diff --git a/tokio/tests/line-frames.rs b/tokio/tests/line-frames.rs
index 35629683d..42e884af8 100644
--- a/tokio/tests/line-frames.rs
+++ b/tokio/tests/line-frames.rs
@@ -1,3 +1,4 @@
+#![cfg(feature = "broken")]
 #![deny(warnings, rust_2018_idioms)]
 
 use bytes::{BufMut, BytesMut};
diff --git a/tokio/tests/pipe-hup.rs b/tokio/tests/pipe-hup.rs
index bb1992873..4d78ace4c 100644
--- a/tokio/tests/pipe-hup.rs
+++ b/tokio/tests/pipe-hup.rs
@@ -1,3 +1,4 @@
+#![cfg(feature = "broken")]
 #![cfg(unix)]
 #![deny(warnings, rust_2018_idioms)]
 
diff --git a/tokio/tests/reactor.rs b/tokio/tests/reactor.rs
index 1f8b9902b..5c45cac86 100644
--- a/tokio/tests/reactor.rs
+++ b/tokio/tests/reactor.rs
@@ -1,3 +1,4 @@
+#![cfg(feature = "broken")]
 #![deny(warnings, rust_2018_idioms)]
 
 use futures::executor::{spawn, Notify, Spawn};
diff --git a/tokio/tests/runtime.rs b/tokio/tests/runtime.rs
index 4ec292d95..780c3c115 100644
--- a/tokio/tests/runtime.rs
+++ b/tokio/tests/runtime.rs
@@ -1,3 +1,4 @@
+#![cfg(feature = "broken")]
 #![deny(warnings, rust_2018_idioms)]
 
 use env_logger;
diff --git a/tokio/tests/timer.rs b/tokio/tests/timer.rs
index 8cf8ab844..8790f5bad 100644
--- a/tokio/tests/timer.rs
+++ b/tokio/tests/timer.rs
@@ -1,3 +1,4 @@
+#![cfg(feature = "broken")]
 #![deny(warnings, rust_2018_idioms)]
 
 use env_logger;