async-await: Use Context instead of Waker in poll (#1041)

Rust nightly std::future::Future recently changed Waker
to Context.

Change to use Context

Co-Authored-By: Kintaro <[email protected]>

azure-pipelines.yml

@@ -74,7 +74,7 @@ jobs:
   parameters:
     name: async_await
     displayName: Async / Await
-    rust: nightly-2019-02-28
+    rust: nightly-2019-04-08
     noDefaultFeatures: ''
     benches: true
     crates:

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

@@ -3,7 +3,7 @@ use futures::{Future, Poll};
 use std::future::Future as StdFuture;
 use std::pin::Pin;
 use std::ptr;
-use std::task::{Poll as StdPoll, RawWaker, RawWakerVTable, Waker};
+use std::task::{Context, Poll as StdPoll, RawWaker, RawWakerVTable, Waker};
 
 /// Convert an 0.3 `Future` to an 0.1 `Future`.
 #[derive(Debug)]
@@ -45,8 +45,9 @@ where
         use futures::Async::*;
 
         let waker = noop_waker();
+        let mut context = Context::from_waker(&waker);
 
-        let res = self.0.as_mut().poll(&waker);
+        let res = self.0.as_mut().poll(&mut context);
 
         match res {
             StdPoll::Ready(Ok(val)) => Ok(Ready(val)),
@@ -76,8 +77,4 @@ unsafe fn wake(_data: *const ()) {
     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.");
 }
 
-const NOOP_WAKER_VTABLE: RawWakerVTable = RawWakerVTable {
-    clone: clone_raw,
-    drop: drop_raw,
-    wake,
-};
+const NOOP_WAKER_VTABLE: RawWakerVTable = RawWakerVTable::new(clone_raw, wake, drop_raw);

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

@@ -2,7 +2,7 @@ use futures::{Async, Future};
 
 use std::future::Future as StdFuture;
 use std::pin::Pin;
-use std::task::{Poll as StdPoll, Waker};
+use std::task::{Context, Poll as StdPoll};
 
 /// Converts an 0.1 `Future` into an 0.3 `Future`.
 #[derive(Debug)]
@@ -53,7 +53,7 @@ where
 {
     type Output = Result<T::Item, T::Error>;
 
-    fn poll(mut self: Pin<&mut Self>, _waker: &Waker) -> StdPoll<Self::Output> {
+    fn poll(mut self: Pin<&mut Self>, _context: &mut Context) -> StdPoll<Self::Output> {
         use futures::Async::{NotReady, Ready};
 
         // TODO: wire in cx

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

@@ -3,7 +3,7 @@ use tokio_io::AsyncWrite;
 use std::future::Future;
 use std::io;
 use std::pin::Pin;
-use std::task::{Poll, Waker};
+use std::task::{Context, Poll};
 
 /// A future used to fully flush an I/O object.
 #[derive(Debug)]
@@ -23,7 +23,7 @@ impl<'a, T: AsyncWrite + ?Sized> Flush<'a, T> {
 impl<'a, T: AsyncWrite + ?Sized> Future for Flush<'a, T> {
     type Output = io::Result<()>;
 
-    fn poll(mut self: Pin<&mut Self>, _wx: &Waker) -> Poll<Self::Output> {
+    fn poll(mut self: Pin<&mut Self>, _context: &mut Context) -> Poll<Self::Output> {
         use crate::compat::forward::convert_poll;
         convert_poll(self.writer.poll_flush())
     }

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

@@ -25,7 +25,7 @@ impl<'a, T: AsyncRead + ?Sized> Read<'a, T> {
 impl<'a, T: AsyncRead + ?Sized> Future for Read<'a, T> {
     type Output = io::Result<usize>;
 
-    fn poll(mut self: Pin<&mut Self>, _waker: &task::Waker) -> Poll<Self::Output> {
+    fn poll(mut self: Pin<&mut Self>, _context: &mut task::Context) -> Poll<Self::Output> {
         use crate::compat::forward::convert_poll;
 
         let this = &mut *self;

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

@@ -30,7 +30,7 @@ fn eof() -> io::Error {
 impl<'a, T: AsyncRead + ?Sized> Future for ReadExact<'a, T> {
     type Output = io::Result<()>;
 
-    fn poll(mut self: Pin<&mut Self>, _waker: &task::Waker) -> Poll<Self::Output> {
+    fn poll(mut self: Pin<&mut Self>, _context: &mut task::Context) -> Poll<Self::Output> {
         use crate::compat::forward::convert_poll;
 
         let this = &mut *self;

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

@@ -25,7 +25,7 @@ impl<'a, T: AsyncWrite + ?Sized> Write<'a, T> {
 impl<'a, T: AsyncWrite + ?Sized> Future for Write<'a, T> {
     type Output = io::Result<usize>;
 
-    fn poll(mut self: Pin<&mut Self>, _waker: &task::Waker) -> Poll<io::Result<usize>> {
+    fn poll(mut self: Pin<&mut Self>, _context: &mut task::Context) -> Poll<io::Result<usize>> {
         use crate::compat::forward::convert_poll;
 
         let this = &mut *self;

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

@@ -30,7 +30,7 @@ fn zero_write() -> io::Error {
 impl<'a, T: AsyncWrite + ?Sized> Future for WriteAll<'a, T> {
     type Output = io::Result<()>;
 
-    fn poll(mut self: Pin<&mut Self>, _waker: &task::Waker) -> Poll<io::Result<()>> {
+    fn poll(mut self: Pin<&mut Self>, _context: &mut task::Context) -> Poll<io::Result<()>> {
         use crate::compat::forward::convert_poll;
 
         let this = &mut *self;

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

@@ -27,7 +27,7 @@ impl<'a, T: Sink + Unpin + ?Sized> Send<'a, T> {
 impl<T: Sink + Unpin + ?Sized> Future for Send<'_, T> {
     type Output = Result<(), T::SinkError>;
 
-    fn poll(mut self: Pin<&mut Self>, _waker: &task::Waker) -> Poll<Self::Output> {
+    fn poll(mut self: Pin<&mut Self>, _context: &mut task::Context) -> Poll<Self::Output> {
         use crate::compat::forward::convert_poll;
         use futures::AsyncSink::{NotReady, Ready};
 

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

@@ -2,7 +2,7 @@ use futures::Stream;
 
 use std::future::Future;
 use std::pin::Pin;
-use std::task::{Poll, Waker};
+use std::task::{Context, Poll};
 
 /// A future of the next element of a stream.
 #[derive(Debug)]
@@ -21,7 +21,7 @@ impl<'a, T: Stream + Unpin> Next<'a, T> {
 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>, _waker: &Waker) -> Poll<Self::Output> {
+    fn poll(mut self: Pin<&mut Self>, _context: &mut Context) -> Poll<Self::Output> {
         use crate::compat::forward::convert_poll_stream;
 
         convert_poll_stream(self.stream.poll())

tokio/src/async_await.rs

@@ -1,6 +1,6 @@
 use std::future::Future as StdFuture;
 use std::pin::Pin;
-use std::task::{Poll, Waker};
+use std::task::{Context, Poll};
 
 fn map_ok<T: StdFuture>(future: T) -> impl StdFuture<Output = Result<(), ()>> {
     MapOk(future)
@@ -17,8 +17,8 @@ impl<T> MapOk<T> {
 impl<T: StdFuture> StdFuture for MapOk<T> {
     type Output = Result<(), ()>;
 
-    fn poll(self: Pin<&mut Self>, waker: &Waker) -> Poll<Self::Output> {
-        match self.future().poll(waker) {
+    fn poll(self: Pin<&mut Self>, context: &mut Context) -> Poll<Self::Output> {
+        match self.future().poll(context) {
             Poll::Ready(_) => Poll::Ready(Ok(())),
             Poll::Pending => Poll::Pending,
         }