Merge branch 'master' into warnings

docs/src/concepts/tasks.md

@@ -2,7 +2,7 @@
 
 Now that we know what Futures are, we want to run them!
 
-In `async-std`, the [`tasks`][tasks] module is responsible for this. The simplest way is using the `block_on` function:
+In `async-std`, the [`task`][tasks] module is responsible for this. The simplest way is using the `block_on` function:
 
 ```rust,edition2018
 # extern crate async_std;

src/io/write/write_fmt.rs

@@ -11,7 +11,7 @@ pub struct WriteFmtFuture<'a, T: Unpin + ?Sized> {
     pub(crate) writer: &'a mut T,
     pub(crate) res: Option<io::Result<Vec<u8>>>,
     pub(crate) buffer: Option<Vec<u8>>,
-    pub(crate) amt: u64,
+    pub(crate) amt: usize,
 }
 
 impl<T: Write + Unpin + ?Sized> Future for WriteFmtFuture<'_, T> {
@@ -37,15 +37,15 @@ impl<T: Write + Unpin + ?Sized> Future for WriteFmtFuture<'_, T> {
 
         // Copy the data from the buffer into the writer until it's done.
         loop {
-            if *amt == buffer.len() as u64 {
+            if *amt == buffer.len() {
                 futures_core::ready!(Pin::new(&mut **writer).poll_flush(cx))?;
                 return Poll::Ready(Ok(()));
             }
-            let i = futures_core::ready!(Pin::new(&mut **writer).poll_write(cx, buffer))?;
+            let i = futures_core::ready!(Pin::new(&mut **writer).poll_write(cx, &buffer[*amt..]))?;
             if i == 0 {
                 return Poll::Ready(Err(io::ErrorKind::WriteZero.into()));
             }
-            *amt += i as u64;
+            *amt += i;
         }
     }
 }

src/lib.rs

@@ -111,7 +111,7 @@
 //! [files]: fs/struct.File.html
 //! [TCP]: net/struct.TcpStream.html
 //! [UDP]: net/struct.UdpSocket.html
-//! [`io`]: fs/struct.File.html
+//! [`io`]: io/index.html
 //! [`sync`]: sync/index.html
 //! [`channel`]: channel/index.html
 //!

src/net/tcp/listener.rs

@@ -1,6 +1,6 @@
 use std::fmt;
-use std::future::Future;
 use std::net::SocketAddr;
+use std::net::TcpStream as StdTcpStream;
 use std::pin::Pin;
 
 use async_io::Async;
@@ -149,8 +149,7 @@ impl TcpListener {
     #[must_use]
     pub fn incoming(&self) -> Incoming<'_> {
         Incoming {
-            listener: self,
-            accept: None,
+            incoming: Box::pin(self.watcher.incoming()),
         }
     }
 
@@ -188,35 +187,21 @@ impl TcpListener {
 /// [`TcpListener`]: struct.TcpListener.html
 /// [`std::net::Incoming`]: https://doc.rust-lang.org/std/net/struct.Incoming.html
 pub struct Incoming<'a> {
-    listener: &'a TcpListener,
-    accept: Option<
-        Pin<Box<dyn Future<Output = io::Result<(TcpStream, SocketAddr)>> + Send + Sync + 'a>>,
-    >,
+    incoming: Pin<Box<dyn Stream<Item = io::Result<Async<StdTcpStream>>> + Send + Sync + 'a>>,
 }
 
 impl Stream for Incoming<'_> {
     type Item = io::Result<TcpStream>;
 
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        loop {
-            if self.accept.is_none() {
-                self.accept = Some(Box::pin(self.listener.accept()));
-            }
-
-            if let Some(f) = &mut self.accept {
-                let res = ready!(f.as_mut().poll(cx));
-                self.accept = None;
-                return Poll::Ready(Some(res.map(|(stream, _)| stream)));
-            }
-        }
+        let res = ready!(Pin::new(&mut self.incoming).poll_next(cx));
+        Poll::Ready(res.map(|res| res.map(|stream| TcpStream { watcher: Arc::new(stream) })))
     }
 }
 
 impl fmt::Debug for Incoming<'_> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Incoming")
-            .field("listener", self.listener)
-            .finish()
+        write!(f, "Incoming {{ ... }}")
     }
 }
 

src/os/unix/net/listener.rs

@@ -1,8 +1,8 @@
 //! Unix-specific networking extensions.
 
 use std::fmt;
-use std::future::Future;
 use std::os::unix::net::UnixListener as StdUnixListener;
+use std::os::unix::net::UnixStream as StdUnixStream;
 use std::pin::Pin;
 
 use async_io::Async;
@@ -130,8 +130,7 @@ impl UnixListener {
     #[must_use]
     pub fn incoming(&self) -> Incoming<'_> {
         Incoming {
-            listener: self,
-            accept: None,
+            incoming: Box::pin(self.watcher.incoming()),
         }
     }
 
@@ -179,34 +178,21 @@ impl fmt::Debug for UnixListener {
 /// [`incoming`]: struct.UnixListener.html#method.incoming
 /// [`UnixListener`]: struct.UnixListener.html
 pub struct Incoming<'a> {
-    listener: &'a UnixListener,
-    accept: Option<
-        Pin<Box<dyn Future<Output = io::Result<(UnixStream, SocketAddr)>> + Send + Sync + 'a>>,
-    >,
+    incoming: Pin<Box<dyn Stream<Item = io::Result<Async<StdUnixStream>>> + Send + Sync + 'a>>,
 }
 
 impl Stream for Incoming<'_> {
     type Item = io::Result<UnixStream>;
 
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        loop {
-            if self.accept.is_none() {
-                self.accept = Some(Box::pin(self.listener.accept()));
-            }
-
-            if let Some(f) = &mut self.accept {
-                let res = ready!(f.as_mut().poll(cx));
-                self.accept = None;
-                return Poll::Ready(Some(res.map(|(stream, _)| stream)));
-            }
-        }
+        let res = ready!(Pin::new(&mut self.incoming).poll_next(cx));
+        Poll::Ready(res.map(|res| res.map(|stream| UnixStream { watcher: Arc::new(stream) })))
     }
 }
 
 impl fmt::Debug for Incoming<'_> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Incoming")
-            .field("listener", self.listener)
             .finish()
     }
 }

src/task/current.rs

@@ -22,7 +22,28 @@ use crate::task::{Task, TaskLocalsWrapper};
 /// #
 /// # })
 /// ```
-#[must_use] pub fn current() -> Task {
-    TaskLocalsWrapper::get_current(|t| t.task().clone())
-        .expect("`task::current()` called outside the context of a task")
+#[must_use]
+pub fn current() -> Task {
+    try_current().expect("`task::current()` called outside the context of a task")
 }
+
+/// Returns a handle to the current task if called within the context of a task created by [`block_on`],
+/// [`spawn`], or [`Builder::spawn`], otherwise returns `None`.
+///
+/// [`block_on`]: fn.block_on.html
+/// [`spawn`]: fn.spawn.html
+/// [`Builder::spawn`]: struct.Builder.html#method.spawn
+///
+/// # Examples
+///
+/// ```
+/// use async_std::task;
+///
+/// match task::try_current() {
+///     Some(t) => println!("The name of this task is {:?}", t.name()),
+///     None    => println!("Not inside a task!"),
+/// }
+/// ```
+pub fn try_current() -> Option<Task> {
+    TaskLocalsWrapper::get_current(|t| t.task().clone())
+}

src/task/mod.rs

@@ -133,7 +133,7 @@ cfg_std! {
 cfg_default! {
     pub use block_on::block_on;
     pub use builder::Builder;
-    pub use current::current;
+    pub use current::{current, try_current};
     pub use task::Task;
     pub use task_id::TaskId;
     pub use join_handle::JoinHandle;