Upgrade rust/crates/tokio to 1.2.0

Test: make
Change-Id: Ib0f6a5201b51e9d122b6e867388a3856e16f803a

1 files changed, 147 insertions, 7 deletions

diff --git a/src/net/udp.rs b/src/net/udp.rs
index 23abe98..86b4fe9 100644
--- a/src/net/udp.rs
+++ b/src/net/udp.rs
@@ -7,6 +7,10 @@ use std::io;
 use std::net::{self, Ipv4Addr, Ipv6Addr, SocketAddr};
 use std::task::{Context, Poll};
 
+cfg_io_util! {
+    use bytes::BufMut;
+}
+
 cfg_net! {
     /// A UDP socket
     ///
@@ -18,8 +22,13 @@ cfg_net! {
     /// * one to one: [`connect`](`UdpSocket::connect`) and associate with a single address, using [`send`](`UdpSocket::send`)
     ///   and [`recv`](`UdpSocket::recv`) to communicate only with that remote address
     ///
-    /// `UdpSocket` can also be used concurrently to `send_to` and `recv_from` in different tasks,
-    /// all that's required is that you `Arc<UdpSocket>` and clone a reference for each task.
+    /// This type does not provide a `split` method, because this functionality
+    /// can be achieved by wrapping the socket in an [`Arc`]. Note that you do
+    /// not need a `Mutex` to share the `UdpSocket` — an `Arc<UdpSocket>` is
+    /// enough. This is because all of the methods take `&self` instead of `&mut
+    /// self`.
+    ///
+    /// [`Arc`]: std::sync::Arc
     ///
     /// # Streams
     ///
@@ -74,11 +83,12 @@ cfg_net! {
     /// }
     /// ```
     ///
-    /// # Example: Sending/Receiving concurrently
+    /// # Example: Splitting with `Arc`
     ///
-    /// Because `send_to` and `recv_from` take `&self`. It's perfectly alright to `Arc<UdpSocket>`
-    /// and share the references to multiple tasks, in order to send/receive concurrently. Here is
-    /// a similar "echo" example but that supports concurrent sending/receiving:
+    /// Because `send_to` and `recv_from` take `&self`. It's perfectly alright
+    /// to use an `Arc<UdpSocket>` and share the references to multiple tasks.
+    /// Here is a similar "echo" example that supports concurrent
+    /// sending/receiving:
     ///
     /// ```no_run
     /// use tokio::{net::UdpSocket, sync::mpsc};
@@ -683,6 +693,137 @@ impl UdpSocket {
             .try_io(Interest::READABLE, || self.io.recv(buf))
     }
 
+    cfg_io_util! {
+        /// Try to receive data from the stream into the provided buffer, advancing the
+        /// buffer's internal cursor, returning how many bytes were read.
+        ///
+        /// The function must be called with valid byte array buf of sufficient size
+        /// to hold the message bytes. If a message is too long to fit in the
+        /// supplied buffer, excess bytes may be discarded.
+        ///
+        /// When there is no pending data, `Err(io::ErrorKind::WouldBlock)` is
+        /// returned. This function is usually paired with `readable()`.
+        ///
+        /// # Examples
+        ///
+        /// ```no_run
+        /// use tokio::net::UdpSocket;
+        /// use std::io;
+        ///
+        /// #[tokio::main]
+        /// async fn main() -> io::Result<()> {
+        ///     // Connect to a peer
+        ///     let socket = UdpSocket::bind("127.0.0.1:8080").await?;
+        ///     socket.connect("127.0.0.1:8081").await?;
+        ///
+        ///     loop {
+        ///         // Wait for the socket to be readable
+        ///         socket.readable().await?;
+        ///
+        ///         let mut buf = Vec::with_capacity(1024);
+        ///
+        ///         // Try to recv data, this may still fail with `WouldBlock`
+        ///         // if the readiness event is a false positive.
+        ///         match socket.try_recv_buf(&mut buf) {
+        ///             Ok(n) => {
+        ///                 println!("GOT {:?}", &buf[..n]);
+        ///                 break;
+        ///             }
+        ///             Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
+        ///                 continue;
+        ///             }
+        ///             Err(e) => {
+        ///                 return Err(e);
+        ///             }
+        ///         }
+        ///     }
+        ///
+        ///     Ok(())
+        /// }
+        /// ```
+        pub fn try_recv_buf<B: BufMut>(&self, buf: &mut B) -> io::Result<usize> {
+            self.io.registration().try_io(Interest::READABLE, || {
+                let dst = buf.chunk_mut();
+                let dst =
+                    unsafe { &mut *(dst as *mut _ as *mut [std::mem::MaybeUninit<u8>] as *mut [u8]) };
+
+                // Safety: We trust `UdpSocket::recv` to have filled up `n` bytes in the
+                // buffer.
+                let n = (&*self.io).recv(dst)?;
+
+                unsafe {
+                    buf.advance_mut(n);
+                }
+
+                Ok(n)
+            })
+        }
+
+        /// Try to receive a single datagram message on the socket. On success,
+        /// returns the number of bytes read and the origin.
+        ///
+        /// The function must be called with valid byte array buf of sufficient size
+        /// to hold the message bytes. If a message is too long to fit in the
+        /// supplied buffer, excess bytes may be discarded.
+        ///
+        /// When there is no pending data, `Err(io::ErrorKind::WouldBlock)` is
+        /// returned. This function is usually paired with `readable()`.
+        ///
+        /// # Examples
+        ///
+        /// ```no_run
+        /// use tokio::net::UdpSocket;
+        /// use std::io;
+        ///
+        /// #[tokio::main]
+        /// async fn main() -> io::Result<()> {
+        ///     // Connect to a peer
+        ///     let socket = UdpSocket::bind("127.0.0.1:8080").await?;
+        ///
+        ///     loop {
+        ///         // Wait for the socket to be readable
+        ///         socket.readable().await?;
+        ///
+        ///         let mut buf = Vec::with_capacity(1024);
+        ///
+        ///         // Try to recv data, this may still fail with `WouldBlock`
+        ///         // if the readiness event is a false positive.
+        ///         match socket.try_recv_buf_from(&mut buf) {
+        ///             Ok((n, _addr)) => {
+        ///                 println!("GOT {:?}", &buf[..n]);
+        ///                 break;
+        ///             }
+        ///             Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
+        ///                 continue;
+        ///             }
+        ///             Err(e) => {
+        ///                 return Err(e);
+        ///             }
+        ///         }
+        ///     }
+        ///
+        ///     Ok(())
+        /// }
+        /// ```
+        pub fn try_recv_buf_from<B: BufMut>(&self, buf: &mut B) -> io::Result<(usize, SocketAddr)> {
+            self.io.registration().try_io(Interest::READABLE, || {
+                let dst = buf.chunk_mut();
+                let dst =
+                    unsafe { &mut *(dst as *mut _ as *mut [std::mem::MaybeUninit<u8>] as *mut [u8]) };
+
+                // Safety: We trust `UdpSocket::recv_from` to have filled up `n` bytes in the
+                // buffer.
+                let (n, addr) = (&*self.io).recv_from(dst)?;
+
+                unsafe {
+                    buf.advance_mut(n);
+                }
+
+                Ok((n, addr))
+            })
+        }
+    }
+
     /// Sends data on the socket to the given address. On success, returns the
     /// number of bytes written.
     ///
@@ -904,7 +1045,6 @@ impl UdpSocket {
     /// async fn main() -> io::Result<()> {
     ///     // Connect to a peer
     ///     let socket = UdpSocket::bind("127.0.0.1:8080").await?;
-    ///     socket.connect("127.0.0.1:8081").await?;
     ///
     ///     loop {
     ///         // Wait for the socket to be readable