Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1589 insertions, 0 deletions

diff --git a/third_party/rust/tokio/src/net/udp.rs b/third_party/rust/tokio/src/net/udp.rs
new file mode 100644
index 0000000000..12af5152c2
--- /dev/null
+++ b/third_party/rust/tokio/src/net/udp.rs
@@ -0,0 +1,1589 @@
+use crate::io::{Interest, PollEvented, ReadBuf, Ready};
+use crate::net::{to_socket_addrs, ToSocketAddrs};
+
+use std::convert::TryFrom;
+use std::fmt;
+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.
+    ///
+    /// UDP is "connectionless", unlike TCP. Meaning, regardless of what address you've bound to, a `UdpSocket`
+    /// is free to communicate with many different remotes. In tokio there are basically two main ways to use `UdpSocket`:
+    ///
+    /// * one to many: [`bind`](`UdpSocket::bind`) and use [`send_to`](`UdpSocket::send_to`)
+    ///   and [`recv_from`](`UdpSocket::recv_from`) to communicate with many different addresses
+    /// * 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
+    ///
+    /// This type does not provide a `split` method, because this functionality
+    /// can be achieved by instead 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`. Once you have wrapped it in an `Arc`, you can call
+    /// `.clone()` on the `Arc<UdpSocket>` to get multiple shared handles to the
+    /// same socket. An example of such usage can be found further down.
+    ///
+    /// [`Arc`]: std::sync::Arc
+    ///
+    /// # Streams
+    ///
+    /// If you need to listen over UDP and produce a [`Stream`], you can look
+    /// at [`UdpFramed`].
+    ///
+    /// [`UdpFramed`]: https://docs.rs/tokio-util/latest/tokio_util/udp/struct.UdpFramed.html
+    /// [`Stream`]: https://docs.rs/futures/0.3/futures/stream/trait.Stream.html
+    ///
+    /// # Example: one to many (bind)
+    ///
+    /// Using `bind` we can create a simple echo server that sends and recv's with many different clients:
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// use std::io;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     let sock = UdpSocket::bind("0.0.0.0:8080").await?;
+    ///     let mut buf = [0; 1024];
+    ///     loop {
+    ///         let (len, addr) = sock.recv_from(&mut buf).await?;
+    ///         println!("{:?} bytes received from {:?}", len, addr);
+    ///
+    ///         let len = sock.send_to(&buf[..len], addr).await?;
+    ///         println!("{:?} bytes sent", len);
+    ///     }
+    /// }
+    /// ```
+    ///
+    /// # Example: one to one (connect)
+    ///
+    /// Or using `connect` we can echo with a single remote address using `send` and `recv`:
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// use std::io;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     let sock = UdpSocket::bind("0.0.0.0:8080").await?;
+    ///
+    ///     let remote_addr = "127.0.0.1:59611";
+    ///     sock.connect(remote_addr).await?;
+    ///     let mut buf = [0; 1024];
+    ///     loop {
+    ///         let len = sock.recv(&mut buf).await?;
+    ///         println!("{:?} bytes received from {:?}", len, remote_addr);
+    ///
+    ///         let len = sock.send(&buf[..len]).await?;
+    ///         println!("{:?} bytes sent", len);
+    ///     }
+    /// }
+    /// ```
+    ///
+    /// # Example: Splitting with `Arc`
+    ///
+    /// 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};
+    /// use std::{io, net::SocketAddr, sync::Arc};
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     let sock = UdpSocket::bind("0.0.0.0:8080".parse::<SocketAddr>().unwrap()).await?;
+    ///     let r = Arc::new(sock);
+    ///     let s = r.clone();
+    ///     let (tx, mut rx) = mpsc::channel::<(Vec<u8>, SocketAddr)>(1_000);
+    ///
+    ///     tokio::spawn(async move {
+    ///         while let Some((bytes, addr)) = rx.recv().await {
+    ///             let len = s.send_to(&bytes, &addr).await.unwrap();
+    ///             println!("{:?} bytes sent", len);
+    ///         }
+    ///     });
+    ///
+    ///     let mut buf = [0; 1024];
+    ///     loop {
+    ///         let (len, addr) = r.recv_from(&mut buf).await?;
+    ///         println!("{:?} bytes received from {:?}", len, addr);
+    ///         tx.send((buf[..len].to_vec(), addr)).await.unwrap();
+    ///     }
+    /// }
+    /// ```
+    ///
+    pub struct UdpSocket {
+        io: PollEvented<mio::net::UdpSocket>,
+    }
+}
+
+impl UdpSocket {
+    /// This function will create a new UDP socket and attempt to bind it to
+    /// the `addr` provided.
+    ///
+    /// Binding with a port number of 0 will request that the OS assigns a port
+    /// to this listener. The port allocated can be queried via the `local_addr`
+    /// method.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// use std::io;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     let sock = UdpSocket::bind("0.0.0.0:8080").await?;
+    ///     // use `sock`
+    /// #   let _ = sock;
+    ///     Ok(())
+    /// }
+    /// ```
+    pub async fn bind<A: ToSocketAddrs>(addr: A) -> io::Result<UdpSocket> {
+        let addrs = to_socket_addrs(addr).await?;
+        let mut last_err = None;
+
+        for addr in addrs {
+            match UdpSocket::bind_addr(addr) {
+                Ok(socket) => return Ok(socket),
+                Err(e) => last_err = Some(e),
+            }
+        }
+
+        Err(last_err.unwrap_or_else(|| {
+            io::Error::new(
+                io::ErrorKind::InvalidInput,
+                "could not resolve to any address",
+            )
+        }))
+    }
+
+    fn bind_addr(addr: SocketAddr) -> io::Result<UdpSocket> {
+        let sys = mio::net::UdpSocket::bind(addr)?;
+        UdpSocket::new(sys)
+    }
+
+    fn new(socket: mio::net::UdpSocket) -> io::Result<UdpSocket> {
+        let io = PollEvented::new(socket)?;
+        Ok(UdpSocket { io })
+    }
+
+    /// Creates new `UdpSocket` from a previously bound `std::net::UdpSocket`.
+    ///
+    /// This function is intended to be used to wrap a UDP socket from the
+    /// standard library in the Tokio equivalent. The conversion assumes nothing
+    /// about the underlying socket; it is left up to the user to set it in
+    /// non-blocking mode.
+    ///
+    /// This can be used in conjunction with socket2's `Socket` interface to
+    /// configure a socket before it's handed off, such as setting options like
+    /// `reuse_address` or binding to multiple addresses.
+    ///
+    /// # Panics
+    ///
+    /// This function panics if thread-local runtime is not set.
+    ///
+    /// The runtime is usually set implicitly when this function is called
+    /// from a future driven by a tokio runtime, otherwise runtime can be set
+    /// explicitly with [`Runtime::enter`](crate::runtime::Runtime::enter) function.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// # use std::{io, net::SocketAddr};
+    ///
+    /// # #[tokio::main]
+    /// # async fn main() -> io::Result<()> {
+    /// let addr = "0.0.0.0:8080".parse::<SocketAddr>().unwrap();
+    /// let std_sock = std::net::UdpSocket::bind(addr)?;
+    /// std_sock.set_nonblocking(true)?;
+    /// let sock = UdpSocket::from_std(std_sock)?;
+    /// // use `sock`
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn from_std(socket: net::UdpSocket) -> io::Result<UdpSocket> {
+        let io = mio::net::UdpSocket::from_std(socket);
+        UdpSocket::new(io)
+    }
+
+    /// Turns a [`tokio::net::UdpSocket`] into a [`std::net::UdpSocket`].
+    ///
+    /// The returned [`std::net::UdpSocket`] will have nonblocking mode set as
+    /// `true`.  Use [`set_nonblocking`] to change the blocking mode if needed.
+    ///
+    /// # Examples
+    ///
+    /// ```rust,no_run
+    /// use std::error::Error;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> Result<(), Box<dyn Error>> {
+    ///     let tokio_socket = tokio::net::UdpSocket::bind("127.0.0.1:0").await?;
+    ///     let std_socket = tokio_socket.into_std()?;
+    ///     std_socket.set_nonblocking(false)?;
+    ///     Ok(())
+    /// }
+    /// ```
+    ///
+    /// [`tokio::net::UdpSocket`]: UdpSocket
+    /// [`std::net::UdpSocket`]: std::net::UdpSocket
+    /// [`set_nonblocking`]: fn@std::net::UdpSocket::set_nonblocking
+    pub fn into_std(self) -> io::Result<std::net::UdpSocket> {
+        #[cfg(unix)]
+        {
+            use std::os::unix::io::{FromRawFd, IntoRawFd};
+            self.io
+                .into_inner()
+                .map(|io| io.into_raw_fd())
+                .map(|raw_fd| unsafe { std::net::UdpSocket::from_raw_fd(raw_fd) })
+        }
+
+        #[cfg(windows)]
+        {
+            use std::os::windows::io::{FromRawSocket, IntoRawSocket};
+            self.io
+                .into_inner()
+                .map(|io| io.into_raw_socket())
+                .map(|raw_socket| unsafe { std::net::UdpSocket::from_raw_socket(raw_socket) })
+        }
+    }
+
+    /// Returns the local address that this socket is bound to.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// # use std::{io, net::SocketAddr};
+    ///
+    /// # #[tokio::main]
+    /// # async fn main() -> io::Result<()> {
+    /// let addr = "0.0.0.0:8080".parse::<SocketAddr>().unwrap();
+    /// let sock = UdpSocket::bind(addr).await?;
+    /// // the address the socket is bound to
+    /// let local_addr = sock.local_addr()?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn local_addr(&self) -> io::Result<SocketAddr> {
+        self.io.local_addr()
+    }
+
+    /// Connects the UDP socket setting the default destination for send() and
+    /// limiting packets that are read via recv from the address specified in
+    /// `addr`.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// # use std::{io, net::SocketAddr};
+    ///
+    /// # #[tokio::main]
+    /// # async fn main() -> io::Result<()> {
+    /// let sock = UdpSocket::bind("0.0.0.0:8080".parse::<SocketAddr>().unwrap()).await?;
+    ///
+    /// let remote_addr = "127.0.0.1:59600".parse::<SocketAddr>().unwrap();
+    /// sock.connect(remote_addr).await?;
+    /// let mut buf = [0u8; 32];
+    /// // recv from remote_addr
+    /// let len = sock.recv(&mut buf).await?;
+    /// // send to remote_addr
+    /// let _len = sock.send(&buf[..len]).await?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub async fn connect<A: ToSocketAddrs>(&self, addr: A) -> io::Result<()> {
+        let addrs = to_socket_addrs(addr).await?;
+        let mut last_err = None;
+
+        for addr in addrs {
+            match self.io.connect(addr) {
+                Ok(_) => return Ok(()),
+                Err(e) => last_err = Some(e),
+            }
+        }
+
+        Err(last_err.unwrap_or_else(|| {
+            io::Error::new(
+                io::ErrorKind::InvalidInput,
+                "could not resolve to any address",
+            )
+        }))
+    }
+
+    /// Waits for any of the requested ready states.
+    ///
+    /// This function is usually paired with `try_recv()` or `try_send()`. It
+    /// can be used to concurrently recv / send to the same socket on a single
+    /// task without splitting the socket.
+    ///
+    /// The function may complete without the socket being ready. This is a
+    /// false-positive and attempting an operation will return with
+    /// `io::ErrorKind::WouldBlock`.
+    ///
+    /// # Cancel safety
+    ///
+    /// This method is cancel safe. Once a readiness event occurs, the method
+    /// will continue to return immediately until the readiness event is
+    /// consumed by an attempt to read or write that fails with `WouldBlock` or
+    /// `Poll::Pending`.
+    ///
+    /// # Examples
+    ///
+    /// Concurrently receive from and send to the socket on the same task
+    /// without splitting.
+    ///
+    /// ```no_run
+    /// use tokio::io::{self, Interest};
+    /// use tokio::net::UdpSocket;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     let socket = UdpSocket::bind("127.0.0.1:8080").await?;
+    ///     socket.connect("127.0.0.1:8081").await?;
+    ///
+    ///     loop {
+    ///         let ready = socket.ready(Interest::READABLE | Interest::WRITABLE).await?;
+    ///
+    ///         if ready.is_readable() {
+    ///             // The buffer is **not** included in the async task and will only exist
+    ///             // on the stack.
+    ///             let mut data = [0; 1024];
+    ///             match socket.try_recv(&mut data[..]) {
+    ///                 Ok(n) => {
+    ///                     println!("received {:?}", &data[..n]);
+    ///                 }
+    ///                 // False-positive, continue
+    ///                 Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {}
+    ///                 Err(e) => {
+    ///                     return Err(e);
+    ///                 }
+    ///             }
+    ///         }
+    ///
+    ///         if ready.is_writable() {
+    ///             // Write some data
+    ///             match socket.try_send(b"hello world") {
+    ///                 Ok(n) => {
+    ///                     println!("sent {} bytes", n);
+    ///                 }
+    ///                 // False-positive, continue
+    ///                 Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {}
+    ///                 Err(e) => {
+    ///                     return Err(e);
+    ///                 }
+    ///             }
+    ///         }
+    ///     }
+    /// }
+    /// ```
+    pub async fn ready(&self, interest: Interest) -> io::Result<Ready> {
+        let event = self.io.registration().readiness(interest).await?;
+        Ok(event.ready)
+    }
+
+    /// Waits for the socket to become writable.
+    ///
+    /// This function is equivalent to `ready(Interest::WRITABLE)` and is
+    /// usually paired with `try_send()` or `try_send_to()`.
+    ///
+    /// The function may complete without the socket being writable. This is a
+    /// false-positive and attempting a `try_send()` will return with
+    /// `io::ErrorKind::WouldBlock`.
+    ///
+    /// # Cancel safety
+    ///
+    /// This method is cancel safe. Once a readiness event occurs, the method
+    /// will continue to return immediately until the readiness event is
+    /// consumed by an attempt to write that fails with `WouldBlock` or
+    /// `Poll::Pending`.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// use std::io;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     // Bind socket
+    ///     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 writable
+    ///         socket.writable().await?;
+    ///
+    ///         // Try to send data, this may still fail with `WouldBlock`
+    ///         // if the readiness event is a false positive.
+    ///         match socket.try_send(b"hello world") {
+    ///             Ok(n) => {
+    ///                 break;
+    ///             }
+    ///             Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
+    ///                 continue;
+    ///             }
+    ///             Err(e) => {
+    ///                 return Err(e);
+    ///             }
+    ///         }
+    ///     }
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    pub async fn writable(&self) -> io::Result<()> {
+        self.ready(Interest::WRITABLE).await?;
+        Ok(())
+    }
+
+    /// Polls for write/send readiness.
+    ///
+    /// If the udp stream is not currently ready for sending, this method will
+    /// store a clone of the `Waker` from the provided `Context`. When the udp
+    /// stream becomes ready for sending, `Waker::wake` will be called on the
+    /// waker.
+    ///
+    /// Note that on multiple calls to `poll_send_ready` or `poll_send`, only
+    /// the `Waker` from the `Context` passed to the most recent call is
+    /// scheduled to receive a wakeup. (However, `poll_recv_ready` retains a
+    /// second, independent waker.)
+    ///
+    /// This function is intended for cases where creating and pinning a future
+    /// via [`writable`] is not feasible. Where possible, using [`writable`] is
+    /// preferred, as this supports polling from multiple tasks at once.
+    ///
+    /// # Return value
+    ///
+    /// The function returns:
+    ///
+    /// * `Poll::Pending` if the udp stream is not ready for writing.
+    /// * `Poll::Ready(Ok(()))` if the udp stream is ready for writing.
+    /// * `Poll::Ready(Err(e))` if an error is encountered.
+    ///
+    /// # Errors
+    ///
+    /// This function may encounter any standard I/O error except `WouldBlock`.
+    ///
+    /// [`writable`]: method@Self::writable
+    pub fn poll_send_ready(&self, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        self.io.registration().poll_write_ready(cx).map_ok(|_| ())
+    }
+
+    /// Sends data on the socket to the remote address that the socket is
+    /// connected to.
+    ///
+    /// The [`connect`] method will connect this socket to a remote address.
+    /// This method will fail if the socket is not connected.
+    ///
+    /// [`connect`]: method@Self::connect
+    ///
+    /// # Return
+    ///
+    /// On success, the number of bytes sent is returned, otherwise, the
+    /// encountered error is returned.
+    ///
+    /// # Cancel safety
+    ///
+    /// This method is cancel safe. If `send` is used as the event in a
+    /// [`tokio::select!`](crate::select) statement and some other branch
+    /// completes first, then it is guaranteed that the message was not sent.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use tokio::io;
+    /// use tokio::net::UdpSocket;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     // Bind socket
+    ///     let socket = UdpSocket::bind("127.0.0.1:8080").await?;
+    ///     socket.connect("127.0.0.1:8081").await?;
+    ///
+    ///     // Send a message
+    ///     socket.send(b"hello world").await?;
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    pub async fn send(&self, buf: &[u8]) -> io::Result<usize> {
+        self.io
+            .registration()
+            .async_io(Interest::WRITABLE, || self.io.send(buf))
+            .await
+    }
+
+    /// Attempts to send data on the socket to the remote address to which it
+    /// was previously `connect`ed.
+    ///
+    /// The [`connect`] method will connect this socket to a remote address.
+    /// This method will fail if the socket is not connected.
+    ///
+    /// Note that on multiple calls to a `poll_*` method in the send direction,
+    /// only the `Waker` from the `Context` passed to the most recent call will
+    /// be scheduled to receive a wakeup.
+    ///
+    /// # Return value
+    ///
+    /// The function returns:
+    ///
+    /// * `Poll::Pending` if the socket is not available to write
+    /// * `Poll::Ready(Ok(n))` `n` is the number of bytes sent
+    /// * `Poll::Ready(Err(e))` if an error is encountered.
+    ///
+    /// # Errors
+    ///
+    /// This function may encounter any standard I/O error except `WouldBlock`.
+    ///
+    /// [`connect`]: method@Self::connect
+    pub fn poll_send(&self, cx: &mut Context<'_>, buf: &[u8]) -> Poll<io::Result<usize>> {
+        self.io
+            .registration()
+            .poll_write_io(cx, || self.io.send(buf))
+    }
+
+    /// Tries to send data on the socket to the remote address to which it is
+    /// connected.
+    ///
+    /// When the socket buffer is full, `Err(io::ErrorKind::WouldBlock)` is
+    /// returned. This function is usually paired with `writable()`.
+    ///
+    /// # Returns
+    ///
+    /// If successful, `Ok(n)` is returned, where `n` is the number of bytes
+    /// sent. If the socket is not ready to send data,
+    /// `Err(ErrorKind::WouldBlock)` is returned.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// use std::io;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     // Bind a UDP socket
+    ///     let socket = UdpSocket::bind("127.0.0.1:8080").await?;
+    ///
+    ///     // Connect to a peer
+    ///     socket.connect("127.0.0.1:8081").await?;
+    ///
+    ///     loop {
+    ///         // Wait for the socket to be writable
+    ///         socket.writable().await?;
+    ///
+    ///         // Try to send data, this may still fail with `WouldBlock`
+    ///         // if the readiness event is a false positive.
+    ///         match socket.try_send(b"hello world") {
+    ///             Ok(n) => {
+    ///                 break;
+    ///             }
+    ///             Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
+    ///                 continue;
+    ///             }
+    ///             Err(e) => {
+    ///                 return Err(e);
+    ///             }
+    ///         }
+    ///     }
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    pub fn try_send(&self, buf: &[u8]) -> io::Result<usize> {
+        self.io
+            .registration()
+            .try_io(Interest::WRITABLE, || self.io.send(buf))
+    }
+
+    /// Waits for the socket to become readable.
+    ///
+    /// This function is equivalent to `ready(Interest::READABLE)` and is usually
+    /// paired with `try_recv()`.
+    ///
+    /// The function may complete without the socket being readable. This is a
+    /// false-positive and attempting a `try_recv()` will return with
+    /// `io::ErrorKind::WouldBlock`.
+    ///
+    /// # Cancel safety
+    ///
+    /// This method is cancel safe. Once a readiness event occurs, the method
+    /// will continue to return immediately until the readiness event is
+    /// consumed by an attempt to read that fails with `WouldBlock` or
+    /// `Poll::Pending`.
+    ///
+    /// # 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?;
+    ///
+    ///         // The buffer is **not** included in the async task and will
+    ///         // only exist on the stack.
+    ///         let mut buf = [0; 1024];
+    ///
+    ///         // Try to recv data, this may still fail with `WouldBlock`
+    ///         // if the readiness event is a false positive.
+    ///         match socket.try_recv(&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 async fn readable(&self) -> io::Result<()> {
+        self.ready(Interest::READABLE).await?;
+        Ok(())
+    }
+
+    /// Polls for read/receive readiness.
+    ///
+    /// If the udp stream is not currently ready for receiving, this method will
+    /// store a clone of the `Waker` from the provided `Context`. When the udp
+    /// socket becomes ready for reading, `Waker::wake` will be called on the
+    /// waker.
+    ///
+    /// Note that on multiple calls to `poll_recv_ready`, `poll_recv` or
+    /// `poll_peek`, only the `Waker` from the `Context` passed to the most
+    /// recent call is scheduled to receive a wakeup. (However,
+    /// `poll_send_ready` retains a second, independent waker.)
+    ///
+    /// This function is intended for cases where creating and pinning a future
+    /// via [`readable`] is not feasible. Where possible, using [`readable`] is
+    /// preferred, as this supports polling from multiple tasks at once.
+    ///
+    /// # Return value
+    ///
+    /// The function returns:
+    ///
+    /// * `Poll::Pending` if the udp stream is not ready for reading.
+    /// * `Poll::Ready(Ok(()))` if the udp stream is ready for reading.
+    /// * `Poll::Ready(Err(e))` if an error is encountered.
+    ///
+    /// # Errors
+    ///
+    /// This function may encounter any standard I/O error except `WouldBlock`.
+    ///
+    /// [`readable`]: method@Self::readable
+    pub fn poll_recv_ready(&self, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
+        self.io.registration().poll_read_ready(cx).map_ok(|_| ())
+    }
+
+    /// Receives a single datagram message on the socket from the remote address
+    /// to which it is connected. On success, returns the number of bytes 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.
+    ///
+    /// The [`connect`] method will connect this socket to a remote address.
+    /// This method will fail if the socket is not connected.
+    ///
+    /// # Cancel safety
+    ///
+    /// This method is cancel safe. If `recv_from` is used as the event in a
+    /// [`tokio::select!`](crate::select) statement and some other branch
+    /// completes first, it is guaranteed that no messages were received on this
+    /// socket.
+    ///
+    /// [`connect`]: method@Self::connect
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// use std::io;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     // Bind socket
+    ///     let socket = UdpSocket::bind("127.0.0.1:8080").await?;
+    ///     socket.connect("127.0.0.1:8081").await?;
+    ///
+    ///     let mut buf = vec![0; 10];
+    ///     let n = socket.recv(&mut buf).await?;
+    ///
+    ///     println!("received {} bytes {:?}", n, &buf[..n]);
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    pub async fn recv(&self, buf: &mut [u8]) -> io::Result<usize> {
+        self.io
+            .registration()
+            .async_io(Interest::READABLE, || self.io.recv(buf))
+            .await
+    }
+
+    /// Attempts to receive a single datagram message on the socket from the remote
+    /// address to which it is `connect`ed.
+    ///
+    /// The [`connect`] method will connect this socket to a remote address. This method
+    /// resolves to an error if the socket is not connected.
+    ///
+    /// Note that on multiple calls to a `poll_*` method in the recv direction, only the
+    /// `Waker` from the `Context` passed to the most recent call will be scheduled to
+    /// receive a wakeup.
+    ///
+    /// # Return value
+    ///
+    /// The function returns:
+    ///
+    /// * `Poll::Pending` if the socket is not ready to read
+    /// * `Poll::Ready(Ok(()))` reads data `ReadBuf` if the socket is ready
+    /// * `Poll::Ready(Err(e))` if an error is encountered.
+    ///
+    /// # Errors
+    ///
+    /// This function may encounter any standard I/O error except `WouldBlock`.
+    ///
+    /// [`connect`]: method@Self::connect
+    pub fn poll_recv(&self, cx: &mut Context<'_>, buf: &mut ReadBuf<'_>) -> Poll<io::Result<()>> {
+        let n = ready!(self.io.registration().poll_read_io(cx, || {
+            // Safety: will not read the maybe uninitialized bytes.
+            let b = unsafe {
+                &mut *(buf.unfilled_mut() as *mut [std::mem::MaybeUninit<u8>] as *mut [u8])
+            };
+
+            self.io.recv(b)
+        }))?;
+
+        // Safety: We trust `recv` to have filled up `n` bytes in the buffer.
+        unsafe {
+            buf.assume_init(n);
+        }
+        buf.advance(n);
+        Poll::Ready(Ok(()))
+    }
+
+    /// Tries to receive a single datagram message on the socket from the remote
+    /// address to which it is connected. On success, returns the number of
+    /// bytes 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?;
+    ///
+    ///         // The buffer is **not** included in the async task and will
+    ///         // only exist on the stack.
+    ///         let mut buf = [0; 1024];
+    ///
+    ///         // Try to recv data, this may still fail with `WouldBlock`
+    ///         // if the readiness event is a false positive.
+    ///         match socket.try_recv(&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(&self, buf: &mut [u8]) -> io::Result<usize> {
+        self.io
+            .registration()
+            .try_io(Interest::READABLE, || self.io.recv(buf))
+    }
+
+    cfg_io_util! {
+        /// Tries 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)
+            })
+        }
+
+        /// Tries 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.
+    ///
+    /// Address type can be any implementor of [`ToSocketAddrs`] trait. See its
+    /// documentation for concrete examples.
+    ///
+    /// It is possible for `addr` to yield multiple addresses, but `send_to`
+    /// will only send data to the first address yielded by `addr`.
+    ///
+    /// This will return an error when the IP version of the local socket does
+    /// not match that returned from [`ToSocketAddrs`].
+    ///
+    /// [`ToSocketAddrs`]: crate::net::ToSocketAddrs
+    ///
+    /// # Cancel safety
+    ///
+    /// This method is cancel safe. If `send_to` is used as the event in a
+    /// [`tokio::select!`](crate::select) statement and some other branch
+    /// completes first, then it is guaranteed that the message was not sent.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// use std::io;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     let socket = UdpSocket::bind("127.0.0.1:8080").await?;
+    ///     let len = socket.send_to(b"hello world", "127.0.0.1:8081").await?;
+    ///
+    ///     println!("Sent {} bytes", len);
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    pub async fn send_to<A: ToSocketAddrs>(&self, buf: &[u8], target: A) -> io::Result<usize> {
+        let mut addrs = to_socket_addrs(target).await?;
+
+        match addrs.next() {
+            Some(target) => self.send_to_addr(buf, target).await,
+            None => Err(io::Error::new(
+                io::ErrorKind::InvalidInput,
+                "no addresses to send data to",
+            )),
+        }
+    }
+
+    /// Attempts to send data on the socket to a given address.
+    ///
+    /// Note that on multiple calls to a `poll_*` method in the send direction, only the
+    /// `Waker` from the `Context` passed to the most recent call will be scheduled to
+    /// receive a wakeup.
+    ///
+    /// # Return value
+    ///
+    /// The function returns:
+    ///
+    /// * `Poll::Pending` if the socket is not ready to write
+    /// * `Poll::Ready(Ok(n))` `n` is the number of bytes sent.
+    /// * `Poll::Ready(Err(e))` if an error is encountered.
+    ///
+    /// # Errors
+    ///
+    /// This function may encounter any standard I/O error except `WouldBlock`.
+    pub fn poll_send_to(
+        &self,
+        cx: &mut Context<'_>,
+        buf: &[u8],
+        target: SocketAddr,
+    ) -> Poll<io::Result<usize>> {
+        self.io
+            .registration()
+            .poll_write_io(cx, || self.io.send_to(buf, target))
+    }
+
+    /// Tries to send data on the socket to the given address, but if the send is
+    /// blocked this will return right away.
+    ///
+    /// This function is usually paired with `writable()`.
+    ///
+    /// # Returns
+    ///
+    /// If successful, returns the number of bytes sent
+    ///
+    /// Users should ensure that when the remote cannot receive, the
+    /// [`ErrorKind::WouldBlock`] is properly handled. An error can also occur
+    /// if the IP version of the socket does not match that of `target`.
+    ///
+    /// [`ErrorKind::WouldBlock`]: std::io::ErrorKind::WouldBlock
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// use std::error::Error;
+    /// use std::io;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> Result<(), Box<dyn Error>> {
+    ///     let socket = UdpSocket::bind("127.0.0.1:8080").await?;
+    ///
+    ///     let dst = "127.0.0.1:8081".parse()?;
+    ///
+    ///     loop {
+    ///         socket.writable().await?;
+    ///
+    ///         match socket.try_send_to(&b"hello world"[..], dst) {
+    ///             Ok(sent) => {
+    ///                 println!("sent {} bytes", sent);
+    ///                 break;
+    ///             }
+    ///             Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
+    ///                 // Writable false positive.
+    ///                 continue;
+    ///             }
+    ///             Err(e) => return Err(e.into()),
+    ///         }
+    ///     }
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    pub fn try_send_to(&self, buf: &[u8], target: SocketAddr) -> io::Result<usize> {
+        self.io
+            .registration()
+            .try_io(Interest::WRITABLE, || self.io.send_to(buf, target))
+    }
+
+    async fn send_to_addr(&self, buf: &[u8], target: SocketAddr) -> io::Result<usize> {
+        self.io
+            .registration()
+            .async_io(Interest::WRITABLE, || self.io.send_to(buf, target))
+            .await
+    }
+
+    /// Receives 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.
+    ///
+    /// # Cancel safety
+    ///
+    /// This method is cancel safe. If `recv_from` is used as the event in a
+    /// [`tokio::select!`](crate::select) statement and some other branch
+    /// completes first, it is guaranteed that no messages were received on this
+    /// socket.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// use std::io;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     let socket = UdpSocket::bind("127.0.0.1:8080").await?;
+    ///
+    ///     let mut buf = vec![0u8; 32];
+    ///     let (len, addr) = socket.recv_from(&mut buf).await?;
+    ///
+    ///     println!("received {:?} bytes from {:?}", len, addr);
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    pub async fn recv_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
+        self.io
+            .registration()
+            .async_io(Interest::READABLE, || self.io.recv_from(buf))
+            .await
+    }
+
+    /// Attempts to receive a single datagram on the socket.
+    ///
+    /// Note that on multiple calls to a `poll_*` method in the recv direction, only the
+    /// `Waker` from the `Context` passed to the most recent call will be scheduled to
+    /// receive a wakeup.
+    ///
+    /// # Return value
+    ///
+    /// The function returns:
+    ///
+    /// * `Poll::Pending` if the socket is not ready to read
+    /// * `Poll::Ready(Ok(addr))` reads data from `addr` into `ReadBuf` if the socket is ready
+    /// * `Poll::Ready(Err(e))` if an error is encountered.
+    ///
+    /// # Errors
+    ///
+    /// This function may encounter any standard I/O error except `WouldBlock`.
+    pub fn poll_recv_from(
+        &self,
+        cx: &mut Context<'_>,
+        buf: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<SocketAddr>> {
+        let (n, addr) = ready!(self.io.registration().poll_read_io(cx, || {
+            // Safety: will not read the maybe uninitialized bytes.
+            let b = unsafe {
+                &mut *(buf.unfilled_mut() as *mut [std::mem::MaybeUninit<u8>] as *mut [u8])
+            };
+
+            self.io.recv_from(b)
+        }))?;
+
+        // Safety: We trust `recv` to have filled up `n` bytes in the buffer.
+        unsafe {
+            buf.assume_init(n);
+        }
+        buf.advance(n);
+        Poll::Ready(Ok(addr))
+    }
+
+    /// Tries 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?;
+    ///
+    ///         // The buffer is **not** included in the async task and will
+    ///         // only exist on the stack.
+    ///         let mut buf = [0; 1024];
+    ///
+    ///         // Try to recv data, this may still fail with `WouldBlock`
+    ///         // if the readiness event is a false positive.
+    ///         match socket.try_recv_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_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
+        self.io
+            .registration()
+            .try_io(Interest::READABLE, || self.io.recv_from(buf))
+    }
+
+    /// Tries to read or write from the socket using a user-provided IO operation.
+    ///
+    /// If the socket is ready, the provided closure is called. The closure
+    /// should attempt to perform IO operation from the socket by manually
+    /// calling the appropriate syscall. If the operation fails because the
+    /// socket is not actually ready, then the closure should return a
+    /// `WouldBlock` error and the readiness flag is cleared. The return value
+    /// of the closure is then returned by `try_io`.
+    ///
+    /// If the socket is not ready, then the closure is not called
+    /// and a `WouldBlock` error is returned.
+    ///
+    /// The closure should only return a `WouldBlock` error if it has performed
+    /// an IO operation on the socket that failed due to the socket not being
+    /// ready. Returning a `WouldBlock` error in any other situation will
+    /// incorrectly clear the readiness flag, which can cause the socket to
+    /// behave incorrectly.
+    ///
+    /// The closure should not perform the IO operation using any of the methods
+    /// defined on the Tokio `UdpSocket` type, as this will mess with the
+    /// readiness flag and can cause the socket to behave incorrectly.
+    ///
+    /// Usually, [`readable()`], [`writable()`] or [`ready()`] is used with this function.
+    ///
+    /// [`readable()`]: UdpSocket::readable()
+    /// [`writable()`]: UdpSocket::writable()
+    /// [`ready()`]: UdpSocket::ready()
+    pub fn try_io<R>(
+        &self,
+        interest: Interest,
+        f: impl FnOnce() -> io::Result<R>,
+    ) -> io::Result<R> {
+        self.io.registration().try_io(interest, f)
+    }
+
+    /// Receives data from the socket, without removing it from the input queue.
+    /// On success, returns the number of bytes read and the address from whence
+    /// the data came.
+    ///
+    /// # Notes
+    ///
+    /// On Windows, if the data is larger than the buffer specified, the buffer
+    /// is filled with the first part of the data, and peek_from returns the error
+    /// WSAEMSGSIZE(10040). The excess data is lost.
+    /// Make sure to always use a sufficiently large buffer to hold the
+    /// maximum UDP packet size, which can be up to 65536 bytes in size.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// use std::io;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     let socket = UdpSocket::bind("127.0.0.1:8080").await?;
+    ///
+    ///     let mut buf = vec![0u8; 32];
+    ///     let (len, addr) = socket.peek_from(&mut buf).await?;
+    ///
+    ///     println!("peeked {:?} bytes from {:?}", len, addr);
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    pub async fn peek_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
+        self.io
+            .registration()
+            .async_io(Interest::READABLE, || self.io.peek_from(buf))
+            .await
+    }
+
+    /// Receives data from the socket, without removing it from the input queue.
+    /// On success, returns the number of bytes read.
+    ///
+    /// # Notes
+    ///
+    /// Note that on multiple calls to a `poll_*` method in the recv direction, only the
+    /// `Waker` from the `Context` passed to the most recent call will be scheduled to
+    /// receive a wakeup
+    ///
+    /// On Windows, if the data is larger than the buffer specified, the buffer
+    /// is filled with the first part of the data, and peek returns the error
+    /// WSAEMSGSIZE(10040). The excess data is lost.
+    /// Make sure to always use a sufficiently large buffer to hold the
+    /// maximum UDP packet size, which can be up to 65536 bytes in size.
+    ///
+    /// # Return value
+    ///
+    /// The function returns:
+    ///
+    /// * `Poll::Pending` if the socket is not ready to read
+    /// * `Poll::Ready(Ok(addr))` reads data from `addr` into `ReadBuf` if the socket is ready
+    /// * `Poll::Ready(Err(e))` if an error is encountered.
+    ///
+    /// # Errors
+    ///
+    /// This function may encounter any standard I/O error except `WouldBlock`.
+    pub fn poll_peek_from(
+        &self,
+        cx: &mut Context<'_>,
+        buf: &mut ReadBuf<'_>,
+    ) -> Poll<io::Result<SocketAddr>> {
+        let (n, addr) = ready!(self.io.registration().poll_read_io(cx, || {
+            // Safety: will not read the maybe uninitialized bytes.
+            let b = unsafe {
+                &mut *(buf.unfilled_mut() as *mut [std::mem::MaybeUninit<u8>] as *mut [u8])
+            };
+
+            self.io.peek_from(b)
+        }))?;
+
+        // Safety: We trust `recv` to have filled up `n` bytes in the buffer.
+        unsafe {
+            buf.assume_init(n);
+        }
+        buf.advance(n);
+        Poll::Ready(Ok(addr))
+    }
+
+    /// Gets the value of the `SO_BROADCAST` option for this socket.
+    ///
+    /// For more information about this option, see [`set_broadcast`].
+    ///
+    /// [`set_broadcast`]: method@Self::set_broadcast
+    pub fn broadcast(&self) -> io::Result<bool> {
+        self.io.broadcast()
+    }
+
+    /// Sets the value of the `SO_BROADCAST` option for this socket.
+    ///
+    /// When enabled, this socket is allowed to send packets to a broadcast
+    /// address.
+    pub fn set_broadcast(&self, on: bool) -> io::Result<()> {
+        self.io.set_broadcast(on)
+    }
+
+    /// Gets the value of the `IP_MULTICAST_LOOP` option for this socket.
+    ///
+    /// For more information about this option, see [`set_multicast_loop_v4`].
+    ///
+    /// [`set_multicast_loop_v4`]: method@Self::set_multicast_loop_v4
+    pub fn multicast_loop_v4(&self) -> io::Result<bool> {
+        self.io.multicast_loop_v4()
+    }
+
+    /// Sets the value of the `IP_MULTICAST_LOOP` option for this socket.
+    ///
+    /// If enabled, multicast packets will be looped back to the local socket.
+    ///
+    /// # Note
+    ///
+    /// This may not have any affect on IPv6 sockets.
+    pub fn set_multicast_loop_v4(&self, on: bool) -> io::Result<()> {
+        self.io.set_multicast_loop_v4(on)
+    }
+
+    /// Gets the value of the `IP_MULTICAST_TTL` option for this socket.
+    ///
+    /// For more information about this option, see [`set_multicast_ttl_v4`].
+    ///
+    /// [`set_multicast_ttl_v4`]: method@Self::set_multicast_ttl_v4
+    pub fn multicast_ttl_v4(&self) -> io::Result<u32> {
+        self.io.multicast_ttl_v4()
+    }
+
+    /// Sets the value of the `IP_MULTICAST_TTL` option for this socket.
+    ///
+    /// Indicates the time-to-live value of outgoing multicast packets for
+    /// this socket. The default value is 1 which means that multicast packets
+    /// don't leave the local network unless explicitly requested.
+    ///
+    /// # Note
+    ///
+    /// This may not have any affect on IPv6 sockets.
+    pub fn set_multicast_ttl_v4(&self, ttl: u32) -> io::Result<()> {
+        self.io.set_multicast_ttl_v4(ttl)
+    }
+
+    /// Gets the value of the `IPV6_MULTICAST_LOOP` option for this socket.
+    ///
+    /// For more information about this option, see [`set_multicast_loop_v6`].
+    ///
+    /// [`set_multicast_loop_v6`]: method@Self::set_multicast_loop_v6
+    pub fn multicast_loop_v6(&self) -> io::Result<bool> {
+        self.io.multicast_loop_v6()
+    }
+
+    /// Sets the value of the `IPV6_MULTICAST_LOOP` option for this socket.
+    ///
+    /// Controls whether this socket sees the multicast packets it sends itself.
+    ///
+    /// # Note
+    ///
+    /// This may not have any affect on IPv4 sockets.
+    pub fn set_multicast_loop_v6(&self, on: bool) -> io::Result<()> {
+        self.io.set_multicast_loop_v6(on)
+    }
+
+    /// Gets the value of the `IP_TTL` option for this socket.
+    ///
+    /// For more information about this option, see [`set_ttl`].
+    ///
+    /// [`set_ttl`]: method@Self::set_ttl
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// # use std::io;
+    ///
+    /// # async fn dox() -> io::Result<()> {
+    /// let sock = UdpSocket::bind("127.0.0.1:8080").await?;
+    ///
+    /// println!("{:?}", sock.ttl()?);
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn ttl(&self) -> io::Result<u32> {
+        self.io.ttl()
+    }
+
+    /// Sets the value for the `IP_TTL` option on this socket.
+    ///
+    /// This value sets the time-to-live field that is used in every packet sent
+    /// from this socket.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use tokio::net::UdpSocket;
+    /// # use std::io;
+    ///
+    /// # async fn dox() -> io::Result<()> {
+    /// let sock = UdpSocket::bind("127.0.0.1:8080").await?;
+    /// sock.set_ttl(60)?;
+    ///
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn set_ttl(&self, ttl: u32) -> io::Result<()> {
+        self.io.set_ttl(ttl)
+    }
+
+    /// Executes an operation of the `IP_ADD_MEMBERSHIP` type.
+    ///
+    /// This function specifies a new multicast group for this socket to join.
+    /// The address must be a valid multicast address, and `interface` is the
+    /// address of the local interface with which the system should join the
+    /// multicast group. If it's equal to `INADDR_ANY` then an appropriate
+    /// interface is chosen by the system.
+    pub fn join_multicast_v4(&self, multiaddr: Ipv4Addr, interface: Ipv4Addr) -> io::Result<()> {
+        self.io.join_multicast_v4(&multiaddr, &interface)
+    }
+
+    /// Executes an operation of the `IPV6_ADD_MEMBERSHIP` type.
+    ///
+    /// This function specifies a new multicast group for this socket to join.
+    /// The address must be a valid multicast address, and `interface` is the
+    /// index of the interface to join/leave (or 0 to indicate any interface).
+    pub fn join_multicast_v6(&self, multiaddr: &Ipv6Addr, interface: u32) -> io::Result<()> {
+        self.io.join_multicast_v6(multiaddr, interface)
+    }
+
+    /// Executes an operation of the `IP_DROP_MEMBERSHIP` type.
+    ///
+    /// For more information about this option, see [`join_multicast_v4`].
+    ///
+    /// [`join_multicast_v4`]: method@Self::join_multicast_v4
+    pub fn leave_multicast_v4(&self, multiaddr: Ipv4Addr, interface: Ipv4Addr) -> io::Result<()> {
+        self.io.leave_multicast_v4(&multiaddr, &interface)
+    }
+
+    /// Executes an operation of the `IPV6_DROP_MEMBERSHIP` type.
+    ///
+    /// For more information about this option, see [`join_multicast_v6`].
+    ///
+    /// [`join_multicast_v6`]: method@Self::join_multicast_v6
+    pub fn leave_multicast_v6(&self, multiaddr: &Ipv6Addr, interface: u32) -> io::Result<()> {
+        self.io.leave_multicast_v6(multiaddr, interface)
+    }
+
+    /// Returns the value of the `SO_ERROR` option.
+    ///
+    /// # Examples
+    /// ```
+    /// use tokio::net::UdpSocket;
+    /// use std::io;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> io::Result<()> {
+    ///     // Create a socket
+    ///     let socket = UdpSocket::bind("0.0.0.0:8080").await?;
+    ///
+    ///     if let Ok(Some(err)) = socket.take_error() {
+    ///         println!("Got error: {:?}", err);
+    ///     }
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    pub fn take_error(&self) -> io::Result<Option<io::Error>> {
+        self.io.take_error()
+    }
+}
+
+impl TryFrom<std::net::UdpSocket> for UdpSocket {
+    type Error = io::Error;
+
+    /// Consumes stream, returning the tokio I/O object.
+    ///
+    /// This is equivalent to
+    /// [`UdpSocket::from_std(stream)`](UdpSocket::from_std).
+    fn try_from(stream: std::net::UdpSocket) -> Result<Self, Self::Error> {
+        Self::from_std(stream)
+    }
+}
+
+impl fmt::Debug for UdpSocket {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.io.fmt(f)
+    }
+}
+
+#[cfg(all(unix))]
+mod sys {
+    use super::UdpSocket;
+    use std::os::unix::prelude::*;
+
+    impl AsRawFd for UdpSocket {
+        fn as_raw_fd(&self) -> RawFd {
+            self.io.as_raw_fd()
+        }
+    }
+}
+
+#[cfg(windows)]
+mod sys {
+    use super::UdpSocket;
+    use std::os::windows::prelude::*;
+
+    impl AsRawSocket for UdpSocket {
+        fn as_raw_socket(&self) -> RawSocket {
+            self.io.as_raw_socket()
+        }
+    }
+}