1 files changed, 233 insertions, 0 deletions
diff --git a/tokio/src/net/unix/datagram.rs b/tokio/src/net/unix/datagram.rs
new file mode 100644
index 00000000..f9c47dec
--- /dev/null
+++ b/tokio/src/net/unix/datagram.rs
@@ -0,0 +1,233 @@
+use crate::net::util::PollEvented;
+
+use futures_core::ready;
+use futures_util::future::poll_fn;
+use std::convert::TryFrom;
+use std::fmt;
+use std::io;
+use std::net::Shutdown;
+use std::os::unix::io::{AsRawFd, RawFd};
+use std::os::unix::net::{self, SocketAddr};
+use std::path::Path;
+use std::task::{Context, Poll};
+
+/// An I/O object representing a Unix datagram socket.
+pub struct UnixDatagram {
+    io: PollEvented<mio_uds::UnixDatagram>,
+}
+
+impl UnixDatagram {
+    /// Creates a new `UnixDatagram` bound to the specified path.
+    pub fn bind<P>(path: P) -> io::Result<UnixDatagram>
+    where
+        P: AsRef<Path>,
+    {
+        let socket = mio_uds::UnixDatagram::bind(path)?;
+        UnixDatagram::new(socket)
+    }
+
+    /// Creates an unnamed pair of connected sockets.
+    ///
+    /// This function will create a pair of interconnected Unix sockets for
+    /// communicating back and forth between one another. Each socket will
+    /// be associated with the default event loop's handle.
+    pub fn pair() -> io::Result<(UnixDatagram, UnixDatagram)> {
+        let (a, b) = mio_uds::UnixDatagram::pair()?;
+        let a = UnixDatagram::new(a)?;
+        let b = UnixDatagram::new(b)?;
+
+        Ok((a, b))
+    }
+
+    /// Consumes a `UnixDatagram` in the standard library and returns a
+    /// nonblocking `UnixDatagram` from this crate.
+    ///
+    /// The returned datagram will be associated with the given event loop
+    /// specified by `handle` and is ready to perform I/O.
+    pub fn from_std(datagram: net::UnixDatagram) -> io::Result<UnixDatagram> {
+        let socket = mio_uds::UnixDatagram::from_datagram(datagram)?;
+        let io = PollEvented::new(socket)?;
+        Ok(UnixDatagram { io })
+    }
+
+    fn new(socket: mio_uds::UnixDatagram) -> io::Result<UnixDatagram> {
+        let io = PollEvented::new(socket)?;
+        Ok(UnixDatagram { io })
+    }
+
+    /// Creates a new `UnixDatagram` which is not bound to any address.
+    pub fn unbound() -> io::Result<UnixDatagram> {
+        let socket = mio_uds::UnixDatagram::unbound()?;
+        UnixDatagram::new(socket)
+    }
+
+    /// Connects the socket to the specified address.
+    ///
+    /// The `send` method may be used to send data to the specified address.
+    /// `recv` and `recv_from` will only receive data from that address.
+    pub fn connect<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
+        self.io.get_ref().connect(path)
+    }
+
+    /// Sends data on the socket to the socket's peer.
+    pub async fn send(&mut self, buf: &[u8]) -> io::Result<usize> {
+        poll_fn(|cx| self.poll_send_priv(cx, buf)).await
+    }
+
+    // Poll IO functions that takes `&self` are provided for the split API.
+    //
+    // They are not public because (taken from the doc of `PollEvented`):
+    //
+    // While `PollEvented` is `Sync` (if the underlying I/O type is `Sync`), the
+    // caller must ensure that there are at most two tasks that use a
+    // `PollEvented` instance concurrently. One for reading and one for writing.
+    // While violating this requirement is "safe" from a Rust memory model point
+    // of view, it will result in unexpected behavior in the form of lost
+    // notifications and tasks hanging.
+    pub(crate) fn poll_send_priv(
+        &self,
+        cx: &mut Context<'_>,
+        buf: &[u8],
+    ) -> Poll<io::Result<usize>> {
+        ready!(self.io.poll_write_ready(cx))?;
+
+        match self.io.get_ref().send(buf) {
+            Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
+                self.io.clear_write_ready(cx)?;
+                Poll::Pending
+            }
+            x => Poll::Ready(x),
+        }
+    }
+
+    /// Receives data from the socket.
+    pub async fn recv(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        poll_fn(|cx| self.poll_recv_priv(cx, buf)).await
+    }
+
+    pub(crate) fn poll_recv_priv(
+        &self,
+        cx: &mut Context<'_>,
+        buf: &mut [u8],
+    ) -> Poll<io::Result<usize>> {
+        ready!(self.io.poll_read_ready(cx, mio::Ready::readable()))?;
+
+        match self.io.get_ref().recv(buf) {
+            Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
+                self.io.clear_read_ready(cx, mio::Ready::readable())?;
+                Poll::Pending
+            }
+            x => Poll::Ready(x),
+        }
+    }
+
+    /// Sends data on the socket to the specified address.
+    pub async fn send_to<P>(&mut self, buf: &[u8], target: P) -> io::Result<usize>
+    where
+        P: AsRef<Path> + Unpin,
+    {
+        poll_fn(|cx| self.poll_send_to_priv(cx, buf, target.as_ref())).await
+    }
+
+    pub(crate) fn poll_send_to_priv(
+        &self,
+        cx: &mut Context<'_>,
+        buf: &[u8],
+        target: &Path,
+    ) -> Poll<io::Result<usize>> {
+        ready!(self.io.poll_write_ready(cx))?;
+
+        match self.io.get_ref().send_to(buf, target) {
+            Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
+                self.io.clear_write_ready(cx)?;
+                Poll::Pending
+            }
+            x => Poll::Ready(x),
+        }
+    }
+
+    /// Receives data from the socket.
+    pub async fn recv_from(&mut self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
+        poll_fn(|cx| self.poll_recv_from_priv(cx, buf)).await
+    }
+
+    pub(crate) fn poll_recv_from_priv(
+        &self,
+        cx: &mut Context<'_>,
+        buf: &mut [u8],
+    ) -> Poll<Result<(usize, SocketAddr), io::Error>> {
+        ready!(self.io.poll_read_ready(cx, mio::Ready::readable()))?;
+
+        match self.io.get_ref().recv_from(buf) {
+            Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
+                self.io.clear_read_ready(cx, mio::Ready::readable())?;
+                Poll::Pending
+            }
+            x => Poll::Ready(x),
+        }
+    }
+
+    /// Returns the local address that this socket is bound to.
+    pub fn local_addr(&self) -> io::Result<SocketAddr> {
+        self.io.get_ref().local_addr()
+    }
+
+    /// Returns the address of this socket's peer.
+    ///
+    /// The `connect` method will connect the socket to a peer.
+    pub fn peer_addr(&self) -> io::Result<SocketAddr> {
+        self.io.get_ref().peer_addr()
+    }
+
+    /// Returns the value of the `SO_ERROR` option.
+    pub fn take_error(&self) -> io::Result<Option<io::Error>> {
+        self.io.get_ref().take_error()
+    }
+
+    /// Shut down the read, write, or both halves of this connection.
+    ///
+    /// This function will cause all pending and future I/O calls on the
+    /// specified portions to immediately return with an appropriate value
+    /// (see the documentation of `Shutdown`).
+    pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
+        self.io.get_ref().shutdown(how)
+    }
+}
+
+impl TryFrom<UnixDatagram> for mio_uds::UnixDatagram {
+    type Error = io::Error;
+
+    /// Consumes value, returning the mio I/O object.
+    ///
+    /// See [`PollEvented::into_inner`] for more details about
+    /// resource deregistration that happens during the call.
+    ///
+    /// [`PollEvented::into_inner`]: crate::util::PollEvented::into_inner
+    fn try_from(value: UnixDatagram) -> Result<Self, Self::Error> {
+        value.io.into_inner()
+    }
+}
+
+impl TryFrom<net::UnixDatagram> for UnixDatagram {
+    type Error = io::Error;
+
+    /// Consumes stream, returning the tokio I/O object.
+    ///
+    /// This is equivalent to
+    /// [`UnixDatagram::from_std(stream)`](UnixDatagram::from_std).
+    fn try_from(stream: net::UnixDatagram) -> Result<Self, Self::Error> {
+        Self::from_std(stream)
+    }
+}
+
+impl fmt::Debug for UnixDatagram {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.io.get_ref().fmt(f)
+    }
+}
+
+impl AsRawFd for UnixDatagram {
+    fn as_raw_fd(&self) -> RawFd {
+        self.io.get_ref().as_raw_fd()
+    }
+}