1 files changed, 116 insertions, 0 deletions
diff --git a/third_party/rust/mio/src/sys/unix/sourcefd.rs b/third_party/rust/mio/src/sys/unix/sourcefd.rs
new file mode 100644
index 0000000000..84e776d21d
--- /dev/null
+++ b/third_party/rust/mio/src/sys/unix/sourcefd.rs
@@ -0,0 +1,116 @@
+use crate::{event, Interest, Registry, Token};
+
+use std::io;
+use std::os::unix::io::RawFd;
+
+/// Adapter for [`RawFd`] providing an [`event::Source`] implementation.
+///
+/// `SourceFd` enables registering any type with an FD with [`Poll`].
+///
+/// While only implementations for TCP and UDP are provided, Mio supports
+/// registering any FD that can be registered with the underlying OS selector.
+/// `SourceFd` provides the necessary bridge.
+///
+/// Note that `SourceFd` takes a `&RawFd`. This is because `SourceFd` **does
+/// not** take ownership of the FD. Specifically, it will not manage any
+/// lifecycle related operations, such as closing the FD on drop. It is expected
+/// that the `SourceFd` is constructed right before a call to
+/// [`Registry::register`]. See the examples for more detail.
+///
+/// [`event::Source`]: ../event/trait.Source.html
+/// [`Poll`]: ../struct.Poll.html
+/// [`Registry::register`]: ../struct.Registry.html#method.register
+///
+/// # Examples
+///
+/// Basic usage.
+///
+#[cfg_attr(
+    all(feature = "os-poll", feature = "net", feature = "os-ext"),
+    doc = "```"
+)]
+#[cfg_attr(
+    not(all(feature = "os-poll", feature = "net", feature = "os-ext")),
+    doc = "```ignore"
+)]
+/// # use std::error::Error;
+/// # fn main() -> Result<(), Box<dyn Error>> {
+/// use mio::{Interest, Poll, Token};
+/// use mio::unix::SourceFd;
+///
+/// use std::os::unix::io::AsRawFd;
+/// use std::net::TcpListener;
+///
+/// // Bind a std listener
+/// let listener = TcpListener::bind("127.0.0.1:0")?;
+///
+/// let poll = Poll::new()?;
+///
+/// // Register the listener
+/// poll.registry().register(
+///     &mut SourceFd(&listener.as_raw_fd()),
+///     Token(0),
+///     Interest::READABLE)?;
+/// #     Ok(())
+/// # }
+/// ```
+///
+/// Implementing [`event::Source`] for a custom type backed by a [`RawFd`].
+///
+#[cfg_attr(all(feature = "os-poll", feature = "os-ext"), doc = "```")]
+#[cfg_attr(not(all(feature = "os-poll", feature = "os-ext")), doc = "```ignore")]
+/// use mio::{event, Interest, Registry, Token};
+/// use mio::unix::SourceFd;
+///
+/// use std::os::unix::io::RawFd;
+/// use std::io;
+///
+/// # #[allow(dead_code)]
+/// pub struct MyIo {
+///     fd: RawFd,
+/// }
+///
+/// impl event::Source for MyIo {
+///     fn register(&mut self, registry: &Registry, token: Token, interests: Interest)
+///         -> io::Result<()>
+///     {
+///         SourceFd(&self.fd).register(registry, token, interests)
+///     }
+///
+///     fn reregister(&mut self, registry: &Registry, token: Token, interests: Interest)
+///         -> io::Result<()>
+///     {
+///         SourceFd(&self.fd).reregister(registry, token, interests)
+///     }
+///
+///     fn deregister(&mut self, registry: &Registry) -> io::Result<()> {
+///         SourceFd(&self.fd).deregister(registry)
+///     }
+/// }
+/// ```
+#[derive(Debug)]
+pub struct SourceFd<'a>(pub &'a RawFd);
+
+impl<'a> event::Source for SourceFd<'a> {
+    fn register(
+        &mut self,
+        registry: &Registry,
+        token: Token,
+        interests: Interest,
+    ) -> io::Result<()> {
+        registry.selector().register(*self.0, token, interests)
+    }
+
+    fn reregister(
+        &mut self,
+        registry: &Registry,
+        token: Token,
+        interests: Interest,
+    ) -> io::Result<()> {
+        registry.selector().reregister(*self.0, token, interests)
+    }
+
+    fn deregister(&mut self, registry: &Registry) -> io::Result<()> {
+        registry.selector().deregister(*self.0)
+    }
+}