mio/sys/unix/
sourcefd.rs

1use std::io;
2#[cfg(not(target_os = "hermit"))]
3use std::os::fd::RawFd;
4// TODO: once <https://github.com/rust-lang/rust/issues/126198> is fixed this
5// can use `std::os::fd` and be merged with the above.
6#[cfg(target_os = "hermit")]
7use std::os::hermit::io::RawFd;
8
9use crate::{event, Interest, Registry, Token};
10
11/// Adapter for [`RawFd`] providing an [`event::Source`] implementation.
12///
13/// `SourceFd` enables registering any type with an FD with [`Poll`].
14///
15/// While only implementations for TCP and UDP are provided, Mio supports
16/// registering any FD that can be registered with the underlying OS selector.
17/// `SourceFd` provides the necessary bridge.
18///
19/// Note that `SourceFd` takes a `&RawFd`. This is because `SourceFd` **does
20/// not** take ownership of the FD. Specifically, it will not manage any
21/// lifecycle related operations, such as closing the FD on drop. It is expected
22/// that the `SourceFd` is constructed right before a call to
23/// [`Registry::register`]. See the examples for more detail.
24///
25/// [`event::Source`]: ../event/trait.Source.html
26/// [`Poll`]: ../struct.Poll.html
27/// [`Registry::register`]: ../struct.Registry.html#method.register
28///
29/// # Examples
30///
31/// Basic usage.
32///
33#[cfg_attr(
34    all(feature = "os-poll", feature = "net", feature = "os-ext"),
35    doc = "```"
36)]
37#[cfg_attr(
38    not(all(feature = "os-poll", feature = "net", feature = "os-ext")),
39    doc = "```ignore"
40)]
41/// # use std::error::Error;
42/// # fn main() -> Result<(), Box<dyn Error>> {
43/// use mio::{Interest, Poll, Token};
44/// use mio::unix::SourceFd;
45///
46/// use std::os::fd::AsRawFd;
47/// use std::net::TcpListener;
48///
49/// // Bind a std listener
50/// let listener = TcpListener::bind("127.0.0.1:0")?;
51///
52/// let poll = Poll::new()?;
53///
54/// // Register the listener
55/// poll.registry().register(
56///     &mut SourceFd(&listener.as_raw_fd()),
57///     Token(0),
58///     Interest::READABLE)?;
59/// #     Ok(())
60/// # }
61/// ```
62///
63/// Implementing [`event::Source`] for a custom type backed by a [`RawFd`].
64///
65#[cfg_attr(all(feature = "os-poll", feature = "os-ext"), doc = "```")]
66#[cfg_attr(not(all(feature = "os-poll", feature = "os-ext")), doc = "```ignore")]
67/// use mio::{event, Interest, Registry, Token};
68/// use mio::unix::SourceFd;
69///
70/// use std::os::fd::RawFd;
71/// use std::io;
72///
73/// # #[allow(dead_code)]
74/// pub struct MyIo {
75///     fd: RawFd,
76/// }
77///
78/// impl event::Source for MyIo {
79///     fn register(&mut self, registry: &Registry, token: Token, interests: Interest)
80///         -> io::Result<()>
81///     {
82///         SourceFd(&self.fd).register(registry, token, interests)
83///     }
84///
85///     fn reregister(&mut self, registry: &Registry, token: Token, interests: Interest)
86///         -> io::Result<()>
87///     {
88///         SourceFd(&self.fd).reregister(registry, token, interests)
89///     }
90///
91///     fn deregister(&mut self, registry: &Registry) -> io::Result<()> {
92///         SourceFd(&self.fd).deregister(registry)
93///     }
94/// }
95/// ```
96#[derive(Debug)]
97pub struct SourceFd<'a>(pub &'a RawFd);
98
99impl<'a> event::Source for SourceFd<'a> {
100    fn register(
101        &mut self,
102        registry: &Registry,
103        token: Token,
104        interests: Interest,
105    ) -> io::Result<()> {
106        registry.selector().register(*self.0, token, interests)
107    }
108
109    fn reregister(
110        &mut self,
111        registry: &Registry,
112        token: Token,
113        interests: Interest,
114    ) -> io::Result<()> {
115        registry.selector().reregister(*self.0, token, interests)
116    }
117
118    fn deregister(&mut self, registry: &Registry) -> io::Result<()> {
119        registry.selector().deregister(*self.0)
120    }
121}
mio/sys/unix/sourcefd.rs

mio/sys/unix/
sourcefd.rs
