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/// #[cfg(unix)]
45/// use mio::unix::SourceFd;
46/// #[cfg(target_os = "wasi")]
47/// use mio::wasi::SourceFd;
48///
49/// use std::os::fd::AsRawFd;
50/// use std::net::TcpListener;
51///
52/// // Bind a std listener
53/// let listener = TcpListener::bind("127.0.0.1:0")?;
54///
55/// let poll = Poll::new()?;
56///
57/// // Register the listener
58/// poll.registry().register(
59///     &mut SourceFd(&listener.as_raw_fd()),
60///     Token(0),
61///     Interest::READABLE)?;
62/// #     Ok(())
63/// # }
64/// ```
65///
66/// Implementing [`event::Source`] for a custom type backed by a [`RawFd`].
67///
68#[cfg_attr(all(feature = "os-poll", feature = "os-ext"), doc = "```")]
69#[cfg_attr(not(all(feature = "os-poll", feature = "os-ext")), doc = "```ignore")]
70/// use mio::{event, Interest, Registry, Token};
71/// #[cfg(unix)]
72/// use mio::unix::SourceFd;
73/// #[cfg(target_os = "wasi")]
74/// use mio::wasi::SourceFd;
75///
76/// use std::os::fd::RawFd;
77/// use std::io;
78///
79/// # #[allow(dead_code)]
80/// pub struct MyIo {
81///     fd: RawFd,
82/// }
83///
84/// impl event::Source for MyIo {
85///     fn register(&mut self, registry: &Registry, token: Token, interests: Interest)
86///         -> io::Result<()>
87///     {
88///         SourceFd(&self.fd).register(registry, token, interests)
89///     }
90///
91///     fn reregister(&mut self, registry: &Registry, token: Token, interests: Interest)
92///         -> io::Result<()>
93///     {
94///         SourceFd(&self.fd).reregister(registry, token, interests)
95///     }
96///
97///     fn deregister(&mut self, registry: &Registry) -> io::Result<()> {
98///         SourceFd(&self.fd).deregister(registry)
99///     }
100/// }
101/// ```
102#[derive(Debug)]
103pub struct SourceFd<'a>(pub &'a RawFd);
104
105impl<'a> event::Source for SourceFd<'a> {
106    fn register(
107        &mut self,
108        registry: &Registry,
109        token: Token,
110        interests: Interest,
111    ) -> io::Result<()> {
112        registry.selector().register(*self.0, token, interests)
113    }
114
115    fn reregister(
116        &mut self,
117        registry: &Registry,
118        token: Token,
119        interests: Interest,
120    ) -> io::Result<()> {
121        registry.selector().reregister(*self.0, token, interests)
122    }
123
124    fn deregister(&mut self, registry: &Registry) -> io::Result<()> {
125        registry.selector().deregister(*self.0)
126    }
127}
mio/sys/unix/sourcefd.rs

mio/sys/unix/
sourcefd.rs
