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