rustix/backend/linux_raw/event/
poll_fd.rs

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1use crate::fd::{AsFd, BorrowedFd};
2use bitflags::bitflags;
3
4bitflags! {
5    /// `POLL*` flags for use with [`poll`].
6    ///
7    /// [`poll`]: crate::event::poll
8    #[repr(transparent)]
9    #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
10    pub struct PollFlags: u16 {
11        /// `POLLIN`
12        const IN = linux_raw_sys::general::POLLIN as u16;
13        /// `POLLPRI`
14        const PRI = linux_raw_sys::general::POLLPRI as u16;
15        /// `POLLOUT`
16        const OUT = linux_raw_sys::general::POLLOUT as u16;
17        /// `POLLRDNORM`
18        const RDNORM = linux_raw_sys::general::POLLRDNORM as u16;
19        /// `POLLWRNORM`
20        const WRNORM = linux_raw_sys::general::POLLWRNORM as u16;
21        /// `POLLRDBAND`
22        const RDBAND = linux_raw_sys::general::POLLRDBAND as u16;
23        /// `POLLWRBAND`
24        const WRBAND = linux_raw_sys::general::POLLWRBAND as u16;
25        /// `POLLERR`
26        const ERR = linux_raw_sys::general::POLLERR as u16;
27        /// `POLLHUP`
28        const HUP = linux_raw_sys::general::POLLHUP as u16;
29        /// `POLLNVAL`
30        const NVAL = linux_raw_sys::general::POLLNVAL as u16;
31        /// `POLLRDHUP`
32        const RDHUP = linux_raw_sys::general::POLLRDHUP as u16;
33
34        /// <https://docs.rs/bitflags/*/bitflags/#externally-defined-flags>
35        const _ = !0;
36    }
37}
38
39/// `struct pollfd`—File descriptor and flags for use with [`poll`].
40///
41/// [`poll`]: crate::event::poll
42#[doc(alias = "pollfd")]
43#[repr(C)]
44#[derive(Debug, Clone)]
45pub struct PollFd<'fd> {
46    pub(crate) fd: BorrowedFd<'fd>,
47    pub(crate) events: u16,
48    pub(crate) revents: u16,
49}
50
51impl<'fd> PollFd<'fd> {
52    /// Constructs a new `PollFd` holding `fd` and `events`.
53    #[inline]
54    pub fn new<Fd: AsFd>(fd: &'fd Fd, events: PollFlags) -> Self {
55        Self::from_borrowed_fd(fd.as_fd(), events)
56    }
57
58    /// Sets the contained file descriptor to `fd`.
59    #[inline]
60    pub fn set_fd<Fd: AsFd>(&mut self, fd: &'fd Fd) {
61        self.fd = fd.as_fd();
62    }
63
64    /// Clears the ready events.
65    #[inline]
66    pub fn clear_revents(&mut self) {
67        self.revents = 0;
68    }
69
70    /// Constructs a new `PollFd` holding `fd` and `events`.
71    ///
72    /// This is the same as `new`, but can be used to avoid borrowing the
73    /// `BorrowedFd`, which can be tricky in situations where the `BorrowedFd`
74    /// is a temporary.
75    #[inline]
76    pub fn from_borrowed_fd(fd: BorrowedFd<'fd>, events: PollFlags) -> Self {
77        Self {
78            fd,
79            events: events.bits(),
80            revents: 0,
81        }
82    }
83
84    /// Returns the ready events.
85    #[inline]
86    pub fn revents(&self) -> PollFlags {
87        // Use `.unwrap()` here because in theory we know we know all the bits
88        // the OS might set here, but OS's have added extensions in the past.
89        PollFlags::from_bits(self.revents).unwrap()
90    }
91}
92
93impl<'fd> AsFd for PollFd<'fd> {
94    #[inline]
95    fn as_fd(&self) -> BorrowedFd<'_> {
96        self.fd.as_fd()
97    }
98}
rustix/backend/linux_raw/event/poll_fd.rs

rustix/backend/linux_raw/event/
poll_fd.rs
