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}
99