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