vendor/rustix/src/backend/libc/io/poll_fd.rs

   1 use super::super::c;
   2 use super::super::conv::borrowed_fd;
   3 #[cfg(windows)]
   4 use super::super::fd::RawFd;
   5 use super::super::fd::{AsFd, AsRawFd, BorrowedFd, LibcFd};
   6 use bitflags::bitflags;
   7 use core::marker::PhantomData;
   8 #[cfg(windows)]
   9 use std::fmt;
  10
  11 bitflags! {
  12     /// `POLL*` flags for use with [`poll`].
  13     ///
  14     /// [`poll`]: crate::io::poll
  15     pub struct PollFlags: c::c_short {
  16         /// `POLLIN`
  17         const IN = c::POLLIN;
  18         /// `POLLPRI`
  19         #[cfg(not(target_os = "wasi"))]
  20         const PRI = c::POLLPRI;
  21         /// `POLLOUT`
  22         const OUT = c::POLLOUT;
  23         /// `POLLRDNORM`
  24         #[cfg(not(target_os = "redox"))]
  25         const RDNORM = c::POLLRDNORM;
  26         /// `POLLWRNORM`
  27         #[cfg(not(target_os = "redox"))]
  28         const WRNORM = c::POLLWRNORM;
  29         /// `POLLRDBAND`
  30         #[cfg(not(any(target_os = "redox", target_os = "wasi")))]
  31         const RDBAND = c::POLLRDBAND;
  32         /// `POLLWRBAND`
  33         #[cfg(not(any(target_os = "redox", target_os = "wasi")))]
  34         const WRBAND = c::POLLWRBAND;
  35         /// `POLLERR`
  36         const ERR = c::POLLERR;
  37         /// `POLLHUP`
  38         const HUP = c::POLLHUP;
  39         /// `POLLNVAL`
  40         const NVAL = c::POLLNVAL;
  41         /// `POLLRDHUP`
  42         #[cfg(all(
  43             any(target_os = "android", target_os = "linux"),
  44             not(any(target_arch = "sparc", target_arch = "sparc64"))),
  45         )]
  46         const RDHUP = c::POLLRDHUP;
  47     }
  48 }
  49
  50 /// `struct pollfd`—File descriptor and flags for use with [`poll`].
  51 ///
  52 /// [`poll`]: crate::io::poll
  53 #[doc(alias = "pollfd")]
  54 #[derive(Clone)]
  55 #[cfg_attr(not(windows), derive(Debug))]
  56 #[repr(transparent)]
  57 pub struct PollFd<'fd> {
  58     pollfd: c::pollfd,
  59     _phantom: PhantomData<BorrowedFd<'fd>>,
  60 }
  61
  62 #[cfg(windows)]
  63 impl<'fd> fmt::Debug for PollFd<'fd> {
  64     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
  65         fmt.debug_struct("pollfd")
  66             .field("fd", &self.pollfd.fd)
  67             .field("events", &self.pollfd.events)
  68             .field("revents", &self.pollfd.revents)
  69             .finish()
  70     }
  71 }
  72
  73 impl<'fd> PollFd<'fd> {
  74     /// Constructs a new `PollFd` holding `fd` and `events`.
  75     #[inline]
  76     pub fn new<Fd: AsFd>(fd: &'fd Fd, events: PollFlags) -> Self {
  77         Self::from_borrowed_fd(fd.as_fd(), events)
  78     }
  79
  80     /// Sets the contained file descriptor to `fd`.
  81     #[inline]
  82     pub fn set_fd<Fd: AsFd>(&mut self, fd: &'fd Fd) {
  83         self.pollfd.fd = fd.as_fd().as_raw_fd() as LibcFd;
  84     }
  85
  86     /// Clears the ready events.
  87     #[inline]
  88     pub fn clear_revents(&mut self) {
  89         self.pollfd.revents = 0;
  90     }
  91
  92     /// Constructs a new `PollFd` holding `fd` and `events`.
  93     ///
  94     /// This is the same as `new`, but can be used to avoid borrowing the
  95     /// `BorrowedFd`, which can be tricky in situations where the `BorrowedFd`
  96     /// is a temporary.
  97     #[inline]
  98     pub fn from_borrowed_fd(fd: BorrowedFd<'fd>, events: PollFlags) -> Self {
  99         Self {
 100             pollfd: c::pollfd {
 101                 fd: borrowed_fd(fd),
 102                 events: events.bits(),
 103                 revents: 0,
 104             },
 105             _phantom: PhantomData,
 106         }
 107     }
 108
 109     /// Returns the ready events.
 110     #[inline]
 111     pub fn revents(&self) -> PollFlags {
 112         // Use `unwrap()` here because in theory we know we know all the bits
 113         // the OS might set here, but OS's have added extensions in the past.
 114         PollFlags::from_bits(self.pollfd.revents).unwrap()
 115     }
 116 }
 117
 118 #[cfg(not(windows))]
 119 impl<'fd> AsFd for PollFd<'fd> {
 120     #[inline]
 121     fn as_fd(&self) -> BorrowedFd<'_> {
 122         // SAFETY: Our constructors and `set_fd` require `pollfd.fd` to be
 123         // valid for the `fd lifetime.
 124         unsafe { BorrowedFd::borrow_raw(self.pollfd.fd) }
 125     }
 126 }
 127
 128 #[cfg(windows)]
 129 impl<'fd> io_lifetimes::AsSocket for PollFd<'fd> {
 130     #[inline]
 131     fn as_socket(&self) -> BorrowedFd<'_> {
 132         // SAFETY: Our constructors and `set_fd` require `pollfd.fd` to be
 133         // valid for the `fd lifetime.
 134         unsafe { BorrowedFd::borrow_raw(self.pollfd.fd as RawFd) }
 135     }
 136 }