1 use crate::fd::{AsFd, BorrowedFd}; 2 use bitflags::bitflags; 3 4 bitflags! { 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)] 45 pub struct PollFd<'fd> { 46 pub(crate) fd: BorrowedFd<'fd>, 47 pub(crate) events: u16, 48 pub(crate) revents: u16, 49 } 50 51 impl<'fd> PollFd<'fd> { 52 /// Constructs a new `PollFd` holding `fd` and `events`. 53 #[inline] new<Fd: AsFd>(fd: &'fd Fd, events: PollFlags) -> Self54 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] set_fd<Fd: AsFd>(&mut self, fd: &'fd Fd)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] clear_revents(&mut self)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] from_borrowed_fd(fd: BorrowedFd<'fd>, events: PollFlags) -> Self76 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] revents(&self) -> PollFlags86 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 93 impl<'fd> AsFd for PollFd<'fd> { 94 #[inline] as_fd(&self) -> BorrowedFd<'_>95 fn as_fd(&self) -> BorrowedFd<'_> { 96 self.fd.as_fd() 97 } 98 } 99