vendor/rustix/tests/io/poll.rs

   1 use rustix::fd::{AsFd, AsRawFd, FromRawFd, IntoRawFd, OwnedFd};
   2 #[cfg(not(windows))]
   3 use rustix::io::{poll, retry_on_intr};
   4 use rustix::io::{PollFd, PollFlags};
   5
   6 #[cfg(not(windows))]
   7 #[test]
   8 fn test_poll() {
   9     use rustix::io::{pipe, read, write};
  10
  11     // Create a pipe.
  12     let (reader, writer) = pipe().unwrap();
  13     let mut poll_fds = [PollFd::new(&reader, PollFlags::IN)];
  14     assert_eq!(poll_fds[0].as_fd().as_raw_fd(), reader.as_fd().as_raw_fd());
  15
  16     // `poll` should say there's nothing ready to be read from the pipe.
  17     let num = retry_on_intr(|| poll(&mut poll_fds, 0)).unwrap();
  18     assert_eq!(num, 0);
  19     assert!(poll_fds[0].revents().is_empty());
  20     assert_eq!(poll_fds[0].as_fd().as_raw_fd(), reader.as_fd().as_raw_fd());
  21
  22     // Write a byte to the pipe.
  23     assert_eq!(retry_on_intr(|| write(&writer, b"a")).unwrap(), 1);
  24
  25     // `poll` should now say there's data to be read.
  26     let num = retry_on_intr(|| poll(&mut poll_fds, -1)).unwrap();
  27     assert_eq!(num, 1);
  28     assert_eq!(poll_fds[0].revents(), PollFlags::IN);
  29     assert_eq!(poll_fds[0].as_fd().as_raw_fd(), reader.as_fd().as_raw_fd());
  30
  31     let mut temp = poll_fds[0].clone();
  32     assert_eq!(temp.revents(), PollFlags::IN);
  33     temp.clear_revents();
  34     assert!(temp.revents().is_empty());
  35
  36     // Read the byte from the pipe.
  37     let mut buf = [b'\0'];
  38     assert_eq!(retry_on_intr(|| read(&reader, &mut buf)).unwrap(), 1);
  39     assert_eq!(buf[0], b'a');
  40     assert_eq!(poll_fds[0].as_fd().as_raw_fd(), reader.as_fd().as_raw_fd());
  41
  42     // Poll should now say there's no more data to be read.
  43     let num = retry_on_intr(|| poll(&mut poll_fds, 0)).unwrap();
  44     assert_eq!(num, 0);
  45     assert!(poll_fds[0].revents().is_empty());
  46     assert_eq!(poll_fds[0].as_fd().as_raw_fd(), reader.as_fd().as_raw_fd());
  47 }
  48
  49 #[test]
  50 fn test_poll_fd_set_fd() {
  51     // Make up some file descriptors so that we can test that set_fd works.
  52     let a = unsafe { OwnedFd::from_raw_fd(777) };
  53     let mut poll_fd = PollFd::new(&a, PollFlags::empty());
  54     assert_eq!(poll_fd.as_fd().as_raw_fd(), 777);
  55
  56     let b = unsafe { OwnedFd::from_raw_fd(888) };
  57     poll_fd.set_fd(&b);
  58     assert_eq!(poll_fd.as_fd().as_raw_fd(), 888);
  59
  60     // Don't attempt to close our made-up file descriptors.
  61     let _ = a.into_raw_fd();
  62     let _ = b.into_raw_fd();
  63 }