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|
#[cfg(unix)]
use std::{
os::fd::{AsRawFd, FromRawFd, OwnedFd, RawFd},
sync::Arc,
time::{Duration, Instant},
};
#[cfg(unix)]
pub(crate) fn duplicate_fd(fd: RawFd) -> std::io::Result<RawFd> {
let duplicated = unsafe { libc::dup(fd) };
if duplicated < 0 {
return Err(std::io::Error::last_os_error());
}
Ok(duplicated)
}
#[cfg(unix)]
pub(crate) fn set_cloexec(fd: RawFd) -> std::io::Result<()> {
let flags = unsafe { libc::fcntl(fd, libc::F_GETFD) };
if flags < 0 {
return Err(std::io::Error::last_os_error());
}
if unsafe { libc::fcntl(fd, libc::F_SETFD, flags | libc::FD_CLOEXEC) } < 0 {
return Err(std::io::Error::last_os_error());
}
Ok(())
}
#[cfg(unix)]
pub(crate) fn set_nonblocking(fd: RawFd) -> std::io::Result<()> {
let flags = unsafe { libc::fcntl(fd, libc::F_GETFL) };
if flags < 0 {
return Err(std::io::Error::last_os_error());
}
if unsafe { libc::fcntl(fd, libc::F_SETFL, flags | libc::O_NONBLOCK) } < 0 {
return Err(std::io::Error::last_os_error());
}
Ok(())
}
#[cfg(unix)]
pub(crate) fn duplicate_cloexec_fd(fd: RawFd) -> std::io::Result<RawFd> {
let duplicated = duplicate_fd(fd)?;
if let Err(err) = set_cloexec(duplicated) {
let _ = unsafe { libc::close(duplicated) };
return Err(err);
}
Ok(duplicated)
}
#[cfg(unix)]
#[derive(Clone)]
pub(crate) struct WakeWriter {
fd: Arc<OwnedFd>,
}
#[cfg(unix)]
impl WakeWriter {
pub(crate) fn wake(&self) -> std::io::Result<()> {
loop {
let byte = [1u8];
let written =
unsafe { libc::write(self.fd.as_raw_fd(), byte.as_ptr().cast(), byte.len()) };
if written >= 0 {
return Ok(());
}
let err = std::io::Error::last_os_error();
if err.kind() == std::io::ErrorKind::WouldBlock {
return Ok(());
}
if err.kind() != std::io::ErrorKind::Interrupted {
return Err(err);
}
}
}
}
#[cfg(unix)]
pub(crate) struct WakePipe {
pub(crate) read_fd: OwnedFd,
pub(crate) writer: WakeWriter,
}
#[cfg(unix)]
pub(crate) fn create_wake_pipe() -> std::io::Result<WakePipe> {
let mut fds = [-1; 2];
if unsafe { libc::pipe(fds.as_mut_ptr()) } < 0 {
return Err(std::io::Error::last_os_error());
}
let read_fd = unsafe { OwnedFd::from_raw_fd(fds[0]) };
let write_fd = unsafe { OwnedFd::from_raw_fd(fds[1]) };
for fd in [read_fd.as_raw_fd(), write_fd.as_raw_fd()] {
set_cloexec(fd).and_then(|_| set_nonblocking(fd))?;
}
Ok(WakePipe {
read_fd,
writer: WakeWriter {
fd: Arc::new(write_fd),
},
})
}
#[cfg(unix)]
pub(crate) fn drain_wake_fd(fd: RawFd) -> std::io::Result<()> {
let mut buf = [0u8; 64];
loop {
let read = unsafe { libc::read(fd, buf.as_mut_ptr().cast(), buf.len()) };
if read == 0 {
return Ok(());
}
if read > 0 {
continue;
}
let err = std::io::Error::last_os_error();
if err.kind() == std::io::ErrorKind::WouldBlock {
return Ok(());
}
if err.kind() != std::io::ErrorKind::Interrupted {
return Err(err);
}
}
}
#[cfg(unix)]
#[derive(Default)]
pub(crate) struct PtyWakeReadiness {
pub(crate) pty_read_ready: bool,
pub(crate) pty_write_ready: bool,
pub(crate) wake_ready: bool,
}
#[cfg(unix)]
pub(crate) fn poll_pty_and_wake(
pty_fd: RawFd,
wake_fd: RawFd,
poll_pty_read: bool,
poll_pty_write: bool,
timeout_ms: i32,
) -> std::io::Result<PtyWakeReadiness> {
let poll_pty = poll_pty_read || poll_pty_write;
let mut pty_events = 0;
if poll_pty_read {
pty_events |= libc::POLLIN;
}
if poll_pty_write {
pty_events |= libc::POLLOUT;
}
let mut poll_fds = [
libc::pollfd {
fd: if poll_pty { pty_fd } else { -1 },
events: pty_events,
revents: 0,
},
libc::pollfd {
fd: wake_fd,
events: libc::POLLIN,
revents: 0,
},
];
let deadline =
(timeout_ms >= 0).then(|| Instant::now() + Duration::from_millis(timeout_ms as u64));
let mut remaining_timeout_ms = timeout_ms;
loop {
for poll_fd in &mut poll_fds {
poll_fd.revents = 0;
}
let result = unsafe {
libc::poll(
poll_fds.as_mut_ptr(),
poll_fds.len() as _,
remaining_timeout_ms,
)
};
if result < 0 {
let err = std::io::Error::last_os_error();
if err.kind() == std::io::ErrorKind::Interrupted {
let Some(deadline) = deadline else {
continue;
};
let remaining = deadline.saturating_duration_since(Instant::now());
if remaining.is_zero() {
return Ok(PtyWakeReadiness::default());
}
remaining_timeout_ms = remaining.as_millis().clamp(1, i32::MAX as u128) as i32;
continue;
}
return Err(err);
}
let pty_revents = if poll_pty { poll_fds[0].revents } else { 0 };
let wake_revents = poll_fds[1].revents;
if (pty_revents | wake_revents) & libc::POLLNVAL != 0 {
return Err(std::io::Error::new(
std::io::ErrorKind::BrokenPipe,
"poll encountered invalid PTY actor fd",
));
}
if pty_revents & libc::POLLERR != 0 {
return Err(std::io::Error::new(
std::io::ErrorKind::BrokenPipe,
"poll encountered PTY fd error",
));
}
return Ok(PtyWakeReadiness {
pty_read_ready: pty_revents & (libc::POLLIN | libc::POLLHUP) != 0,
pty_write_ready: pty_revents & (libc::POLLOUT | libc::POLLHUP) != 0,
wake_ready: wake_revents & (libc::POLLIN | libc::POLLHUP | libc::POLLERR) != 0,
});
}
}
#[cfg(unix)]
pub(crate) fn resize_pty_fd(
fd: RawFd,
rows: u16,
cols: u16,
cell_width_px: u32,
cell_height_px: u32,
) -> std::io::Result<()> {
let size = libc::winsize {
ws_row: rows,
ws_col: cols,
ws_xpixel: (cols as u32)
.saturating_mul(cell_width_px)
.min(u16::MAX as u32) as u16,
ws_ypixel: (rows as u32)
.saturating_mul(cell_height_px)
.min(u16::MAX as u32) as u16,
};
if unsafe { libc::ioctl(fd, libc::TIOCSWINSZ, &size) } < 0 {
return Err(std::io::Error::last_os_error());
}
Ok(())
}
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