os_pipe/
unix.rs

1use crate::PipeReader;
2use crate::PipeWriter;
3use libc::c_int;
4use std::fs::File;
5use std::io;
6use std::os::unix::prelude::*;
7
8// We need to atomically create pipes and set the CLOEXEC flag on them. This is
9// done with the pipe2() API. However, macOS doesn't support pipe2. There, all
10// we can do is call pipe() followed by fcntl(), and hope that no other threads
11// fork() in between. The following code is copied from the nix crate, where it
12// works but is deprecated.
13#[cfg(not(any(target_os = "aix", target_vendor = "apple", target_os = "haiku")))]
14fn pipe2_cloexec() -> io::Result<(OwnedFd, OwnedFd)> {
15    let mut fds: [c_int; 2] = [0; 2];
16    let res = unsafe { libc::pipe2(fds.as_mut_ptr(), libc::O_CLOEXEC) };
17    if res != 0 {
18        return Err(io::Error::last_os_error());
19    }
20    unsafe { Ok((OwnedFd::from_raw_fd(fds[0]), OwnedFd::from_raw_fd(fds[1]))) }
21}
22
23#[cfg(any(target_os = "aix", target_vendor = "apple", target_os = "haiku"))]
24fn pipe2_cloexec() -> io::Result<(OwnedFd, OwnedFd)> {
25    let mut fds: [c_int; 2] = [0; 2];
26    let res = unsafe { libc::pipe(fds.as_mut_ptr()) };
27    if res != 0 {
28        return Err(io::Error::last_os_error());
29    }
30    // Wrap the fds immediately, so that we'll drop them and close them in the unlikely event that
31    // any of the following fcntls fails.
32    let owned_fds = unsafe { (OwnedFd::from_raw_fd(fds[0]), OwnedFd::from_raw_fd(fds[1])) };
33    let res = unsafe { libc::fcntl(fds[0], libc::F_SETFD, libc::FD_CLOEXEC) };
34    if res != 0 {
35        return Err(io::Error::last_os_error());
36    }
37    let res = unsafe { libc::fcntl(fds[1], libc::F_SETFD, libc::FD_CLOEXEC) };
38    if res != 0 {
39        return Err(io::Error::last_os_error());
40    }
41    Ok(owned_fds)
42}
43
44pub(crate) fn pipe() -> io::Result<(PipeReader, PipeWriter)> {
45    let (read_fd, write_fd) = pipe2_cloexec()?;
46    Ok((read_fd.into(), write_fd.into()))
47}
48
49pub(crate) fn dup(handle: impl AsFd) -> io::Result<OwnedFd> {
50    handle.as_fd().try_clone_to_owned()
51}
52
53impl IntoRawFd for PipeReader {
54    fn into_raw_fd(self) -> RawFd {
55        self.0.into_raw_fd()
56    }
57}
58
59impl AsRawFd for PipeReader {
60    fn as_raw_fd(&self) -> RawFd {
61        self.0.as_raw_fd()
62    }
63}
64
65impl FromRawFd for PipeReader {
66    unsafe fn from_raw_fd(fd: RawFd) -> PipeReader {
67        unsafe { PipeReader(File::from_raw_fd(fd)) }
68    }
69}
70
71impl From<PipeReader> for OwnedFd {
72    fn from(pr: PipeReader) -> Self {
73        pr.0.into()
74    }
75}
76
77impl AsFd for PipeReader {
78    fn as_fd(&self) -> BorrowedFd<'_> {
79        self.0.as_fd()
80    }
81}
82
83impl From<OwnedFd> for PipeReader {
84    fn from(fd: OwnedFd) -> Self {
85        PipeReader(fd.into())
86    }
87}
88
89impl IntoRawFd for PipeWriter {
90    fn into_raw_fd(self) -> RawFd {
91        self.0.into_raw_fd()
92    }
93}
94
95impl AsRawFd for PipeWriter {
96    fn as_raw_fd(&self) -> RawFd {
97        self.0.as_raw_fd()
98    }
99}
100
101impl FromRawFd for PipeWriter {
102    unsafe fn from_raw_fd(fd: RawFd) -> PipeWriter {
103        unsafe { PipeWriter(File::from_raw_fd(fd)) }
104    }
105}
106
107impl From<PipeWriter> for OwnedFd {
108    fn from(pw: PipeWriter) -> Self {
109        pw.0.into()
110    }
111}
112
113impl AsFd for PipeWriter {
114    fn as_fd(&self) -> BorrowedFd<'_> {
115        self.0.as_fd()
116    }
117}
118
119impl From<OwnedFd> for PipeWriter {
120    fn from(fd: OwnedFd) -> Self {
121        PipeWriter(fd.into())
122    }
123}
os_pipe/unix.rs

os_pipe/
unix.rs
