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(
14    target_os = "aix",
15    target_os = "ios",
16    target_os = "visionos",
17    target_os = "macos",
18    target_os = "haiku"
19)))]
20fn pipe2_cloexec() -> io::Result<(OwnedFd, OwnedFd)> {
21    let mut fds: [c_int; 2] = [0; 2];
22    let res = unsafe { libc::pipe2(fds.as_mut_ptr(), libc::O_CLOEXEC) };
23    if res != 0 {
24        return Err(io::Error::last_os_error());
25    }
26    unsafe { Ok((OwnedFd::from_raw_fd(fds[0]), OwnedFd::from_raw_fd(fds[1]))) }
27}
28
29#[cfg(any(
30    target_os = "aix",
31    target_os = "ios",
32    target_os = "visionos",
33    target_os = "macos",
34    target_os = "haiku"
35))]
36fn pipe2_cloexec() -> io::Result<(OwnedFd, OwnedFd)> {
37    let mut fds: [c_int; 2] = [0; 2];
38    let res = unsafe { libc::pipe(fds.as_mut_ptr()) };
39    if res != 0 {
40        return Err(io::Error::last_os_error());
41    }
42    // Wrap the fds immediately, so that we'll drop them and close them in the unlikely event that
43    // any of the following fcntls fails.
44    let owned_fds = unsafe { (OwnedFd::from_raw_fd(fds[0]), OwnedFd::from_raw_fd(fds[1])) };
45    let res = unsafe { libc::fcntl(fds[0], libc::F_SETFD, libc::FD_CLOEXEC) };
46    if res != 0 {
47        return Err(io::Error::last_os_error());
48    }
49    let res = unsafe { libc::fcntl(fds[1], libc::F_SETFD, libc::FD_CLOEXEC) };
50    if res != 0 {
51        return Err(io::Error::last_os_error());
52    }
53    Ok(owned_fds)
54}
55
56pub(crate) fn pipe() -> io::Result<(PipeReader, PipeWriter)> {
57    let (read_fd, write_fd) = pipe2_cloexec()?;
58    Ok((read_fd.into(), write_fd.into()))
59}
60
61pub(crate) fn dup(handle: impl AsFd) -> io::Result<OwnedFd> {
62    handle.as_fd().try_clone_to_owned()
63}
64
65impl IntoRawFd for PipeReader {
66    fn into_raw_fd(self) -> RawFd {
67        self.0.into_raw_fd()
68    }
69}
70
71impl AsRawFd for PipeReader {
72    fn as_raw_fd(&self) -> RawFd {
73        self.0.as_raw_fd()
74    }
75}
76
77impl FromRawFd for PipeReader {
78    unsafe fn from_raw_fd(fd: RawFd) -> PipeReader {
79        unsafe { PipeReader(File::from_raw_fd(fd)) }
80    }
81}
82
83impl From<PipeReader> for OwnedFd {
84    fn from(pr: PipeReader) -> Self {
85        pr.0.into()
86    }
87}
88
89impl AsFd for PipeReader {
90    fn as_fd(&self) -> BorrowedFd<'_> {
91        self.0.as_fd()
92    }
93}
94
95impl From<OwnedFd> for PipeReader {
96    fn from(fd: OwnedFd) -> Self {
97        PipeReader(fd.into())
98    }
99}
100
101impl IntoRawFd for PipeWriter {
102    fn into_raw_fd(self) -> RawFd {
103        self.0.into_raw_fd()
104    }
105}
106
107impl AsRawFd for PipeWriter {
108    fn as_raw_fd(&self) -> RawFd {
109        self.0.as_raw_fd()
110    }
111}
112
113impl FromRawFd for PipeWriter {
114    unsafe fn from_raw_fd(fd: RawFd) -> PipeWriter {
115        unsafe { PipeWriter(File::from_raw_fd(fd)) }
116    }
117}
118
119impl From<PipeWriter> for OwnedFd {
120    fn from(pw: PipeWriter) -> Self {
121        pw.0.into()
122    }
123}
124
125impl AsFd for PipeWriter {
126    fn as_fd(&self) -> BorrowedFd<'_> {
127        self.0.as_fd()
128    }
129}
130
131impl From<OwnedFd> for PipeWriter {
132    fn from(fd: OwnedFd) -> Self {
133        PipeWriter(fd.into())
134    }
135}
os_pipe/unix.rs

os_pipe/
unix.rs
