diff --git a/src/librustc_data_structures/flock.rs b/src/librustc_data_structures/flock.rs index 2a0139fa90d..d6fc552e661 100644 --- a/src/librustc_data_structures/flock.rs +++ b/src/librustc_data_structures/flock.rs @@ -12,13 +12,12 @@ use std::path::Path; cfg_if! { if #[cfg(unix)] { - use std::ffi::{CString, OsStr}; - use std::mem; use std::os::unix::prelude::*; + use std::fs::{File, OpenOptions}; #[derive(Debug)] pub struct Lock { - fd: libc::c_int, + _file: File, } impl Lock { @@ -27,63 +26,35 @@ cfg_if! { create: bool, exclusive: bool) -> io::Result { - let os: &OsStr = p.as_ref(); - let buf = CString::new(os.as_bytes()).unwrap(); - let open_flags = if create { - libc::O_RDWR | libc::O_CREAT + let file = OpenOptions::new() + .read(true) + .write(true) + .create(create) + .mode(libc::S_IRWXU as u32) + .open(p)?; + + let mut operation = if exclusive { + libc::LOCK_EX } else { - libc::O_RDWR + libc::LOCK_SH }; - - let fd = unsafe { - libc::open(buf.as_ptr(), open_flags, - libc::S_IRWXU as libc::c_int) - }; - - if fd < 0 { - return Err(io::Error::last_os_error()); + if !wait { + operation |= libc::LOCK_NB } - let lock_type = if exclusive { - libc::F_WRLCK - } else { - libc::F_RDLCK - }; - - let mut flock: libc::flock = unsafe { mem::zeroed() }; - flock.l_type = lock_type as libc::c_short; - flock.l_whence = libc::SEEK_SET as libc::c_short; - flock.l_start = 0; - flock.l_len = 0; - - let cmd = if wait { libc::F_SETLKW } else { libc::F_SETLK }; - let ret = unsafe { - libc::fcntl(fd, cmd, &flock) - }; + let ret = unsafe { libc::flock(file.as_raw_fd(), operation) }; if ret == -1 { let err = io::Error::last_os_error(); - unsafe { libc::close(fd); } Err(err) } else { - Ok(Lock { fd }) + Ok(Lock { _file: file }) } } } - impl Drop for Lock { - fn drop(&mut self) { - let mut flock: libc::flock = unsafe { mem::zeroed() }; - flock.l_type = libc::F_UNLCK as libc::c_short; - flock.l_whence = libc::SEEK_SET as libc::c_short; - flock.l_start = 0; - flock.l_len = 0; - - unsafe { - libc::fcntl(self.fd, libc::F_SETLK, &flock); - libc::close(self.fd); - } - } - } + // Note that we don't need a Drop impl to execute `flock(fd, LOCK_UN)`. Lock acquired by + // `flock` is associated with the file descriptor and closing the file release it + // automatically. } else if #[cfg(windows)] { use std::mem; use std::os::windows::prelude::*;