lock.py 文件源码

def acquire(self):
        """Acquire the lock file.

        :raises errors.LockError: if lock is already held
        :raises OSError: if unable to open or stat the lock file

        """
        while self._fd is None:
            # Open the file
            fd = os.open(self._path, os.O_CREAT | os.O_WRONLY, 0o600)
            try:
                self._try_lock(fd)
                if self._lock_success(fd):
                    self._fd = fd
            finally:
                # Close the file if it is not the required one
                if self._fd is None:
                    os.close(fd)