| 34 | |
| 35 | |
| 36 | class _NixFileLock(AbstractFileLock): |
| 37 | |
| 38 | def __init__(self, path): |
| 39 | super(_NixFileLock, self).__init__(path) |
| 40 | from fcntl import flock, LOCK_EX, LOCK_UN, LOCK_NB |
| 41 | |
| 42 | self._locker = lambda lock, blocking: flock(lock, LOCK_EX if blocking else LOCK_EX | LOCK_NB) |
| 43 | self._unlocker = lambda lock: flock(lock, LOCK_UN) |
| 44 | # nonbuffered random access rw mode |
| 45 | self._lock = os.fdopen(os.open(self.path, os.O_RDWR | os.O_CREAT | os_O_CLOEXEC), 'r+b', 0) |
| 46 | |
| 47 | def acquire(self, blocking=True): |
| 48 | import errno |
| 49 | |
| 50 | try: |
| 51 | self._locker(self._lock, blocking) |
| 52 | except IOError as e: |
| 53 | if e.errno in (errno.EAGAIN, errno.EACCES) and not blocking: |
| 54 | return False |
| 55 | raise |
| 56 | return True |
| 57 | |
| 58 | def release(self): |
| 59 | self._unlocker(self._lock) |
| 60 | |
| 61 | def __del__(self): |
| 62 | if hasattr(self, "_lock"): |
| 63 | self._lock.close() |
| 64 | |
| 65 | |
| 66 | class _WinFileLock(AbstractFileLock): |