不跨机器
import os
import time
import errno
class FileLockException(Exception):
pass
class FileLock(object):
def __init__(self, file_name, timeout=10, delay=.05):
self.is_locked = False
self.lockfile = os.path.join(os.getcwd(), '%s.lock' % file_name)
self.file_name = file_name
self.timeout = timeout
self.delay = delay
def acquire(self):
start_time = time.time()
while True:
try:
self.fd = os.open(self.lockfile, os.O_CREAT | os.O_EXCL | os.O_RDWR)
break
except OSError as e:
if e.errno != errno.EEXIST:
raise
if (time.time() - start_time) >= self.timeout:
raise FileLockException('Timeout')
time.sleep(self.delay)
self.is_locked = True
def release(self):
if self.is_locked:
os.close(self.fd)
os.unlink(self.lockfile)
self.is_locked = False
def __enter__(self):
if not self.is_locked:
self.acquire()
return self
def __exit__(self, type, value, traceback):
if self.is_locked:
self.release()
def __del__(self):
self.release()