systemlist.py 文件源码

def acquire_lock(path):
    """
        little tool to do EAGAIN until lockfile released
    :param path:
    :return: path
    """
    lock_file = open(path, 'w')
    while True:
        send_to_syslog("attempting to acquire lock %s" % path)
        try:
            fcntl.lockf(lock_file, fcntl.LOCK_EX | fcntl.LOCK_NB)
            send_to_syslog("acquired lock %s" % path)
            return lock_file
        except IOError as e:
            send_to_syslog("failed to acquire lock %s because '%s' - waiting 1 second" % (path, e))
            time.sleep(1)