python基于mysql实现的简单队列以及跨进程锁

#!/usr/bin/env python2.7 # # -*- coding:utf-8 -*- # # Author : yunjianfei # E-mail : yunjianfei@126.com # Date : 2014/02/25 # Desc : # import logging, time import MySQLdb class Glock: def __init__(self, db): self.db = db def _execute(self, sql): cursor = self.db.cursor() try: ret = None cursor.execute(sql) if cursor.rowcount != 1: logging.error("Multiple rows returned in mysql lock function.") ret = None else: ret = cursor.fetchone() cursor.close() return ret except Exception, ex: logging.error("Execute sql \"%s\" failed! Exception: %s", sql, str(ex)) cursor.close() return None def lock(self, lockstr, timeout): sql = "SELECT GET_LOCK(‘%s‘, %s)" % (lockstr, timeout) ret = self._execute(sql) if ret[0] == 0: logging.debug("Another client has previously locked ‘%s‘.", lockstr) return False elif ret[0] == 1: logging.debug("The lock ‘%s‘ was obtained successfully.", lockstr) return True else: logging.error("Error occurred!") return None def unlock(self, lockstr): sql = "SELECT RELEASE_LOCK(‘%s‘)" % (lockstr) ret = self._execute(sql) if ret[0] == 0: logging.debug("The lock ‘%s‘ the lock is not released(the lock was not established by this thread).", lockstr) return False elif ret[0] == 1: logging.debug("The lock ‘%s‘ the lock was released.", lockstr) return True else: logging.error("The lock ‘%s‘ did not exist.", lockstr) return None #Init logging def init_logging(): sh = logging.StreamHandler() logger = logging.getLogger() logger.setLevel(logging.DEBUG) formatter = logging.Formatter(‘%(asctime)s -%(module)s:%(filename)s-L%(lineno)d-%(levelname)s: %(message)s‘) sh.setFormatter(formatter) logger.addHandler(sh) logging.info("Current log level is : %s",logging.getLevelName(logger.getEffectiveLevel())) def main(): init_logging() db = MySQLdb.connect(host=‘localhost‘, user=‘root‘, passwd=‘‘) lock_name = ‘queue‘ l = Glock(db) ret = l.lock(lock_name, 10) if ret != True: logging.error("Can‘t get lock! exit!") quit() time.sleep(10) logging.info("You can do some synchronization work across processes!") ##TODO ## you can do something in here ## l.unlock(lock_name) if __name__ == "__main__": main()

[@tj-10-47 test]# ./glock.py 
2014-03-14 17:08:46,873 -glock:glock.py-L70-INFO: Current log level is : DEBUG
2014-03-14 17:08:50,299 -glock:glock.py-L43-DEBUG: The lock ‘queue‘ was obtained successfully.
2014-03-14 17:09:00,299 -glock:glock.py-L81-INFO: You can do some synchronization work across processes!
2014-03-14 17:09:00,300 -glock:glock.py-L56-DEBUG: The lock ‘queue‘ the lock was released.
[@tj-10-47 test]#