python多进程全局共享counter（multiprocessing包实现）

 

 

# -*- coding: UTF-8 -*- 

from multiprocessing import Pool, Lock, Value
import os

tests_count = 80

lock = Lock()

counter = Value('i', 0) # int type，相当于java里面的原子变量


def run(fn):
    global tests_count, lock, counter
    with lock:
        counter.value += 1

    print 'NO. (%d/%d) test start. PID: %d ' %(counter.value, tests_count,  os.getpid())
    # do something below ...


if __name__ == "__main__":
    pool = Pool(10)
    # 80个任务，会运行run()80次，每次传入xrange数组一个元素
    pool.map(run, xrange(80))
    pool.close()
    pool.join()

 

输出：

NO. (1/80) test start. PID: 23785 

NO. (2/80) test start. PID: 23785 

NO. (3/80) test start. PID: 23786 

NO. (5/80) test start. PID: 23786 

...

NO. (77/80) test start. PID: 23785 

NO. (78/80) test start. PID: 23791 

NO. (79/80) test start. PID: 23786 

 

注意事项：

如果使用multiprocessing包，则要按照它的套路走，标准库threading包里面threading.Lock()、acquire()、release()这几个同步方法不生效了，因为Pool是多进程的。上面code可以直接run