Python多进程同步Lock、Semaphore、Event实例

同步的方法基本与多线程相同。

1) Lock

当多个进程需要访问共享资源的时候，Lock可以用来避免访问的冲突。

复制代码 代码如下:

import multiprocessing
import sys

def worker_with(lock, f):
with lock:
fs = open(f,"a+")
fs.write('Lock acquired via with\n')
fs.close()

def worker_no_with(lock, f):
lock.acquire()
try:
fs = open(f,"a+")
fs.write('Lock acquired directly\n')
fs.close()
finally:
lock.release()

if name == "main":

f = "file.txt"  

lock = multiprocessing.Lock()  
w = multiprocessing.Process(target=worker_with, args=(lock, f))  
nw = multiprocessing.Process(target=worker_no_with, args=(lock, f))

w.start()  
nw.start()

w.join()  
nw.join()