Python实现进程同步和通信的方法

# -*- coding:utf-8 -*-
from multiprocessing import Process,Pool
import os,time

def run_proc(name):    ##定义一个函数用于进程调用
  for i in range(5):  
    time.sleep(0.2)  #休眠0.2秒
    print 'Run child process %s (%s)' % (name, os.getpid())
#执行一次该函数共需1秒的时间

if __name__ =='__main__': #执行主进程
  print 'Run the main process (%s).' % (os.getpid())
  mainStart = time.time() #记录主进程开始的时间
  p = Pool(8)      #开辟进程池
  for i in range(16):                 #开辟14个进程
    p.apply_async(run_proc,args=('Process'+str(i),))#每个进程都调用run_proc函数，
                            #args表示给该函数传递的参数。

  print 'Waiting for all subprocesses done ...'
  p.close() #关闭进程池
  p.join() #等待开辟的所有进程执行完后，主进程才继续往下执行
  print 'All subprocesses done'
  mainEnd = time.time() #记录主进程结束时间
  print 'All process ran %0.2f seconds.' % (mainEnd-mainStart) #主进程执行时间

Run the main process (36652). 
Waiting for all subprocesses done … 
Run child process Process0 (36708)Run child process Process1 (36748)

Run child process Process3 (36736) 
Run child process Process2 (36716) 
Run child process Process4 (36768)

# -*- coding:utf-8 -*-

lock = Lock()  #申明一个全局的lock对象
def run_proc(name):
  global lock   #引用全局锁
  for i in range(5):
    time.sleep(0.2)
    lock.acquire() #申请锁
    print 'Run child process %s (%s)' % (name, os.getpid())
    lock.release()  #释放锁

# -*- coding:utf-8 -*-
from multiprocessing import Process, Pool
import os
import time
L1 = [1, 2, 3]
def add(a, b):
  global L1
  L1 += range(a, b)
  print L1
if __name__ == '__main__':
  p1 = Process(target=add, args=(20, 30))
  p2 = Process(target=add, args=(30, 40))
  p1.start()
  p2.start()
  p1.join()
  p2.join()
  print L1

# -*- coding:utf-8 -*-
from multiprocessing import Process, Queue, Lock
L = [1, 2, 3]
def add(q, lock, a, b):
  lock.acquire() # 加锁避免写入时出现不可预知的错误
  L1 = range(a, b)
  lock.release()
  q.put(L1)
  print L1
if __name__ == '__main__':
  q = Queue()
  lock = Lock()
  p1 = Process(target=add, args=(q, lock, 20, 30))
  p2 = Process(target=add, args=(q, lock, 30, 40))
  p1.start()
  p2.start()
  p1.join()
  p2.join()
  L += q.get() + q.get()
  print L

# -*- coding:utf-8 -*-
from multiprocessing import Process, Pipe
def proc1(pipe):
  s = 'Hello,This is proc1'
  pipe.send(s)
def proc2(pipe):
  while True:
    print "proc2 recieve:", pipe.recv()
if __name__ == "__main__":
  pipe = Pipe()
  p1 = Process(target=proc1, args=(pipe[0],))
  p2 = Process(target=proc2, args=(pipe[1],))
  p1.start()
  p2.start()
  p1.join()
  p2.join(2)  #限制执行时间最多为2秒
  print '\nend all processes.'

# -*- coding:utf-8 -*-
from multiprocessing import Process, Pipe
def proc1(pipe):
  s = 'Hello,This is proc1'
  pipe.send(s)
def proc2(pipe):
  while True:
    print "proc2 recieve:", pipe.recv()
if __name__ == "__main__":
  pipe = Pipe(duplex=False)
  p1 = Process(target=proc1, args=(pipe[1],)) #pipe[1]为发送端
  p2 = Process(target=proc2, args=(pipe[0],)) #pipe[0]为接收端
  p1.start()
  p2.start()
  p1.join()
  p2.join(2) # 限制执行时间最多为2秒
  print '\nend all processes.' 

from multiprocessing import Process, Manager
def func(dt, lt):
  for i in range(10):
    key = 'arg' + str(i)
    dt[key] = i * i

  lt += range(11, 16)

if __name__ == "__main__":
  manager = Manager()
  dt = manager.dict()
  lt = manager.list()

  p = Process(target=func, args=(dt, lt))
  p.start()
  p.join()
  print dt, '\n', lt