from multiprocessing import Pool
import os, time, random
def long_time_task(name):
print('Run task %s (%s)...'%(name,os.getpid()))
start = time.time()
time.sleep(random.random()*3)
end = time.time()
print('Task %s runs %0.2f seconds.' %(name, (end-start)))
if __name__=='__main__':
print('parent process %s.',% os.getpid())
p=pool(4)
for i in range(5):
p.apply_asyn(long_time_task,args(i,))
print('Waiting for all subprocesses done...')
p.close()
p.join()
print('All subprocesses done.')
