from multiprocessing import Pool
import os,timedef Foo(i):
time.sleep(2)
print("in process",os.getpid())
return i +100def Bar(arg):
print('-->exec done',arg,os.getpid())if __name__ == "__main__":
pool =Pool(2)#允许进程池同时放入5个
print("主进程",os.getpid())
for i in range(10):
pool.apply_async(func=Foo,args=(i,),callback=Bar)#callback回调执行完func才会执行callback,callback是主进程执行的,作用是连接一次,而子进程需要每次都需要重新连接
#pool.apply()串行 pool.apply_async()并行
print("end")
pool.close()
pool.join()#进程池中进程执行完毕后在关闭,如果注释,那么程序直接关闭