标签：gre tar 多进程编程 接受 print close man pip end
1. 不能使用python自带的queue进行通信，不然无法接受到数据
from queue import Queue def producer(queue): queue.put("a") time.sleep(2) def consumer(queue): time.sleep(2) data = queue.get() print(data) if __name__ == "__main__": queue = Queue(10) my_producer = Process(target=producer, args=(queue,)) my_consumer = Process(target=consumer, args=(queue,)) my_producer.start() my_consumer.start() my_producer.join() my_consumer.join()
2. 必须使用multiprocessing中的Queue
import time from multiprocessing import Process, Queue, Pool, Manager, Pipe def producer(queue): queue.put("a") time.sleep(2) def consumer(queue): time.sleep(2) data = queue.get() print(data) if __name__ == "__main__": queue = Queue(10) my_producer = Process(target=producer, args=(queue,)) my_consumer = Process(target=consumer, args=(queue,)) my_producer.start() my_consumer.start() my_producer.join() my_consumer.join()
3. 全局变量不适用于多进程编程，可以使用与多线程编程
def producer(a): a += 100 time.sleep(2) def consumer(a): time.sleep(2) print(a) if __name__ == "__main__": a = 1 my_producer = Process(target=producer, args=(a,)) my_consumer = Process(target=consumer, args=(a,)) my_producer.start() my_consumer.start() my_producer.join() my_consumer.join()
4. multiprocessing中的queue不能用于pool进程池, pool中的进程间通信需要使用manager中的queue
def producer(queue): queue.put("a") time.sleep(2) def consumer(queue): time.sleep(2) data = queue.get() print(data) if __name__ == "__main__": queue = Manager().Queue(10) pool = Pool(2) pool.apply_async(producer, args=(queue,)) pool.apply_async(consumer, args=(queue,)) pool.close() pool.join()
5. 通过pipe实现进程间通信，pipe的性能高于queue，因为queque中加了锁
def producer(pipe): pipe.send("bobby") def consumer(pipe): print(pipe.recv()) if __name__ == "__main__": recevie_pipe, send_pipe = Pipe() #pipe只能适用于两个进程 my_producer= Process(target=producer, args=(send_pipe, )) my_consumer = Process(target=consumer, args=(recevie_pipe,)) my_producer.start() my_consumer.start() my_producer.join() my_consumer.join()
6. 多线程可以想用共享变量，但是必须使用Manager中的dict
def add_data(p_dict, key, value): p_dict[key] = value if __name__ == "__main__": progress_dict = Manager().dict() first_progress = Process(target=add_data, args=(progress_dict, "bobby1", 22)) second_progress = Process(target=add_data, args=(progress_dict, "bobby2", 23)) first_progress.start() second_progress.start() first_progress.join() second_progress.join() print(progress_dict)
标签：gre tar 多进程编程 接受 print close man pip end
原文地址：https://www.cnblogs.com/callyblog/p/11180960.html
