标签：python 多进程
#!/usr/bin/python # -*- coding:utf-8 -*- from multiprocessing import Process import time, random, os # print(os.cpu_count()) # # # # 定义一个任务 # def piao(name): # print(‘%s is piaoing‘ % name) # time.sleep(3) # cpu阻塞，切换到主进程 # print(‘%s is piao end‘ % name) # # # if __name__ == ‘__main__‘: # # target指定执行目标，args指定位置参数，指定为元组，kwargs指定字典 # p1 = Process(target=piao, args=(‘lh‘,)，name=‘<p1>‘) # 产生对象 # # 创建子进程，赋值主进程地址空间，开启一个子进程,创建进程需要时间， # # 发送系统调用，只是一个系统调用，指挥操作系统启动子进 # # 程，主进程并不等待子进程 # p1.start() # 开启子进程 # # time.sleep(1) # # print(‘主进程‘) # # 谁先执行完谁先打印
class Piao(Process): def __init__(self, name): super().__init__() # 重用父类方法, self.name = name def run(self): # 方法名必须为run print(‘%s is piaoing...‘ % self.name) time.sleep(3) print(‘%s is piao end‘ % self.name) if __name__ == ‘__main__‘: p1 = Piao(‘lh‘) p1.start() # 相当于p1.run() print(‘主进程‘)
#!/usr/bin/python # -*- coding:utf-8 -*- # import threading, time # # v = 10 # # lock = threading.Lock() #只能有一个使用锁 # lock = threading.RLock() # 递归锁 # # # def task(arg): # time.sleep(2) # lock.accquire() # 申请使用锁，其他线程等待 # global v # v -= 1 # print(v) # lock.release() # 交还释放 # for i in range(10): # t = threading.Thread(target=task, args=(i,)) # t.start() # 多个人同时使用锁，一批批操作 # import threading, time # # v = 10 # # lock = threading.BoundedSemaphore(3) #同时三个使用该锁 # # lock = threading.RLock() # 递归锁 # # # def task(arg): # # lock.acquire() # 申请使用锁，其他线程等待 # time.sleep(1) # global v # v -= 1 # print(v) # lock.release() # 交还释放 # # for i in range(10): # t = threading.Thread(target=task, args=(i,)) # t.start() # 时间锁.解脱锁的限制 # import threading, time # # v = 10 # # lock = threading.Event() # 同时三个使用该锁 # # # # lock = threading.RLock() # 递归锁 # # # def task(arg): # time.sleep(1) # lock.wait() # 锁住多有线程 # print(arg) # # # for i in range(10): # t = threading.Thread(target=task, args=(i,)) # t.start() # # while True: # value = input(‘>>>‘) # if value == ‘1‘: # lock.set() # lock.clear() #想怎么锁就怎么锁 import threading, time v = 10 lock = threading.Condition() # 同时三个使用该锁 # lock = threading.RLock() # 递归锁 def task(arg): time.sleep(1) lock.acquire() lock.wait()# 锁住多有线程 print(arg) lock.release() for i in range(10): t = threading.Thread(target=task, args=(i,)) t.start() while True: value = input(‘>>>‘) lock.acquire() lock.notify(int(value)) lock.release()
from multiprocessing import Process import time, random # def piao(name): # print(‘%s is piaoing‘ % name) # time.sleep(random.randint(1, 3)) # print(‘%s is piao end‘ % name) # # # if __name__ == ‘__main__‘: # p1 = Process(target=piao, args=(‘egon‘,)) # p2 = Process(target=piao, args=(‘lh‘,)) # p3 = Process(target=piao, args=(‘apla‘,)) # p4 = Process(target=piao, args=(‘tom‘,)) # # # 开启顺序不一定，谁先执行完谁打印 # p1.start() # 不是阻塞操作，在发系统调用 # p2.start() # 不是阻塞操作，在发系统调用 # p3.start() # 不是阻塞操作，在发系统调用 # p4.start() # 不是阻塞操作，在发系统调用 # # # p1.join() # 主进程等待p1执行完毕，hold # # p1.join() # 主进程等待 # # p2.join() # # p3.join() # # p4.join() # p_l = [p1, p2, p3, p4] # for p in p_l: # p.start() # # for p in p_l: # p.join() # print(‘主进程‘) # 每次都是主进程先打印，原因是cpu性能低 # 守护进程 def piao(name): print(‘%s is piaoing‘ % name) time.sleep(random.randint(1, 3)) print(‘%s is piao end‘ % name) if __name__ == ‘__main__‘: p1 = Process(target=piao, args=(‘egon‘,)) p1.daemon = True # 主进程运行完成后子进程执行完也会被回收 p1.start() print(p1.pid) print(p1.name) print(p1.is_alive()) # True p1.terminate() # 把p1干掉，僵尸进程 time.sleep(0.5) print(p1.is_alive()) # False 不能立即干掉进程 print(‘主进程‘)
from multiprocessing import Process, Lock import json, time, random def work(dbfile, name, lock): # lock.acquire() # 加锁，谁先拿到，其他进程无法使用，加锁是并发，join是排队 with lock: # 上下文管理 with open(dbfile, encoding=‘utf-8‘) as f: dic = json.loads(f.read()) if dic[‘count‘] > 0: dic[‘count‘] -= 1 time.sleep(random.randint(1, 3)) # 模拟网络延迟 with open(dbfile, ‘w‘, encoding=‘utf-8‘) as f: f.write(json.dumps(dic)) print(‘%s抢票成功！！！‘ % name) else: print(‘%s抢票失败！！！‘ % name) # lock.release() # 锁要释放，不然其他的进程无法使用 if __name__ == ‘__main__‘: lock = Lock() p_l = [] for i in range(100): p = Process(target=work, args=(‘a.txt‘, ‘用户%s‘ % i, lock)) p_l.append(p) p.start() for p in p_l: p.join() print(‘主进程‘)
from multiprocessing import Process, JoinableQueue import random, time def consumer(q, name): while True: # time.sleep(random.randint(1, 3)) res = q.get() # 一直在取状态 q.task_done() # 执行完成 # if res is None: # break print(‘\033[41m消费者%s拿到%s\033[0m‘ % (name, res)) def producer(seq, q, name): for item in seq: # time.sleep(random.randint(1, 3)) q.put(item) print(‘\033[42m生产者%s拿到%s\033[0m‘ % (name, item)) # q.put(None) q.join() print(‘**************>>‘) # 本行执行说明生产者执行完成，消费者把所有任务执行 if __name__ == ‘__main__‘: q = JoinableQueue() c = Process(target=consumer, args=(q, ‘lh‘)) c.daemon=True #设置守护进程，朱金城结束，c就结束 c.start() seq = [‘包子%s‘ % i for i in range(10)] p = Process(target=producer, args=(seq, q, ‘厨师1‘)) p.start() # 生产者进程 p.join() # 主进程等待p结束，p等待c把数据取完，c一旦取完数据，p.join就不在阻塞，进而追进程结束 # ，主进程结束会回收守护进程c，而且此时c也没有存在的必要只要join生产者就行，生产者在等待消费者取走 # c.join() print(‘主进程‘) # [i for i in range(10)] 列表生成式 # [i for i in range(10) if i > 5] 列表生成式
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标签：python 多进程
原文地址：http://11870872.blog.51cto.com/11860872/1943642
