python Event事件、进程池与线程池、协程解析

from threading import Eventfrom threading import Threadimport time# 调用Event实例化出对象e = Event()## # 若该方法出现在任务中，则为False，阻塞# e.wait() # False# # 若该方法出现在任务中，则将其他线程的False改为True，进入就绪态和运行态# e.set() # Truedef light(): print('红灯亮...') time.sleep(5) # 应该发出信号，告诉其他线程准备执行 e.set() # 将car中的False变为True print('绿灯亮...')def car(name): print('正在等红灯...') # 让所有汽车任务进入阻塞态 e.wait() # False print(f'{name}正在加速飘逸...')# 让一个light线程控制多个car线程t = Thread(target=light)t.start()for i in range(10): t = Thread(target=car, args=(f'汽车{i}号', )) t.start()

from concurrent.futures import ThreadPoolExecutorimport timepool = ThreadPoolExecutor(5) # 5代表只能开启5个进程, 不加默认使用cpu的进程数# ThreadPoolExecutor(5) # 5代表只能开启5个线程# pool.submit() #异步提交任务， 括号里传函数地址def task(): print('线程任务开始了...') time.sleep(1) print('线程任务结束了...')for line in range(5): pool.submit(task)

from concurrent.futures import ThreadPoolExecutorimport timepool = ThreadPoolExecutor(5) # 5代表只能开启5个进程, 不加默认使用cpu的进程数# ThreadPoolExecutor(5) # 5代表只能开启5个线程# pool.submit() #异步提交任务， 括号里传函数地址def task(): print('线程任务开始了...') time.sleep(1) print('线程任务结束了...') return 123# 回调函数def call_back(res): print(type(res)) res2 = res.result() # 注意：赋值操作不要与接收的res同名 print(res2)for line in range(5): pool.submit(task).add_done_callback(call_back)

import timedef func1(): for i in range(10000000):  i+1def func2(): for i in range(10000000):  i+1start = time.time()func1()func2()stop = time.time()print(stop - start) # 1.0312113761901855# 基于yield实现并发 在计算密集型的情况下效率更低def func1(): while True:  10000000+1  yielddef func2(): g = func1() for i in range(10000000):  i+1  next(g) # 每次执行next相当于切换到func1下面start = time.time()func2()stop = time.time()print(stop - start) # 1.3294126987457275

import timefrom gevent import monkeymonkey.patch_all() # 可以监听该程序下所有的IO操作from gevent import spawn, joinall # 用于做切换 + 保存状态def func1(): print('1') time.sleep(1) # IO操作def func2(): print('2') time.sleep(3)def func3(): print('3') time.sleep(5)start = time.time()s1 = spawn(func1)s2 = spawn(func2)s3 = spawn(func3)s1.join() # 发送信号，相当于等待自己（在单线程的情况下）s2.join()s3.join()# joinall((s1, s2, s3)) # 一个个执行很麻烦，可以用joinall把这些全部装进去end = time.time()print(end - start) # 5.006161451339722

from gevent import monkeyfrom gevent import spawnimport socketmonkey.patch_all()server = socket.socket()server.bind(('127.0.0.1', 9999))server.listen(5)def task(conn): while True:  try:   data = conn.recv(1024)   if len(data) == 0:    break   print(data.decode('utf-8'))   send_data = data.upper()   conn.send(send_data)  except Exception:   break conn.close()def server2(): while True:  conn, addr = server.accept()  print(addr)  spawn(task, conn)if __name__ == '__main__': s = spawn(server2) s.join()

import socketfrom threading import Thread, current_threaddef client(): client = socket.socket() client.connect(('127.0.0.1', 9999)) number = 0 while True:  send_data = f'{current_thread().name} {number}'  client.send(send_data.encode('utf-8'))  data = client.recv(1024)  print(data.decode('utf-8'))  number += 1for i in range(400): t = Thread(target=client) t.start()