多线程简介01--函数式和继承式实现多线程及互斥锁

• 一，函数与方法的区别
• 1，函数属于整一个文件，方法属于某一个类，方法是不可以离开类存在的
• 2，函数可以直接调用，方法必须用对象或类调用
• 注意：虽然函数属于整个文件，但是如果把函数写成类的声明中，不会被识别
• 3，函数与方法之间不能相互调用
• 二，方法的注意点
• 方法可以没有声明，只有实现（在企业开发中，强烈建议不能这么做）
• 方法只有声明，没有实现，会报错

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多线程
cpu:
程序：代码指令集合
进程：程序的执行过程
线程：指令执行的最小单位
线程安全                      慢      同步
非线程安全（线程不安全）      快      异步
锁？
线程锁-互斥锁 Lock     lock.acquire()   lock.release()
继承方式实现多线程
线程的状态（生命周期）
      创建状态---->就绪状态----->运行状态------>死亡状态
                         |          |
                        |-挂起状态-|

eg1

import threading
def demo(name):
    for i in range(10):
        print(name,i)
t1 = threading.Thread(target = demo, args = ("逍遥",))
t2 = threading.Thread(target = demo, args = ("雪花",))
t1.start()
t2.start()

eg2

import threading
import time
def run(name):
    for i in range(1,101):
        print(name,"跑了",i,"米")
        time.sleep(0.2)
t1 = threading.Thread(target = run, args = ("红",))
t2 = threading.Thread(target = run, args = ("蓝",))
t3 = threading.Thread(target = run, args = ("黄",))
t1.start()
t2.start()
t3.start()

eg3

import threading,time
list = []
def store(name):
    while True:
        list.append("方便面")
        print(name,"存了一袋方便面，仓库剩余方便面为：",len(list))
        time.sleep(1)
def take(name):
    while True:
        if len(list) == 0:
            time.sleep(1)
        else:
            list.pop()
            print(name,"取了一袋方便面，仓库剩余方便面为：",len(list))
        time.sleep(1.5)
t1 = threading.Thread(target = store, args = ("p1",))
t2 = threading.Thread(target = store, args = ("p2",))
t3 = threading.Thread(target = store, args = ("p3",))
t4 = threading.Thread(target = take, args = ("p4",))
t5 = threading.Thread(target = take, args = ("p5",))
t6 = threading.Thread(target = take, args = ("p6",))
t7 = threading.Thread(target = take, args = ("p7",))
t1.start()
t2.start()
t3.start()
t4.start()
t5.start()
t6.start()
t7.start()

eg3 error

import threading,time
list = []
for i in range(100):
    list.append("方便面")
def take(name):
    while len(list) > 0:
        time.sleep(0.1)
        list.pop()
        print(name,"取了一袋方便面，仓库剩余为：",len(list))
t1 = threading.Thread(target = take, args = ("p1",))
t2 = threading.Thread(target = take, args = ("p2",))
t3 = threading.Thread(target = take, args = ("p3",))
t1.start()
t2.start()
t3.start()

继承

import threading
class MyThread(threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self)
    def run(self):
        for i in range(100):
            print(i)
t1 = MyThread()
t2 = MyThread()
t1.start()
t2.start()

互斥锁

import threading,time
list = ["烤冷面"]
lock = threading.Lock()
def take():
    lock.acquire()
    time.sleep(1)
    while len(list) > 0:
        list.pop()
        print("取走一份")
    lock.release()
t1 = threading.Thread(target = take)
t2 = threading.Thread(target = take)
t3 = threading.Thread(target = take)
t1.start()
t2.start()
t3.start()