day 30

一.进程通信(IPC)

管道:
队列: 管道+锁
#管道
#队列=管道+锁
from multiprocessing import Queue

# q=Queue()
# q.put(['first',])
# q.put({'x':2})
# q.put(3)
# # q.put(4)
#
# print(q.get())
# print(q.get())
# print(q.get())
# print(q.get())

# 了解:
q=Queue(3)
# q.put(['first',],block=True,timeout=3)
# q.put({'x':2},block=True,timeout=3)
# q.put(3,block=True,timeout=3)
# q.put(4,block=True,timeout=3)

q.put_nowait(1) #q.put(1,block=False)
q.put_nowait(2)
q.put_nowait(3)
# q.put_nowait(4)

# print(q.get(block=True,timeout=3))
# print(q.get(block=True,timeout=3))
# print(q.get(block=True,timeout=3))
# print(q.get(block=True,timeout=3))

print(q.get_nowait()) #q.get(block=false)
print(q.get_nowait()) #q.get(block=false)
print(q.get_nowait()) #q.get(block=false)
print(q.get_nowait()) #q.get(block=false)

二.生产者与消费者模型

'''
1. 什么是生产者消费者模型
    生产者:代指生产数据的任务
    消费者:代指处理数据的任务
    该模型的工作方式:
        生产生产数据传递消费者处理

        实现方式:
            生产者---->队列<------消费者

2. 为何要用
    当程序中出现明细的两类任务,一类负责生产数据,一类负责处理数据
    就可以引入生产者消费者模型来实现生产者与消费者的解耦合,平衡生产能力与消费能力,从提升效率

3. 如何用
'''

'''
import time,random
from multiprocessing import Process,Queue

def producer(name,food,q):
    for i in range(3):
        res='%s%s' %(food,i)
        time.sleep(random.randint(1,3)) #模拟生产数据的时间
        q.put(res)
        print('厨师[%s]生产了<%s>' %(name,res))

def consumer(name,q):
    while True:
        res=q.get()
        if res is None:break
        time.sleep(random.randint(1,3)) #模拟处理数据的时间
        print('吃货[%s]吃了<%s>' %(name,res))

if __name__ == '__main__':
    q=Queue()
    # 生产者们
    p1=Process(target=producer,args=('小Egon','泔水',q))
    p2=Process(target=producer,args=('中Egon','屎包子',q))
    p3=Process(target=producer,args=('大Egon','腰子汤',q))
    # 消费者们
    c1=Process(target=consumer,args=('刘清正',q))
    c2=Process(target=consumer,args=('吴三江',q))

    p1.start()
    p2.start()
    p3.start()
    c1.start()
    c2.start()

    p1.join()
    p2.join()
    p3.join()
    q.put(None)
    q.put(None)
    print('主')
'''


import time,random
from multiprocessing import Process,JoinableQueue

def producer(name,food,q):
    for i in range(3):
        res='%s%s' %(food,i)
        time.sleep(random.randint(1,3)) #模拟生产数据的时间
        q.put(res)
        print('厨师[%s]生产了<%s>' %(name,res))

def consumer(name,q):
    while True:
        res=q.get()
        time.sleep(random.randint(1,3)) #模拟处理数据的时间
        print('吃货[%s]吃了<%s>' %(name,res))
        q.task_done()

if __name__ == '__main__':
    q=JoinableQueue()
    # 生产者们
    p1=Process(target=producer,args=('小Egon','泔水',q))
    p2=Process(target=producer,args=('中Egon','屎包子',q))
    p3=Process(target=producer,args=('大Egon','腰子汤',q))
    # 消费者们
    c1=Process(target=consumer,args=('刘清正',q))
    c2=Process(target=consumer,args=('吴三江',q))
    c1.daemon=True
    c2.daemon=True

    p1.start()
    p2.start()
    p3.start()
    c1.start()
    c2.start()

    p1.join()
    p2.join()
    p3.join()
    q.join() # 主进程等q结束,即q内数据被取干净了
    print('主')

三.线程理论:

1 什么是线程
    进程其实一个资源单位,而进程内的线程才是cpu上的执行单位
    线程其实指的就是代码的执行过程

2 为何要用线程
    线程vs进程
        1. 同一进程下的多个线程共享该进程内的资源
        2. 创建线程的开销要远远小于进程

四.开启线程的两种方式:

'''


from threading import Thread
import time

def task(name):
    print('%s is running' %name)
    time.sleep(2)
    print('%s is done' %name)

if __name__ == '__main__':
    t=Thread(target=task,args=('线程1',))
    t.start()
    print('主')

'''

from threading import Thread
import time

class Mythread(Thread):
    def run(self):
        print('%s is running' %self.name)
        time.sleep(2)
        print('%s is done' %self.name)

if __name__ == '__main__':
    t=Mythread()
    t.start()
    print('主')

五.线程的特性介绍:

# from threading import Thread
# import time
#
# n=100
# def task():
#     global n
#     n=0
#
# if __name__ == '__main__':
#     t=Thread(target=task)
#     t.start()
#     t.join()
#     print('主',n)


# from threading import Thread
# import time,os
#
# def task():
#     print('%s is running' %os.getpid())
#
# if __name__ == '__main__':
#     t=Thread(target=task)
#     t.start()
#     print('主',os.getpid())


from threading import Thread,active_count,current_thread
import time,os

def task():
    print('%s is running' %current_thread().name)
    time.sleep(2)

if __name__ == '__main__':
    t=Thread(target=task,)
    t.start()
    # t.join()
    # print('主',active_count())
    print('主',current_thread().name)

六.守护线程:

# from threading import Thread
# import time
#
# def task(name):
#     print('%s is running' %name)
#     time.sleep(2)
#     print('%s is done' %name)
#
# if __name__ == '__main__':
#     t=Thread(target=task,args=('线程1',))
#     t.daemon=True
#     t.start()
#     print('主')


from threading import Thread
from multiprocessing import Process
import time
def foo():
    print(123)
    time.sleep(1)
    print("end123")

def bar():
    print(456)
    time.sleep(3)
    print("end456")

if __name__ == '__main__':
    # t1=Thread(target=foo)
    # t2=Thread(target=bar)

    t1=Process(target=foo)
    t2=Process(target=bar)
    t1.daemon=True
    t1.start()
    t2.start()
    print("main-------")

    '''
    123
    main-------
    456
    end456
    '''

    '''
    main-------
    123
    456
    end456
    '''

    '''
    main-------
    456
    end456
    '''

七.线程互斥锁

from threading import Thread,Lock
import time

mutex=Lock()
n=100
def task():
    global n
    mutex.acquire()
    temp=n
    time.sleep(0.1)
    n=temp-1
    mutex.release()

if __name__ == '__main__':
    t_l=[]
    for i in range(100):
        t=Thread(target=task)
        t_l.append(t)
        t.start()

    for t in t_l:
        t.join()
    print(n)