Python的条件锁与事件共享详解

基本code
# 事件消息机制
import queue
import threading
import random
from threading import Event
from threading import Thread
class WriteThread(Thread):
  def __init__(self,q,wt,rt):
    super().__init__();
    self.queue=q;
    self.rt=rt;
    self.wt=wt;
  def run(self):
     self.rt.set()
     
     self.wt.wait();
     self.wt.clear();
     
class ReadThread(Thread):
  def __init__(self,q,wt,rt):
    super().__init__();
    self.queue=q;
    self.rt=rt;
    self.wt=wt;  
   def run(self):
     while True:
       self.rt.wait();
       self.wt.wait();
       self.wt.clear()

# -*- coding: utf-8 -*-
"""
Created on Tue Sep 10 20:10:10 2019

@author: DGW-PC
"""
# 事件消息机制
import queue
import threading
import random
from threading import Event
from threading import Thread

class WriteThread(Thread):
  def __init__(self,q,wt,rt):
    super().__init__();
    self.queue=q;
    self.rt=rt;
    self.wt=wt;
  def run(self):
    data=[random.randint(1,100) for _ in range(0,10)];
    self.queue.put(data);
    print("WriteThread写队列:",data);
    self.rt.set(); # 发送读事件
    print("WriteThread通知读");
    print("WriteThread等待写");
    self.wt.wait();
    print("WriteThread收到写事件");
    self.wt.clear();
class ReadThread(Thread):
  def __init__(self,q,wt,rt):
    super().__init__();
    self.queue=q;
    self.rt=rt;
    self.wt=wt;
  def run(self):
    while True:
      self.rt.wait();# 等待写事件 带来
      print("ReadThread 收到读事件");
      print("ReadThread 开始读{0}".format(self.queue.get()));
      print("ReadThread 发送写事件");
      self.wt.set();
      self.rt.clear();
q=queue.Queue();
rt=Event();
wt=Event();
writethread=WriteThread(q,wt,rt); # 实例化对象的
readthread=ReadThread(q,wt,rt);  # 实例化对象的

writethread.start();
readthread.start();

基本code
from threading import Thread
from threading import Condition
import random
import time
lock=Condition(); # 声明条件锁
flag=0;
def cnsumer():
  lock.acquire();
  while flag==0:
    lock.wait();
  
  业务代码---    
lock.relarse();
   
def product():
  lock.acquire();
  
  释放锁之前对控制变量进行操作，数据的操作控制 可以作为全局变量来锁定
  lock.notifyALl();
  lock.relarse();

# -*- coding: utf-8 -*-
"""
Created on Wed Sep 11 21:40:41 2019

@author: DGW-PC
"""
# 条件锁生产者消费者
from threading import Thread
from threading import Condition
import random
import time

flag=0; # 声明控制标志
goods=0; # 事物表示
lock=Condition();
def consumer(x):
  global flag;
  global goods;
  lock.acquire(); # 取得锁
  while flag==0: # 便于多次进行消费
     print("consumer %d进入等待" % x);
     lock.wait();
  print("consumer {0}:消费了{1}".format(x,goods));# format 次序从0开始
  flag-=1;
  lock.release(); #释放锁
  
def product(x):
  global flag;
  global goods;
  time.sleep(3);
  lock.acquire();
  goods=random.randint(1,1000);
  print("product {0} 产生了{1}".format(x,goods));
  flag+=1;
  lock.notifyAll();
  lock.release();

threads=[];

for i in range(0,2):
  t1=Thread(target=consumer,args=(i,));
  t2=Thread(target=product,args=(i,));
  t1.start();
  t2.start();
  threads.append(t1);
  threads.append(t2);

for x in threads:
  x.join();