039条件变量同步(Condition)

也是锁，这个锁多加了wait(),notify()唤醒一个进程,notifyall()唤醒全部进程方法，创建的时候默认是Rlock类型的锁，可以设置为lock类型的，默认就ok

 from random import randint
 import threading
 import time

 class Producer(threading.Thread):
     def run(self):
         global L
         while True:
             val = randint(0,100)
             print('生产者',self.name,':append',str(val),L)
             if lock_con.acquire():
                 L.append(val)
                 lock_con.notify()
                 lock_con.release()
             time.sleep(3)

 class Consumer(threading.Thread):
     def run(self):
         global  L
         while True:
             lock_con.acquire()
             if len(L) == 0:
                 lock_con.wait()
             print('消费者',self.name,'delete',str(L[0]),L)
             del L[0]
             lock_con.release()
         time.sleep(0.5)

 if __name__ == '__main__':
     L = []
     lock_con = threading.Condition()
     threads = []
     for i in range(5):
         threads.append(Producer())
         threads.append(Consumer())
     for t in threads:
         t.start()
     for t in threads:
         t.join()

使用例子

###########java改编：单生产单消费

 import time
 import threading

 class Res:
     def __init__(self):
         self.flag = False
         self.count = 0
         self.product = ''

     def set(self,name):
         lock_con.acquire()
         if self.flag:
             lock_con.wait()
         time.sleep(0.00001)
         self.count += 1
         self.product = ''.join([name,'**',str(self.count)])
         self.message = ''.join([self.product,'__生产者__',str(threading.current_thread())])
         print(self.message)
         self.flag = True
         lock_con.notify()
         lock_con.release()

     def get_product(self):
         lock_con.acquire()
         time.sleep(0.00001)
         if not self.flag:
             lock_con.wait()
         self.message = ''.join([self.product,'__消费者__',str(threading.current_thread())])
         print(self.message)
         self.flag = False
         lock_con.notify()
         lock_con.release()

 class Producer(threading.Thread):
     def __init__(self,r):
         threading.Thread.__init__(self)
         self.r = r

     def run(self):
         for i in range(100):
             self.r.set('大白兔奶糖')

 class Consumer(threading.Thread):
     def __init__(self,r):
         threading.Thread.__init__(self)
         self.r = r

     def run(self):
         for i in range(100):
             self.r.get_product()

 if __name__ == '__main__':
     lock_con = threading.Condition()
     r = Res()
     c = Consumer(r)
     p = Producer(r)
     c.start()
     p.start()

单生产单消费

############多生产多消费

 import time
 import threading

 class Res:
     def __init__(self):
         self.flag = False
         self.count = 0
         self.product = ''

     def set(self,name):
         lock_con.acquire()
         while self.flag:
             lock_con.wait()
         time.sleep(0.00001)
         self.count += 1
         self.product = ''.join([name,'**',str(self.count)])
         self.message = ''.join([self.product,'__生产者__',str(threading.current_thread())])
         print(self.message)
         self.flag = True
         lock_con.notifyAll()
         lock_con.release()

     def get_product(self):
         lock_con.acquire()
         time.sleep(0.00001)
         while not self.flag:
             lock_con.wait()
         self.message = ''.join([self.product,'__消费者__',str(threading.current_thread())])
         print(self.message)
         self.flag = False
         lock_con.notifyAll()
         lock_con.release()

 class Producer(threading.Thread):
     def __init__(self,r):
         threading.Thread.__init__(self)
         self.r = r

     def run(self):
         for i in range(100):
             self.r.set('大白兔奶糖')

 class Consumer(threading.Thread):
     def __init__(self,r):
         threading.Thread.__init__(self)
         self.r = r

     def run(self):
         for i in range(100):
             self.r.get_product()

 if __name__ == '__main__':
     lock_con = threading.Condition()
     r = Res()
     l = []
     for i in range(5):
         l.append(Consumer(r))
     for i in range(5):
         l.append(Producer(r))
     for a in l:
         a.start()

多生产多消费

个人觉得例子理解是最好的，所以我学的东西一般使用例子