Python 线程（三）：Condition(条件变量)

　　　　条件变量是属于线程的高级应用，所以我们一般需要引入threading模块，而在条件变量中，最经典的例子，恐怕就是生产者与消费者的问题了。

　　Condition:  一个比Lock, RLock更高级的锁

　　wait:　　　 等待被唤醒

　　notify/notifyAll : 唤醒一个线程，或者唤醒所有线程

　　注意：Condition，在wait之前必须require

　　代码：

import threading
import time

class Buf:
    def __init__(self):

        self.cond = threading.Condition()
        self.data = []

    def isFull(self):
        return len(self.data) == 5

    def isEmpty(self):
        return len(self.data) == 0

    def get(self):

        self.cond.acquire()

        while self.isEmpty():
            self.cond.wait()

        temp = self.data.pop(0)

        self.cond.notify()
        self.cond.release()
        return temp

    def put(self, putInfo):
        self.cond.acquire()

        while self.isFull():
            self.cond.wait()

        self.data.append(putInfo)

        self.cond.notify()
        self.cond.release()


def Product(num):
    for i in range(num):
        info.put(i+1)
        print "Product %s
" % (str(i+1))

def Customer(id, num):
    for i in range(num):
        temp = info.get()
        print "Customer%s %s
" % (id, str(temp))

info = Buf();


if __name__ == "__main__":
    p = threading.Thread(target=Product, args=(10, ))
    c1 = threading.Thread(target=Customer, args=('A', 5))
    c2 = threading.Thread(target=Customer, args=('B', 5))

    p.start()
    time.sleep(1)
    c1.start()
    c2.start()

    p.join()
    c1.join()
    c2.join()

    print "Game Over"