python 多线程笔记（4）-- 车站售票模拟

import threading
import time
import random

class Worker(threading.Thread):
'''售票员'''
def __init__(self, wait_num=5, index=0):
super().__init__()
self.wait_num = wait_num          # 当前排队人数
self.setName('窗口' + str(index)) # 窗口号

def run(self):
global counter, mutex

while counter and self.wait_num: # 若有余票且有人排队
# ============================
# 窗口问询
# ============================
time.sleep(random.randrange(2,10)) # 比较耗时，时间随机

# ============================
# 出票
# ============================
mutex.acquire()         # 锁住①
if counter == 0:        # 如果票数为0
mutex.release()     # 解锁③ -----> 这句很重要！！！
print(self.getName(), '：抱歉，票已售完')
break

counter = counter - 1   # 票数减一
print('{}：当前余票 {} 张'.format(self.getName(), counter))
mutex.release()         # 解锁③

# ============================
# 排队人数变化
# ============================
self.wait_num -= 1                      # 排队人数减一
self.wait_num += random.randrange(0,2)  # 排队人数随机增加

if __name__ == '__main__':
# 剩余车票数
counter = 20

# 创建锁
mutex = threading.Lock()

# 开4个售票窗口
workers = []
for i in range(4):
wait_num = random.randrange(2,10) # 窗口前排队人数随机
workers.append(Worker(wait_num, i+1))

# 开始售票
for w in workers:
w.start()

# 阻塞主程/后台静默？自己选
#for w in workers:
#    w.join()