PythonStudy——事件 Event

import time
from threading import Event, Thread

# import  time
#
# is_running = False
#
# def boot_server():
#     global is_running
#     print("Server is running ......")
#     time.sleep(2)
#     print("Server run successfully......")
#     is_running =True
#
# def connect_server():
#     while True:
#         if is_running:
#             print("连接服务器成功!!!")
#             break
#
#         else:
#             time.sleep(0.1)
#             print("error 服务器未启动!!!")

# t1 = Thread(target=boot_server)
# t1.start()
# # t1.join() # 此处要是没有join就会循环报错 ,因为服务器还没有成功启动
# t2 = Thread(target=connect_server)
# t2.start()


# 用上述例子引出Event
# 创建事件(服务器成功事件)
boot_event = Event()

def boot_server():
    print("正在启动服务器......")
    time.sleep(3)
    print("服务器启动成功......")
    # 标记事件已经发生
    boot_event.set()

def connect_server():
    # 等待事件发生
    boot_event.wait()
    print("连接服务器成功......")

t1 = Thread(target=boot_server)
t1.start()

t2 = Thread(target=connect_server)
t2.start()

# boot_event.clear() # 恢复事件的状态 为False
# boot_event.is_set() # 返回事件的状态
# boot_event.wait() # 等待事件的发生 等待事件的状态值被设置(set)成True
# boot_event.set() # 将事件的状态值设置为 True