基於 signal模塊實現:
signal包負責在Python程序內部處理信號,典型的操作包括預設信號處理函數,暫 停並等待信號,以及定時發出SIGALRM等。要注意,signal包主要是針對UNIX平臺(比如Linux, MAC OS),而Windows內核中由於對信號機制的支持不充分,所以在Windows上的Python不能發揮信號系統的功能。
# coding:utf8
import time
import signal
# 自定義超時異常
class TimeoutError(Exception):
def __init__(self, msg):
super(TimeoutError, self).__init__()
self.msg = msg
def time_out(interval, callback):
def decorator(func):
def handler(signum, frame):
raise TimeoutError("run func timeout")
def wrapper(*args, **kwargs):
try:
signal.signal(signal.SIGALRM, handler)
signal.alarm(interval) # interval秒後向進程發送SIGALRM信號
result = func(*args, **kwargs)
signal.alarm(0) # 函數在規定時間執行完後關閉alarm鬧鐘
return result
except TimeoutError, e:
callback(e)
return wrapper
return decorator
def timeout_callback(e):
print(e.msg)
@time_out(2, timeout_callback)
def task1():
print("task1 start")
time.sleep(3)
print("task1 end")
@time_out(2, timeout_callback)
def task2():
print("task2 start")
time.sleep(1)
print("task2 end")
if __name__ == "__main__":
task1()
task2()
輸出:
task1 start
run func timeout
task2 start
task2 end
基於子線程阻塞實現超時:
# coding:utf8
import time
import threading
def callback_func():
print('超時回調')
def time_out(interval, callback=None):
def decorator(func):
def wrapper(*args, **kwargs):
t =threading.Thread(target=func, args=args, kwargs=kwargs)
t.setDaemon(True) # 設置主線程技術子線程立刻結束
t.start()
t.join(interval) # 主線程阻塞等待interval秒
if t.is_alive() and callback:
return threading.Timer(0, callback).start() # 立即執行回調函數
else:
return
return wrapper
return decorator
@time_out(2, callback_func)
def task3(hh):
print('**********task3****************')
for i in range(3):
time.sleep(1)
print(i)
print(hh)
@time_out(2, callback_func)
def task4(hh):
print('**********task4****************')
for i in range(3):
# time.sleep(1)
print(i)
print(hh)
if __name__ == '__main__':
task3('參數')
task4('參數')
輸出:
**********task3****************
0
參數
1
參數
超時回調
**********task4****************
0
參數
1
參數
2
參數