Python装饰器限制函数运行时间超时则退出执行

# coding=utf-8
import signal
import time
def set_timeout(num, callback):
  def wrap(func):
    def handle(signum, frame): # 收到信号 SIGALRM 后的回调函数，第一个参数是信号的数字，第二个参数是the interrupted stack frame.
      raise RuntimeError
    def to_do(*args, **kwargs):
      try:
        signal.signal(signal.SIGALRM, handle) # 设置信号和回调函数
        signal.alarm(num) # 设置 num 秒的闹钟
        print('start alarm signal.')
        r = func(*args, **kwargs)
        print('close alarm signal.')
        signal.alarm(0) # 关闭闹钟
        return r
      except RuntimeError as e:
        callback()
    return to_do
  return wrap
def after_timeout(): # 超时后的处理函数
  print("Time out!")
@set_timeout(2, after_timeout) # 限时 2 秒超时
def connect(): # 要执行的函数
  time.sleep(3) # 函数执行时间，写大于2的值，可测试超时
  print('Finished without timeout.')
if __name__ == '__main__':
  connect()

# -*- coding: utf-8 -*-
from threading import Thread
import time
class TimeoutException(Exception):
  pass
ThreadStop = Thread._Thread__stop
def timelimited(timeout):
  def decorator(function):
    def decorator2(*args,**kwargs):
      class TimeLimited(Thread):
        def __init__(self,_error= None,):
          Thread.__init__(self)
          self._error = _error
        def run(self):
          try:
            self.result = function(*args,**kwargs)
          except Exception,e:
            self._error = str(e)
        def _stop(self):
          if self.isAlive():
            ThreadStop(self)
      t = TimeLimited()
      t.start()
      t.join(timeout)
      if isinstance(t._error,TimeoutException):
        t._stop()
        raise TimeoutException('timeout for %s' % (repr(function)))
      if t.isAlive():
        t._stop()
        raise TimeoutException('timeout for %s' % (repr(function)))
      if t._error is None:
        return t.result
    return decorator2
  return decorator
@timelimited(2) # 设置运行超时时间2S
def fn_1(secs):
  time.sleep(secs)
  return 'Finished without timeout'
def do_something_after_timeout():
  print('Time out!')
if __name__ == "__main__":
  try:
    print(fn_1(3)) # 设置函数执行3S
  except TimeoutException as e:
    print(str(e))
    do_something_after_timeout()