对python周期性定时器的示例详解

#!/usr/bin/python
#coding:utf-8

import threading
import os
import sys

class _Timer(threading.Thread):
  def __init__(self, interval, function, args=[], kwargs={}):
    threading.Thread.__init__(self)
    self.interval = interval 
    self.function = function
    self.args = args
    self.kwargs = kwargs
    self.finished = threading.Event()

  def cancel(self):
    self.finished.set() 

  def run(self):
    self.finished.wait(self.interval) 
    if not self.finished.is_set():
      self.function(*self.args, **self.kwargs)
    self.finished.set()
    
class LoopTimer(_Timer):
  def __init__(self, interval, function, args=[], kwargs={}):
    _Timer.__init__(self, interval, function, args, kwargs)

  def run(self):
    while True:
      if not self.finished.is_set():
        self.finished.wait(self.interval)
        self.function(*self.args, **self.kwargs) 
      else:
        break


def testlooptimer():
  print("loop timer")


if __name__ == '__main__':
  t = LoopTimer(3.0,testlooptimer)
  t.start()

import py_timer

def serv_start():
#Perform first fork.
try:
      thread_timer = py_timer.LoopTimer(timeout, start_timer)
      thread_timer.start()
      thread_timer.cancel() #

    except Exception, ex:                            
      print("daemon: %s %s", type(ex), ex)



def start_timer():

print 'hello'