最近在项目中遇到这一需求：

我需要一个函数工作，比如远程连接一个端口，远程读取文件等，但是我给的时间有限，比如，4秒钟如果你还没有读取完成或者连接成功，我就不等了，很可能对方已经宕机或者拒绝了。这样可以批量做一些事情而不需要一直等，浪费时间。

结合我的需求，我想到这种办法：

1、在主进程执行，调用一个进程执行函数，然后主进程sleep，等时间到了，就kill 执行函数的进程。

测试一个例子：

import time import threading def p(i): print i class task(threading.Thread): def __init__(self,fun,i): threading.Thread.__init__(self) self.fun = fun self.i = i self.thread_stop = False def run(self): while not self.thread_stop: self.fun(self.i) def stop(self): self.thread_stop = True def test(): thread1 = task(p,2) thread1.start() time.sleep(4) thread1.stop() return if __name__ == '__main__': test()

经过测试只定了4秒钟。

经过我的一番折腾，想到了join函数，这个函数式用来等待一个线程结束的，如果这个函数没有结束的话，那么，就会阻塞当前运行的程序。关键是，这个参数有一个可选参数：join([timeout]): 阻塞当前上下文环境的线程，直到调用此方法的线程终止或到达指定的timeout（可选参数）。

不多说了贴下面代码大家看下：

#!/usr/bin/env python #-*-coding:utf-8-*- ''''' author:cogbee time:2014-6-13 function:readme ''' import pdb import time import threading import os #pdb.set_trace() class task(threading.Thread): def __init__(self,ip): threading.Thread.__init__(self) self.ip = ip self.thread_stop = False def run(self): while not self.thread_stop: #//添加你要做的事情，如果成功了就设置一下<span style="font-family: Arial, Helvetica, sans-serif;">self.thread_stop变量。</span> [python] view plaincopy在CODE上查看代码片派生到我的代码片 if file != '': self.thread_stop = True def stop(self): self.thread_stop = True def test(eachline): global file list = [] for ip in eachline: thread1 = task(ip) thread1.start() thread1.join(3) if thread1.isAlive(): thread1.stop() continue #将可以读取的都存起来 if file != '': list.append(ip) print list if __name__ == '__main__': eachline = ['1.1.1.1','222.73.5.54'] test(eachline)

下面给大家分享我写的一段杀死线程的代码。

由于python线程没有提供abort方法，分享下面一段代码杀死线程：

import threading import inspect import ctypes def _async_raise(tid, exctype): """raises the exception, performs cleanup if needed""" if not inspect.isclass(exctype): raise TypeError("Only types can be raised (not instances)") res = ctypes.pythonapi.PyThreadState_SetAsyncExc(tid, ctypes.py_object(exctype)) if res == 0: raise ValueError("invalid thread id") elif res != 1: # """if it returns a number greater than one, you're in trouble, # and you should call it again with exc=NULL to revert the effect""" ctypes.pythonapi.PyThreadState_SetAsyncExc(tid, 0) raise SystemError("PyThreadState_SetAsyncExc failed")class Thread(threading.Thread): def _get_my_tid(self): """determines this (self's) thread id""" if not self.isAlive(): raise threading.ThreadError("the thread is not active") # do we have it cached? if hasattr(self, "_thread_id"): return self._thread_id # no, look for it in the _active dict for tid, tobj in threading._active.items(): if tobj is self: self._thread_id = tid return tid raise AssertionError("could not determine the thread's id")def raise_exc(self, exctype): """raises the given exception type in the context of this thread""" _async_raise(self._get_my_tid(), exctype)def terminate(self): """raises SystemExit in the context of the given thread, which should cause the thread to exit silently (unless caught)""" self.raise_exc(SystemExit)

使用例子：

>>> import time >>> from thread2 import Thread >>> >>> def f(): ... try: ... while True: ... time.sleep(0.1) ... finally: ... print "outta here" ... >>> t = Thread(target = f) >>> t.start() >>> t.isAlive() True >>> t.terminate() >>> t.join() outta here >>> t.isAlive() False

试了一下，很不错，只是在要kill的线程中如果有time.sleep()时，好像工作不正常，没有找出真正的原因是什么。已经是很强大了。哈哈。