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python杀死一个线程的方法

2020-11-27 来源:化拓教育网

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self.thread_stop变量。 
[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。

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