CODEWITHSUNDEEP
pythonmultithreading
Leonard Niehaus
Leonard Niehaus

Reputation: 530

Safely stop all running threads in Python

I'm using the example below to stop threads safely. But how do I stop all threads which are currently running, if I don't know exactly which threads are running?

class exampleThread(threading.Thread): 
    def __init__(self, name): 
        threading.Thread.__init__(self) 
        self.name = name

    def run(self): 
        try: 
            print('this thread is running')
            sleep(10)

        finally: 
            print('example thread ended') 

    def get_id(self): 
        if hasattr(self, '_thread_id'): 
            return self._thread_id 
        for id, thread in threading._active.items(): 
            if thread is self: 
                return id
    def raise_exception(self): 
        thread_id = self.get_id() 
        res = ctypes.pythonapi.PyThreadState_SetAsyncExc(thread_id, 
              ctypes.py_object(SystemExit)) 
        if res > 1: 
            ctypes.pythonapi.PyThreadState_SetAsyncExc(thread_id, 0) 
            print('Exception raise failure')


    example = exampleThread('example') 
    example.start()

Now my thread is running. But how do I kill multiple threads at the same time, without knowing if they are running and example is declared?

Upvotes: 1

Views: 446

Answers (1)

Mahmoud Elshahat
Mahmoud Elshahat

Reputation: 1959

To kill a thread safely let it listen to a signal, it could be internal variable or queue

here we defined a method called "kill()" it will set the variable "running" to False if you need to kill the thread 

import threading
from time import sleep

class exampleThread(threading.Thread): 
    def __init__(self, name): 
        threading.Thread.__init__(self) 
        self.name = name
        self.running=True

    def run(self): 
        try: 
            while self.running:  # watch for incoming kill signal
                print('this thread is running')
                sleep(1)

        finally: 
            print('example thread ended') 

    def kill(self):  # self kill safely
        self.running = False

    def get_id(self): 
        if hasattr(self, '_thread_id'): 
            return self._thread_id 
        for id, thread in threading._active.items(): 
            if thread is self: 
                return id
    def raise_exception(self): 
        thread_id = self.get_id() 
        res = ctypes.pythonapi.PyThreadState_SetAsyncExc(thread_id, 
              ctypes.py_object(SystemExit)) 
        if res > 1: 
            ctypes.pythonapi.PyThreadState_SetAsyncExc(thread_id, 0) 
            print('Exception raise failure')


example = exampleThread('example') 
example.start()

sleep(2)
# alive = example.isAlive()

example.kill()

Upvotes: 1

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