How to stop a specific Thread among others? - python-3.x

Question

I'm using threads for a project which look like this :
thread1 = Thread(target=function, args=('x','y',1,2))
thread2 = Thread(target=function, args=('a','b',1,2))
thread1.start()
thread2.start()
Everything is working but I wanted to add an option to my code. To kill my threads i'm currently using While X==True in my targeted function. So when I want to kill a Thread i have to pass While==False.
The issue is doing that kill all the threads who use this function.
So how can i kill only thread1 without doing the same for thread2 if both were running together and using the same targeted function ?
Thank you !
Below a simplified example of what i'm actually doing
def test_thread(freq):
starttime=time.time()
while RUN==True:
try:
if 1==1:
print('1')
sleep(freq - ((time.time() - starttime) % freq))
except Exception as Ex:
print(Ex)
pass
RUN = True
run_test = Thread(target=test_thread, args=(20))
run_test.start()

Answer 1

You could pass a different, mutable object as an argument to each of the two threads:
class Stopper:
def __init__(self):
self.flag = True
def ok_to_keep_going(self):
return self.flag
def stop_now(self):
self.flag = False
def test_thread(freq, stopper):
...
while stopper.ok_to_keep_going():
...
if __name__ == '__main__':
t1_stopper = Stopper()
t2_stopper = Stopper()
t1 = Thread(target=test_thread, args=(T1_FREQ, t1_stopper))
t2 = Thread(target=test_thread, args=(T2_FREQ, t2_stopper))
t1.start()
t2.start()
Now you can stop thread 1 by calling t1_stopper.stop_now(), or stop thread 2 by calling t2_stopper.stop_now()
Or, for fewer lines of code:
def test_thread(freq, stopper):
...
while stopper[0]:
...
if __name__ == '__main__':
t1_stopper = [True]
t2_stopper = [True]
t1 = Thread(target=test_thread, args=(T1_FREQ, t1_stopper))
t2 = Thread(target=test_thread, args=(T2_FREQ, t2_stopper))
t1.start()
t2.start()
Now you stop thread t1 by setting t1_stopper[0]=False.