列出所有活动的多线程.Timer对象

Question

Is there a way to obtain a list of all the active threading.Timer objects in order to cancel all of them before exiting? Otherwise the program hangs to wait their completion.

I could keep a list of them, but then I also have to remove them when they fire. Instead I wanted to know if there was a way to obtain all of them.

Answer 1

threading.enumerate() returns a list that will include Timers that are Alive - they are instances of threading._Timer .

>>> t = threading.Timer(30, foo, kwargs = d)
>>> t.start()
>>> t.isAlive()
True
>>> for thing in threading.enumerate():
    if isinstance(thing, threading._Timer):
        thing.cancel()


>>> t.isAlive()
False
>>> 

Answer 2

If you just need to cancel the timers when exiting from the program, you can set the daemon flag for the timers and they will be killed on exit instead of waiting for their completion:

from threading import Timer
timer = Timer(10, fn)
timer.setDaemon(True)
timer.start()