How to break while loop based on events raised in a thread (Python 2.7)

I am using the below class1 code to detect some event through the method

check_for_the_event()
      # Some class1def check_for_the_event(self):
thread1 = threading.Timer(2, self.check_for_the_event)
thread1.start()# some processingif event is detected:
   self.event_ok = Trueelse:
   self.event_ok = False

then I pass an instance of that class to the below class to know when the
event is on or off and act upon its value accordingly using the following
below code:

              # execution of other part of the program (where
self.another_class_instance.event_ok = False and
self.some_other_condition is true)
              current_time = current_time_some_cond = current_max_time
= time.time()
              while not self.another_class_instance.event_ok and
self.some_other_condition:
                while self.some_other_condition and not
self.another_class_instance.event_ok:#self.some_other_condition takes
up to 10 secs to be checked (minimum 5 secs)
                    if time.time() > current_time + 5:
                        current_time = time.time()
                        # some processing
                else:
                    while not self.another_class_instance.event_ok:
                        #processing
                        if time.time() > current_max_time + 60 * 2 and
not self.another_class_instance.event_ok:
                            #some other processing
                        if time.time() > current_time_some_cond + 10
and not self.cond1 and not self.another_class_instance.event_ok:
                            # some processing that takes 2-3 seconds
                            self.cond1 = True
                            current_time_some_cond = time.time()
                        elif self.cond1 and time.time() >
current_time_some_cond + 10 and not
self.another_class_instance.event_ok:
                            current_time_some_cond = time.time()
                            #some other processing that takes 2-3 seconds
                    else:
                        pass
            else:
                pass

The problem is the real time execution of the program (in class2) requires
an instant check to be performed and that cannot wait until the current
loop instructions finish, and I want is to break out of the outer while
loop if the event is on without further checking any other condition.

for now I perform multiple checks at each if or while statement, but is
there a IO async based method that breaks out of the loop when the event is
raised in the thread?