MainThread blocks all others

[Nodir Gulyamov]

Hello All!
    I met some strange situation. In MainThread my program wating changes of 
some variable. This variable should be changed in another thread, but loop, 
which wait changing variable blocks all other threads.
Code below:

class class1:
    def __init__(self):
        self.counter = 0
        result = doSomeJob()

    def increaseCounter(self):
        self.counter += 1

    doSomeJob(self):
        ##### BLOCKING HERE ###
        while counter != 1:
            pass
        # ... continue...

# this class subscribed to some observer which implements thread
class monitor:
    def __init__(self, klass):
        #do some init
        self.c = klass
    def update(self):
        self.c.increaseCounter()

if __name__ == "__main__":
    cl1 = class1()
    m = monitor(cl1)
    mo = MonitorObserver(m)


I am very confused how to resolve this problem. Any help will be 
appreciated.

Thanks in advance to All.

Best regards,
/Gelios