Are Python instance variables thread-safe?

Question

OK, check following codes first:

class DemoClass():      def __init__(self):         #### I really want to know if self.Counter is thread-safe.          self.Counter = 0      def Increase(self):         self.Counter = self.Counter + 1      def Decrease(self):         self.Counter = self.Counter - 1      def DoThis(self):         while True:             Do something              if A happens:                 self.Increase()             else:                 self.Decrease()              time.sleep(randomSecs)      def DoThat(self):         while True:             Do other things              if B happens:                 self.Increase()             else:                 self.Decrease()              time.sleep(randomSecs)      def ThreadSafeOrNot(self):         InterestingThreadA = threading.Thread(target = self.DoThis, args = ())         InterestingThreadA.start()          InterestingThreadB = threading.Thread(target = self.DoThat, args = ())         InterestingThreadB.start() 

I'm facing same situation as above. I really want to know if it's thread-safe for self.Counter, well if not, what options do I have? I can only think of threading.RLock() to lock this resource, any better idea?

Answer 1

You can use Locks, RLocks, Semaphores, Conditions, Events and Queues.
And this article helped me a lot.
Check it out: Laurent Luce's Blog