thread_race_condition_solution_conditional_variable.py

from threading import *
import time

cond = Condition()
done = 1

def task(name):
    global done

    with cond: # `with` releases the resources when exception occurs
        if (done == 1):
            done = 2
            print("Waiting on condition variable for task", name)
            cond.wait()
            print("Condition met", name)
        else:
            for i in range(5):
                print(".")
                time.sleep(1)
            
            print("Signaling condition variable", name)
            cond.notify_all()
            print("Notification done", name)

if __name__ == "__main__":
    t1 = Thread(target=task, args=('t1',))
    t2 = Thread(target=task, args=('t2',))

    t1.start()
    t2.start()
    t1.join()
    t2.join()