Learn Web Development with Python

Dealing with race conditions

Now that we have the tools to start threads and run them, let's simulate a race condition such as the one we discussed earlier:

# race.pyimport threadingfrom time import sleepfrom random import randomcounter = 0randsleep = lambda: sleep(0.1 * random())def incr(n):    global counter    for count in range(n):        current = counter        randsleep()        counter = current + 1        randsleep()n = 5t1 = threading.Thread(target=incr, args=(n, ))t2 = threading.Thread(target=incr, args=(n, ))t1.start()t2.start()t1.join()t2.join()print(f'Counter: {counter}')

In this example, we define the incr function, which gets a number n in input, and loops over n. In each cycle, it reads the value of the counter, sleeps for a random amount of time (between ...