Advanced Python Programming

Implementation in Python

Now, let's implement the specification in the preceding example, in order to solve the problem of race conditions. Navigate to the Chapter21/example2.py file and consider our corrected update() function, as follows:

# Chapter21/example2.pyimport randomimport timedef update():    global counter    with count_lock:        current_counter = counter # reading in shared resource        time.sleep(random.randint(0, 1)) # simulating heavy calculations        counter = current_counter + 1

You can see that all of the execution instructions of a thread specified in the update() function are under the context manager of a lock object named count_lock. So, every time a thread is called to run the function, it will have to first acquire the lock object, ...