What are some examples of race conditions in programming?

What are some examples of race conditions in programming?

Race conditions occur when multiple threads or processes access shared data concurrently, leading to unpredictable results. For example, if two threads increment a shared counter without proper synchronization, the final count may be incorrect.

Can you give me a specific code example?

Sure! Here's a simple example in Python:

import threading

counter = 0

def increment():
    global counter
    for _ in range(100000):
        counter += 1

thread1 = threading.Thread(target=increment)
thread2 = threading.Thread(target=increment)

thread1.start()
thread2.start()

thread1.join()
thread2.join()

print(counter)  # This may not always print 200000 due to race conditions.

How can I prevent race conditions in my code?

You can prevent race conditions by using synchronization mechanisms like locks, semaphores, or by using atomic operations. For example, in Python, you can use the threading.Lock to ensure that only one thread can access the shared resource at a time.

What are some common synchronization techniques?

Common synchronization techniques include mutexes, semaphores, monitors, and condition variables. Each has its use cases and trade-offs depending on the problem you're solving.