How do I use semaphores in my code?

How do I use semaphores in my code?

Semaphores are synchronization tools used to control access to a common resource in concurrent programming. Would you like an example?

Yes, please provide a code example.

Sure! Here's a simple example in Python using the threading module:

import threading

# Create a semaphore with a limit of 2
semaphore = threading.Semaphore(2)

def access_resource(thread_id):
    print(f'Thread {thread_id} is trying to access the resource.')
    semaphore.acquire()
    print(f'Thread {thread_id} has accessed the resource.')
    # Simulate resource usage
    semaphore.release()
    print(f'Thread {thread_id} has released the resource.')

# Create multiple threads
threads = [threading.Thread(target=access_resource, args=(i,)) for i in range(5)]

# Start the threads
for thread in threads:
    thread.start()

# Wait for all threads to complete
for thread in threads:
    thread.join()

What does the semaphore limit mean in this example?

The semaphore limit defines how many threads can access the resource simultaneously. In this case, a limit of 2 means only two threads can access the resource at the same time.