How do semaphores work in multithreading?

How do semaphores work in multithreading?

Semaphores are synchronization tools that control access to shared resources in multithreading. They help prevent race conditions.

Can you explain the difference between binary and counting semaphores?

Sure! A binary semaphore can only take values 0 or 1, while a counting semaphore can take any non-negative integer value.

When should I use semaphores instead of mutexes?

Use semaphores when you need to control access to a resource by multiple threads, while mutexes are for exclusive access.

Can you give me a code example of using a semaphore?

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

import threading

semaphore = threading.Semaphore(2)

def access_resource():
    with semaphore:
        print("Resource accessed")

This allows up to 2 threads to access the resource simultaneously.

What are some common pitfalls when using semaphores?

Common pitfalls include forgetting to release the semaphore, leading to deadlocks, and using them inappropriately, which can complicate code.