What is the difference between semaphores and mutexes?

What is the difference between semaphores and mutexes?

Semaphores and mutexes are both synchronization primitives used in concurrent programming, but they serve different purposes. A mutex is a lock that allows only one thread to access a resource at a time, while a semaphore can allow multiple threads to access a limited number of resources.

Can you give an example of when to use a semaphore?

Sure! Use a semaphore when you have a pool of resources, like a fixed number of database connections. The semaphore can limit the number of threads that access the connections simultaneously.

What about mutexes? When should I use them?

Use a mutex when you need to protect a shared resource from being accessed by multiple threads at the same time, ensuring that only one thread can modify the resource.

Are there any performance differences between them?

Yes, mutexes can be more efficient for protecting single resources, while semaphores can introduce overhead due to their counting mechanism, especially when managing multiple resources.