What are the differences between semaphores and mutexes?

What are the differences 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 resource, up to a specified limit.

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

Sure! Use a semaphore when you want to limit access to a resource to a certain number of threads, like a connection pool. A mutex is better when you need exclusive access to a resource.

Are there any performance differences between using semaphores and mutexes?

Yes, mutexes generally have lower overhead than semaphores because they only allow one thread at a time, while semaphores manage multiple threads, which can introduce more complexity.

What happens if a thread forgets to release a mutex?

If a thread forgets to release a mutex, it can lead to a deadlock situation where other threads are blocked indefinitely, waiting for the mutex to be released.