What is the difference between locks and semaphores?

What is the difference between locks and semaphores?

Locks and semaphores are both synchronization primitives used in concurrent programming, but they serve different purposes. A lock is used to ensure that only one thread can access a resource at a time, while a semaphore can allow multiple threads to access a resource up to a certain limit.

Can you give me an example of when to use a lock?

Sure! You would use a lock when you have a shared resource, like a variable or a file, that should not be accessed by more than one thread at a time to prevent data corruption.

And when would I use a semaphore instead?

You would use a semaphore when you want to limit the number of threads that can access a resource simultaneously. For example, if you have a pool of database connections, you might use a semaphore to limit access to a maximum of 5 connections.

Are there any downsides to using locks?

Yes, using locks can lead to issues like deadlocks, where two or more threads are waiting for each other to release locks, causing the program to hang. It's important to design your locking strategy carefully.