What are the differences between conditional variables and semaphores in C++?

Can you explain the differences between conditional variables and semaphores in C++?

Sure! Conditional variables are used for signaling between threads, allowing one thread to wait for a condition to be true, while semaphores are used to control access to a shared resource by multiple threads.

How do they work in terms of thread synchronization?

Conditional variables allow threads to wait until a specific condition is met, using 'wait' and 'notify' methods. Semaphores, on the other hand, maintain a count that represents the number of available resources, using 'wait' (or 'P') and 'signal' (or 'V') operations.

When should I use one over the other?

Use conditional variables when you need to wait for a specific condition to occur, and semaphores when you need to limit access to a resource based on a count.

Can you give an example of each?

Certainly! For conditional variables, consider a producer-consumer scenario where a consumer waits for data to be produced. For semaphores, think of a scenario where multiple threads need to access a limited number of database connections.