What is the difference between a condition variable and a semaphore?

What is the difference between a condition variable and a semaphore?

A condition variable is a synchronization primitive that allows threads to wait until a particular condition occurs, while a semaphore is a signaling mechanism that controls access to a shared resource by maintaining a count.

Can you give me an example of when to use each?

Sure! Use a condition variable when you want threads to wait for a specific condition to be true, like waiting for a buffer to have data. Use a semaphore when you want to limit the number of threads accessing a resource, like limiting access to a pool of database connections.

Are there any performance differences between them?

Yes, condition variables can be more efficient for signaling between threads, while semaphores can introduce more overhead due to their counting mechanism. The choice depends on the specific use case.

What are some common pitfalls when using these synchronization tools?

Common pitfalls include forgetting to signal a condition variable, leading to deadlocks, or using semaphores incorrectly, which can cause resource starvation.