Advantages of Semaphores

The following are some main advantages of using semaphores over similar constructs:

1. Fine-Grained Control: To access a resource concurrently, semaphores can be configured to allow a specific number of threads.
2. Generalization: Semaphores are more versatile and can be used to implement other synchronization primitives.
3. Multiple Resources: Counting semaphores can be used to manage multiple instances of a resource. This makes them suitable for scenarios where you need to control access to a pool of resources (e.g., a thread pool or a connection pool).
4. Blocking and Waiting: Blocking and waiting mechanisms in semaphores allow threads to wait until a resource becomes available again.
5. Timeouts: A timeout could be specified when acquiring a semaphore, which makes it more useful.

The C++20 <semaphore> header is part of the Concurrency Library Technical Specification (TS). Semaphores are synchronization primitives that help control access to shared resources in multi-threaded programs. The <semaphore> header provides the standard C++ way to work with semaphores.

In this article, we have covered important sections of semaphore headers such as the main classes, and usage of semaphore headers in C++20 along with examples.