What are the different types of semaphores in Java?

What are the different types of semaphores in Java?

In Java, there are two main types of semaphores: counting semaphores and binary semaphores. Counting semaphores allow a specified number of threads to access a resource, while binary semaphores only allow one thread at a time.

Can you explain how counting semaphores work?

Sure! Counting semaphores maintain a count that represents the number of permits available. When a thread acquires a permit, the count decreases, and when it releases a permit, the count increases. This allows multiple threads to access a resource concurrently up to the limit set by the semaphore.

What about binary semaphores? How are they different?

Binary semaphores, also known as mutexes, can only be in one of two states: available or unavailable. They are used to ensure mutual exclusion, allowing only one thread to access a resource at a time.

Are there any practical examples of using semaphores in Java?

Yes! A common example is controlling access to a pool of database connections, where counting semaphores can limit the number of concurrent connections.