Also known as
Create a lock which mediates access to a pool of resources. Only a limited number of threads, specified at the creation of the semaphore, can access the resources at any given time. A semaphore which only allows one concurrent access to a resource is called a binary semaphore.
Use a Semaphore when
- you have a pool of resources to allocate to different threads
- concurrent access to a resource could lead to a race condition
- [Semaphore(programming)] (http://en.wikipedia.org/wiki/Semaphore_(programming))
- [Semaphores] (http://tutorials.jenkov.com/java-concurrency/semaphores.html)