218ba44dbf
* Upgrade maven plugins * Upgrade maven plugins Some general code cleanup was necessary due to upgrade of PMD and checkstyle. Also needed to add Junit 4 as a dependency due to Mockito.timout issue found here: https://github.com/mockito/mockito/issues/152
layout, title, folder, permalink, categories, tags
| layout | title | folder | permalink | categories | tags | ||
|---|---|---|---|---|---|---|---|
| pattern | Semaphore | semaphore | /patterns/semaphore/ | Concurrency |
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Also known as
Counting Semaphore
Intent
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.
Applicability
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
Credits
- [Semaphore(programming)] (http://en.wikipedia.org/wiki/Semaphore_(programming))
- [Semaphores] (http://tutorials.jenkov.com/java-concurrency/semaphores.html)