[IGNITE-6043] Fix GridCacheSemaphoreImpl methods semantics

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Not A Problem
• Affects Version/s: 2.1
• Component/s: data structures
• Assignee: Andrey Kuznetsov
• Reporter: Andrey Kuznetsov
• Created: 11/Aug/17 06:31
• Updated: 27/Sep/17 09:03
• Resolved: 27/Sep/17 09:03

Description

Current semaphore implementation, GridCacheSemaphoreImpl, has inverted method semantics: acquire() releases the permit and release() acquires it. Also, debug-level method availablePermits() returns permits acquired so far. This confusing behaviour should be fixed.

Also, it's worth noting in IgniteSemaphore's javadoc its unbounded nature, as opposed to java.util.concurrent.Semaphore.