com.basho.riak.client.raw.pbc

Class PoolSemaphore

java.lang.Object

java.util.concurrent.Semaphore

com.basho.riak.client.raw.pbc.PoolSemaphore

All Implemented Interfaces:

Serializable

public class PoolSemaphore
extends Semaphore

Wraps a semaphore for the cluster and a semaphore for the pool. Used by RiakConnectionPool

Author:

russell

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
PoolSemaphore(Semaphore clusterSemaphore, int poolPermits) Creates a pool Semaphore with permits permits.

Method Summary

Methods

Modifier and Type	Method and Description
void	release() Both semaphores are released
boolean	tryAcquire(int permits) Tries to acquire from the cluster semaphore, and only if that succeeds does it try the pool semaphore.
boolean	tryAcquire(long timeout, TimeUnit unit) Tries to acquire on the cluster semaphore, and only if that succeeds does it try the pool semaphore.

Methods inherited from class java.util.concurrent.Semaphore

acquire, acquire, acquireUninterruptibly, acquireUninterruptibly, availablePermits, drainPermits, getQueuedThreads, getQueueLength, hasQueuedThreads, isFair, reducePermits, release, toString, tryAcquire, tryAcquire

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

PoolSemaphore

public PoolSemaphore(Semaphore clusterSemaphore,
             int poolPermits)

Creates a pool Semaphore with permits permits. Calls to tryAcquire(long, TimeUnit), release() and tryAcquire(int) call both cluster and pool Semaphore

Parameters:

cluster - a Semaphore configured for the total cluster maximum number of connections

permits - maximum connections for the pool

Method Detail

release

public void release()

Both semaphores are released

Overrides:

release in class Semaphore

tryAcquire

public boolean tryAcquire(long timeout,
                 TimeUnit unit)
                   throws InterruptedException

Tries to acquire on the cluster semaphore, and only if that succeeds does it try the pool semaphore.

Warning: this means potentially double the timeout

TODO configure option for timeout to be shared (i.e. pool semaphore gets remaining time after cluster acquire)

Overrides:

tryAcquire in class Semaphore

Throws:

InterruptedException

See Also:

Semaphore.tryAcquire(long, java.util.concurrent.TimeUnit)

tryAcquire

public boolean tryAcquire(int permits)

Tries to acquire from the cluster semaphore, and only if that succeeds does it try the pool semaphore.

Overrides:

tryAcquire in class Semaphore

See Also:

Semaphore.tryAcquire(int)