com.github.rholder.moar.concurrent

Class HeapQueueingStrategy<E>

java.lang.Object

com.github.rholder.moar.concurrent.HeapQueueingStrategy<E>

Type Parameters:

E - the type of elements held in the target queue

All Implemented Interfaces:

QueueingStrategy<E>

public class HeapQueueingStrategy<E>
extends java.lang.Object
implements QueueingStrategy<E>

This QueueingStrategy slows down the rate at which items can be added to a queue based on the amount of free heap space available.

Constructor Summary

Constructors

Constructor and Description
HeapQueueingStrategy(double percentOfHeapBeforeFlowControl, long maxDelay, long dequeueHint) Construct a new HeapQueueingStrategy with the given parameters.

Method Summary

Methods

Modifier and Type	Method and Description
void	onAfterAdd() Perform this action after adding a value to the queue.
void	onAfterRemove(E value) Increment the count of removed items from the queue.
void	onBeforeAdd(E value) Block for a varying amount based on how close the system is to the max heap space.
void	onBeforeRemove() Perform this action before removing a value from the queue.

Methods inherited from class java.lang.Object

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

Constructor Detail

HeapQueueingStrategy

public HeapQueueingStrategy(double percentOfHeapBeforeFlowControl,
                    long maxDelay,
                    long dequeueHint)

Construct a new HeapQueueingStrategy with the given parameters.

Parameters:

percentOfHeapBeforeFlowControl - the percentage of the heap that must be available before the queue begins to start delaying addition operations

maxDelay - the maximum amount of time to delay an addition operation in milliseconds

dequeueHint - after this many dequeue operations, signal the JVM to run a garbage collection

Method Detail

onBeforeAdd

public void onBeforeAdd(E value)

Block for a varying amount based on how close the system is to the max heap space. Only kick in when we have passed the percentOfHeapBeforeFlowControl threshold.

Specified by:

onBeforeAdd in interface QueueingStrategy<E>

Parameters:

value - value that is to be added to the queue

onAfterAdd

public void onAfterAdd()

Description copied from interface: QueueingStrategy

Perform this action after adding a value to the queue.

Specified by:

onAfterAdd in interface QueueingStrategy<E>

onBeforeRemove

public void onBeforeRemove()

Description copied from interface: QueueingStrategy

Perform this action before removing a value from the queue.

Specified by:

onBeforeRemove in interface QueueingStrategy<E>

onAfterRemove

public void onAfterRemove(E value)

Increment the count of removed items from the queue. Calling this will optionally request that the garbage collector run to free up heap space for every nth dequeue, where n is the value set for the dequeueHint.

Specified by:

onAfterRemove in interface QueueingStrategy<E>

Parameters:

value - value that was removed from the queue