org.compass.core.util.concurrent
Class ScalingQueue<E>

java.lang.Object
  java.util.AbstractCollection<E>
      java.util.AbstractQueue<E>
          java.util.concurrent.LinkedBlockingQueue<E>
              org.compass.core.util.concurrent.ScalingQueue<E>

All Implemented Interfaces:

Serializable, Iterable<E>, Collection<E>, BlockingQueue<E>, Queue<E>

public class ScalingQueue<E>
extends LinkedBlockingQueue<E>

A scaling queue that works with a ThreadPoolExecutor in when offerring which takes the active count and the max threads into account.

Author:

kimchy

See Also:

Serialized Form

Constructor Summary

ScalingQueue()
Creates a TaskQueue with a capacity of Integer.MAX_VALUE.

ScalingQueue(int capacity)
Creates a TaskQueue with the given (fixed) capacity.

Method Summary

boolean	offer(E o) Inserts the specified element at the tail of this queue if there is at least one available thread to run the current task.
void	setThreadPoolExecutor(ThreadPoolExecutor executor) Sets the executor this queue belongs to.

Methods inherited from class java.util.concurrent.LinkedBlockingQueue

clear, drainTo, drainTo, iterator, offer, peek, poll, poll, put, remainingCapacity, remove, size, take, toArray, toArray, toString

Methods inherited from class java.util.AbstractQueue

add, addAll, element, remove

Methods inherited from class java.util.AbstractCollection

contains, containsAll, isEmpty, removeAll, retainAll

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.concurrent.BlockingQueue

add

Methods inherited from interface java.util.Queue

element, remove

Methods inherited from interface java.util.Collection

addAll, contains, containsAll, equals, hashCode, isEmpty, removeAll, retainAll

Constructor Detail

ScalingQueue

public ScalingQueue()

Creates a TaskQueue with a capacity of Integer.MAX_VALUE.

ScalingQueue

public ScalingQueue(int capacity)

Creates a TaskQueue with the given (fixed) capacity.

Parameters:

capacity - the capacity of this queue.

Method Detail

setThreadPoolExecutor

public void setThreadPoolExecutor(ThreadPoolExecutor executor)

Sets the executor this queue belongs to.

offer

public boolean offer(E o)

Inserts the specified element at the tail of this queue if there is at least one available thread to run the current task. If all pool threads are actively busy, it rejects the offer.

Specified by:

offer in interface BlockingQueue<E>

Specified by:

offer in interface Queue<E>

Overrides:

offer in class LinkedBlockingQueue<E>

Parameters:

o - the element to add.

Returns:

true if it was possible to add the element to this queue, else false

See Also:

ThreadPoolExecutor.execute(Runnable)