Package org.apache.hadoop.hbase.util

Class StealJobQueue<T>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractQueue<E>

java.util.concurrent.PriorityBlockingQueue<T>

org.apache.hadoop.hbase.util.StealJobQueue<T>

All Implemented Interfaces:

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

@Private
public class StealJobQueue<T>
extends PriorityBlockingQueue<T>

This queue allows a ThreadPoolExecutor to steal jobs from another ThreadPoolExecutor. This queue also acts as the factory for creating the PriorityBlockingQueue to be used in the steal-from ThreadPoolExecutor. The behavior of this queue is the same as a normal PriorityBlockingQueue except the take/poll(long,TimeUnit) methods would also check whether there are jobs in the steal-from queue if this q ueue is empty. Note the workers in ThreadPoolExecutor must be pre-started so that they can steal job from the other queue, otherwise the worker will only be started after there are jobs submitted to main queue.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
private final Lock	lock
private final Condition	notEmpty
private static final long	serialVersionUID
private BlockingQueue<T>	stealFromQueue

Constructor Summary

Constructors

Constructor	Description
StealJobQueue(int initCapacity, int stealFromQueueInitCapacity, Comparator<? super T> comparator)
StealJobQueue(Comparator<? super T> comparator)

Method Summary

Modifier and Type	Method	Description
BlockingQueue<T>	getStealFromQueue()	Get a queue whose job might be stolen by the consumer of this original queue
boolean	offer(T t)
T	poll(long timeout, TimeUnit unit)
T	take()

Methods inherited from class java.util.concurrent.PriorityBlockingQueue

add, clear, comparator, contains, drainTo, drainTo, forEach, iterator, offer, peek, poll, put, remainingCapacity, remove, removeAll, removeIf, retainAll, size, spliterator, toArray, toArray, toString

Methods inherited from class java.util.AbstractQueue

addAll, element, remove

Methods inherited from class java.util.AbstractCollection

containsAll, isEmpty

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

addAll, containsAll, equals, hashCode, isEmpty, parallelStream, stream, toArray

Methods inherited from interface java.util.Queue

element, remove

Field Details

serialVersionUID

private static final long serialVersionUID

See Also:

• Constant Field Values

stealFromQueue

private BlockingQueue<T> stealFromQueue

lock

private final Lock lock

notEmpty

private final transient Condition notEmpty

Constructor Details

StealJobQueue

public StealJobQueue(Comparator<? super T> comparator)

StealJobQueue

public StealJobQueue(int initCapacity,
 int stealFromQueueInitCapacity,
 Comparator<? super T> comparator)

Method Details

getStealFromQueue

public BlockingQueue<T> getStealFromQueue()

Get a queue whose job might be stolen by the consumer of this original queue

Returns:

the queue whose job could be stolen

offer

public boolean offer(T t)

Specified by:

offer in interface BlockingQueue<T>

Specified by:

offer in interface Queue<T>

Overrides:

offer in class PriorityBlockingQueue<T>

take

public T take()
       throws InterruptedException

Specified by:

take in interface BlockingQueue<T>

Overrides:

take in class PriorityBlockingQueue<T>

Throws:

InterruptedException

poll

public T poll(long timeout,
 TimeUnit unit)
       throws InterruptedException

Specified by:

poll in interface BlockingQueue<T>

Overrides:

poll in class PriorityBlockingQueue<T>

Throws:

InterruptedException