Package uk.ac.ebi.utils.threading

Class HackedBlockingQueue<E>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractQueue<E>

java.util.concurrent.LinkedBlockingQueue<E>

uk.ac.ebi.utils.threading.HackedBlockingQueue<E>

All Implemented Interfaces:

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

public class HackedBlockingQueue<E>
extends LinkedBlockingQueue<E>

Tricks the behaviour of LinkedBlockingQueue so that methods like offer(Object) and poll() actually invoke LinkedBlockingQueue.put(Object) and LinkedBlockingQueue.take(), i.e., the queue always waits for itself to be free-of/filled-with-some value/s.

This can be used in ThreadPoolExecutor, which of AbstractExecutorService.submit(Runnable) methods can raise RejectedExecutionException by calling offer(). By passing this class to its constructor, the executor will always wait for a free thread, either in the executor or in the task queue.

Credits.

Author:

brandizi

Date:

22 Dec 2017

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
HackedBlockingQueue()
HackedBlockingQueue(int capacity)
HackedBlockingQueue(Collection<? extends E> c)

Method Summary

Modifier and Type	Method	Description
static ThreadPoolExecutor	createExecutor()	Defaults to Runtime.availableProcessors() and a submission queue that is twice this number.
static ThreadPoolExecutor	createExecutor(int poolSize, int queueSize)	Using an instance of this class, returns a fixed size ThreadPoolExecutor that blocks ExecutorService.submit(Runnable) when both the pool and the submission queue are full.
boolean	offer(E e)
boolean	offer(E e, long timeout, TimeUnit unit)
E	poll()
E	poll(long timeout, TimeUnit unit)

Methods inherited from class java.util.concurrent.LinkedBlockingQueue

clear, contains, drainTo, drainTo, forEach, iterator, peek, put, remainingCapacity, remove, removeAll, removeIf, retainAll, size, spliterator, take, toArray, toArray, toString

Methods inherited from class java.util.AbstractQueue

add, 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.concurrent.BlockingQueue

add

Methods inherited from interface java.util.Collection

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

Methods inherited from interface java.util.Queue

element, remove

Constructor Details

HackedBlockingQueue

public HackedBlockingQueue()

HackedBlockingQueue

public HackedBlockingQueue(Collection<? extends E> c)

HackedBlockingQueue

public HackedBlockingQueue(int capacity)

Method Details

offer

public boolean offer(E e)

Specified by:

offer in interface BlockingQueue<E>

Specified by:

offer in interface Queue<E>

Overrides:

offer in class LinkedBlockingQueue<E>

offer

public boolean offer(E e,
 long timeout,
 TimeUnit unit)
              throws InterruptedException

Specified by:

offer in interface BlockingQueue<E>

Overrides:

offer in class LinkedBlockingQueue<E>

Throws:

InterruptedException

poll

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

Specified by:

poll in interface BlockingQueue<E>

Overrides:

poll in class LinkedBlockingQueue<E>

Throws:

InterruptedException

poll

public E poll()

Specified by:

poll in interface Queue<E>

Overrides:

poll in class LinkedBlockingQueue<E>

createExecutor

public static ThreadPoolExecutor createExecutor(int poolSize,
 int queueSize)

Using an instance of this class, returns a fixed size ThreadPoolExecutor that blocks ExecutorService.submit(Runnable) when both the pool and the submission queue are full.

createExecutor

public static ThreadPoolExecutor createExecutor()

Defaults to Runtime.availableProcessors() and a submission queue that is twice this number.