Package org.apache.tomcat.util.threads

Class TaskQueue

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractQueue<E>

java.util.concurrent.LinkedBlockingQueue<Runnable>

org.apache.tomcat.util.threads.TaskQueue

All Implemented Interfaces:

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

public class TaskQueue
extends LinkedBlockingQueue<Runnable>

As task queue specifically designed to run with a thread pool executor. The task queue is optimised to properly utilize threads within a thread pool executor. If you use a normal queue, the executor will spawn threads when there are idle threads and you won't be able to force items onto the queue itself.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected static final StringManager	sm

Constructor Summary

Constructors

Constructor	Description
TaskQueue()
TaskQueue(int capacity)
TaskQueue(Collection<? extends Runnable> c)

Method Summary

Modifier and Type	Method	Description
boolean	force(Runnable o)	Used to add a task to the queue if the task has been rejected by the Executor.
boolean	force(Runnable o, long timeout, TimeUnit unit)	Deprecated. Unused.
boolean	offer(Runnable o)
Runnable	poll(long timeout, TimeUnit unit)
void	setParent(ThreadPoolExecutor tp)
Runnable	take()

Methods inherited from class java.util.concurrent.LinkedBlockingQueue

clear, 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

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

Field Details

sm

protected static final StringManager sm

Constructor Details

TaskQueue

public TaskQueue()

TaskQueue

public TaskQueue(int capacity)

TaskQueue

public TaskQueue(Collection<? extends Runnable> c)

Method Details

setParent

public void setParent(ThreadPoolExecutor tp)

force

public boolean force(Runnable o)

Used to add a task to the queue if the task has been rejected by the Executor.

Parameters:

o - The task to add to the queue

Returns:

true if the task was added to the queue, otherwise false

force

@Deprecated
public boolean force(Runnable o,
 long timeout,
 TimeUnit unit)
              throws InterruptedException

Deprecated.

Unused. Will be removed in Tomcat 10.1.x.

Used to add a task to the queue if the task has been rejected by the Executor.

Parameters:

o - The task to add to the queue

timeout - The timeout to use when adding the task

unit - The units in which the timeout is expressed

Returns:

true if the task was added to the queue, otherwise false

Throws:

InterruptedException - If the call is interrupted before the timeout expires

offer

public boolean offer(Runnable o)

Specified by:

offer in interface BlockingQueue<Runnable>

Specified by:

offer in interface Queue<Runnable>

Overrides:

offer in class LinkedBlockingQueue<Runnable>

poll

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

Specified by:

poll in interface BlockingQueue<Runnable>

Overrides:

poll in class LinkedBlockingQueue<Runnable>

Throws:

InterruptedException

take

public Runnable take()
              throws InterruptedException

Specified by:

take in interface BlockingQueue<Runnable>

Overrides:

take in class LinkedBlockingQueue<Runnable>

Throws:

InterruptedException