Module org.eclipse.jetty.util

Package org.eclipse.jetty.util.thread

Class ThreadIdPool<E>

java.lang.Object

org.eclipse.jetty.util.thread.ThreadIdPool<E>

All Implemented Interfaces:

Dumpable

public class ThreadIdPool<E>
extends Object
implements Dumpable

A fixed sized pool of items that uses ThreadId to avoid contention. This class can be used, instead of a ThreadLocal, when pooling items that are expensive to create, but only used briefly in the scope of a single thread. It is safe to use with VirtualThreads, as unlike a ThreadLocal pool, the number of items is limited.

This is a light-weight version of ConcurrentPool that is best used when items do not reserve an index in the pool even when acquired.

See Also:

• ConcurrentPool

Nested Class Summary

Nested classes/interfaces inherited from interface org.eclipse.jetty.util.component.Dumpable

Dumpable.DumpableContainer

Field Summary

Fields inherited from interface org.eclipse.jetty.util.component.Dumpable

KEY

Constructor Summary

Constructors

Constructor	Description
ThreadIdPool()
ThreadIdPool(int capacity)

Method Summary

Modifier and Type	Method	Description
<A, R> R	apply(Supplier<E> supplier, BiFunction<E,A,R> function, A argument)	Apply an item, either from the pool or supplier, to a function, then give it back to the pool.
<R> R	apply(Supplier<E> supplier, Function<E,R> function)	Apply an item, either from the pool or supplier, to a function, then give it back to the pool.
int	capacity()
void	dump(Appendable out, String indent)	Dump this object (and children) into an Appendable using the provided indent after any new lines.
int	offer(E e)	Offer an item to the pool.
boolean	remove(E e, int index)	Remove a specific item from the pool from a specific index
List<E>	removeAll()	Removes all items from the pool.
int	size()
E	take()	Take an item from the pool.
E	takeOrElse(Supplier<E> supplier)	Take an item with a take() operation, else if that returns null then use the supplier (which may construct a new instance).
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.jetty.util.component.Dumpable

dump, dumpSelf

Constructor Details

ThreadIdPool

public ThreadIdPool()

ThreadIdPool

public ThreadIdPool(int capacity)

Method Details

capacity

public int capacity()

Returns:

the maximum number of items

size

public int size()

Returns:

the number of items available

offer

public int offer(E e)

Offer an item to the pool.

Parameters:

e - The item to offer

Returns:

The index the item was added at or -1, if it was not added

See Also:

• remove(Object, int)

take

public E take()

Take an item from the pool.

Returns:

The taken item or null if none available.

remove

public boolean remove(E e,
 int index)

Remove a specific item from the pool from a specific index

Parameters:

e - The item to remove

index - The index the item was given to, as returned by offer(Object)

Returns:

True if the item was in the pool and was able to be removed.

removeAll

public List<E> removeAll()

Removes all items from the pool.

Returns:

A list of all removed items

takeOrElse

public E takeOrElse(Supplier<E> supplier)

Take an item with a take() operation, else if that returns null then use the supplier (which may construct a new instance).

Parameters:

supplier - The supplier for an item to be used if an item cannot be taken from the pool.

Returns:

An item, never null.

apply

public <R> R apply(Supplier<E> supplier,
 Function<E,R> function)

Apply an item, either from the pool or supplier, to a function, then give it back to the pool. This is equivalent of takeOrElse(Supplier); then Function.apply(Object); followed by offer(Object).

Type Parameters:

R - The type of the function return

Parameters:

supplier - The supplier for an item to be used if an item cannot be taken from the pool.

function - A function producing a result from an item. This may be a method reference to a method on the item taking no arguments and producing a result.

Returns:

Te result of the function applied to the item and the argument

apply

public <A,
R> R apply(Supplier<E> supplier,
 BiFunction<E,A,R> function,
 A argument)

Apply an item, either from the pool or supplier, to a function, then give it back to the pool. This is equivalent of takeOrElse(Supplier); then BiFunction.apply(Object, Object); followed by offer(Object).

Type Parameters:

A - The type of the function argument

R - The type of the function return

Parameters:

supplier - The supplier for an item to be used if an item cannot be taken from the pool.

function - A function producing a result from an item and an argument. This may be a method reference to a method on the item taking an argument and producing a result.

argument - The argument to pass to the function.

Returns:

Te result of the function applied to the item and the argument

dump

public void dump(Appendable out,
 String indent)
          throws IOException

Description copied from interface: Dumpable

Dump this object (and children) into an Appendable using the provided indent after any new lines. The indent should not be applied to the first object dumped.

Specified by:

dump in interface Dumpable

Parameters:

out - The appendable to dump to

indent - The indent to apply after any new lines.

Throws:

IOException - if unable to write to Appendable

toString

public String toString()

Overrides:

toString in class Object