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:

  • 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:

    • 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