Package org.apache.commons.pool2

Class PoolUtils.ErodingFactor

java.lang.Object
org.apache.commons.pool2.PoolUtils.ErodingFactor
Enclosing class:
PoolUtils
private static final class PoolUtils.ErodingFactor extends Object
Encapsulate the logic for when the next poolable object should be discarded. Each time update is called, the next time to shrink is recomputed, based on the float factor, number of idle instances in the pool and high water mark. Float factor is assumed to be between 0 and 1. Values closer to 1 cause less frequent erosion events. Erosion event timing also depends on numIdle. When this value is relatively high (close to previously established high water mark), erosion occurs more frequently.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private final float
    factor
    Determines frequency of "erosion" events
    private int
    idleHighWaterMark
    High water mark - largest numIdle encountered
    private final ReentrantLock
    lock
     
    private static final float
    MAX_INTERVAL
     
    private long
    nextShrinkMillis
    Time of next shrink event

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    private
    ErodingFactor(float factor)
    Creates a new ErodingFactor with the given erosion factor.

  • Method Summary

    Modifier and Type
    Method
    Description
    private long
    getNextShrink()
    Gets the time of the next erosion event.
    String
    toString()
    void
    update(long nowMillis, int numIdle)
    Updates internal state using the supplied time and numIdle.

    Methods inherited from class java.lang.Object

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

  • Field Details

    • MAX_INTERVAL

      private static final float MAX_INTERVAL
      See Also:

    • factor

      private final float factor
      Determines frequency of "erosion" events

    • nextShrinkMillis

      private transient volatile long nextShrinkMillis
      Time of next shrink event

    • idleHighWaterMark

      private transient volatile int idleHighWaterMark
      High water mark - largest numIdle encountered

    • lock

      private final ReentrantLock lock

  • Constructor Details

    • ErodingFactor

      private ErodingFactor(float factor)
      Creates a new ErodingFactor with the given erosion factor.
      Parameters:
      factor - erosion factor

  • Method Details

    • getNextShrink

      private long getNextShrink()
      Gets the time of the next erosion event.
      Returns:
      next shrink time

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • update

      public void update(long nowMillis, int numIdle)
      Updates internal state using the supplied time and numIdle.
      Parameters:
      nowMillis - current time
      numIdle - number of idle elements in the pool