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  1. Commons Pool
  2. POOL-284

"Returned object not currently part of this pool" when using mutable objects

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 2.2
    • Fix Version/s: 2.4.1
    • Labels:
      None

      Description

      I'm using pool to reuse expensive Sets (storing millions of items). Here is a test which fails:

              GenericObjectPoolConfig config = new GenericObjectPoolConfig ();
              GenericObjectPool<Set> aPool = new GenericObjectPool<> ( new BasePooledObjectFactory<Set> ()
              {
                  @Override
                  public Set create () throws Exception
                  {
                      return new HashSet();
                  }
      
                  @Override
                  public PooledObject<Set> wrap ( Set o )
                  {
                      return new DefaultPooledObject<> ( o );
                  }
      
                  @Override
                  public void passivateObject ( PooledObject<Set> p ) throws Exception
                  {
                      p.getObject ().clear ();
                      super.passivateObject ( p );
                  }
              }, config );
      
              Set set = aPool.borrowObject ();
      
              set.add ( new Object () );
              
              aPool.returnObject ( set );
      

      This is because GenericObjectPool uses a HashMap<Object, PooledObject> to correlate objects and state. HashMap stores objects correlated to their hashCode. So in case object's state change then hashCode will change, thus Map will fail to correlate this object since it stores old hashCode

        Attachments

        1. identityWrapper.patch
          4 kB
          Phil Steitz
        2. StaticBucketMap-mods.patch
          3 kB
          Phil Steitz
        3. pool-283-4.patch
          23 kB
          Phil Steitz

          Activity

            People

            • Assignee:
              Unassigned
              Reporter:
              yavalek Valentin Mayamsin
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              Dates

              • Created:
                Updated:
                Resolved: