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ByteBufferPoolImpl.javaAPI DocJava SE 5 API6587Fri Aug 26 14:54:32 BST 2005com.sun.corba.se.impl.transport

ByteBufferPoolImpl

public class ByteBufferPoolImpl extends Object implements com.sun.corba.se.pept.transport.ByteBufferPool
author
Charlie Hunt

Fields Summary
private com.sun.corba.se.spi.orb.ORB
itsOrb
private int
itsByteBufferSize
private ArrayList
itsPool
private int
itsObjectCounter
private boolean
debug
Constructors Summary
public ByteBufferPoolImpl(com.sun.corba.se.spi.orb.ORB theORB)


    // Construct a ByteBufferPool for a pool of NIO ByteBuffers
    // of ORB fragment size.
      
    
        itsByteBufferSize = theORB.getORBData().getGIOPFragmentSize();
        itsPool = new ArrayList();
        itsOrb = theORB;
        debug = theORB.transportDebugFlag;
Methods Summary
public intactiveCount()

         return itsObjectCounter;
public java.nio.ByteBuffergetByteBuffer(int theAskSize)

        ByteBuffer abb = null;

        if ((theAskSize <= itsByteBufferSize) &&
	    !itsOrb.getORBData().disableDirectByteBufferUse())
        {
            // check if there's one in the pool, if not allocate one.
            int poolSize;
            synchronized (itsPool)
            {
                poolSize = itsPool.size();
                if (poolSize > 0)
                {
                    abb = (ByteBuffer)itsPool.remove(poolSize - 1);

                    // clear ByteBuffer before returning it
                    abb.clear();
                }
            }

            // NOTE: Moved the 'else' part of the above if statement
            //       outside the synchronized block since it is likely
            //       less expensive to check poolSize than to allocate a
            //       DirectByteBuffer in the synchronized block.
            if (poolSize <= 0)
            {
                abb = ByteBuffer.allocateDirect(itsByteBufferSize);
            }

            // increment the number of ByteBuffers gotten from pool
            // IMPORTANT: Since this counter is used only for information
            //            purposes, it does not use synchronized access.
            itsObjectCounter++;
        }
        else
        {
            // Requested ByteBuffer size larger than the pool manages.
            // Just allocate a non-direct ByteBuffer 
            abb = ByteBuffer.allocate(theAskSize);
        }

	return abb;
public voidreleaseByteBuffer(java.nio.ByteBuffer thebb)

        if (thebb.isDirect())
        {
            synchronized (itsPool)
            {
                // use with debug to determine if byteBuffer is already
                // in the pool.
                boolean refInPool = false;
                int bbAddr = 0;

                if (debug)
                {
                    // Check to make sure we don't have 'thebb' reference
                    // already in the pool before adding it.

                    for (int i = 0; i < itsPool.size() && refInPool == false; i++)
                    {
                         ByteBuffer tmpbb = (ByteBuffer)itsPool.get(i);
                         if (thebb == tmpbb)
                         {
                             refInPool = true;
                             bbAddr = System.identityHashCode(thebb);
                         }
                    }

                }

                // NOTE: The else part of this if will only get called
                //       if debug = true and refInPool = true, see logic above.
                if (refInPool == false || debug == false)
                {
                    // add ByteBuffer back to the pool
                    itsPool.add(thebb);
                }
                else // otherwise, log a stack trace with duplicate message
                {
                    String threadName = Thread.currentThread().getName();
                    Throwable t =
                            new Throwable(threadName + 
                                         ": Duplicate ByteBuffer reference (" +
                                         bbAddr + ")");
                    t.printStackTrace(System.out);
                }
            }

            // decrement the count of ByteBuffers released
            // IMPORTANT: Since this counter is used only for information
            //            purposes, it does not use synchronized access.
            itsObjectCounter--;
        }
        else
        {
            // ByteBuffer not pooled nor needed
            thebb = null;
        }