/*
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * Copyright (c) 1999-2001 Apple Computer, Inc.  All Rights Reserved. The
 * contents of this file constitute Original Code as defined in and are
 * subject to the Apple Public Source License Version 1.2 (the 'License').
 * You may not use this file except in compliance with the License.  Please
 * obtain a copy of the License at http://www.apple.com/publicsource and
 * read it before using this file.
 *
 * This Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.  Please
 * see the License for the specific language governing rights and
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 */
/*
	File:		OSBufferPool.cpp

	Contains:	Fast access to fixed size buffers.
	
	Written By: Denis Serenyi
	
*/

#include "OSBufferPool.h"
#include "OSMemory.h"

void*	OSBufferPool::Get()
{
	OSMutexLocker locker(&fMutex);
	if (fQueue.GetLength() == 0)
	{
		fTotNumBuffers++;
		char* theNewBuf = NEW char[fBufSize + sizeof(OSQueueElem)];
		
		//
		// We need to construct a Queue Element, but we don't actually need
		// to use it in this function, so to avoid a compiler warning just
		// don't assign the result to anything.
		(void)new (theNewBuf) OSQueueElem(theNewBuf + sizeof(OSQueueElem));

		return theNewBuf + sizeof(OSQueueElem);
	}
	return fQueue.DeQueue()->GetEnclosingObject();
}

void OSBufferPool::Put(void* inBuffer)
{
	OSMutexLocker locker(&fMutex);
	fQueue.EnQueue((OSQueueElem*)((char*)inBuffer - sizeof(OSQueueElem)));
}