--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/commsfwutils/commsbufs/mbufmgrimpl/inc/MBufPoolChain.h	Thu Dec 17 09:22:25 2009 +0200
@@ -0,0 +1,90 @@
+/**
+* Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:
+* RMBufPoolChain declaration
+* 
+*
+*/
+
+/**
+@file
+@internalTechnology
+*/
+
+#ifndef MBUF_POOL_CHAIN_H
+#define MBUF_POOL_CHAIN_H
+
+#include "commsbufpool.h"
+
+// forward decleration(s) to avoid circular dependency by including this file
+// - this is a symptom of multiple class declerations within the same header file
+//   eg. es_mbman.h required for CMBufPool, but also contains CMBufManager which inturn requires RMBufPoolChain defined in this file!
+class RMBufPoolChain;
+class CMBufPool;
+class CMBufPoolManager;
+
+#include <es_mbuf.h>
+#include <elements/rworkerlock.h>     // RWorkerThread decleration
+class CCommsBufPool;
+// this class is internal to MBM, but alas this can't be enforced by C++ (except by not exporting its header file)
+NONSHARABLE_CLASS(CMBufPoolChain) : public CCommsBufPool
+	{
+	friend class CMBufPoolManager;	// to allow access to private members
+	
+	 	
+public:	
+	static CMBufPoolChain* NewL(TInt aMBufSize, TInt aInitialAllocation, TInt aMinGrowth, TInt aHighGrowthThresholdPercentage, TInt aPoolCeiling, CMBufPoolManager& aMBufPoolManager);
+	~CMBufPoolChain();
+	
+	TInt GrowthSize(TInt aSize);
+	void ExtendFreeList(CMBufPool* aPool);  // assumed that the caller has already acquired the lock, refer comments within the definition
+	
+	TInt Alloc(RMBufQ& aList, TInt aSize, TBool aIsAllocPool);
+	static TInt Compare(const TInt* aMBufSize, const CMBufPoolChain& aRHSPoolChain);
+	static TInt Compare(const CMBufPoolChain& aLHSPoolChain, const CMBufPoolChain& aRHSPoolChain);
+
+	CMBufPoolManager& MBufPoolManager();
+	
+	TBool CanExtend() const;
+	TInt ExtendSize() const;
+	TBool HonourPoolCeiling() const;	
+private:
+	CMBufPoolChain(TInt aMBufSize, TInt aInitialAllocation, TInt aMinGrowth, TInt aHighGrowthThresholdPercentage, TInt aPoolCeiling, CMBufPoolManager& aMBufPoolManager);	
+	CMBufPoolChain(TInt aMBufSize, CMBufPoolManager& aMBufPoolManager); // to be used only in searching for existing poolchain
+
+	void ConstructL();
+private:
+
+	RWorkerLock iLockFreeList;				// lock for free list
+    TInt iLenFree;					// number of bytes free within the pool chain
+    TInt iLenTotal;				// number of bytes allocated (free + used) within the pool chain
+    RMBufQ iFreeMBufs;				// free list of mbufs ready to be consumed, use of plural naming implies the queue (hence the name isn't appended)
+    TDblQue<CMBufPool> iPools;
+
+    const TInt iInitialAllocation; // initial allocation size in num of MBufs (not bytes)
+    TInt iMinGrowth;  				// minimum (automatic) incremental allocation in num of MBufs (not bytes) - actual allocate may be larger (refer )
+    TInt iGrowthThreshold; 		// if the num of free mbufs is <= this value, then a a new pool is automatically allocated
+
+	TBool iSignalled;				// background growth in progress
+	TInt iNumMBufsToAdd;			// background growth
+	TBool iNoMoreSpace;				// last background growth failed
+	TInt iLastGrowth;				// last attempted growth
+	TInt iMaxGrowthAttempt;			// largest growth attempt
+
+	TInt iDbgPoolLimit;				// limit size of pool chain
+	TInt	iPoolCeiling;			// Pool size limit in bytes
+	CMBufPoolManager& iMBufPoolManager;
+	};
+
+#endif  // MBUF_POOL_CHAIN_H