1 /**

     2 * Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:

    15 * RMBufPoolChain decleration

    16 * 

    17 *

    18 */

    19 

    20 

    21 

    22 /**

    23  @file

    24  @internalTechnology

    25 */

    26 

    27 #ifndef MBUF_POOL_CHAIN_H

    28 #define MBUF_POOL_CHAIN_H

    29 

    30 #include <e32def.h>     // for std types

    31 

    32 // forward decleration(s) to avoid circular dependency by including this file

    33 // - this is a symptom of multiple class declerations within the same header file

    34 //   eg. es_mbman.h required for CMBufPool, but also contains CMBufManager which inturn requires RMBufPoolChain defined in this file!

    35 class RMBufPoolChain;

    36 #include <es_mbman.h>       // for CMBufPool

    37 

    38 

    39 // this class is internal to MBM, but alas this can't be enforced by C++ (except by not exporting its header file)

    40 class RMBufPoolChain

    41 	{

    42 	friend class CMBufPoolManager;	// to allow access to private members

    43    

    44 	RMBufPoolChain(TInt aMBufSize, CMBufPoolManager& aMBufPoolManager); // to be used only in searching for existing poolchain

    45 	RMBufPoolChain(TInt aMBufSize, TInt aInitialAllocation, TInt aMinGrowth, TInt aHighGrowthThresholdPercentage, CMBufPoolManager& aMBufPoolManager);

    46 

    47 	void OpenL();

    48 	void Close();

    49 	

    50 public:	

    51 	

    52 	TInt GrowthSize(TInt aSize);

    53 	void ExtendFreeList(CMBufPool* aPool);  // assumed that the caller has already acquired the lock, refer comments within the definition

    54 	

    55 	TInt Alloc(RMBufQ& aList, TInt aSize, TBool aIsAllocPool);

    56 	static TInt Compare(const TInt* aMBufSize, const RMBufPoolChain& aRHSPoolChain);

    57 	static TInt Compare(const RMBufPoolChain& aLHSPoolChain, const RMBufPoolChain& aRHSPoolChain);

    58 	CMBufPoolManager& MBufPoolManager();

    59 	

    60 private:

    61 

    62 	RWorkerLock iLockFreeList;				// lock for free list

    63     TInt iLenFree;					// number of bytes free within the pool chain

    64     TInt iLenTotal;				// number of bytes allocated (free + used) within the pool chain

    65     RMBufQ iFreeMBufs;				// free list of mbufs ready to be consumed, use of plural naming implies the queue (hence the name isn't appended)

    66     TDblQue<CMBufPool> iPools;

    67 

    68    	const TInt iMBufSize;          // size (in bytes) of contained mbufs, also stored within mbuf but kept here for encapsulation & ease of reference

    69     const TInt iInitialAllocation; // initial allocation size in num of MBufs (not bytes)

    70     TInt iMinGrowth;  				// minimum (automatic) incremental allocation in num of MBufs (not bytes) - actual allocate may be larger (refer )

    71     TInt iGrowthThreshold; 		// if the num of free mbufs is <= this value, then a a new pool is automatically allocated

    72 

    73 	TBool iSignalled;				// background growth in progress

    74 	TInt iNumMBufsToAdd;			// background growth

    75 	TBool iNoMoreSpace;				// last background growth failed

    76 	TInt iLastGrowth;				// last attempted growth

    77 	TInt iMaxGrowthAttempt;			// largest growth attempt

    78 

    79 	TInt iDbgPoolLimit;				// limit size of pool chain

    80 	

    81 	CMBufPoolManager& iMBufPoolManager;

    82 	};

    83 

    84 #endif  // MBUF_POOL_CHAIN_H