kernel/eka/memmodel/epoc/flexible/mmu/mslaballoc.h
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     1 // Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).
       
     2 // All rights reserved.
       
     3 // This component and the accompanying materials are made available
       
     4 // under the terms of the License "Eclipse Public License v1.0"
       
     5 // which accompanies this distribution, and is available
       
     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
       
     7 //
       
     8 // Initial Contributors:
       
     9 // Nokia Corporation - initial contribution.
       
    10 //
       
    11 // Contributors:
       
    12 //
       
    13 // Description:
       
    14 //
       
    15 
       
    16 /**
       
    17  @file
       
    18  @internalComponent
       
    19 */
       
    20 
       
    21 #ifndef MSLABALLOC_H
       
    22 #define MSLABALLOC_H
       
    23 
       
    24 #include "mcleanup.h"
       
    25 
       
    26 /**
       
    27 Slab allocator.
       
    28 */
       
    29 class RSlabAllocatorBase
       
    30 	{
       
    31 public:
       
    32 	RSlabAllocatorBase(TBool aDelayedCleanup);
       
    33 	~RSlabAllocatorBase();
       
    34 
       
    35 	/**
       
    36 	Construct a slab allocator.
       
    37 
       
    38 	@param aMaxSlabs	Maximum number of slabs to use. (Number of bits in \a slabBits.)
       
    39 	@param aObjectSize	Size of objects to allocate.
       
    40 	*/
       
    41 	TInt Construct(TUint aMaxSlabs, TUint aObjectSize);
       
    42 
       
    43 	/**
       
    44 	Construct a slab allocator using fixed virtual memory.
       
    45 
       
    46 	@param aMaxSlabs	Maximum number of slabs to use. (Number of bits in \a slabBits.)
       
    47 	@param aObjectSize	Size of objects to allocate.
       
    48 	@param aBase		Virtual address for start of memory where slabs will be allocated.
       
    49 						Zero indicates 'anywhere'.
       
    50 	*/
       
    51 	TInt Construct(TUint aMaxSlabs, TUint aObjectSize, TLinAddr aBase);
       
    52 
       
    53 	/**
       
    54 	Set the memory object to be used for the slab allocator.
       
    55 	*/
       
    56 	FORCE_INLINE void SetMemory(DMemoryObject* aMemory, TUint aReserveCount)
       
    57 		{
       
    58 		__NK_ASSERT_DEBUG(!iMemory);
       
    59 		iMemory = aMemory;
       
    60 		iReserveCount = aReserveCount;
       
    61 		}
       
    62 
       
    63 	/**
       
    64 	Allocate an object.
       
    65 
       
    66 	@return Allocated object, or the null pointer if there is insufficient memory to perform the allocation.
       
    67 
       
    68 	@pre MmuLock held
       
    69 	@post MmuLock held, but has always beet flashed
       
    70 	*/
       
    71 	TAny* Alloc();
       
    72 
       
    73 	/**
       
    74 	Free an object previously allocated with #Alloc.
       
    75 
       
    76 	@param aObject The object.
       
    77 
       
    78 	@pre MmuLock held
       
    79 	@post MmuLock held, but has always beet flashed
       
    80 	*/
       
    81 	void Free(TAny* aObject);
       
    82 
       
    83 protected:
       
    84 	class TSlabHeader : public SDblQueLink
       
    85 		{
       
    86 	public:
       
    87 		SDblQue iFreeList;		///< List of unallocated objects in list.
       
    88 		TUint iAllocCount;		///< Number of objects allocated in this slab.
       
    89 		TAny* iHighWaterMark;	///< End of initialise region in slab.
       
    90 		};
       
    91 
       
    92 private:
       
    93 	TBool NewSlab();
       
    94 	void InitSlab(TLinAddr aPage);
       
    95 	void FreeSlab(TSlabHeader* aSlab);
       
    96 	static void CleanupTrampoline(TAny* aSelf);
       
    97 	void Cleanup();
       
    98 #ifdef _DEBUG
       
    99 	void CheckSlab(TSlabHeader* aSlab);
       
   100 #endif
       
   101 
       
   102 private:
       
   103 	SDblQue iFreeList;			///< List of slabs which have unallocated objects in them.
       
   104 	TUint iFreeCount;			///< Number of unallocated objects.
       
   105 	TUint iReserveCount;		///< Number of unallocated objects to keep in reserve (to allow for recursion during allocation).
       
   106 	TUint iObjectsPerSlab;		///< Number of objects in each slab.
       
   107 	TUint iObjectSize;			///< Size, in bytes, of objects to be allocated.
       
   108 	TSpinLock iSpinLock;		///< Spinlock which protects iFreeList, iFreeCount  and TSlabHeader contents.
       
   109 
       
   110 	TMemoryCleanup iCleanup;	///< Used to queue Cleanup() if iDelayedCleanup is true.
       
   111 	TBool iDelayedCleanup;		///< True, if Free() should not free empty slabs.
       
   112 
       
   113 	TBool iAllocatingSlab;		///< True if a new slab page is being allocated.
       
   114 	TBitMapAllocator* iSlabMap;	///< Bitmap of allocated slabs.
       
   115 	DMemoryObject* iMemory;		///< The memory object used to store slabs.
       
   116 	DMemoryMapping* iMapping;	///< The memory mapping used for slabs.
       
   117 	TLinAddr iBase;				///< Address of first slab.
       
   118 	};
       
   119 
       
   120 
       
   121 /**
       
   122 Template for a slab allocator which can allocate up to N objects of type T.
       
   123 */
       
   124 template <class T, TUint N>
       
   125 class RSlabAllocator : public RSlabAllocatorBase
       
   126 	{
       
   127 public:
       
   128 	enum
       
   129 		{
       
   130 		EObjectSize = sizeof(T)>sizeof(SDblQueLink) ? sizeof(T) : sizeof(SDblQueLink),
       
   131 		EObjectsPerSlab = (KPageSize-sizeof(TSlabHeader))/EObjectSize,
       
   132 		EMaxSlabs = (N+EObjectsPerSlab-1)/EObjectsPerSlab
       
   133 		};
       
   134 
       
   135 	FORCE_INLINE RSlabAllocator()
       
   136 		: RSlabAllocatorBase(EFalse)
       
   137 		{
       
   138 		__ASSERT_COMPILE(EObjectsPerSlab>0);
       
   139 		}
       
   140 
       
   141 	FORCE_INLINE TInt Construct()
       
   142 		{
       
   143 		return RSlabAllocatorBase::Construct(EMaxSlabs,EObjectSize);
       
   144 		}
       
   145 
       
   146 	/**
       
   147 	Allocate an object.
       
   148 
       
   149 	@return Allocated object, or the null pointer if there is insufficient memory to perform the allocation.
       
   150 	*/
       
   151 	FORCE_INLINE T* Alloc()
       
   152 		{
       
   153 		return (T*)RSlabAllocatorBase::Alloc();
       
   154 		}
       
   155 
       
   156 	/**
       
   157 	Free an object previously allocated with #Alloc.
       
   158 
       
   159 	@param aObject Object.
       
   160 	*/
       
   161 	FORCE_INLINE void Free(T* aObject)
       
   162 		{
       
   163 		RSlabAllocatorBase::Free(aObject);
       
   164 		}
       
   165 	};
       
   166 
       
   167 
       
   168 /**
       
   169 Template for a slab allocator for allocating objects of type T, using the
       
   170 virtual address region [B..E)
       
   171 */
       
   172 template <class T, TLinAddr B, TLinAddr E>
       
   173 class RStaticSlabAllocator : public RSlabAllocatorBase
       
   174 	{
       
   175 public:
       
   176 	enum
       
   177 		{
       
   178 		EObjectSize = sizeof(T)>sizeof(SDblQueLink) ? sizeof(T) : sizeof(SDblQueLink),
       
   179 		EObjectsPerSlab = (KPageSize-sizeof(TSlabHeader))/EObjectSize,
       
   180 		EMaxSlabs = (E-B)/KPageSize
       
   181 		};
       
   182 
       
   183 	FORCE_INLINE RStaticSlabAllocator()
       
   184 		: RSlabAllocatorBase(ETrue)
       
   185 		{
       
   186 		__ASSERT_COMPILE(EObjectsPerSlab>0);
       
   187 		}
       
   188 
       
   189 	FORCE_INLINE TInt Construct()
       
   190 		{
       
   191 		return RSlabAllocatorBase::Construct(EMaxSlabs,EObjectSize,B);
       
   192 		}
       
   193 
       
   194 	/**
       
   195 	Allocate an object.
       
   196 
       
   197 	@return Allocated object, or the null pointer if there is insufficient memory to perform the allocation.
       
   198 	*/
       
   199 	FORCE_INLINE T* Alloc()
       
   200 		{
       
   201 		return (T*)RSlabAllocatorBase::Alloc();
       
   202 		}
       
   203 
       
   204 	/**
       
   205 	Free an object previously allocated with #Alloc.
       
   206 
       
   207 	@param aObject Object.
       
   208 	*/
       
   209 	FORCE_INLINE void Free(T* aObject)
       
   210 		{
       
   211 		RSlabAllocatorBase::Free(aObject);
       
   212 		}
       
   213 	};
       
   214 
       
   215 #endif
       
   216