--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/kernel/eka/memmodel/epoc/flexible/mmu/mslaballoc.h	Thu Dec 17 09:24:54 2009 +0200
@@ -0,0 +1,216 @@
+// 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 the License "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:
+//
+
+/**
+ @file
+ @internalComponent
+*/
+
+#ifndef MSLABALLOC_H
+#define MSLABALLOC_H
+
+#include "mcleanup.h"
+
+/**
+Slab allocator.
+*/
+class RSlabAllocatorBase
+	{
+public:
+	RSlabAllocatorBase(TBool aDelayedCleanup);
+	~RSlabAllocatorBase();
+
+	/**
+	Construct a slab allocator.
+
+	@param aMaxSlabs	Maximum number of slabs to use. (Number of bits in \a slabBits.)
+	@param aObjectSize	Size of objects to allocate.
+	*/
+	TInt Construct(TUint aMaxSlabs, TUint aObjectSize);
+
+	/**
+	Construct a slab allocator using fixed virtual memory.
+
+	@param aMaxSlabs	Maximum number of slabs to use. (Number of bits in \a slabBits.)
+	@param aObjectSize	Size of objects to allocate.
+	@param aBase		Virtual address for start of memory where slabs will be allocated.
+						Zero indicates 'anywhere'.
+	*/
+	TInt Construct(TUint aMaxSlabs, TUint aObjectSize, TLinAddr aBase);
+
+	/**
+	Set the memory object to be used for the slab allocator.
+	*/
+	FORCE_INLINE void SetMemory(DMemoryObject* aMemory, TUint aReserveCount)
+		{
+		__NK_ASSERT_DEBUG(!iMemory);
+		iMemory = aMemory;
+		iReserveCount = aReserveCount;
+		}
+
+	/**
+	Allocate an object.
+
+	@return Allocated object, or the null pointer if there is insufficient memory to perform the allocation.
+
+	@pre MmuLock held
+	@post MmuLock held, but has always beet flashed
+	*/
+	TAny* Alloc();
+
+	/**
+	Free an object previously allocated with #Alloc.
+
+	@param aObject The object.
+
+	@pre MmuLock held
+	@post MmuLock held, but has always beet flashed
+	*/
+	void Free(TAny* aObject);
+
+protected:
+	class TSlabHeader : public SDblQueLink
+		{
+	public:
+		SDblQue iFreeList;		///< List of unallocated objects in list.
+		TUint iAllocCount;		///< Number of objects allocated in this slab.
+		TAny* iHighWaterMark;	///< End of initialise region in slab.
+		};
+
+private:
+	TBool NewSlab();
+	void InitSlab(TLinAddr aPage);
+	void FreeSlab(TSlabHeader* aSlab);
+	static void CleanupTrampoline(TAny* aSelf);
+	void Cleanup();
+#ifdef _DEBUG
+	void CheckSlab(TSlabHeader* aSlab);
+#endif
+
+private:
+	SDblQue iFreeList;			///< List of slabs which have unallocated objects in them.
+	TUint iFreeCount;			///< Number of unallocated objects.
+	TUint iReserveCount;		///< Number of unallocated objects to keep in reserve (to allow for recursion during allocation).
+	TUint iObjectsPerSlab;		///< Number of objects in each slab.
+	TUint iObjectSize;			///< Size, in bytes, of objects to be allocated.
+	TSpinLock iSpinLock;		///< Spinlock which protects iFreeList, iFreeCount  and TSlabHeader contents.
+
+	TMemoryCleanup iCleanup;	///< Used to queue Cleanup() if iDelayedCleanup is true.
+	TBool iDelayedCleanup;		///< True, if Free() should not free empty slabs.
+
+	TBool iAllocatingSlab;		///< True if a new slab page is being allocated.
+	TBitMapAllocator* iSlabMap;	///< Bitmap of allocated slabs.
+	DMemoryObject* iMemory;		///< The memory object used to store slabs.
+	DMemoryMapping* iMapping;	///< The memory mapping used for slabs.
+	TLinAddr iBase;				///< Address of first slab.
+	};
+
+
+/**
+Template for a slab allocator which can allocate up to N objects of type T.
+*/
+template <class T, TUint N>
+class RSlabAllocator : public RSlabAllocatorBase
+	{
+public:
+	enum
+		{
+		EObjectSize = sizeof(T)>sizeof(SDblQueLink) ? sizeof(T) : sizeof(SDblQueLink),
+		EObjectsPerSlab = (KPageSize-sizeof(TSlabHeader))/EObjectSize,
+		EMaxSlabs = (N+EObjectsPerSlab-1)/EObjectsPerSlab
+		};
+
+	FORCE_INLINE RSlabAllocator()
+		: RSlabAllocatorBase(EFalse)
+		{
+		__ASSERT_COMPILE(EObjectsPerSlab>0);
+		}
+
+	FORCE_INLINE TInt Construct()
+		{
+		return RSlabAllocatorBase::Construct(EMaxSlabs,EObjectSize);
+		}
+
+	/**
+	Allocate an object.
+
+	@return Allocated object, or the null pointer if there is insufficient memory to perform the allocation.
+	*/
+	FORCE_INLINE T* Alloc()
+		{
+		return (T*)RSlabAllocatorBase::Alloc();
+		}
+
+	/**
+	Free an object previously allocated with #Alloc.
+
+	@param aObject Object.
+	*/
+	FORCE_INLINE void Free(T* aObject)
+		{
+		RSlabAllocatorBase::Free(aObject);
+		}
+	};
+
+
+/**
+Template for a slab allocator for allocating objects of type T, using the
+virtual address region [B..E)
+*/
+template <class T, TLinAddr B, TLinAddr E>
+class RStaticSlabAllocator : public RSlabAllocatorBase
+	{
+public:
+	enum
+		{
+		EObjectSize = sizeof(T)>sizeof(SDblQueLink) ? sizeof(T) : sizeof(SDblQueLink),
+		EObjectsPerSlab = (KPageSize-sizeof(TSlabHeader))/EObjectSize,
+		EMaxSlabs = (E-B)/KPageSize
+		};
+
+	FORCE_INLINE RStaticSlabAllocator()
+		: RSlabAllocatorBase(ETrue)
+		{
+		__ASSERT_COMPILE(EObjectsPerSlab>0);
+		}
+
+	FORCE_INLINE TInt Construct()
+		{
+		return RSlabAllocatorBase::Construct(EMaxSlabs,EObjectSize,B);
+		}
+
+	/**
+	Allocate an object.
+
+	@return Allocated object, or the null pointer if there is insufficient memory to perform the allocation.
+	*/
+	FORCE_INLINE T* Alloc()
+		{
+		return (T*)RSlabAllocatorBase::Alloc();
+		}
+
+	/**
+	Free an object previously allocated with #Alloc.
+
+	@param aObject Object.
+	*/
+	FORCE_INLINE void Free(T* aObject)
+		{
+		RSlabAllocatorBase::Free(aObject);
+		}
+	};
+
+#endif
+