// Copyright (c) 1994-2009 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:

// kernel\eka\include\slab.h

// 

//

#ifndef __KERNEL_MODE__

class slab;

class slabhdr;

#define MAXSLABSIZE		56

#define	PAGESHIFT		12

#define PAGESIZE		(1<<PAGESHIFT)

#define	SLABSHIFT		10

#define	SLABSIZE		(1 << SLABSHIFT)

#define CELLALIGN		8

const unsigned slabfull  = 0;

const TInt	slabsperpage = (int)(PAGESIZE/SLABSIZE);

#define HIBIT(bits) (((unsigned)bits & 0xc) ? 2 + ((unsigned)bits>>3) : ((unsigned) bits>>1))

#define LOWBIT(bits)	(((unsigned) bits&3) ? 1 - ((unsigned)bits&1) : 3 - (((unsigned)bits>>2)&1))

#define ZEROBITS(header)	(((unsigned)header & 0x70000000) ? 0 : 1)

class slabhdr

{

	public:

		unsigned iHeader;

		// made up of

		// bits   |    31    | 30..28 | 27..18 | 17..12 |  11..8  |   7..0   |

		//        +----------+--------+--------+--------+---------+----------+

		// field  | floating |  zero  | used-4 |  size  | pagemap | free pos |

		//

		slab** iParent;		// reference to iParent's pointer to this slab in tree

		slab* iChild1;		// 1st iChild in tree

		slab* iChild2;		// 2nd iChild in tree

};

const TInt KMaxSlabPayload = SLABSIZE - sizeof(slabhdr);

#define MAXUSEDM4BITS   0x0fc00000

#define FLOATING_BIT    0x80000000

inline unsigned HeaderFloating(unsigned h)

{return (h&0x80000000);}

const unsigned maxuse = (SLABSIZE - sizeof(slabhdr))>>2;

const unsigned firstpos = sizeof(slabhdr)>>2;

#ifdef _DEBUG

#define CHECKTREE(x) DoCheckSlabTree(x,EFalse)

#define CHECKSLAB(s,t,p) DoCheckSlab(s,t,p)

#define CHECKSLABBFR(s,p) {TUint32 b[4]; BuildPartialSlabBitmap(b,s,p);}

#else

#define CHECKTREE(x) (void)0

#define CHECKSLAB(s,t,p) (void)0

#define CHECKSLABBFR(s,p) (void)0

#endif

class slabset

{

	public:

		slab* iPartial;

};

class slab : public slabhdr

{

	public:

		void Init(unsigned clz);

		//static slab* SlabFor( void* p);

		static slab* SlabFor(const void* p) ;

		unsigned char iPayload[SLABSIZE-sizeof(slabhdr)];

};

class page

{

	public:

		inline static page* PageFor(slab* s);

		//slab iSlabs;

		slab iSlabs[slabsperpage];

};

inline page* page::PageFor(slab* s)

{

	return reinterpret_cast<page*>((unsigned(s))&~(PAGESIZE-1));

}

#endif   // __KERNEL_MODE__