/*

 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1.  Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer. 

 * 2.  Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution. 

 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of

 *     its contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission. 

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY

 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef BlockAllocatorSymbian_h

#define BlockAllocatorSymbian_h

#include <e32cmn.h>

#include <e32std.h>

#include <hal.h>

#define SYMBIAN_PAGESIZE(x) (HAL::Get(HALData::EMemoryPageSize, x));

#define SYMBIAN_FREERAM(x)  (HAL::Get(HALData::EMemoryRAMFree, x));

#define SYMBIAN_ROUNDUPTOMULTIPLE(x, multipleof)    ( (x + multipleof - 1) & ~(multipleof - 1) )

// Set sane defaults if -D<flagname=value> wasn't provided via compiler args

#ifndef JSCCOLLECTOR_VIRTUALMEM_RESERVATION

#if defined(__WINS__) 

    // Emulator has limited virtual address space

    #define JSCCOLLECTOR_VIRTUALMEM_RESERVATION (4*1024*1024)

#else

    // HW has plenty of virtual addresses

    #define JSCCOLLECTOR_VIRTUALMEM_RESERVATION (128*1024*1024)

#endif

#endif

namespace WTF {

/** 

 *  Allocates contiguous region of size blockSize with blockSize-aligned address. 

 *  blockSize must be a multiple of system page size (typically 4K on Symbian/ARM)

 *

 *  @param reservationSize Virtual address range to be reserved upon creation of chunk (bytes).

 *  @param blockSize Size of a single allocation. Returned address will also be blockSize-aligned.

 */

class AlignedBlockAllocator {

    public:

        AlignedBlockAllocator(TUint32 reservationSize, TUint32 blockSize);

        ~AlignedBlockAllocator();

        void destroy();

        void* alloc();

        void free(void* data);

    private: 

        RChunk   m_chunk; // Symbian chunk that lets us reserve/commit/decommit

        TUint    m_offset; // offset of first committed region from base 

        TInt     m_pageSize; // cached value of system page size, typically 4K on Symbian

        TUint32  m_reservation;

        TUint32  m_blockSize;  

        // Tracks comitted/decommitted state of a blockSize region

        struct {

            TUint32 *bits; // array of bit flags 

            TUint32  numBits; // number of regions to keep track of

            bool get(TUint32 n) const

            {

                return !!(bits[n >> 5] & (1 << (n & 0x1F)));

            }

            void set(TUint32 n)

            {

                bits[n >> 5] |= (1 << (n & 0x1F));

            }

            void clear(TUint32 n)

            {

                bits[n >> 5] &= ~(1 << (n & 0x1F));

            }

            void clearAll()

            {

               for (TUint32 i = 0; i < numBits; i++)

                    clear(i);

            }

            TInt findFree() const

            {

                for (TUint32 i = 0; i < numBits; i++) {

                    if (!get(i)) 

                        return i;

                }

                return -1;

            }

        } m_map;  

};

}

#endif // end of BlockAllocatorSymbian_h