1 /*

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

     3  *

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

     5  * modification, are permitted provided that the following conditions

     6  * are met:

     7  *

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

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

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

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

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

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

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

    15  *     from this software without specific prior written permission. 

    16  *

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

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

    19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

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

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

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

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

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

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

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

    27  */

    28 

    29 #ifndef BlockAllocatorSymbian_h

    30 #define BlockAllocatorSymbian_h

    31 

    32 #include <e32cmn.h>

    33 #include <e32std.h>

    34 #include <hal.h>

    35 

    36 

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

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

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

    40 

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

    42 #ifndef JSCCOLLECTOR_VIRTUALMEM_RESERVATION

    43 #if defined(__WINS__) 

    44     // Emulator has limited virtual address space

    45     #define JSCCOLLECTOR_VIRTUALMEM_RESERVATION (4*1024*1024)

    46 #else

    47     // HW has plenty of virtual addresses

    48     #define JSCCOLLECTOR_VIRTUALMEM_RESERVATION (128*1024*1024)

    49 #endif

    50 #endif

    51 

    52 namespace WTF {

    53 

    54 /** 

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

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

    57  *

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

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

    60  */

    61 class AlignedBlockAllocator {

    62     public:

    63         AlignedBlockAllocator(TUint32 reservationSize, TUint32 blockSize);

    64         ~AlignedBlockAllocator();

    65         void destroy();

    66         void* alloc();

    67         void free(void* data);

    68     

    69     private: 

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

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

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

    73         TUint32  m_reservation;

    74         TUint32  m_blockSize;  

    75 

    76         // Tracks comitted/decommitted state of a blockSize region

    77         struct {

    78             

    79             TUint32 *bits; // array of bit flags 

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

    81             

    82             bool get(TUint32 n) const

    83             {

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

    85             }

    86             

    87             void set(TUint32 n)

    88             {

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

    90             }

    91             

    92             void clear(TUint32 n)

    93             {

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

    95             }

    96             

    97             void clearAll()

    98             {

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

   100                     clear(i);

   101             }

   102             

   103             TInt findFree() const

   104             {

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

   106                     if (!get(i)) 

   107                         return i;

   108                 }

   109                 return -1;

   110             }

   111             

   112         } m_map;  

   113 

   114 };

   115  

   116 }

   117 

   118 #endif // end of BlockAllocatorSymbian_h

   119 

   120