text: /*
   * 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
  
  
  