C++ MagickMemoryMethods类代码示例

MagickExport void *ResizeMagickMemory(void *memory,const size_t size)
{
  register void
    *block;

  if (memory == (void *) NULL)
    return(AcquireMagickMemory(size));
#if !defined(MAGICKCORE_ZERO_CONFIGURATION_SUPPORT)
  block=memory_methods.resize_memory_handler(memory,size == 0 ? 1UL : size);
  if (block == (void *) NULL)
    memory=RelinquishMagickMemory(memory);
#else
  LockSemaphoreInfo(memory_semaphore);
  block=ResizeBlock(memory,size == 0 ? 1UL : size);
  if (block == (void *) NULL)
    {
      if (ExpandHeap(size == 0 ? 1UL : size) == MagickFalse)
        {
          UnlockSemaphoreInfo(memory_semaphore);
          memory=RelinquishMagickMemory(memory);
          ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
        }
      block=ResizeBlock(memory,size == 0 ? 1UL : size);
      assert(block != (void *) NULL);
    }
  UnlockSemaphoreInfo(memory_semaphore);
  memory=RelinquishMagickMemory(memory);
#endif
  return(block);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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+   E x p a n d H e a p                                                       %
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%
%  ExpandHeap() get more memory from the system.  It returns MagickTrue on
%  success otherwise MagickFalse.
%
%  The format of the ExpandHeap method is:
%
%      MagickBooleanType ExpandHeap(size_t size)
%
%  A description of each parameter follows:
%
%    o size: the size of the memory in bytes we require.
%
*/
static MagickBooleanType ExpandHeap(size_t size)
{
  DataSegmentInfo
    *segment_info;

  MagickBooleanType
    mapped;

  register ssize_t
    i;

  register void
    *block;

  size_t
    blocksize;

  void
    *segment;

  blocksize=((size+12*sizeof(size_t))+SegmentSize-1) & -SegmentSize;
  assert(memory_pool.number_segments < MaxSegments);
  segment=MapBlob(-1,IOMode,0,blocksize);
  mapped=segment != (void *) NULL ? MagickTrue : MagickFalse;
  if (segment == (void *) NULL)
    segment=(void *) memory_methods.acquire_memory_handler(blocksize);
  if (segment == (void *) NULL)
    return(MagickFalse);
  segment_info=(DataSegmentInfo *) free_segments;
  free_segments=segment_info->next;
  segment_info->mapped=mapped;
  segment_info->length=blocksize;
  segment_info->allocation=segment;
  segment_info->bound=(char *) segment+blocksize;
  i=(ssize_t) memory_pool.number_segments-1;
  for ( ; (i >= 0) && (memory_pool.segments[i]->allocation > segment); i--)
    memory_pool.segments[i+1]=memory_pool.segments[i];
  memory_pool.segments[i+1]=segment_info;
  memory_pool.number_segments++;
  size=blocksize-12*sizeof(size_t);
  block=(char *) segment_info->allocation+4*sizeof(size_t);
  *BlockHeader(block)=size | PreviousBlockBit;
  *BlockFooter(block,size)=size;
  InsertFreeBlock(block,AllocationPolicy(size));
  block=NextBlock(block);
  assert(block < segment_info->bound);
  *BlockHeader(block)=2*sizeof(size_t);
  *BlockHeader(NextBlock(block))=PreviousBlockBit;
  return(MagickTrue);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
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%   A c q u i r e M a g i c k M e m o r y                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  AcquireMagickMemory() returns a pointer to a block of memory at least size
%  bytes suitably aligned for any use.
%
%  The format of the AcquireMagickMemory method is:
%
%      void *AcquireMagickMemory(const size_t size)
%
%  A description of each parameter follows:
%
%    o size: the size of the memory in bytes to allocate.
%
*/
MagickExport void *AcquireMagickMemory(const size_t size)
{
  register void
    *memory;

#if !defined(MAGICKCORE_ZERO_CONFIGURATION_SUPPORT)
  memory=memory_methods.acquire_memory_handler(size == 0 ? 1UL : size);
#else
  if (memory_semaphore == (SemaphoreInfo *) NULL)
    ActivateSemaphoreInfo(&memory_semaphore);
  if (free_segments == (DataSegmentInfo *) NULL)
    {
      LockSemaphoreInfo(memory_semaphore);
      if (free_segments == (DataSegmentInfo *) NULL)
        {
          register ssize_t
            i;

          assert(2*sizeof(size_t) > (size_t) (~SizeMask));
          (void) ResetMagickMemory(&memory_pool,0,sizeof(memory_pool));
          memory_pool.allocation=SegmentSize;
          memory_pool.blocks[MaxBlocks]=(void *) (-1);
          for (i=0; i < MaxSegments; i++)
          {
            if (i != 0)
              memory_pool.segment_pool[i].previous=
                (&memory_pool.segment_pool[i-1]);
            if (i != (MaxSegments-1))
              memory_pool.segment_pool[i].next=(&memory_pool.segment_pool[i+1]);
          }
          free_segments=(&memory_pool.segment_pool[0]);
        }
      UnlockSemaphoreInfo(memory_semaphore);
    }
  LockSemaphoreInfo(memory_semaphore);
  memory=AcquireBlock(size == 0 ? 1UL : size);
  if (memory == (void *) NULL)
    {
      if (ExpandHeap(size == 0 ? 1UL : size) != MagickFalse)
        memory=AcquireBlock(size == 0 ? 1UL : size);
    }
  UnlockSemaphoreInfo(memory_semaphore);
#endif
  return(memory);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e l i n q u i s h M a g i c k M e m o r y                               %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  RelinquishMagickMemory() frees memory acquired with AcquireMagickMemory()
%  or AcquireQuantumMemory() for reuse.
%
%  The format of the RelinquishMagickMemory method is:
%
%      void *RelinquishMagickMemory(void *memory)
%
%  A description of each parameter follows:
%
%    o memory: A pointer to a block of memory to free for reuse.
%
*/
MagickExport void *RelinquishMagickMemory(void *memory)
{
  if (memory == (void *) NULL)
    return((void *) NULL);
#if !defined(MAGICKCORE_ZERO_CONFIGURATION_SUPPORT)
  memory_methods.destroy_memory_handler(memory);
#else
  LockSemaphoreInfo(memory_semaphore);
  assert((SizeOfBlock(memory) % (4*sizeof(size_t))) == 0);
  assert((*BlockHeader(NextBlock(memory)) & PreviousBlockBit) != 0);
  if ((*BlockHeader(memory) & PreviousBlockBit) == 0)
    {
      void
        *previous;

      /*
        Coalesce with previous adjacent block.
      */
      previous=PreviousBlock(memory);
      RemoveFreeBlock(previous,AllocationPolicy(SizeOfBlock(previous)));
      *BlockHeader(previous)=(SizeOfBlock(previous)+SizeOfBlock(memory)) |
        (*BlockHeader(previous) & ~SizeMask);
      memory=previous;
    }
  if ((*BlockHeader(NextBlock(NextBlock(memory))) & PreviousBlockBit) == 0)
    {
      void
        *next;

      /*
        Coalesce with next adjacent block.
      */
      next=NextBlock(memory);
      RemoveFreeBlock(next,AllocationPolicy(SizeOfBlock(next)));
      *BlockHeader(memory)=(SizeOfBlock(memory)+SizeOfBlock(next)) |
        (*BlockHeader(memory) & ~SizeMask);
    }
  *BlockFooter(memory,SizeOfBlock(memory))=SizeOfBlock(memory);
  *BlockHeader(NextBlock(memory))&=(~PreviousBlockBit);
  InsertFreeBlock(memory,AllocationPolicy(SizeOfBlock(memory)));
  UnlockSemaphoreInfo(memory_semaphore);
#endif
  return((void *) NULL);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   A c q u i r e M a g i c k M e m o r y                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  AcquireMagickMemory() returns a pointer to a block of memory at least size
%  bytes suitably aligned for any use.
%
%  The format of the AcquireMagickMemory method is:
%
%      void *AcquireMagickMemory(const size_t size)
%
%  A description of each parameter follows:
%
%    o size: the size of the memory in bytes to allocate.
%
*/
MagickExport void *AcquireMagickMemory(const size_t size)
{
  register void
    *memory;

#if !defined(MAGICKCORE_EMBEDDABLE_SUPPORT)
  memory=memory_methods.acquire_memory_handler(size == 0 ? 1UL : size);
#else
  if (free_segments == (DataSegmentInfo *) NULL)
    {
      AcquireSemaphoreInfo(&memory_semaphore);
      if (free_segments == (DataSegmentInfo *) NULL)
        {
          register long
            i;

          assert(2*sizeof(size_t) > (size_t) (~SizeMask));
          (void) ResetMagickMemory(&memory_info,0,sizeof(memory_info));
          memory_info.allocation=SegmentSize;
          memory_info.blocks[MaxBlocks]=(void *) (-1);
          for (i=0; i < MaxSegments; i++)
          {
            if (i != 0)
              memory_info.segment_pool[i].previous=
                (&memory_info.segment_pool[i-1]);
            if (i != (MaxSegments-1))
              memory_info.segment_pool[i].next=(&memory_info.segment_pool[i+1]);
          }
          free_segments=(&memory_info.segment_pool[0]);
        }
      RelinquishSemaphoreInfo(memory_semaphore);
    }
  AcquireSemaphoreInfo(&memory_semaphore);
  memory=AcquireBlock(size == 0 ? 1UL : size);
  if (memory == (void *) NULL)
    {
      if (ExpandHeap(size == 0 ? 1UL : size) != MagickFalse)
        memory=AcquireBlock(size == 0 ? 1UL : size);
    }
  RelinquishSemaphoreInfo(memory_semaphore);
#endif
  return(memory);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
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+   D e s t r o y M a g i c k M e m o r y                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  DestroyMagickMemory() deallocates memory associated with the memory manager.
%
%  The format of the DestroyMagickMemory method is:
%
%      DestroyMagickMemory(void)
%
*/
MagickExport void DestroyMagickMemory(void)
{
#if defined(MAGICKCORE_EMBEDDABLE_SUPPORT)
  register long
    i;

  AcquireSemaphoreInfo(&memory_semaphore);
  RelinquishSemaphoreInfo(memory_semaphore);
  for (i=0; i < (long) memory_info.number_segments; i++)
    if (memory_info.segments[i]->mapped == MagickFalse)
      memory_methods.destroy_memory_handler(
        memory_info.segments[i]->allocation);
    else
      (void) UnmapBlob(memory_info.segments[i]->allocation,
        memory_info.segments[i]->length);
  free_segments=(DataSegmentInfo *) NULL;
  (void) ResetMagickMemory(&memory_info,0,sizeof(memory_info));
  DestroySemaphoreInfo(&memory_semaphore);
#endif
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
+   D e s t r o y M a g i c k M e m o r y                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  DestroyMagickMemory() deallocates memory associated with the memory manager.
%
%  The format of the DestroyMagickMemory method is:
%
%      DestroyMagickMemory(void)
%
*/
MagickExport void DestroyMagickMemory(void)
{
#if defined(MAGICKCORE_ZERO_CONFIGURATION_SUPPORT)
  register ssize_t
    i;

  if (memory_semaphore == (SemaphoreInfo *) NULL)
    ActivateSemaphoreInfo(&memory_semaphore);
  LockSemaphoreInfo(memory_semaphore);
  for (i=0; i < (ssize_t) memory_pool.number_segments; i++)
    if (memory_pool.segments[i]->mapped == MagickFalse)
      memory_methods.destroy_memory_handler(
        memory_pool.segments[i]->allocation);
    else
      (void) UnmapBlob(memory_pool.segments[i]->allocation,
        memory_pool.segments[i]->length);
  free_segments=(DataSegmentInfo *) NULL;
  (void) ResetMagickMemory(&memory_pool,0,sizeof(memory_pool));
  UnlockSemaphoreInfo(memory_semaphore);
  DestroySemaphoreInfo(&memory_semaphore);
#endif
}