ftdbgmem.c

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      node = pnode[0];
      if ( !node )
        break;

      if ( node->address == address )
        break;

      pnode = &node->link;
    }
    return pnode;
  }


  static void
  ft_mem_table_set( FT_MemTable  table,
                    FT_Byte*     address,
                    FT_ULong     size )
  {
    FT_MemNode  *pnode, node;


    if ( table )
    {
      pnode = ft_mem_table_get_nodep( table, address );
      node  = *pnode;
      if ( node )
      {
        if ( node->size < 0 )
        {
          /* this block was already freed.  This means that our memory is */
          /* now completely corrupted!                                    */
          ft_mem_debug_panic(
            "memory heap corrupted (allocating freed block)" );
        }
        else
        {
          /* this block was already allocated.  This means that our memory */
          /* is also corrupted!                                            */
          ft_mem_debug_panic(
            "memory heap corrupted (re-allocating allocated block)" );
        }
      }

      /* we need to create a new node in this table */
      node = (FT_MemNode)ft_mem_table_alloc( table, sizeof ( *node ) );
      if ( node == NULL )
        ft_mem_debug_panic( "not enough memory to run memory tests" );

      node->address = address;
      node->size    = size;

      node->alloc_file_name = table->file_name;
      node->alloc_line_no   = table->line_no;

      node->free_file_name = NULL;
      node->free_line_no   = 0;

      node->link = pnode[0];

      pnode[0] = node;
      table->nodes++;

      table->alloc_total   += size;
      table->alloc_current += size;
      if ( table->alloc_current > table->alloc_max )
        table->alloc_max = table->alloc_current;

      if ( table->nodes * 3 < table->size  ||
           table->size  * 3 < table->nodes )
        ft_mem_table_resize( table );
    }
  }


  static void
  ft_mem_table_remove( FT_MemTable  table,
                       FT_Byte*     address )
  {
    if ( table )
    {
      FT_MemNode  *pnode, node;


      pnode = ft_mem_table_get_nodep( table, address );
      node  = *pnode;
      if ( node )
      {
        if ( node->size < 0 )
          ft_mem_debug_panic(
            "freeing memory block at %p more than once at (%s:%ld)\n"
            "block allocated at (%s:%ld) and released at (%s:%ld)",
            address,
            FT_FILENAME( table->file_name ), table->line_no,
            FT_FILENAME( node->alloc_file_name ), node->alloc_line_no,
            FT_FILENAME( node->free_file_name ), node->free_line_no );

        /* we simply invert the node's size to indicate that the node */
        /* was freed.  We also change its contents.                   */
        FT_MEM_SET( address, 0xF3, node->size );

        table->alloc_current -= node->size;
        node->size            = -node->size;
        node->free_file_name  = table->file_name;
        node->free_line_no    = table->line_no;
      }
      else
        ft_mem_debug_panic(
          "trying to free unknown block at %p in (%s:%ld)\n",
          address,
          FT_FILENAME( table->file_name ), table->line_no );
    }
  }


  extern FT_Pointer
  ft_mem_debug_alloc( FT_Memory  memory,
                      FT_Long    size )
  {
    FT_MemTable  table = (FT_MemTable)memory->user;
    FT_Byte*     block;


    if ( size <= 0 )
      ft_mem_debug_panic( "negative block size allocation (%ld)", size );

    /* return NULL if the maximum number of allocations was reached */
    if ( table->bound_count &&
         table->alloc_count >= table->alloc_count_max )
      return NULL;

    /* return NULL if this allocation would overflow the maximum heap size */
    if ( table->bound_total && 
         table->alloc_current + (FT_ULong)size > table->alloc_total_max )
      return NULL;         

    block = (FT_Byte *)ft_mem_table_alloc( table, size );
    if ( block )
      ft_mem_table_set( table, block, (FT_ULong)size );

    table->alloc_count++;

    table->file_name = NULL;
    table->line_no   = 0;

    return (FT_Pointer) block;
  }


  extern void
  ft_mem_debug_free( FT_Memory   memory,
                     FT_Pointer  block )
  {
    FT_MemTable  table = (FT_MemTable)memory->user;


    if ( block == NULL )
      ft_mem_debug_panic( "trying to free NULL in (%s:%ld)",
                          FT_FILENAME( table->file_name ),
                          table->line_no );

    ft_mem_table_remove( table, (FT_Byte*)block );

    /* we never really free the block */
    table->file_name = NULL;
    table->line_no   = 0;
  }


  extern FT_Pointer
  ft_mem_debug_realloc( FT_Memory   memory,
                        FT_Long     cur_size,
                        FT_Long     new_size,
                        FT_Pointer  block )
  {
    FT_MemTable  table = (FT_MemTable)memory->user;
    FT_MemNode   node, *pnode;
    FT_Pointer   new_block;

    const char*  file_name = FT_FILENAME( table->file_name );
    FT_Long      line_no   = table->line_no;


    if ( block == NULL || cur_size == 0 )
      ft_mem_debug_panic( "trying to reallocate NULL in (%s:%ld)",
                           file_name, line_no );

    if ( new_size <= 0 )
      ft_mem_debug_panic(
        "trying to reallocate %p to size 0 (current is %ld) in (%s:%ld)",
        block, cur_size, file_name, line_no );

    /* check 'cur_size' value */
    pnode = ft_mem_table_get_nodep( table, (FT_Byte*)block );
    node  = *pnode;
    if ( !node )
      ft_mem_debug_panic(
        "trying to reallocate unknown block at %p in (%s:%ld)",
        block, file_name, line_no );

    if ( node->size <= 0 )
      ft_mem_debug_panic(
        "trying to reallocate freed block at %p in (%s:%ld)",
        block, file_name, line_no );

    if ( node->size != cur_size )
      ft_mem_debug_panic( "invalid ft_realloc request for %p. cur_size is "
                          "%ld instead of %ld in (%s:%ld)",
                          block, cur_size, node->size, file_name, line_no );

    new_block = ft_mem_debug_alloc( memory, new_size );
    if ( new_block == NULL )
      return NULL;

    ft_memcpy( new_block, block, cur_size < new_size ? cur_size : new_size );

    table->file_name = file_name;
    table->line_no   = line_no;

    ft_mem_debug_free( memory, (FT_Byte*)block );

    return new_block;
  }


  extern FT_Int
  ft_mem_debug_init( FT_Memory  memory )
  {
    FT_MemTable  table;
    FT_Int       result = 0;


    if ( getenv( "FT2_DEBUG_MEMORY" ) )
    {
      table = ft_mem_table_new( memory );
      if ( table )
      {
        const char*  p;
        
        memory->user    = table;
        memory->alloc   = ft_mem_debug_alloc;
        memory->realloc = ft_mem_debug_realloc;
        memory->free    = ft_mem_debug_free;
        
        p = getenv( "FT2_ALLOC_TOTAL_MAX" );
        if ( p != NULL )
        {
          FT_Long   total_max = atol(p);
          
          if ( total_max > 0 )
          {
            table->bound_total     = 1;
            table->alloc_total_max = (FT_ULong) total_max;
          }
        }
        
        p = getenv( "FT2_ALLOC_COUNT_MAX" );
        if ( p != NULL )
        {
          FT_Long  total_count = atol(p);
          
          if ( total_count > 0 )
          {
            table->bound_count     = 1;
            table->alloc_count_max = (FT_ULong) total_count;
          }
        }

        result = 1;
      }
    }
    return result;
  }


  extern void
  ft_mem_debug_done( FT_Memory  memory )
  {
    FT_MemTable  table = (FT_MemTable)memory->user;


    if ( table )
    {
      memory->free    = table->free;
      memory->realloc = table->realloc;
      memory->alloc   = table->alloc;

      ft_mem_table_destroy( table );
      memory->user = NULL;
    }
  }


  FT_BASE_DEF( FT_Error )
  FT_Alloc_Debug( FT_Memory    memory,
                  FT_Long      size,
                  void*       *P,
                  const char*  file_name,
                  FT_Long      line_no )
  {
    FT_MemTable  table = (FT_MemTable)memory->user;


    if ( table )
    {
      table->file_name = file_name;
      table->line_no   = line_no;
    }
    return FT_Alloc( memory, size, P );
  }


  FT_BASE_DEF( FT_Error )
  FT_Realloc_Debug( FT_Memory    memory,
                    FT_Long      current,
                    FT_Long      size,
                    void*       *P,
                    const char*  file_name,
                    FT_Long      line_no )
  {
    FT_MemTable  table = (FT_MemTable)memory->user;


    if ( table )
    {
      table->file_name = file_name;
      table->line_no   = line_no;
    }
    return FT_Realloc( memory, current, size, P );
  }


  FT_BASE_DEF( void )
  FT_Free_Debug( FT_Memory    memory,
                 FT_Pointer   block,
                 const char*  file_name,
                 FT_Long      line_no )
  {
    FT_MemTable  table = (FT_MemTable)memory->user;


    if ( table )
    {
      table->file_name = file_name;
      table->line_no   = line_no;
    }
    FT_Free( memory, (void **)block );
  }


#else  /* !FT_DEBUG_MEMORY */

  /* ANSI C doesn't like empty source files */
  const FT_Byte  _debug_mem_dummy = 0;

#endif /* !FT_DEBUG_MEMORY */


/* END */