ftdbgmem.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

/***************************************************************************/
/*                                                                         */
/*  ftdbgmem.c                                                             */
/*                                                                         */
/*    Memory debugger (body).                                              */
/*                                                                         */
/*  Copyright 2001, 2002, 2003, 2004, 2005, 2006 by                        */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#include <ft2build.h>
#include FT_CONFIG_CONFIG_H
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_MEMORY_H
#include FT_SYSTEM_H
#include FT_ERRORS_H
#include FT_TYPES_H


#ifdef FT_DEBUG_MEMORY

#define  KEEPALIVE /* `Keep alive' means that freed blocks aren't released
                    * to the heap.  This is useful to detect double-frees
                    * or weird heap corruption, but it uses large amounts of
                    * memory, however.
                    */

#include <stdio.h>
#include <stdlib.h>

  FT_BASE_DEF( const char* )  _ft_debug_file   = 0;
  FT_BASE_DEF( long )         _ft_debug_lineno = 0;

  extern void
  FT_DumpMemory( FT_Memory  memory );


  typedef struct FT_MemSourceRec_*  FT_MemSource;
  typedef struct FT_MemNodeRec_*    FT_MemNode;
  typedef struct FT_MemTableRec_*   FT_MemTable;


#define FT_MEM_VAL( addr )  ((FT_ULong)(FT_Pointer)( addr ))

  /*
   *  This structure holds statistics for a single allocation/release
   *  site.  This is useful to know where memory operations happen the
   *  most.
   */
  typedef struct  FT_MemSourceRec_
  {
    const char*   file_name;
    long          line_no;

    FT_Long       cur_blocks;   /* current number of allocated blocks */
    FT_Long       max_blocks;   /* max. number of allocated blocks    */
    FT_Long       all_blocks;   /* total number of blocks allocated   */

    FT_Long       cur_size;     /* current cumulative allocated size */
    FT_Long       max_size;     /* maximum cumulative allocated size */
    FT_Long       all_size;     /* total cumulative allocated size   */

    FT_Long       cur_max;      /* current maximum allocated size */

    FT_UInt32     hash;
    FT_MemSource  link;

  } FT_MemSourceRec;


  /*
   *  We don't need a resizable array for the memory sources, because
   *  their number is pretty limited within FreeType.
   */
#define FT_MEM_SOURCE_BUCKETS  128

  /*
   *  This structure holds information related to a single allocated
   *  memory block.  If KEEPALIVE is defined, blocks that are freed by
   *  FreeType are never released to the system.  Instead, their `size'
   *  field is set to -size.  This is mainly useful to detect double frees,
   *  at the price of large memory footprint during execution.
   */
  typedef struct  FT_MemNodeRec_
  {
    FT_Byte*      address;
    FT_Long       size;     /* < 0 if the block was freed */

    FT_MemSource  source;

#ifdef KEEPALIVE
    const char*   free_file_name;
    FT_Long       free_line_no;
#endif

    FT_MemNode    link;

  } FT_MemNodeRec;


  /*
   *  The global structure, containing compound statistics and all hash
   *  tables.
   */
  typedef struct  FT_MemTableRec_
  {
    FT_ULong         size;
    FT_ULong         nodes;
    FT_MemNode*      buckets;

    FT_ULong         alloc_total;
    FT_ULong         alloc_current;
    FT_ULong         alloc_max;
    FT_ULong         alloc_count;

    FT_Bool          bound_total;
    FT_ULong         alloc_total_max;

    FT_Bool          bound_count;
    FT_ULong         alloc_count_max;

    FT_MemSource     sources[FT_MEM_SOURCE_BUCKETS];

    FT_Bool          keep_alive;

    FT_Memory        memory;
    FT_Pointer       memory_user;
    FT_Alloc_Func    alloc;
    FT_Free_Func     free;
    FT_Realloc_Func  realloc;

  } FT_MemTableRec;


#define FT_MEM_SIZE_MIN  7
#define FT_MEM_SIZE_MAX  13845163

#define FT_FILENAME( x )  ((x) ? (x) : "unknown file")


  /*
   *  Prime numbers are ugly to handle.  It would be better to implement
   *  L-Hashing, which is 10% faster and doesn't require divisions.
   */
  static const FT_UInt  ft_mem_primes[] =
  {
    7,
    11,
    19,
    37,
    73,
    109,
    163,
    251,
    367,
    557,
    823,
    1237,
    1861,
    2777,
    4177,
    6247,
    9371,
    14057,
    21089,
    31627,
    47431,
    71143,
    106721,
    160073,
    240101,
    360163,
    540217,
    810343,
    1215497,
    1823231,
    2734867,
    4102283,
    6153409,
    9230113,
    13845163,
  };


  static FT_ULong
  ft_mem_closest_prime( FT_ULong  num )
  {
    FT_UInt  i;


    for ( i = 0;
          i < sizeof ( ft_mem_primes ) / sizeof ( ft_mem_primes[0] ); i++ )
      if ( ft_mem_primes[i] > num )
        return ft_mem_primes[i];

    return FT_MEM_SIZE_MAX;
  }


  extern void
  ft_mem_debug_panic( const char*  fmt,
                      ... )
  {
    va_list  ap;


    printf( "FreeType.Debug: " );

    va_start( ap, fmt );
    vprintf( fmt, ap );
    va_end( ap );

    printf( "\n" );
    exit( EXIT_FAILURE );
  }


  static FT_Pointer
  ft_mem_table_alloc( FT_MemTable  table,
                      FT_Long      size )
  {
    FT_Memory   memory = table->memory;
    FT_Pointer  block;


    memory->user = table->memory_user;
    block = table->alloc( memory, size );
    memory->user = table;

    return block;
  }


  static void
  ft_mem_table_free( FT_MemTable  table,
                     FT_Pointer   block )
  {
    FT_Memory  memory = table->memory;


    memory->user = table->memory_user;
    table->free( memory, block );
    memory->user = table;
  }


  static void
  ft_mem_table_resize( FT_MemTable  table )
  {
    FT_ULong  new_size;


    new_size = ft_mem_closest_prime( table->nodes );
    if ( new_size != table->size )
    {
      FT_MemNode*  new_buckets;
      FT_ULong     i;


      new_buckets = (FT_MemNode *)
                      ft_mem_table_alloc( table,
                                          new_size * sizeof ( FT_MemNode ) );
      if ( new_buckets == NULL )
        return;

      FT_ARRAY_ZERO( new_buckets, new_size );

      for ( i = 0; i < table->size; i++ )
      {
        FT_MemNode  node, next, *pnode;
        FT_ULong    hash;


        node = table->buckets[i];
        while ( node )
        {
          next  = node->link;
          hash  = FT_MEM_VAL( node->address ) % new_size;
          pnode = new_buckets + hash;

          node->link = pnode[0];
          pnode[0]   = node;

          node = next;
        }
      }

      if ( table->buckets )
        ft_mem_table_free( table, table->buckets );

      table->buckets = new_buckets;
      table->size    = new_size;
    }
  }


  static FT_MemTable
  ft_mem_table_new( FT_Memory  memory )
  {
    FT_MemTable  table;


    table = (FT_MemTable)memory->alloc( memory, sizeof ( *table ) );
    if ( table == NULL )
      goto Exit;

    FT_ZERO( table );

    table->size  = FT_MEM_SIZE_MIN;
    table->nodes = 0;

    table->memory = memory;

    table->memory_user = memory->user;

    table->alloc   = memory->alloc;
    table->realloc = memory->realloc;
    table->free    = memory->free;

    table->buckets = (FT_MemNode *)
                       memory->alloc( memory,
                                      table->size * sizeof ( FT_MemNode ) );
    if ( table->buckets )
      FT_ARRAY_ZERO( table->buckets, table->size );
    else
    {
      memory->free( memory, table );
      table = NULL;
    }

  Exit:
    return table;
  }


  static void
  ft_mem_table_destroy( FT_MemTable  table )
  {
    FT_ULong  i;


    FT_DumpMemory( table->memory );

    if ( table )
    {
      FT_Long   leak_count = 0;
      FT_ULong  leaks      = 0;


      /* remove all blocks from the table, revealing leaked ones */
      for ( i = 0; i < table->size; i++ )
      {
        FT_MemNode  *pnode = table->buckets + i, next, node = *pnode;


        while ( node )
        {
          next       = node->link;
          node->link = 0;

          if ( node->size > 0 )
          {
            printf(
              "leaked memory block at address %p, size %8ld in (%s:%ld)\n",
              node->address, node->size,
              FT_FILENAME( node->source->file_name ),
              node->source->line_no );

            leak_count++;
            leaks += node->size;

            ft_mem_table_free( table, node->address );
          }

          node->address = NULL;
          node->size    = 0;

          ft_mem_table_free( table, node );
          node = next;
        }
        table->buckets[i] = 0;
      }

      ft_mem_table_free( table, table->buckets );
      table->buckets = NULL;

      table->size  = 0;
      table->nodes = 0;

      /* remove all sources */
      for ( i = 0; i < FT_MEM_SOURCE_BUCKETS; i++ )
      {
        FT_MemSource  source, next;


        for ( source = table->sources[i]; source != NULL; source = next )
        {
          next = source->link;
          ft_mem_table_free( table, source );
        }

        table->sources[i] = NULL;
      }

      printf(
        "FreeType: total memory allocations = %ld\n", table->alloc_total );
      printf(
        "FreeType: maximum memory footprint = %ld\n", table->alloc_max );

      ft_mem_table_free( table, table );

      if ( leak_count > 0 )
        ft_mem_debug_panic(
          "FreeType: %ld bytes of memory leaked in %ld blocks\n",
          leaks, leak_count );

      printf( "FreeType: No memory leaks detected!\n" );
    }
  }


  static FT_MemNode*
  ft_mem_table_get_nodep( FT_MemTable  table,
                          FT_Byte*     address )
  {
    FT_ULong     hash;
    FT_MemNode  *pnode, node;


    hash  = FT_MEM_VAL( address );
    pnode = table->buckets + ( hash % table->size );

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

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

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


  static FT_MemSource
  ft_mem_table_get_source( FT_MemTable  table )
  {
    FT_UInt32     hash;
    FT_MemSource  node, *pnode;


    /* cast to FT_PtrDist first since void* can be larger */
    /* than FT_UInt32 and GCC 4.1.1 emits a warning       */
    hash  = (FT_UInt32)(FT_PtrDist)(void*)_ft_debug_file +
              (FT_UInt32)( 5 * _ft_debug_lineno );
    pnode = &table->sources[hash % FT_MEM_SOURCE_BUCKETS];

    for ( ;; )
    {
      node = *pnode;
      if ( node == NULL )
        break;

      if ( node->file_name == _ft_debug_file &&
           node->line_no   == _ft_debug_lineno   )
        goto Exit;

      pnode = &node->link;
    }

    node = (FT_MemSource)ft_mem_table_alloc( table, sizeof ( *node ) );
    if ( node == NULL )
      ft_mem_debug_panic(
        "not enough memory to perform memory debugging\n" );

    node->file_name = _ft_debug_file;
    node->line_no   = _ft_debug_lineno;

    node->cur_blocks = 0;
    node->max_blocks = 0;
    node->all_blocks = 0;

    node->cur_size   = 0;
    node->max_size   = 0;
    node->all_size   = 0;

    node->cur_max    = 0;

    node->link = NULL;