mdw@git.distorted.org.uk Git - mLib/blob - mem/track.h

   1 /* -*-c-*-
   2  *
   3  * Tracing functions for debugging
   4  *
   5  * (c) 1998 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of the mLib utilities library.
  11  *
  12  * mLib is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * mLib is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with mLib; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 #ifndef MLIB_TRACK_H
  29 #define MLIB_TRACK_H
  30
  31 #ifdef __cplusplus
  32   extern "C" {
  33 #endif
  34
  35 #include <stdlib.h>
  36
  37 /*----- Options and conventions -------------------------------------------*
  38  *
  39  * The following macros affect the tracking system:
  40  *
  41  * @TRACK_ENABLE@:      Enable tracking of memory allocations
  42  * @TRACK_BLAME@:       Register my context blocks in allocations
  43  *
  44  * The reason there are two switches is simple.  It's often the case that a
  45  * library routine allocates memory for its client.  Therefore, whether we
  46  * want to record the library or the client depends on how much we trust
  47  * the two pieces of software.  Setting @TRACK_ENABLE@ and @TRACK_BLAME@
  48  * suggests that the current source file might leak memory, so we want its
  49  * context markers in the list.  Setting @TRACK_ENABLE@ but not
  50  * @TRACK_BLAME@ suggests that we trust this code, but not the code which
  51  * calls it, so we want to preserve the caller's context markers.
  52  *
  53  * Got it?  Good.
  54  */
  55
  56 /*----- Type definitions --------------------------------------------------*/
  57
  58 /* --- A context buffer --- */
  59
  60 typedef struct track_ctx {
  61   struct track_ctx *next;
  62   const char *s;
  63 } track_ctx;
  64
  65 /*----- Functions provided ------------------------------------------------*/
  66
  67 /* --- @track_level@ --- *
  68  *
  69  * Arguments:   @unsigned int l@ = tracing level for allocation messages
  70  *
  71  * Returns:     ---
  72  *
  73  * Use:         Sets the trace level for allocation messages.
  74  */
  75
  76 extern void track_level(unsigned int /*l*/);
  77
  78 /* --- @track_push@ --- *
  79  *
  80  * Arguments:   @track_ctx *ctx@ = context holder to push
  81  *
  82  * Returns:     ---
  83  *
  84  * Use:         Pushes the given context block onto the stack.
  85  */
  86
  87 extern void track_push(track_ctx */*ctx*/);
  88
  89 /* --- @track_pop@ --- *
  90  *
  91  * Arguments:   @track_ctx *ctx@ = context holder to pop
  92  *
  93  * Returns:     ---
  94  *
  95  * Use:         Removes the given context block from the stack.
  96  */
  97
  98 extern void track_pop(track_ctx */*ctx*/);
  99
 100 /* --- @track_malloc@ --- *
 101  *
 102  * Arguments:   @size_t sz@ = size requested
 103  *
 104  * Returns:     Pointer to allocated space, or null
 105  *
 106  * Use:         Allocates memory, and tracks how much is allocated.
 107  */
 108
 109 extern void *track_malloc(size_t /*sz*/);
 110
 111 /* --- @track_free@ --- *
 112  *
 113  * Arguments:   @void *p@ = pointer to an allocated block
 114  *
 115  * Returns:     ---
 116  *
 117  * Use:         Frees memory, and tracks how much is still allocated.
 118  */
 119
 120 extern void track_free(void */*p*/);
 121
 122 /* --- @track_realloc@ --- *
 123  *
 124  * Arguments:   @void *p@ = pointer to an allocated block
 125  *              @size_t sz@ = how big it wants to be
 126  *
 127  * Returns:     Pointer to the new block.
 128  *
 129  * Use:         Reallocates a block, tracking how much memory is still
 130  *              available.
 131  */
 132
 133 extern void *track_realloc(void */*p*/, size_t /*sz*/);
 134
 135 /* --- @track_used@ --- *
 136  *
 137  * Arguments:   ---
 138  *
 139  * Returns:     A count of how much memory is used currently.
 140  *
 141  * Use:         Returns the amount of memory which the @track_@-functions
 142  *              above have counted as being currently allocated.
 143  */
 144
 145 extern unsigned long track_used(void);
 146
 147 /* --- @track_list@ --- *
 148  *
 149  * Arguments:   @unsigned int l@ = trace level to use
 150  *
 151  * Returns:     ---
 152  *
 153  * Use:         Traces a dump of the currently known blocks.  Combined with
 154  *              a verbose dump of allocations and deallocations, and a
 155  *              good idea of which blocks were allocated where, this can
 156  *              be useful for locating memory leaks.  It's not exactly a
 157  *              picnic, though.
 158  */
 159
 160 extern void track_list(unsigned int l);
 161
 162 /*----- Macro wrappers ----------------------------------------------------*/
 163
 164 /* --- If tracking is to be done, set it up --- */
 165
 166 #ifdef TRACK_ENABLE
 167 #  undef malloc
 168 #  define malloc(sz) track_malloc(sz)
 169 #  undef free
 170 #  define free(p) track_free(p)
 171 #  undef realloc
 172 #  define realloc(p, sz) track_realloc(p, sz)
 173 #endif
 174
 175 /* --- Provide a context for doing track-related things --- */
 176
 177 #ifdef TRACK_ENABLE
 178 #  define TRACK(x) x
 179 #else
 180 #  define TRACK(x)
 181 #endif
 182
 183 /* --- Handle contexts --- */
 184
 185 #if defined(TRACK_ENABLE) && defined(TRACK_BLAME)
 186 #  define TRACK_NCTX(name, string) track_ctx name = { 0, string }
 187 #  define TRACK_NPUSH(name) track_push(name)
 188 #  define TRACK_NPOP(name) track_pop(name)
 189 #  define TRACK_CTX(string) TRACK_NCTX(__track_ctx, string)
 190 #  define TRACK_PUSH TRACK_NPUSH(__track_ctx)
 191 #  define TRACK_POP TRACK_NPOP(__track_ctx)
 192 #else
 193 #  define TRACK_NCTX(name, string)
 194 #  define TRACK_NPUSH(name) ((void)0)
 195 #  define TRACK_NPOP(name) ((void)0)
 196 #  define TRACK_CTX(string)
 197 #  define TRACK_PUSH ((void)0)
 198 #  define TRACK_POP ((void)0)
 199 #endif
 200
 201 /*----- That's all, folks -------------------------------------------------*/
 202
 203 #ifdef __cplusplus
 204   }
 205 #endif
 206
 207 #endif