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Change licensing conditions to LGPL.
[mLib] / track.c
1 /* -*-c-*-
2 *
3 * $Id: track.c,v 1.2 1999/05/05 18:50:31 mdw Exp $
4 *
5 * Tracing functions for debugging
6 *
7 * (c) 1998 Straylight/Edgeware
8 */
9
10 /*----- Licensing notice --------------------------------------------------*
11 *
12 * This file is part of the mLib utilities library.
13 *
14 * mLib is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
18 *
19 * mLib is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU Library General Public License for more details.
23 *
24 * You should have received a copy of the GNU Library General Public
25 * License along with mLib; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 */
28
29 /*----- Revision history --------------------------------------------------*
30 *
31 * $Log: track.c,v $
32 * Revision 1.2 1999/05/05 18:50:31 mdw
33 * Change licensing conditions to LGPL.
34 *
35 * Revision 1.1.1.1 1998/06/17 23:44:42 mdw
36 * Initial version of mLib
37 *
38 */
39
40 /*----- Header files ------------------------------------------------------*/
41
42 /* --- ANSI headers --- */
43
44 #include <ctype.h>
45 #include <stdarg.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49
50 /* --- Local headers --- */
51
52 #include "trace.h"
53 #include "track.h"
54
55 /*----- Type definitions --------------------------------------------------*/
56
57 /* --- A track block --- *
58 *
59 * This gets prefixed to every block I manage.
60 */
61
62 typedef union track__block {
63 struct {
64 union track__block *next; /* Link to previous block */
65 union track__block *prev; /* Link to next block */
66 size_t sz; /* Size of the block */
67 const char *ctx; /* Pointer to allocating context */
68 } x; /* Main data area */
69 long double _ld; /* Long double for alignment */
70 void *_p; /* Void pointer for alignment */
71 } track__block;
72
73 /*----- Private state -----------------------------------------------------*/
74
75 /* --- Tracking memory usage --- */
76
77 static unsigned int track__used = 0; /* Count of bytes occupied */
78 static track__block *track__list; /* List of allocated blocks */
79
80 /* --- Trace level for verbose messages --- */
81
82 static unsigned int track__vLevel = 0;
83
84 /* --- Context tracking --- */
85
86 static track_ctx track__baseContext = {
87 0, "[unknown context]"
88 };
89
90 static track_ctx *track__context = &track__baseContext;
91
92 /*----- Functions provided ------------------------------------------------*/
93
94 /* --- @track_setLevel@ --- *
95 *
96 * Arguments: @unsigned int l@ = tracing level for allocation messages
97 *
98 * Returns: ---
99 *
100 * Use: Sets the trace level for allocation messages.
101 */
102
103 void track_setLevel(unsigned int l)
104 {
105 track__vLevel = l;
106 }
107
108 /* --- @track_pushContext@ --- *
109 *
110 * Arguments: @track_ctx *ctx@ = context holder to push
111 *
112 * Returns: ---
113 *
114 * Use: Pushes the given context block onto the stack.
115 */
116
117 void track_pushContext(track_ctx *ctx)
118 {
119 ctx->next = track__context;
120 track__context = ctx;
121 }
122
123 /* --- @track_popContext@ --- *
124 *
125 * Arguments: @track_ctx *ctx@ = context holder to pop
126 *
127 * Returns: ---
128 *
129 * Use: Removes the given context block from the stack.
130 */
131
132 void track_popContext(track_ctx *ctx)
133 {
134 track__context = ctx->next;
135 }
136
137 /* --- @track_malloc@ --- *
138 *
139 * Arguments: @size_t sz@ = size requested
140 *
141 * Returns: Pointer to allocated space, or null
142 *
143 * Use: Allocates memory, and tracks how much is allocated.
144 */
145
146 void *track_malloc(size_t sz)
147 {
148 track__block *q = (malloc)(sz + sizeof(track__block));
149 if (q) {
150 track__used += sz;
151 if (track__vLevel) {
152 trace(track__vLevel, "(track) allocated %lu at %p in %s",
153 (unsigned long)sz, (void *)(q + 1), track__context->s);
154 }
155 q->x.sz = sz;
156 q->x.next = track__list;
157 q->x.prev = 0;
158 q->x.ctx = track__context->s;
159 if (q->x.next)
160 q->x.next->x.prev = q;
161 track__list = q;
162 return (q + 1);
163 }
164 return (0);
165 }
166
167 /* --- @track_free@ --- *
168 *
169 * Arguments: @void *p@ = pointer to an allocated block
170 *
171 * Returns: ---
172 *
173 * Use: Frees memory, and tracks how much is still allocated.
174 */
175
176 void track_free(void *p)
177 {
178 track__block *q;
179
180 if (!p)
181 return;
182 q = (track__block *)p - 1;
183 if (track__vLevel) {
184 trace(track__vLevel, "(track) freed %lu at %p for %s in %s",
185 (unsigned long)q->x.sz, (void *)(q + 1),
186 q->x.ctx, track__context->s);
187 }
188 if (q->x.next)
189 q->x.next->x.prev = q->x.prev;
190 if (q->x.prev)
191 q->x.prev->x.next = q->x.next;
192 else
193 track__list = q->x.next;
194 track__used -= q->x.sz;
195 (free)(q);
196 }
197
198 /* --- @track_realloc@ --- *
199 *
200 * Arguments: @void *p@ = pointer to an allocated block
201 * @size_t sz@ = how big it wants to be
202 *
203 * Returns: Pointer to the new block.
204 *
205 * Use: Reallocates a block, tracking how much memory is still
206 * available.
207 */
208
209 void *track_realloc(void *p, size_t sz)
210 {
211 size_t osz;
212 track__block *q, *qq;
213 if (p) {
214 q = (track__block *)p - 1;
215 osz = q->x.sz;
216 if (q->x.next)
217 q->x.next->x.prev = q->x.prev;
218 if (q->x.prev)
219 q->x.prev->x.next = q->x.next;
220 else
221 track__list = q->x.next;
222 } else {
223 q = 0;
224 osz = 0;
225 }
226 qq = (realloc)(q, sz + sizeof(track__block));
227 if (qq) {
228 if (track__vLevel) {
229 trace(track__vLevel,
230 "(track) reallocated %lu at %p to %lu for %s in %s",
231 (unsigned long)osz, (void *)(q + 1),
232 (unsigned long)sz, (void *)(qq + 1),
233 qq->x.ctx, track__context->s);
234 }
235 qq->x.sz = sz;
236 qq->x.next = track__list;
237 qq->x.prev = 0;
238 if (qq->x.next)
239 qq->x.next->x.prev = qq;
240 track__list = qq;
241 track__used += sz - osz;
242 qq->x.sz = sz;
243 return (qq + 1);
244 }
245 return (0);
246 }
247
248 /* --- @track_used@ --- *
249 *
250 * Arguments: ---
251 *
252 * Returns: A count of how much memory is used currently.
253 *
254 * Use: Returns the amount of memory which the @track_@-functions
255 * above have counted as being currently allocated.
256 */
257
258 unsigned long track_used(void)
259 {
260 return (track__used);
261 }
262
263 /* --- @track_list@ --- *
264 *
265 * Arguments: @unsigned int l@ = trace level to use
266 *
267 * Returns: ---
268 *
269 * Use: Traces a dump of the currently known blocks. Combined with
270 * a verbose dump of allocations and deallocations, and a
271 * good idea of which blocks were allocated where, this can
272 * be useful for locating memory leaks. It's not exactly a
273 * picnic, though.
274 */
275
276 void track_list(unsigned int l)
277 {
278 track__block *q = track__list;
279
280 if (!(tracing() & l))
281 return;
282
283 trace(l, "(track dump) Dumping all blocks. Stand well back...");
284 while (q) {
285 trace(l, "(track dump) %p: %lu in %s",
286 (void *)(q + 1), (unsigned long)q->x.sz, q->x.ctx);
287 q = q->x.next;
288 }
289 }
290
291 /*----- That's all, folks -------------------------------------------------*/
mLib utilities library