1 /*
2 * Copyright (C) 2004, 2005, 2007, 2008, 2011, 2012 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 2000-2002 Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 /* $Id: mutex.c,v 1.18 2011/01/04 23:47:14 tbox Exp $ */
19
20 /*! \file */
21
22 #include <config.h>
23
24 #include <stdio.h>
25 #include <time.h>
26 #include <sys/time.h>
27 #include <errno.h>
28
29 #include <isc/mutex.h>
30 #include <isc/util.h>
31 #include <isc/strerror.h>
32
33 #if HAVE_PTHREADS < 5 /* HP-UX 10.20 has 4, needs this */
34 # define pthread_mutex_init(m, a) \
35 pthread_mutex_init(m, (a) \
36 ? *(const pthread_mutexattr_t *)(a) \
37 : pthread_mutexattr_default)
38 # define PTHREAD_MUTEX_RECURSIVE MUTEX_RECURSIVE_NP
39 # define pthread_mutexattr_settype pthread_mutexattr_setkind_np
40 #endif
41
42 #if ISC_MUTEX_PROFILE
43
44 /*@{*/
45 /*% Operations on timevals; adapted from FreeBSD's sys/time.h */
46 #define timevalclear(tvp) ((tvp)->tv_sec = (tvp)->tv_usec = 0)
47 #define timevaladd(vvp, uvp) \
48 do { \
49 (vvp)->tv_sec += (uvp)->tv_sec; \
50 (vvp)->tv_usec += (uvp)->tv_usec; \
51 if ((vvp)->tv_usec >= 1000000) { \
52 (vvp)->tv_sec++; \
53 (vvp)->tv_usec -= 1000000; \
54 } \
55 } while (0)
56 #define timevalsub(vvp, uvp) \
57 do { \
58 (vvp)->tv_sec -= (uvp)->tv_sec; \
59 (vvp)->tv_usec -= (uvp)->tv_usec; \
60 if ((vvp)->tv_usec < 0) { \
61 (vvp)->tv_sec--; \
62 (vvp)->tv_usec += 1000000; \
63 } \
64 } while (0)
65
66 /*@}*/
67
68 #define ISC_MUTEX_MAX_LOCKERS 32
69
70 typedef struct {
71 const char * file;
72 int line;
73 unsigned count;
74 struct timeval locked_total;
75 struct timeval wait_total;
76 } isc_mutexlocker_t;
77
78 struct isc_mutexstats {
79 const char * file; /*%< File mutex was created in. */
80 int line; /*%< Line mutex was created on. */
81 unsigned count;
82 struct timeval lock_t;
83 struct timeval locked_total;
84 struct timeval wait_total;
85 isc_mutexlocker_t * cur_locker;
86 isc_mutexlocker_t lockers[ISC_MUTEX_MAX_LOCKERS];
87 };
88
89 #ifndef ISC_MUTEX_PROFTABLESIZE
90 #define ISC_MUTEX_PROFTABLESIZE (1024 * 1024)
91 #endif
92 static isc_mutexstats_t stats[ISC_MUTEX_PROFTABLESIZE];
93 static int stats_next = 0;
94 static isc_boolean_t stats_init = ISC_FALSE;
95 static pthread_mutex_t statslock = PTHREAD_MUTEX_INITIALIZER;
96
97
98 isc_result_t
isc_mutex_init_profile(isc_mutex_t * mp,const char * file,int line)99 isc_mutex_init_profile(isc_mutex_t *mp, const char *file, int line) {
100 int i, err;
101
102 err = pthread_mutex_init(&mp->mutex, NULL);
103 if (err == ENOMEM)
104 return (ISC_R_NOMEMORY);
105 if (err != 0)
106 return (ISC_R_UNEXPECTED);
107
108 RUNTIME_CHECK(pthread_mutex_lock(&statslock) == 0);
109
110 if (stats_init == ISC_FALSE)
111 stats_init = ISC_TRUE;
112
113 /*
114 * If all statistics entries have been used, give up and trigger an
115 * assertion failure. There would be no other way to deal with this
116 * because we'd like to keep record of all locks for the purpose of
117 * debugging and the number of necessary locks is unpredictable.
118 * If this failure is triggered while debugging, named should be
119 * rebuilt with an increased ISC_MUTEX_PROFTABLESIZE.
120 */
121 RUNTIME_CHECK(stats_next < ISC_MUTEX_PROFTABLESIZE);
122 mp->stats = &stats[stats_next++];
123
124 RUNTIME_CHECK(pthread_mutex_unlock(&statslock) == 0);
125
126 mp->stats->file = file;
127 mp->stats->line = line;
128 mp->stats->count = 0;
129 timevalclear(&mp->stats->locked_total);
130 timevalclear(&mp->stats->wait_total);
131 for (i = 0; i < ISC_MUTEX_MAX_LOCKERS; i++) {
132 mp->stats->lockers[i].file = NULL;
133 mp->stats->lockers[i].line = 0;
134 mp->stats->lockers[i].count = 0;
135 timevalclear(&mp->stats->lockers[i].locked_total);
136 timevalclear(&mp->stats->lockers[i].wait_total);
137 }
138
139 return (ISC_R_SUCCESS);
140 }
141
142 isc_result_t
isc_mutex_lock_profile(isc_mutex_t * mp,const char * file,int line)143 isc_mutex_lock_profile(isc_mutex_t *mp, const char *file, int line) {
144 struct timeval prelock_t;
145 struct timeval postlock_t;
146 isc_mutexlocker_t *locker = NULL;
147 int i;
148
149 gettimeofday(&prelock_t, NULL);
150
151 if (pthread_mutex_lock(&mp->mutex) != 0)
152 return (ISC_R_UNEXPECTED);
153
154 gettimeofday(&postlock_t, NULL);
155 mp->stats->lock_t = postlock_t;
156
157 timevalsub(&postlock_t, &prelock_t);
158
159 mp->stats->count++;
160 timevaladd(&mp->stats->wait_total, &postlock_t);
161
162 for (i = 0; i < ISC_MUTEX_MAX_LOCKERS; i++) {
163 if (mp->stats->lockers[i].file == NULL) {
164 locker = &mp->stats->lockers[i];
165 locker->file = file;
166 locker->line = line;
167 break;
168 } else if (mp->stats->lockers[i].file == file &&
169 mp->stats->lockers[i].line == line) {
170 locker = &mp->stats->lockers[i];
171 break;
172 }
173 }
174
175 if (locker != NULL) {
176 locker->count++;
177 timevaladd(&locker->wait_total, &postlock_t);
178 }
179
180 mp->stats->cur_locker = locker;
181
182 return (ISC_R_SUCCESS);
183 }
184
185 isc_result_t
isc_mutex_unlock_profile(isc_mutex_t * mp,const char * file,int line)186 isc_mutex_unlock_profile(isc_mutex_t *mp, const char *file, int line) {
187 struct timeval unlock_t;
188
189 UNUSED(file);
190 UNUSED(line);
191
192 if (mp->stats->cur_locker != NULL) {
193 gettimeofday(&unlock_t, NULL);
194 timevalsub(&unlock_t, &mp->stats->lock_t);
195 timevaladd(&mp->stats->locked_total, &unlock_t);
196 timevaladd(&mp->stats->cur_locker->locked_total, &unlock_t);
197 mp->stats->cur_locker = NULL;
198 }
199
200 return ((pthread_mutex_unlock((&mp->mutex)) == 0) ? \
201 ISC_R_SUCCESS : ISC_R_UNEXPECTED);
202 }
203
204
205 void
isc_mutex_statsprofile(FILE * fp)206 isc_mutex_statsprofile(FILE *fp) {
207 isc_mutexlocker_t *locker;
208 int i, j;
209
210 fprintf(fp, "Mutex stats (in us)\n");
211 for (i = 0; i < stats_next; i++) {
212 fprintf(fp, "%-12s %4d: %10u %lu.%06lu %lu.%06lu %5d\n",
213 stats[i].file, stats[i].line, stats[i].count,
214 stats[i].locked_total.tv_sec,
215 stats[i].locked_total.tv_usec,
216 stats[i].wait_total.tv_sec,
217 stats[i].wait_total.tv_usec,
218 i);
219 for (j = 0; j < ISC_MUTEX_MAX_LOCKERS; j++) {
220 locker = &stats[i].lockers[j];
221 if (locker->file == NULL)
222 continue;
223 fprintf(fp, " %-11s %4d: %10u %lu.%06lu %lu.%06lu %5d\n",
224 locker->file, locker->line, locker->count,
225 locker->locked_total.tv_sec,
226 locker->locked_total.tv_usec,
227 locker->wait_total.tv_sec,
228 locker->wait_total.tv_usec,
229 i);
230 }
231 }
232 }
233
234 #endif /* ISC_MUTEX_PROFILE */
235
236 #if ISC_MUTEX_DEBUG && defined(PTHREAD_MUTEX_ERRORCHECK)
237 isc_result_t
isc_mutex_init_errcheck(isc_mutex_t * mp)238 isc_mutex_init_errcheck(isc_mutex_t *mp)
239 {
240 pthread_mutexattr_t attr;
241 int err;
242
243 if (pthread_mutexattr_init(&attr) != 0)
244 return (ISC_R_UNEXPECTED);
245
246 if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK) != 0) {
247 pthread_mutexattr_destroy(&attr);
248 return (ISC_R_UNEXPECTED);
249 }
250
251 err = pthread_mutex_init(mp, &attr) != 0)
252 pthread_mutexattr_destroy(&attr);
253 if (err == ENOMEM)
254 return (ISC_R_NOMEMORY);
255 return ((err == 0) ? ISC_R_SUCCESS : ISC_R_UNEXPECTED);
256 }
257 #endif
258
259 #if ISC_MUTEX_DEBUG && defined(__NetBSD__) && defined(PTHREAD_MUTEX_ERRORCHECK)
260 pthread_mutexattr_t isc__mutex_attrs = {
261 PTHREAD_MUTEX_ERRORCHECK, /* m_type */
262 0 /* m_flags, which appears to be unused. */
263 };
264 #endif
265
266 #if !(ISC_MUTEX_DEBUG && defined(PTHREAD_MUTEX_ERRORCHECK)) && !ISC_MUTEX_PROFILE
267 isc_result_t
isc__mutex_init(isc_mutex_t * mp,const char * file,unsigned int line)268 isc__mutex_init(isc_mutex_t *mp, const char *file, unsigned int line) {
269 char strbuf[ISC_STRERRORSIZE];
270 isc_result_t result = ISC_R_SUCCESS;
271 int err;
272
273 err = pthread_mutex_init(mp, ISC__MUTEX_ATTRS);
274 if (err == ENOMEM)
275 return (ISC_R_NOMEMORY);
276 if (err != 0) {
277 isc__strerror(errno, strbuf, sizeof(strbuf));
278 UNEXPECTED_ERROR(file, line, "isc_mutex_init() failed: %s",
279 strbuf);
280 result = ISC_R_UNEXPECTED;
281 }
282 return (result);
283 }
284 #endif
285