2 * Copyright (C) 2004, 2005, 2007, 2008, 2011, 2012, 2015 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 2000-2002 Internet Software Consortium.
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.
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.
18 /* $Id: mutex.c,v 1.18 2011/01/04 23:47:14 tbox Exp $ */
29 #include <isc/mutex.h>
31 #include <isc/print.h>
32 #include <isc/strerror.h>
37 /*% Operations on timevals; adapted from FreeBSD's sys/time.h */
38 #define timevalclear(tvp) ((tvp)->tv_sec = (tvp)->tv_usec = 0)
39 #define timevaladd(vvp, uvp) \
41 (vvp)->tv_sec += (uvp)->tv_sec; \
42 (vvp)->tv_usec += (uvp)->tv_usec; \
43 if ((vvp)->tv_usec >= 1000000) { \
45 (vvp)->tv_usec -= 1000000; \
48 #define timevalsub(vvp, uvp) \
50 (vvp)->tv_sec -= (uvp)->tv_sec; \
51 (vvp)->tv_usec -= (uvp)->tv_usec; \
52 if ((vvp)->tv_usec < 0) { \
54 (vvp)->tv_usec += 1000000; \
60 #define ISC_MUTEX_MAX_LOCKERS 32
66 struct timeval locked_total;
67 struct timeval wait_total;
70 struct isc_mutexstats {
71 const char * file; /*%< File mutex was created in. */
72 int line; /*%< Line mutex was created on. */
74 struct timeval lock_t;
75 struct timeval locked_total;
76 struct timeval wait_total;
77 isc_mutexlocker_t * cur_locker;
78 isc_mutexlocker_t lockers[ISC_MUTEX_MAX_LOCKERS];
81 #ifndef ISC_MUTEX_PROFTABLESIZE
82 #define ISC_MUTEX_PROFTABLESIZE (1024 * 1024)
84 static isc_mutexstats_t stats[ISC_MUTEX_PROFTABLESIZE];
85 static int stats_next = 0;
86 static isc_boolean_t stats_init = ISC_FALSE;
87 static pthread_mutex_t statslock = PTHREAD_MUTEX_INITIALIZER;
91 isc_mutex_init_profile(isc_mutex_t *mp, const char *file, int line) {
94 err = pthread_mutex_init(&mp->mutex, NULL);
96 return (ISC_R_NOMEMORY);
98 return (ISC_R_UNEXPECTED);
100 RUNTIME_CHECK(pthread_mutex_lock(&statslock) == 0);
102 if (stats_init == ISC_FALSE)
103 stats_init = ISC_TRUE;
106 * If all statistics entries have been used, give up and trigger an
107 * assertion failure. There would be no other way to deal with this
108 * because we'd like to keep record of all locks for the purpose of
109 * debugging and the number of necessary locks is unpredictable.
110 * If this failure is triggered while debugging, named should be
111 * rebuilt with an increased ISC_MUTEX_PROFTABLESIZE.
113 RUNTIME_CHECK(stats_next < ISC_MUTEX_PROFTABLESIZE);
114 mp->stats = &stats[stats_next++];
116 RUNTIME_CHECK(pthread_mutex_unlock(&statslock) == 0);
118 mp->stats->file = file;
119 mp->stats->line = line;
120 mp->stats->count = 0;
121 timevalclear(&mp->stats->locked_total);
122 timevalclear(&mp->stats->wait_total);
123 for (i = 0; i < ISC_MUTEX_MAX_LOCKERS; i++) {
124 mp->stats->lockers[i].file = NULL;
125 mp->stats->lockers[i].line = 0;
126 mp->stats->lockers[i].count = 0;
127 timevalclear(&mp->stats->lockers[i].locked_total);
128 timevalclear(&mp->stats->lockers[i].wait_total);
131 return (ISC_R_SUCCESS);
135 isc_mutex_lock_profile(isc_mutex_t *mp, const char *file, int line) {
136 struct timeval prelock_t;
137 struct timeval postlock_t;
138 isc_mutexlocker_t *locker = NULL;
141 gettimeofday(&prelock_t, NULL);
143 if (pthread_mutex_lock(&mp->mutex) != 0)
144 return (ISC_R_UNEXPECTED);
146 gettimeofday(&postlock_t, NULL);
147 mp->stats->lock_t = postlock_t;
149 timevalsub(&postlock_t, &prelock_t);
152 timevaladd(&mp->stats->wait_total, &postlock_t);
154 for (i = 0; i < ISC_MUTEX_MAX_LOCKERS; i++) {
155 if (mp->stats->lockers[i].file == NULL) {
156 locker = &mp->stats->lockers[i];
160 } else if (mp->stats->lockers[i].file == file &&
161 mp->stats->lockers[i].line == line) {
162 locker = &mp->stats->lockers[i];
167 if (locker != NULL) {
169 timevaladd(&locker->wait_total, &postlock_t);
172 mp->stats->cur_locker = locker;
174 return (ISC_R_SUCCESS);
178 isc_mutex_unlock_profile(isc_mutex_t *mp, const char *file, int line) {
179 struct timeval unlock_t;
184 if (mp->stats->cur_locker != NULL) {
185 gettimeofday(&unlock_t, NULL);
186 timevalsub(&unlock_t, &mp->stats->lock_t);
187 timevaladd(&mp->stats->locked_total, &unlock_t);
188 timevaladd(&mp->stats->cur_locker->locked_total, &unlock_t);
189 mp->stats->cur_locker = NULL;
192 return ((pthread_mutex_unlock((&mp->mutex)) == 0) ? \
193 ISC_R_SUCCESS : ISC_R_UNEXPECTED);
198 isc_mutex_statsprofile(FILE *fp) {
199 isc_mutexlocker_t *locker;
202 fprintf(fp, "Mutex stats (in us)\n");
203 for (i = 0; i < stats_next; i++) {
204 fprintf(fp, "%-12s %4d: %10u %lu.%06lu %lu.%06lu %5d\n",
205 stats[i].file, stats[i].line, stats[i].count,
206 stats[i].locked_total.tv_sec,
207 stats[i].locked_total.tv_usec,
208 stats[i].wait_total.tv_sec,
209 stats[i].wait_total.tv_usec,
211 for (j = 0; j < ISC_MUTEX_MAX_LOCKERS; j++) {
212 locker = &stats[i].lockers[j];
213 if (locker->file == NULL)
215 fprintf(fp, " %-11s %4d: %10u %lu.%06lu %lu.%06lu %5d\n",
216 locker->file, locker->line, locker->count,
217 locker->locked_total.tv_sec,
218 locker->locked_total.tv_usec,
219 locker->wait_total.tv_sec,
220 locker->wait_total.tv_usec,
226 #endif /* ISC_MUTEX_PROFILE */
228 #if ISC_MUTEX_DEBUG && defined(PTHREAD_MUTEX_ERRORCHECK)
230 isc_mutex_init_errcheck(isc_mutex_t *mp)
232 pthread_mutexattr_t attr;
235 if (pthread_mutexattr_init(&attr) != 0)
236 return (ISC_R_UNEXPECTED);
238 if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK) != 0) {
239 pthread_mutexattr_destroy(&attr);
240 return (ISC_R_UNEXPECTED);
243 err = pthread_mutex_init(mp, &attr) != 0)
244 pthread_mutexattr_destroy(&attr);
246 return (ISC_R_NOMEMORY);
247 return ((err == 0) ? ISC_R_SUCCESS : ISC_R_UNEXPECTED);
251 #if ISC_MUTEX_DEBUG && defined(__NetBSD__) && defined(PTHREAD_MUTEX_ERRORCHECK)
252 pthread_mutexattr_t isc__mutex_attrs = {
253 PTHREAD_MUTEX_ERRORCHECK, /* m_type */
254 0 /* m_flags, which appears to be unused. */
258 #if !(ISC_MUTEX_DEBUG && defined(PTHREAD_MUTEX_ERRORCHECK)) && !ISC_MUTEX_PROFILE
260 isc__mutex_init(isc_mutex_t *mp, const char *file, unsigned int line) {
261 char strbuf[ISC_STRERRORSIZE];
262 isc_result_t result = ISC_R_SUCCESS;
265 err = pthread_mutex_init(mp, ISC__MUTEX_ATTRS);
267 return (ISC_R_NOMEMORY);
269 isc__strerror(errno, strbuf, sizeof(strbuf));
270 UNEXPECTED_ERROR(file, line, "isc_mutex_init() failed: %s",
272 result = ISC_R_UNEXPECTED;