2 * Copyright (C) 2004, 2005, 2007, 2008, 2011 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/strerror.h>
36 /*% Operations on timevals; adapted from FreeBSD's sys/time.h */
37 #define timevalclear(tvp) ((tvp)->tv_sec = (tvp)->tv_usec = 0)
38 #define timevaladd(vvp, uvp) \
40 (vvp)->tv_sec += (uvp)->tv_sec; \
41 (vvp)->tv_usec += (uvp)->tv_usec; \
42 if ((vvp)->tv_usec >= 1000000) { \
44 (vvp)->tv_usec -= 1000000; \
47 #define timevalsub(vvp, uvp) \
49 (vvp)->tv_sec -= (uvp)->tv_sec; \
50 (vvp)->tv_usec -= (uvp)->tv_usec; \
51 if ((vvp)->tv_usec < 0) { \
53 (vvp)->tv_usec += 1000000; \
59 #define ISC_MUTEX_MAX_LOCKERS 32
65 struct timeval locked_total;
66 struct timeval wait_total;
69 struct isc_mutexstats {
70 const char * file; /*%< File mutex was created in. */
71 int line; /*%< Line mutex was created on. */
73 struct timeval lock_t;
74 struct timeval locked_total;
75 struct timeval wait_total;
76 isc_mutexlocker_t * cur_locker;
77 isc_mutexlocker_t lockers[ISC_MUTEX_MAX_LOCKERS];
80 #ifndef ISC_MUTEX_PROFTABLESIZE
81 #define ISC_MUTEX_PROFTABLESIZE (16 * 1024)
83 static isc_mutexstats_t stats[ISC_MUTEX_PROFTABLESIZE];
84 static int stats_next = 0;
85 static isc_boolean_t stats_init = ISC_FALSE;
86 static pthread_mutex_t statslock = PTHREAD_MUTEX_INITIALIZER;
90 isc_mutex_init_profile(isc_mutex_t *mp, const char *file, int line) {
93 err = pthread_mutex_init(&mp->mutex, NULL);
95 return (ISC_R_NOMEMORY);
97 return (ISC_R_UNEXPECTED);
99 RUNTIME_CHECK(pthread_mutex_lock(&statslock) == 0);
101 if (stats_init == ISC_FALSE)
102 stats_init = ISC_TRUE;
105 * If all statistics entries have been used, give up and trigger an
106 * assertion failure. There would be no other way to deal with this
107 * because we'd like to keep record of all locks for the purpose of
108 * debugging and the number of necessary locks is unpredictable.
109 * If this failure is triggered while debugging, named should be
110 * rebuilt with an increased ISC_MUTEX_PROFTABLESIZE.
112 RUNTIME_CHECK(stats_next < ISC_MUTEX_PROFTABLESIZE);
113 mp->stats = &stats[stats_next++];
115 RUNTIME_CHECK(pthread_mutex_unlock(&statslock) == 0);
117 mp->stats->file = file;
118 mp->stats->line = line;
119 mp->stats->count = 0;
120 timevalclear(&mp->stats->locked_total);
121 timevalclear(&mp->stats->wait_total);
122 for (i = 0; i < ISC_MUTEX_MAX_LOCKERS; i++) {
123 mp->stats->lockers[i].file = NULL;
124 mp->stats->lockers[i].line = 0;
125 mp->stats->lockers[i].count = 0;
126 timevalclear(&mp->stats->lockers[i].locked_total);
127 timevalclear(&mp->stats->lockers[i].wait_total);
130 return (ISC_R_SUCCESS);
134 isc_mutex_lock_profile(isc_mutex_t *mp, const char *file, int line) {
135 struct timeval prelock_t;
136 struct timeval postlock_t;
137 isc_mutexlocker_t *locker = NULL;
140 gettimeofday(&prelock_t, NULL);
142 if (pthread_mutex_lock(&mp->mutex) != 0)
143 return (ISC_R_UNEXPECTED);
145 gettimeofday(&postlock_t, NULL);
146 mp->stats->lock_t = postlock_t;
148 timevalsub(&postlock_t, &prelock_t);
151 timevaladd(&mp->stats->wait_total, &postlock_t);
153 for (i = 0; i < ISC_MUTEX_MAX_LOCKERS; i++) {
154 if (mp->stats->lockers[i].file == NULL) {
155 locker = &mp->stats->lockers[i];
159 } else if (mp->stats->lockers[i].file == file &&
160 mp->stats->lockers[i].line == line) {
161 locker = &mp->stats->lockers[i];
166 if (locker != NULL) {
168 timevaladd(&locker->wait_total, &postlock_t);
171 mp->stats->cur_locker = locker;
173 return (ISC_R_SUCCESS);
177 isc_mutex_unlock_profile(isc_mutex_t *mp, const char *file, int line) {
178 struct timeval unlock_t;
183 if (mp->stats->cur_locker != NULL) {
184 gettimeofday(&unlock_t, NULL);
185 timevalsub(&unlock_t, &mp->stats->lock_t);
186 timevaladd(&mp->stats->locked_total, &unlock_t);
187 timevaladd(&mp->stats->cur_locker->locked_total, &unlock_t);
188 mp->stats->cur_locker = NULL;
191 return ((pthread_mutex_unlock((&mp->mutex)) == 0) ? \
192 ISC_R_SUCCESS : ISC_R_UNEXPECTED);
197 isc_mutex_statsprofile(FILE *fp) {
198 isc_mutexlocker_t *locker;
201 fprintf(fp, "Mutex stats (in us)\n");
202 for (i = 0; i < stats_next; i++) {
203 fprintf(fp, "%-12s %4d: %10u %lu.%06lu %lu.%06lu\n",
204 stats[i].file, stats[i].line, stats[i].count,
205 stats[i].locked_total.tv_sec,
206 stats[i].locked_total.tv_usec,
207 stats[i].wait_total.tv_sec,
208 stats[i].wait_total.tv_usec
210 for (j = 0; j < ISC_MUTEX_MAX_LOCKERS; j++) {
211 locker = &stats[i].lockers[j];
212 if (locker->file == NULL)
214 fprintf(fp, " %-11s %4d: %10u %lu.%06lu %lu.%06lu\n",
215 locker->file, locker->line, locker->count,
216 locker->locked_total.tv_sec,
217 locker->locked_total.tv_usec,
218 locker->wait_total.tv_sec,
219 locker->wait_total.tv_usec
225 #endif /* ISC_MUTEX_PROFILE */
227 #if ISC_MUTEX_DEBUG && defined(PTHREAD_MUTEX_ERRORCHECK)
229 isc_mutex_init_errcheck(isc_mutex_t *mp)
231 pthread_mutexattr_t attr;
234 if (pthread_mutexattr_init(&attr) != 0)
235 return (ISC_R_UNEXPECTED);
237 if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK) != 0) {
238 pthread_mutexattr_destroy(&attr);
239 return (ISC_R_UNEXPECTED);
242 err = pthread_mutex_init(mp, &attr) != 0)
243 pthread_mutexattr_destroy(&attr);
245 return (ISC_R_NOMEMORY);
246 return ((err == 0) ? ISC_R_SUCCESS : ISC_R_UNEXPECTED);
250 #if ISC_MUTEX_DEBUG && defined(__NetBSD__) && defined(PTHREAD_MUTEX_ERRORCHECK)
251 pthread_mutexattr_t isc__mutex_attrs = {
252 PTHREAD_MUTEX_ERRORCHECK, /* m_type */
253 0 /* m_flags, which appears to be unused. */
257 #if !(ISC_MUTEX_DEBUG && defined(PTHREAD_MUTEX_ERRORCHECK)) && !ISC_MUTEX_PROFILE
259 isc__mutex_init(isc_mutex_t *mp, const char *file, unsigned int line) {
260 char strbuf[ISC_STRERRORSIZE];
261 isc_result_t result = ISC_R_SUCCESS;
264 err = pthread_mutex_init(mp, ISC__MUTEX_ATTRS);
266 return (ISC_R_NOMEMORY);
268 isc__strerror(errno, strbuf, sizeof(strbuf));
269 UNEXPECTED_ERROR(file, line, "isc_mutex_init() failed: %s",
271 result = ISC_R_UNEXPECTED;