contrib/bind-9.5.2/lib/isc/pthreads/mutex.c

   1 /*
   2  * Copyright (C) 2004, 2005, 2007, 2008  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 1.14.128.2 2008/04/04 23:46:31 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 ISC_MUTEX_PROFILE
  34
  35 /*@{*/
  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)                                            \
  39         do {                                                            \
  40                 (vvp)->tv_sec += (uvp)->tv_sec;                         \
  41                 (vvp)->tv_usec += (uvp)->tv_usec;                       \
  42                 if ((vvp)->tv_usec >= 1000000) {                        \
  43                         (vvp)->tv_sec++;                                \
  44                         (vvp)->tv_usec -= 1000000;                      \
  45                 }                                                       \
  46         } while (0)
  47 #define timevalsub(vvp, uvp)                                            \
  48         do {                                                            \
  49                 (vvp)->tv_sec -= (uvp)->tv_sec;                         \
  50                 (vvp)->tv_usec -= (uvp)->tv_usec;                       \
  51                 if ((vvp)->tv_usec < 0) {                               \
  52                         (vvp)->tv_sec--;                                \
  53                         (vvp)->tv_usec += 1000000;                      \
  54                 }                                                       \
  55         } while (0)
  56
  57 /*@}*/
  58
  59 #define ISC_MUTEX_MAX_LOCKERS 32
  60
  61 typedef struct {
  62         const char *            file;
  63         int                     line;
  64         unsigned                count;
  65         struct timeval          locked_total;
  66         struct timeval          wait_total;
  67 } isc_mutexlocker_t;
  68
  69 struct isc_mutexstats {
  70         const char *            file;   /*%< File mutex was created in. */
  71         int                     line;   /*%< Line mutex was created on. */
  72         unsigned                count;
  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];
  78 };
  79
  80 #ifndef ISC_MUTEX_PROFTABLESIZE
  81 #define ISC_MUTEX_PROFTABLESIZE (16 * 1024)
  82 #endif
  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;
  87
  88
  89 isc_result_t
  90 isc_mutex_init_profile(isc_mutex_t *mp, const char *file, int line) {
  91         int i, err;
  92
  93         err = pthread_mutex_init(&mp->mutex, NULL);
  94         if (err == ENOMEM)
  95                 return (ISC_R_NOMEMORY);
  96         if (err != 0)
  97                 return (ISC_R_UNEXPECTED);
  98
  99         RUNTIME_CHECK(pthread_mutex_lock(&statslock) == 0);
 100
 101         if (stats_init == ISC_FALSE)
 102                 stats_init = ISC_TRUE;
 103
 104         /*
 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.
 111          */
 112         RUNTIME_CHECK(stats_next < ISC_MUTEX_PROFTABLESIZE);
 113         mp->stats = &stats[stats_next++];
 114
 115         RUNTIME_CHECK(pthread_mutex_unlock(&statslock) == 0);
 116
 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);
 128         }
 129
 130         return (ISC_R_SUCCESS);
 131 }
 132
 133 isc_result_t
 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;
 138         int i;
 139
 140         gettimeofday(&prelock_t, NULL);
 141
 142         if (pthread_mutex_lock(&mp->mutex) != 0)
 143                 return (ISC_R_UNEXPECTED);
 144
 145         gettimeofday(&postlock_t, NULL);
 146         mp->stats->lock_t = postlock_t;
 147
 148         timevalsub(&postlock_t, &prelock_t);
 149
 150         mp->stats->count++;
 151         timevaladd(&mp->stats->wait_total, &postlock_t);
 152
 153         for (i = 0; i < ISC_MUTEX_MAX_LOCKERS; i++) {
 154                 if (mp->stats->lockers[i].file == NULL) {
 155                         locker = &mp->stats->lockers[i];
 156                         locker->file = file;
 157                         locker->line = line;
 158                         break;
 159                 } else if (mp->stats->lockers[i].file == file &&
 160                            mp->stats->lockers[i].line == line) {
 161                         locker = &mp->stats->lockers[i];
 162                         break;
 163                 }
 164         }
 165
 166         if (locker != NULL) {
 167                 locker->count++;
 168                 timevaladd(&locker->wait_total, &postlock_t);
 169         }
 170
 171         mp->stats->cur_locker = locker;
 172
 173         return (ISC_R_SUCCESS);
 174 }
 175
 176 isc_result_t
 177 isc_mutex_unlock_profile(isc_mutex_t *mp, const char *file, int line) {
 178         struct timeval unlock_t;
 179
 180         UNUSED(file);
 181         UNUSED(line);
 182
 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;
 189         }
 190
 191         return ((pthread_mutex_unlock((&mp->mutex)) == 0) ? \
 192                 ISC_R_SUCCESS : ISC_R_UNEXPECTED);
 193 }
 194
 195
 196 void
 197 isc_mutex_statsprofile(FILE *fp) {
 198         isc_mutexlocker_t *locker;
 199         int i, j;
 200
 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
 209                         );
 210                 for (j = 0; j < ISC_MUTEX_MAX_LOCKERS; j++) {
 211                         locker = &stats[i].lockers[j];
 212                         if (locker->file == NULL)
 213                                 continue;
 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
 220                                 );
 221                 }
 222         }
 223 }
 224
 225 #endif /* ISC_MUTEX_PROFILE */
 226
 227 #if ISC_MUTEX_DEBUG && defined(PTHREAD_MUTEX_ERRORCHECK)
 228 isc_result_t
 229 isc_mutex_init_errcheck(isc_mutex_t *mp)
 230 {
 231         pthread_mutexattr_t attr;
 232         int err;
 233
 234         if (pthread_mutexattr_init(&attr) != 0)
 235                 return (ISC_R_UNEXPECTED);
 236
 237         if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK) != 0)
 238                 return (ISC_R_UNEXPECTED);
 239
 240         err = pthread_mutex_init(mp, &attr) != 0)
 241         if (err == ENOMEM)
 242                 return (ISC_R_NOMEMORY);
 243         return ((err == 0) ? ISC_R_SUCCESS : ISC_R_UNEXPECTED);
 244 }
 245 #endif
 246
 247 #if ISC_MUTEX_DEBUG && defined(__NetBSD__) && defined(PTHREAD_MUTEX_ERRORCHECK)
 248 pthread_mutexattr_t isc__mutex_attrs = {
 249         PTHREAD_MUTEX_ERRORCHECK,       /* m_type */
 250         0                               /* m_flags, which appears to be unused. */
 251 };
 252 #endif
 253
 254 #if !(ISC_MUTEX_DEBUG && defined(PTHREAD_MUTEX_ERRORCHECK)) && !ISC_MUTEX_PROFILE
 255 isc_result_t
 256 isc__mutex_init(isc_mutex_t *mp, const char *file, unsigned int line) {
 257         char strbuf[ISC_STRERRORSIZE];
 258         isc_result_t result = ISC_R_SUCCESS;
 259         int err;
 260
 261         err = pthread_mutex_init(mp, ISC__MUTEX_ATTRS);
 262         if (err == ENOMEM)
 263                 return (ISC_R_NOMEMORY);
 264         if (err != 0) {
 265                 isc__strerror(errno, strbuf, sizeof(strbuf));
 266                 UNEXPECTED_ERROR(file, line, "isc_mutex_init() failed: %s",
 267                                  strbuf);
 268                 result = ISC_R_UNEXPECTED;
 269         }
 270         return (result);
 271 }
 272 #endif