/* $NetBSD: mutex.c,v 1.1.2.2 2024/02/24 13:07:29 martin Exp $ */ /* * Copyright (C) Internet Systems Consortium, Inc. ("ISC") * * SPDX-License-Identifier: MPL-2.0 * * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, you can obtain one at https://mozilla.org/MPL/2.0/. * * See the COPYRIGHT file distributed with this work for additional * information regarding copyright ownership. */ /*! \file */ #include #include #include #include #include #include #include #include #include #include #include #if ISC_MUTEX_PROFILE /*@{*/ /*% Operations on timevals; adapted from FreeBSD's sys/time.h */ #define timevalclear(tvp) ((tvp)->tv_sec = (tvp)->tv_usec = 0) #define timevaladd(vvp, uvp) \ do { \ (vvp)->tv_sec += (uvp)->tv_sec; \ (vvp)->tv_usec += (uvp)->tv_usec; \ if ((vvp)->tv_usec >= 1000000) { \ (vvp)->tv_sec++; \ (vvp)->tv_usec -= 1000000; \ } \ } while (0) #define timevalsub(vvp, uvp) \ do { \ (vvp)->tv_sec -= (uvp)->tv_sec; \ (vvp)->tv_usec -= (uvp)->tv_usec; \ if ((vvp)->tv_usec < 0) { \ (vvp)->tv_sec--; \ (vvp)->tv_usec += 1000000; \ } \ } while (0) /*@}*/ #define ISC_MUTEX_MAX_LOCKERS 32 typedef struct { const char *file; int line; unsigned count; struct timeval locked_total; struct timeval wait_total; } isc_mutexlocker_t; struct isc_mutexstats { const char *file; /*%< File mutex was created in. */ int line; /*%< Line mutex was created on. */ unsigned count; struct timeval lock_t; struct timeval locked_total; struct timeval wait_total; isc_mutexlocker_t *cur_locker; isc_mutexlocker_t lockers[ISC_MUTEX_MAX_LOCKERS]; }; #ifndef ISC_MUTEX_PROFTABLESIZE #define ISC_MUTEX_PROFTABLESIZE (1024 * 1024) #endif /* ifndef ISC_MUTEX_PROFTABLESIZE */ static isc_mutexstats_t stats[ISC_MUTEX_PROFTABLESIZE]; static int stats_next = 0; static bool stats_init = false; static pthread_mutex_t statslock = PTHREAD_MUTEX_INITIALIZER; void isc_mutex_init_profile(isc_mutex_t *mp, const char *file, int line) { int i, err; err = pthread_mutex_init(&mp->mutex, NULL); if (err != 0) { strerror_r(err, strbuf, sizeof(strbuf)); isc_error_fatal(file, line, "pthread_mutex_init failed: %s", strbuf); } RUNTIME_CHECK(pthread_mutex_lock(&statslock) == 0); if (!stats_init) { stats_init = true; } /* * If all statistics entries have been used, give up and trigger an * assertion failure. There would be no other way to deal with this * because we'd like to keep record of all locks for the purpose of * debugging and the number of necessary locks is unpredictable. * If this failure is triggered while debugging, named should be * rebuilt with an increased ISC_MUTEX_PROFTABLESIZE. */ RUNTIME_CHECK(stats_next < ISC_MUTEX_PROFTABLESIZE); mp->stats = &stats[stats_next++]; RUNTIME_CHECK(pthread_mutex_unlock(&statslock) == 0); mp->stats->file = file; mp->stats->line = line; mp->stats->count = 0; timevalclear(&mp->stats->locked_total); timevalclear(&mp->stats->wait_total); for (i = 0; i < ISC_MUTEX_MAX_LOCKERS; i++) { mp->stats->lockers[i].file = NULL; mp->stats->lockers[i].line = 0; mp->stats->lockers[i].count = 0; timevalclear(&mp->stats->lockers[i].locked_total); timevalclear(&mp->stats->lockers[i].wait_total); } } isc_result_t isc_mutex_lock_profile(isc_mutex_t *mp, const char *file, int line) { struct timeval prelock_t; struct timeval postlock_t; isc_mutexlocker_t *locker = NULL; int i; gettimeofday(&prelock_t, NULL); if (pthread_mutex_lock(&mp->mutex) != 0) { return (ISC_R_UNEXPECTED); } gettimeofday(&postlock_t, NULL); mp->stats->lock_t = postlock_t; timevalsub(&postlock_t, &prelock_t); mp->stats->count++; timevaladd(&mp->stats->wait_total, &postlock_t); for (i = 0; i < ISC_MUTEX_MAX_LOCKERS; i++) { if (mp->stats->lockers[i].file == NULL) { locker = &mp->stats->lockers[i]; locker->file = file; locker->line = line; break; } else if (mp->stats->lockers[i].file == file && mp->stats->lockers[i].line == line) { locker = &mp->stats->lockers[i]; break; } } if (locker != NULL) { locker->count++; timevaladd(&locker->wait_total, &postlock_t); } mp->stats->cur_locker = locker; return (ISC_R_SUCCESS); } isc_result_t isc_mutex_unlock_profile(isc_mutex_t *mp, const char *file, int line) { struct timeval unlock_t; UNUSED(file); UNUSED(line); if (mp->stats->cur_locker != NULL) { gettimeofday(&unlock_t, NULL); timevalsub(&unlock_t, &mp->stats->lock_t); timevaladd(&mp->stats->locked_total, &unlock_t); timevaladd(&mp->stats->cur_locker->locked_total, &unlock_t); mp->stats->cur_locker = NULL; } return ((pthread_mutex_unlock((&mp->mutex)) == 0) ? ISC_R_SUCCESS : ISC_R_UNEXPECTED); } void isc_mutex_statsprofile(FILE *fp) { isc_mutexlocker_t *locker; int i, j; fprintf(fp, "Mutex stats (in us)\n"); for (i = 0; i < stats_next; i++) { fprintf(fp, "%-12s %4d: %10u %lu.%06lu %lu.%06lu %5d\n", stats[i].file, stats[i].line, stats[i].count, stats[i].locked_total.tv_sec, stats[i].locked_total.tv_usec, stats[i].wait_total.tv_sec, stats[i].wait_total.tv_usec, i); for (j = 0; j < ISC_MUTEX_MAX_LOCKERS; j++) { locker = &stats[i].lockers[j]; if (locker->file == NULL) { continue; } fprintf(fp, " %-11s %4d: %10u %lu.%06lu %lu.%06lu %5d\n", locker->file, locker->line, locker->count, locker->locked_total.tv_sec, locker->locked_total.tv_usec, locker->wait_total.tv_sec, locker->wait_total.tv_usec, i); } } } #endif /* ISC_MUTEX_PROFILE */ #if ISC_MUTEX_DEBUG && defined(PTHREAD_MUTEX_ERRORCHECK) static bool errcheck_initialized = false; static pthread_mutexattr_t errcheck; static isc_once_t once_errcheck = ISC_ONCE_INIT; static void initialize_errcheck(void) { RUNTIME_CHECK(pthread_mutexattr_init(&errcheck) == 0); RUNTIME_CHECK(pthread_mutexattr_settype(&errcheck, PTHREAD_MUTEX_ERRORCHECK) == 0); errcheck_initialized = true; } void isc_mutex_init_errcheck(isc_mutex_t *mp) { isc_result_t result; int err; result = isc_once_do(&once_errcheck, initialize_errcheck); RUNTIME_CHECK(result == ISC_R_SUCCESS); err = pthread_mutex_init(mp, &errcheck); if (err != 0) { strerror_r(err, strbuf, sizeof(strbuf)); isc_error_fatal(file, line, "pthread_mutex_init failed: %s", strbuf); } } #endif /* if ISC_MUTEX_DEBUG && defined(PTHREAD_MUTEX_ERRORCHECK) */ #if ISC_MUTEX_DEBUG && defined(__NetBSD__) && defined(PTHREAD_MUTEX_ERRORCHECK) pthread_mutexattr_t isc__mutex_attrs = { PTHREAD_MUTEX_ERRORCHECK, /* m_type */ 0 /* m_flags, which appears to be unused. */ }; #endif /* if ISC_MUTEX_DEBUG && defined(__NetBSD__) && \ * defined(PTHREAD_MUTEX_ERRORCHECK) */ #if !(ISC_MUTEX_DEBUG && defined(PTHREAD_MUTEX_ERRORCHECK)) && \ !ISC_MUTEX_PROFILE #ifdef HAVE_PTHREAD_MUTEX_ADAPTIVE_NP static bool attr_initialized = false; static pthread_mutexattr_t attr; static isc_once_t once_attr = ISC_ONCE_INIT; #endif /* HAVE_PTHREAD_MUTEX_ADAPTIVE_NP */ #ifdef HAVE_PTHREAD_MUTEX_ADAPTIVE_NP static void initialize_attr(void) { RUNTIME_CHECK(pthread_mutexattr_init(&attr) == 0); RUNTIME_CHECK(pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ADAPTIVE_NP) == 0); attr_initialized = true; } #endif /* HAVE_PTHREAD_MUTEX_ADAPTIVE_NP */ void isc__mutex_init(isc_mutex_t *mp, const char *file, unsigned int line) { int err; #ifdef HAVE_PTHREAD_MUTEX_ADAPTIVE_NP isc_result_t result = ISC_R_SUCCESS; result = isc_once_do(&once_attr, initialize_attr); RUNTIME_CHECK(result == ISC_R_SUCCESS); err = pthread_mutex_init(mp, &attr); #else /* HAVE_PTHREAD_MUTEX_ADAPTIVE_NP */ err = pthread_mutex_init(mp, ISC__MUTEX_ATTRS); #endif /* HAVE_PTHREAD_MUTEX_ADAPTIVE_NP */ if (err != 0) { char strbuf[ISC_STRERRORSIZE]; strerror_r(err, strbuf, sizeof(strbuf)); isc_error_fatal(file, line, "pthread_mutex_init failed: %s", strbuf); } } #endif /* if !(ISC_MUTEX_DEBUG && defined(PTHREAD_MUTEX_ERRORCHECK)) && \ * !ISC_MUTEX_PROFILE */