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-rw-r--r--lib/isc/pthreads/mutex.c302
1 files changed, 302 insertions, 0 deletions
diff --git a/lib/isc/pthreads/mutex.c b/lib/isc/pthreads/mutex.c
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--- /dev/null
+++ b/lib/isc/pthreads/mutex.c
@@ -0,0 +1,302 @@
+/*
+ * 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 <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <sys/time.h>
+#include <time.h>
+
+#include <isc/mutex.h>
+#include <isc/once.h>
+#include <isc/print.h>
+#include <isc/strerr.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+#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 */
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