/* $NetBSD: mutex.c,v 1.6 2020/05/25 20:47:22 christos Exp $ */
/*
* Copyright (C) 2004, 2005, 2007, 2008, 2011, 2012 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 2000-2002 Internet Software Consortium.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* Id: mutex.c,v 1.18 2011/01/04 23:47:14 tbox Exp */
/*! \file */
#include <config.h>
#include <stdio.h>
#include <time.h>
#include <sys/time.h>
#include <errno.h>
#include <isc/mutex.h>
#include <isc/util.h>
#include <isc/strerror.h>
#if HAVE_PTHREADS < 5 /* HP-UX 10.20 has 4, needs this */
# define pthread_mutex_init(m, a) \
pthread_mutex_init(m, (a) \
? *(const pthread_mutexattr_t *)(a) \
: pthread_mutexattr_default)
# define PTHREAD_MUTEX_RECURSIVE MUTEX_RECURSIVE_NP
# define pthread_mutexattr_settype pthread_mutexattr_setkind_np
#endif
#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
static isc_mutexstats_t stats[ISC_MUTEX_PROFTABLESIZE];
static int stats_next = 0;
static isc_boolean_t stats_init = ISC_FALSE;
static pthread_mutex_t statslock = PTHREAD_MUTEX_INITIALIZER;
isc_result_t
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 == ENOMEM)
return (ISC_R_NOMEMORY);
if (err != 0)
return (ISC_R_UNEXPECTED);
RUNTIME_CHECK(pthread_mutex_lock(&statslock) == 0);
if (stats_init == ISC_FALSE)
stats_init = ISC_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);
}
return (ISC_R_SUCCESS);
}
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)
isc_result_t
isc_mutex_init_errcheck(isc_mutex_t *mp)
{
pthread_mutexattr_t attr;
int err;
if (pthread_mutexattr_init(&attr) != 0)
return (ISC_R_UNEXPECTED);
if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK) != 0) {
pthread_mutexattr_destroy(&attr);
return (ISC_R_UNEXPECTED);
}
err = pthread_mutex_init(mp, &attr) != 0)
pthread_mutexattr_destroy(&attr);
if (err == ENOMEM)
return (ISC_R_NOMEMORY);
return ((err == 0) ? ISC_R_SUCCESS : ISC_R_UNEXPECTED);
}
#endif
#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(PTHREAD_MUTEX_ERRORCHECK)) && !ISC_MUTEX_PROFILE
isc_result_t
isc__mutex_init(isc_mutex_t *mp, const char *file, unsigned int line) {
char strbuf[ISC_STRERRORSIZE];
isc_result_t result = ISC_R_SUCCESS;
int err;
err = pthread_mutex_init(mp, ISC__MUTEX_ATTRS);
if (err == ENOMEM)
return (ISC_R_NOMEMORY);
if (err != 0) {
isc__strerror(errno, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(file, line, "isc_mutex_init() failed: %s",
strbuf);
result = ISC_R_UNEXPECTED;
}
return (result);
}
#endif