dbus-sysdeps-pthread.c
/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dbus-sysdeps-pthread.c Implements threads using pthreads (internal to libdbus)
*
* Copyright (C) 2002, 2003, 2006 Red Hat, Inc.
*
* Licensed under the Academic Free License version 2.1
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <config.h>
#include "dbus-internals.h"
#include "dbus-sysdeps.h"
#include "dbus-threads.h"
#include <sys/time.h>
#include <pthread.h>
#include <string.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <config.h>
/* Whether we have a "monotonic" clock; i.e. a clock not affected by
* changes in system time.
* This is initialized once in check_monotonic_clock below.
* https://bugs.freedesktop.org/show_bug.cgi?id=18121
*/
static dbus_bool_t have_monotonic_clock = 0;
struct DBusRMutex {
pthread_mutex_t lock;
};
struct DBusCMutex {
pthread_mutex_t lock;
};
struct DBusCondVar {
pthread_cond_t cond;
};
#define DBUS_MUTEX(m) ((DBusMutex*) m)
#define DBUS_MUTEX_PTHREAD(m) ((DBusMutexPThread*) m)
#define DBUS_COND_VAR(c) ((DBusCondVar*) c)
#define DBUS_COND_VAR_PTHREAD(c) ((DBusCondVarPThread*) c)
#ifdef DBUS_DISABLE_ASSERT
/* (tmp != 0) is a no-op usage to silence compiler */
#define PTHREAD_CHECK(func_name, result_or_call) \
do { int tmp = (result_or_call); if (tmp != 0) {;} } while (0)
#else
#define PTHREAD_CHECK(func_name, result_or_call) do { \
int tmp = (result_or_call); \
if (tmp != 0) { \
_dbus_warn_check_failed ("pthread function %s failed with %d %s in %s\n", \
func_name, tmp, strerror(tmp), _DBUS_FUNCTION_NAME); \
} \
} while (0)
#endif /* !DBUS_DISABLE_ASSERT */
DBusCMutex *
_dbus_platform_cmutex_new (void)
{
DBusCMutex *pmutex;
int result;
pmutex = dbus_new (DBusCMutex, 1);
if (pmutex == NULL)
return NULL;
result = pthread_mutex_init (&pmutex->lock, NULL);
if (result == ENOMEM || result == EAGAIN)
{
dbus_free (pmutex);
return NULL;
}
else
{
PTHREAD_CHECK ("pthread_mutex_init", result);
}
return pmutex;
}
DBusRMutex *
_dbus_platform_rmutex_new (void)
{
DBusRMutex *pmutex;
pthread_mutexattr_t mutexattr;
int result;
pmutex = dbus_new (DBusRMutex, 1);
if (pmutex == NULL)
return NULL;
pthread_mutexattr_init (&mutexattr);
pthread_mutexattr_settype (&mutexattr, PTHREAD_MUTEX_RECURSIVE);
result = pthread_mutex_init (&pmutex->lock, &mutexattr);
pthread_mutexattr_destroy (&mutexattr);
if (result == ENOMEM || result == EAGAIN)
{
dbus_free (pmutex);
return NULL;
}
else
{
PTHREAD_CHECK ("pthread_mutex_init", result);
}
return pmutex;
}
void
_dbus_platform_cmutex_free (DBusCMutex *mutex)
{
PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&mutex->lock));
dbus_free (mutex);
}
void
_dbus_platform_rmutex_free (DBusRMutex *mutex)
{
PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&mutex->lock));
dbus_free (mutex);
}
void
_dbus_platform_cmutex_lock (DBusCMutex *mutex)
{
PTHREAD_CHECK ("pthread_mutex_lock", pthread_mutex_lock (&mutex->lock));
}
void
_dbus_platform_rmutex_lock (DBusRMutex *mutex)
{
PTHREAD_CHECK ("pthread_mutex_lock", pthread_mutex_lock (&mutex->lock));
}
void
_dbus_platform_cmutex_unlock (DBusCMutex *mutex)
{
PTHREAD_CHECK ("pthread_mutex_unlock", pthread_mutex_unlock (&mutex->lock));
}
void
_dbus_platform_rmutex_unlock (DBusRMutex *mutex)
{
PTHREAD_CHECK ("pthread_mutex_unlock", pthread_mutex_unlock (&mutex->lock));
}
DBusCondVar *
_dbus_platform_condvar_new (void)
{
DBusCondVar *pcond;
pthread_condattr_t attr;
int result;
pcond = dbus_new (DBusCondVar, 1);
if (pcond == NULL)
return NULL;
pthread_condattr_init (&attr);
#ifdef HAVE_MONOTONIC_CLOCK
if (have_monotonic_clock)
pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
#endif
result = pthread_cond_init (&pcond->cond, &attr);
pthread_condattr_destroy (&attr);
if (result == EAGAIN || result == ENOMEM)
{
dbus_free (pcond);
return NULL;
}
else
{
PTHREAD_CHECK ("pthread_cond_init", result);
}
return pcond;
}
void
_dbus_platform_condvar_free (DBusCondVar *cond)
{
PTHREAD_CHECK ("pthread_cond_destroy", pthread_cond_destroy (&cond->cond));
dbus_free (cond);
}
void
_dbus_platform_condvar_wait (DBusCondVar *cond,
DBusCMutex *mutex)
{
PTHREAD_CHECK ("pthread_cond_wait", pthread_cond_wait (&cond->cond, &mutex->lock));
}
dbus_bool_t
_dbus_platform_condvar_wait_timeout (DBusCondVar *cond,
DBusCMutex *mutex,
int timeout_milliseconds)
{
struct timeval time_now;
struct timespec end_time;
int result;
#ifdef HAVE_MONOTONIC_CLOCK
if (have_monotonic_clock)
{
struct timespec monotonic_timer;
clock_gettime (CLOCK_MONOTONIC,&monotonic_timer);
time_now.tv_sec = monotonic_timer.tv_sec;
time_now.tv_usec = monotonic_timer.tv_nsec / 1000;
}
else
/* This else falls through to gettimeofday */
#endif
gettimeofday (&time_now, NULL);
end_time.tv_sec = time_now.tv_sec + timeout_milliseconds / 1000;
end_time.tv_nsec = (time_now.tv_usec + (timeout_milliseconds % 1000) * 1000) * 1000;
if (end_time.tv_nsec > 1000*1000*1000)
{
end_time.tv_sec += 1;
end_time.tv_nsec -= 1000*1000*1000;
}
result = pthread_cond_timedwait (&cond->cond, &mutex->lock, &end_time);
if (result != ETIMEDOUT)
{
PTHREAD_CHECK ("pthread_cond_timedwait", result);
}
/* return true if we did not time out */
return result != ETIMEDOUT;
}
void
_dbus_platform_condvar_wake_one (DBusCondVar *cond)
{
PTHREAD_CHECK ("pthread_cond_signal", pthread_cond_signal (&cond->cond));
}
static void
check_monotonic_clock (void)
{
#ifdef HAVE_MONOTONIC_CLOCK
struct timespec dummy;
if (clock_getres (CLOCK_MONOTONIC, &dummy) == 0)
have_monotonic_clock = TRUE;
#endif
}
dbus_bool_t
_dbus_threads_init_platform_specific (void)
{
/* These have static variables, and we need to handle both the case
* where dbus_threads_init() has been called and when it hasn't;
* so initialize them before any threads are allowed to enter.
*/
check_monotonic_clock ();
(void) _dbus_check_setuid ();
return dbus_threads_init (NULL);
}