static void
_dbus_pthread_mutex_lock (DBusMutex *mutex)
{
DBusMutexPThread *pmutex = DBUS_MUTEX_PTHREAD (mutex);
pthread_t self = pthread_self ();
/* If the count is > 0 then someone had the lock, maybe us. If it is
* 0, then it might immediately change right after we read it,
* but it will be changed by another thread; i.e. if we read 0,
* we assume that this thread doesn't have the lock.
*
* Not 100% sure this is safe, but ... seems like it should be.
*/
if (pmutex->count == 0)
{
/* We know we don't have the lock; someone may have the lock. */
PTHREAD_CHECK ("pthread_mutex_lock", pthread_mutex_lock (&pmutex->lock));
/* We now have the lock. Count must be 0 since it must be 0 when
* the lock is released by another thread, and we just now got
* the lock.
*/
_dbus_assert (pmutex->count == 0);
pmutex->holder = self;
pmutex->count = 1;
}
else
{
/* We know someone had the lock, possibly us. Thus
* pmutex->holder is not pointing to junk, though it may not be
* the lock holder anymore if the lock holder is not us. If the
* lock holder is us, then we definitely have the lock.
*/
if (pthread_equal (pmutex->holder, self))
{
/* We already have the lock. */
_dbus_assert (pmutex->count > 0);
}
else
{
/* Wait for the lock */
PTHREAD_CHECK ("pthread_mutex_lock", pthread_mutex_lock (&pmutex->lock));
pmutex->holder = self;
_dbus_assert (pmutex->count == 0);
}
pmutex->count += 1;
}
}
static DBusMutex*
_dbus_pthread_mutex_new (void)
{
DBusMutexPThread *pmutex;
int result;
pmutex = dbus_new (DBusMutexPThread, 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);
}
/* Only written */
pmutex->count = 0;
/* There's no portable way to have a "null" pthread afaik so we
* can't set pmutex->holder to anything sensible. We only access it
* once the lock is held (which means we've set it).
*/
return DBUS_MUTEX (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;
}
static void
_dbus_pthread_condvar_wake_one (DBusCondVar *cond)
{
DBusCondVarPThread *pcond = DBUS_COND_VAR_PTHREAD (cond);
PTHREAD_CHECK ("pthread_cond_signal", pthread_cond_signal (&pcond->cond));
}
static void
_dbus_pthread_condvar_wake_all (DBusCondVar *cond)
{
DBusCondVarPThread *pcond = DBUS_COND_VAR_PTHREAD (cond);
PTHREAD_CHECK ("pthread_cond_broadcast", pthread_cond_broadcast (&pcond->cond));
}
static DBusCondVar *
_dbus_pthread_condvar_new (void)
{
DBusCondVarPThread *pcond;
pthread_condattr_t attr;
int result;
pcond = dbus_new (DBusCondVarPThread, 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 DBUS_COND_VAR (pcond);
}
static void
_dbus_pthread_condvar_free (DBusCondVar *cond)
{
DBusCondVarPThread *pcond = DBUS_COND_VAR_PTHREAD (cond);
PTHREAD_CHECK ("pthread_cond_destroy", pthread_cond_destroy (&pcond->cond));
dbus_free (pcond);
}
static void
_dbus_pthread_mutex_free (DBusMutex *mutex)
{
DBusMutexPThread *pmutex = DBUS_MUTEX_PTHREAD (mutex);
_dbus_assert (pmutex->count == 0);
PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&pmutex->lock));
dbus_free (pmutex);
}
static dbus_bool_t
_dbus_pthread_condvar_wait_timeout (DBusCondVar *cond,
DBusMutex *mutex,
int timeout_milliseconds)
{
DBusMutexPThread *pmutex = DBUS_MUTEX_PTHREAD (mutex);
DBusCondVarPThread *pcond = DBUS_COND_VAR_PTHREAD (cond);
struct timeval time_now;
struct timespec end_time;
int result;
int old_count;
_dbus_assert (pmutex->count > 0);
_dbus_assert (pthread_equal (pmutex->holder, pthread_self ()));
#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;
}
old_count = pmutex->count;
pmutex->count = 0;
result = pthread_cond_timedwait (&pcond->cond, &pmutex->lock, &end_time);
if (result != ETIMEDOUT)
{
PTHREAD_CHECK ("pthread_cond_timedwait", result);
}
_dbus_assert (pmutex->count == 0);
pmutex->count = old_count;
pmutex->holder = pthread_self(); /* other threads may have locked the mutex in the meantime */
/* return true if we did not time out */
return result != ETIMEDOUT;
}
static void
_dbus_pthread_mutex_unlock (DBusMutex *mutex)
{
DBusMutexPThread *pmutex = DBUS_MUTEX_PTHREAD (mutex);
_dbus_assert (pmutex->count > 0);
pmutex->count -= 1;
if (pmutex->count == 0)
PTHREAD_CHECK ("pthread_mutex_unlock", pthread_mutex_unlock (&pmutex->lock));
/* We leave pmutex->holder set to ourselves, its content is undefined if count is 0 */
}
static void
_dbus_pthread_condvar_wait (DBusCondVar *cond,
DBusMutex *mutex)
{
DBusMutexPThread *pmutex = DBUS_MUTEX_PTHREAD (mutex);
DBusCondVarPThread *pcond = DBUS_COND_VAR_PTHREAD (cond);
int old_count;
_dbus_assert (pmutex->count > 0);
_dbus_assert (pthread_equal (pmutex->holder, pthread_self ()));
old_count = pmutex->count;
pmutex->count = 0; /* allow other threads to lock */
PTHREAD_CHECK ("pthread_cond_wait", pthread_cond_wait (&pcond->cond, &pmutex->lock));
_dbus_assert (pmutex->count == 0);
pmutex->count = old_count;
pmutex->holder = pthread_self(); /* other threads may have locked the mutex in the meantime */
}
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;
}
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;
}
void
_dbus_platform_rmutex_free (DBusRMutex *mutex)
{
PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&mutex->lock));
dbus_free (mutex);
}
void
_dbus_platform_condvar_wake_one (DBusCondVar *cond)
{
PTHREAD_CHECK ("pthread_cond_signal", pthread_cond_signal (&cond->cond));
}
void
_dbus_platform_condvar_wait (DBusCondVar *cond,
DBusCMutex *mutex)
{
PTHREAD_CHECK ("pthread_cond_wait", pthread_cond_wait (&cond->cond, &mutex->lock));
}
void
_dbus_platform_condvar_free (DBusCondVar *cond)
{
PTHREAD_CHECK ("pthread_cond_destroy", pthread_cond_destroy (&cond->cond));
dbus_free (cond);
}
void
_dbus_platform_rmutex_unlock (DBusRMutex *mutex)
{
PTHREAD_CHECK ("pthread_mutex_unlock", pthread_mutex_unlock (&mutex->lock));
}
