#include <config.h>
+#ifdef HAVE_MONOTONIC_CLOCK
/* 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;
+#endif
-typedef struct {
- pthread_mutex_t lock; /**< lock protecting count field */
- volatile int count; /**< count of how many times lock holder has recursively locked */
- volatile pthread_t holder; /**< holder of the lock if count >0,
- valid but arbitrary thread if count
- has ever been >0, uninitialized memory
- if count has never been >0 */
-} DBusMutexPThread;
+struct DBusRMutex {
+ pthread_mutex_t lock; /**< the lock */
+};
+
+struct DBusCMutex {
+ pthread_mutex_t lock; /**< the lock */
+};
-typedef struct {
+struct DBusCondVar {
pthread_cond_t cond; /**< the condition */
-} DBusCondVarPThread;
+};
#define DBUS_MUTEX(m) ((DBusMutex*) m)
#define DBUS_MUTEX_PTHREAD(m) ((DBusMutexPThread*) m)
} while (0)
#endif /* !DBUS_DISABLE_ASSERT */
-static DBusMutex*
-_dbus_pthread_mutex_new (void)
+DBusCMutex *
+_dbus_platform_cmutex_new (void)
{
- DBusMutexPThread *pmutex;
+ DBusCMutex *pmutex;
int result;
-
- pmutex = dbus_new (DBusMutexPThread, 1);
+
+ pmutex = dbus_new (DBusCMutex, 1);
if (pmutex == NULL)
return NULL;
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);
+ return pmutex;
}
-static void
-_dbus_pthread_mutex_free (DBusMutex *mutex)
+DBusRMutex *
+_dbus_platform_rmutex_new (void)
{
- DBusMutexPThread *pmutex = DBUS_MUTEX_PTHREAD (mutex);
+ DBusRMutex *pmutex;
+ pthread_mutexattr_t mutexattr;
+ int result;
- _dbus_assert (pmutex->count == 0);
-
- PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&pmutex->lock));
+ pmutex = dbus_new (DBusRMutex, 1);
+ if (pmutex == NULL)
+ return NULL;
- dbus_free (pmutex);
-}
+ pthread_mutexattr_init (&mutexattr);
+ pthread_mutexattr_settype (&mutexattr, PTHREAD_MUTEX_RECURSIVE);
+ result = pthread_mutex_init (&pmutex->lock, &mutexattr);
+ pthread_mutexattr_destroy (&mutexattr);
-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)
+ if (result == ENOMEM || result == EAGAIN)
{
- /* 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;
+ dbus_free (pmutex);
+ return NULL;
}
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;
+ PTHREAD_CHECK ("pthread_mutex_init", result);
}
+
+ return pmutex;
}
-static void
-_dbus_pthread_mutex_unlock (DBusMutex *mutex)
+void
+_dbus_platform_cmutex_free (DBusCMutex *mutex)
{
- DBusMutexPThread *pmutex = DBUS_MUTEX_PTHREAD (mutex);
+ PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&mutex->lock));
+ dbus_free (mutex);
+}
- _dbus_assert (pmutex->count > 0);
-
- pmutex->count -= 1;
+void
+_dbus_platform_rmutex_free (DBusRMutex *mutex)
+{
+ PTHREAD_CHECK ("pthread_mutex_destroy", pthread_mutex_destroy (&mutex->lock));
+ dbus_free (mutex);
+}
- 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 */
+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));
}
-static DBusCondVar *
-_dbus_pthread_condvar_new (void)
+void
+_dbus_platform_cmutex_unlock (DBusCMutex *mutex)
{
- DBusCondVarPThread *pcond;
+ 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 (DBusCondVarPThread, 1);
+ pcond = dbus_new (DBusCondVar, 1);
if (pcond == NULL)
return NULL;
PTHREAD_CHECK ("pthread_cond_init", result);
}
- return DBUS_COND_VAR (pcond);
+ return 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);
+void
+_dbus_platform_condvar_free (DBusCondVar *cond)
+{
+ PTHREAD_CHECK ("pthread_cond_destroy", pthread_cond_destroy (&cond->cond));
+ dbus_free (cond);
}
-static void
-_dbus_pthread_condvar_wait (DBusCondVar *cond,
- DBusMutex *mutex)
+void
+_dbus_platform_condvar_wait (DBusCondVar *cond,
+ DBusCMutex *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 */
+ PTHREAD_CHECK ("pthread_cond_wait", pthread_cond_wait (&cond->cond, &mutex->lock));
}
-static dbus_bool_t
-_dbus_pthread_condvar_wait_timeout (DBusCondVar *cond,
- DBusMutex *mutex,
- int timeout_milliseconds)
+dbus_bool_t
+_dbus_platform_condvar_wait_timeout (DBusCondVar *cond,
+ DBusCMutex *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)
end_time.tv_nsec -= 1000*1000*1000;
}
- old_count = pmutex->count;
- pmutex->count = 0;
- result = pthread_cond_timedwait (&pcond->cond, &pmutex->lock, &end_time);
+ result = pthread_cond_timedwait (&cond->cond, &mutex->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_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)
+void
+_dbus_platform_condvar_wake_one (DBusCondVar *cond)
{
- DBusCondVarPThread *pcond = DBUS_COND_VAR_PTHREAD (cond);
-
- PTHREAD_CHECK ("pthread_cond_broadcast", pthread_cond_broadcast (&pcond->cond));
+ PTHREAD_CHECK ("pthread_cond_signal", pthread_cond_signal (&cond->cond));
}
-static const DBusThreadFunctions pthread_functions =
-{
- DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_NEW_MASK |
- DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_FREE_MASK |
- DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_LOCK_MASK |
- DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_UNLOCK_MASK |
- DBUS_THREAD_FUNCTIONS_CONDVAR_NEW_MASK |
- DBUS_THREAD_FUNCTIONS_CONDVAR_FREE_MASK |
- DBUS_THREAD_FUNCTIONS_CONDVAR_WAIT_MASK |
- DBUS_THREAD_FUNCTIONS_CONDVAR_WAIT_TIMEOUT_MASK |
- DBUS_THREAD_FUNCTIONS_CONDVAR_WAKE_ONE_MASK|
- DBUS_THREAD_FUNCTIONS_CONDVAR_WAKE_ALL_MASK,
- NULL, NULL, NULL, NULL,
- _dbus_pthread_condvar_new,
- _dbus_pthread_condvar_free,
- _dbus_pthread_condvar_wait,
- _dbus_pthread_condvar_wait_timeout,
- _dbus_pthread_condvar_wake_one,
- _dbus_pthread_condvar_wake_all,
- _dbus_pthread_mutex_new,
- _dbus_pthread_mutex_free,
- _dbus_pthread_mutex_lock,
- _dbus_pthread_mutex_unlock
-};
-
static void
check_monotonic_clock (void)
{
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 ();
- return dbus_threads_init (&pthread_functions);
+ (void) _dbus_check_setuid ();
+
+ return TRUE;
+}
+
+static pthread_mutex_t init_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+void
+_dbus_threads_lock_platform_specific (void)
+{
+ pthread_mutex_lock (&init_mutex);
+}
+
+void
+_dbus_threads_unlock_platform_specific (void)
+{
+ pthread_mutex_unlock (&init_mutex);
}
projects / platform / upstream / dbus.git / blobdiff