if( pthread_mutexattr_init( &attr ) )
abort();
-#ifndef NDEBUG
+#ifdef NDEBUG
+ pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_NORMAL );
+#else
/* Create error-checking mutex to detect problems more easily. */
-# if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
+# if defined (__GLIBC__) && (__GLIBC__ == 2) && (__GLIBC_MINOR__ < 6)
pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
# else
pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
pthread_mutexattr_t attr;
pthread_mutexattr_init( &attr );
-#if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
+#if defined (__GLIBC__) && (__GLIBC__ == 2) && (__GLIBC_MINOR__ < 6)
pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_RECURSIVE_NP );
#else
pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE );
* occur.
* @warning
* A thread cannot join itself (normally VLC will abort if this is attempted).
+ * Also, a detached thread <b>cannot</b> be joined.
*
* @param handle thread handle
* @param p_result [OUT] pointer to write the thread return value or NULL
- * @return 0 on success, a standard error code otherwise.
*/
void vlc_join (vlc_thread_t handle, void **result)
{
VLC_THREAD_ASSERT ("joining thread");
}
+/**
+ * Detaches a thread. When the specified thread completes, it will be
+ * automatically destroyed (in particular, its stack will be reclaimed),
+ * instead of waiting for another thread to call vlc_join(). If the thread has
+ * already completed, it will be destroyed immediately.
+ *
+ * When a thread performs some work asynchronously and may complete much
+ * earlier than it can be joined, detaching the thread can save memory.
+ * However, care must be taken that any resources used by a detached thread
+ * remains valid until the thread completes. This will typically involve some
+ * kind of thread-safe signaling.
+ *
+ * A thread may detach itself.
+ *
+ * @param handle thread handle
+ */
+void vlc_detach (vlc_thread_t handle)
+{
+ int val = pthread_detach (handle);
+ VLC_THREAD_ASSERT ("detaching thread");
+}
+
/**
* Save the current cancellation state (enabled or disabled), then disable
* cancellation for the calling thread.
assert (0);
}
-#ifndef HAVE_POSIX_TIMER
-/* We have no fallback currently. We'll just crash on timer API usage. */
-static void timer_not_supported(void)
+
+struct vlc_timer
+{
+ vlc_thread_t thread;
+ vlc_mutex_t lock;
+ vlc_cond_t wait;
+ void (*func) (void *);
+ void *data;
+ mtime_t value, interval;
+ unsigned users;
+ unsigned overruns;
+};
+
+static void *vlc_timer_do (void *data)
{
- fprintf(stderr, "*** Error: Timer API is not supported on this platform.\n");
- abort();
+ struct vlc_timer *timer = data;
+
+ timer->func (timer->data);
+
+ vlc_mutex_lock (&timer->lock);
+ assert (timer->users > 0);
+ if (--timer->users == 0)
+ vlc_cond_signal (&timer->wait);
+ vlc_mutex_unlock (&timer->lock);
+ return NULL;
}
-#endif
-static void vlc_timer_do (union sigval val)
+static void *vlc_timer_thread (void *data)
{
- vlc_timer_t *id = val.sival_ptr;
- id->func (id->data);
+ struct vlc_timer *timer = data;
+ mtime_t value, interval;
+
+ vlc_mutex_lock (&timer->lock);
+ value = timer->value;
+ interval = timer->interval;
+ vlc_mutex_unlock (&timer->lock);
+
+ for (;;)
+ {
+ vlc_thread_t th;
+
+ mwait (value);
+
+ vlc_mutex_lock (&timer->lock);
+ if (vlc_clone (&th, vlc_timer_do, timer, VLC_THREAD_PRIORITY_INPUT))
+ timer->overruns++;
+ else
+ {
+ vlc_detach (th);
+ timer->users++;
+ }
+ vlc_mutex_unlock (&timer->lock);
+
+ if (interval == 0)
+ return NULL;
+
+ value += interval;
+ }
}
/**
* Initializes an asynchronous timer.
- * @warning Asynchronous timers are processed from an unspecified thread, and
- * a timer is only serialized against itself.
+ * @warning Asynchronous timers are processed from an unspecified thread.
+ * Also, multiple occurences of an interval timer can run concurrently.
*
* @param id pointer to timer to be initialized
* @param func function that the timer will call
*/
int vlc_timer_create (vlc_timer_t *id, void (*func) (void *), void *data)
{
-#ifdef HAVE_POSIX_TIMER
- struct sigevent ev;
-
- memset (&ev, 0, sizeof (ev));
- ev.sigev_notify = SIGEV_THREAD;
- ev.sigev_value.sival_ptr = id;
- ev.sigev_notify_function = vlc_timer_do;
- ev.sigev_notify_attributes = NULL;
- id->func = func;
- id->data = data;
-
-#if (_POSIX_CLOCK_SELECTION >= 0)
- if (timer_create (CLOCK_MONOTONIC, &ev, &id->handle))
-#else
- if (timer_create (CLOCK_REALTIME, &ev, &id->handle))
-#endif
- return errno;
-
- return 0;
-#else
- timer_not_supported();
+ struct vlc_timer *timer = malloc (sizeof (*timer));
+
+ if (timer == NULL)
+ return ENOMEM;
+ vlc_mutex_init (&timer->lock);
+ vlc_cond_init (&timer->wait);
+ assert (func);
+ timer->func = func;
+ timer->data = data;
+ timer->value = 0;
+ timer->interval = 0;
+ timer->users = 0;
+ timer->overruns = 0;
+ *id = timer;
return 0;
-#endif
}
/**
* @warning This function <b>must</b> be called before the timer data can be
* freed and before the timer callback function can be unloaded.
*
- * @param timer to destroy
+ * @param timer timer to destroy
*/
-void vlc_timer_destroy (vlc_timer_t *id)
+void vlc_timer_destroy (vlc_timer_t timer)
{
-#ifdef HAVE_POSIX_TIMER
- int val = timer_delete (id->handle);
- VLC_THREAD_ASSERT ("deleting timer");
-#else
- timer_not_supported();
-#endif
+ vlc_timer_schedule (timer, false, 0, 0);
+ vlc_mutex_lock (&timer->lock);
+ while (timer->users != 0)
+ vlc_cond_wait (&timer->wait, &timer->lock);
+ vlc_mutex_unlock (&timer->lock);
+
+ vlc_cond_destroy (&timer->wait);
+ vlc_mutex_destroy (&timer->lock);
+ free (timer);
}
/**
* the system is busy or suspended, or because a previous iteration of the
* timer is still running. See also vlc_timer_getoverrun().
*
- * @param id initialized timer pointer
+ * @param timer initialized timer
* @param absolute the timer value origin is the same as mdate() if true,
* the timer value is relative to now if false.
* @param value zero to disarm the timer, otherwise the initial time to wait
* @param interval zero to fire the timer just once, otherwise the timer
* repetition interval.
*/
-void vlc_timer_schedule (vlc_timer_t *id, bool absolute,
+void vlc_timer_schedule (vlc_timer_t timer, bool absolute,
mtime_t value, mtime_t interval)
{
-#ifdef HAVE_POSIX_TIMER
- lldiv_t vad = lldiv (value, CLOCK_FREQ);
- lldiv_t itd = lldiv (interval, CLOCK_FREQ);
- struct itimerspec it = {
- .it_interval = {
- .tv_sec = itd.quot,
- .tv_nsec = (1000000000 / CLOCK_FREQ) * itd.rem,
- },
- .it_value = {
- .tv_sec = vad.quot,
- .tv_nsec = (1000000000 / CLOCK_FREQ) * vad.rem,
- },
- };
- int flags = absolute ? TIMER_ABSTIME : 0;
-
- int val = timer_settime (id->handle, flags, &it, NULL);
- VLC_THREAD_ASSERT ("scheduling timer");
-#else
- timer_not_supported();
-#endif
+ static vlc_mutex_t lock = VLC_STATIC_MUTEX;
+
+ vlc_mutex_lock (&lock);
+ vlc_mutex_lock (&timer->lock);
+ if (timer->value)
+ {
+ vlc_mutex_unlock (&timer->lock);
+ vlc_cancel (timer->thread);
+ vlc_join (timer->thread, NULL);
+ vlc_mutex_lock (&timer->lock);
+ timer->value = 0;
+ }
+ if ((value != 0)
+ && (vlc_clone (&timer->thread, vlc_timer_thread, timer,
+ VLC_THREAD_PRIORITY_INPUT) == 0))
+ {
+ timer->value = (absolute ? 0 : mdate ()) + value;
+ timer->interval = interval;
+ }
+ vlc_mutex_unlock (&timer->lock);
+ vlc_mutex_unlock (&lock);
}
/**
- * @param id initialized timer pointer
+ * Fetch and reset the overrun counter for a timer.
+ * @param timer initialized timer
* @return the timer overrun counter, i.e. the number of times that the timer
* should have run but did not since the last actual run. If all is well, this
* is zero.
*/
-unsigned vlc_timer_getoverrun (const vlc_timer_t *id)
+unsigned vlc_timer_getoverrun (vlc_timer_t timer)
{
-#ifdef HAVE_POSIX_TIMER
- int val = timer_getoverrun (id->handle);
-#ifndef NDEBUG
- if (val == -1)
- {
- val = errno;
- VLC_THREAD_ASSERT ("fetching timer overrun counter");
- }
-#endif
- return val;
-#else
- timer_not_supported();
- return 0;
-#endif
+ unsigned ret;
+
+ vlc_mutex_lock (&timer->lock);
+ ret = timer->overruns;
+ timer->overruns = 0;
+ vlc_mutex_unlock (&timer->lock);
+ return ret;
}