X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=ao_write.c;h=5c14aa719af937a4aba4a3a8efd62078c86bef6d;hp=52c4b11e1a11c51a419bb32bbc58c6052c7221cd;hb=bc4fabf9e706f28897ab5c1068a97564f3378750;hpb=751e3811e99c744f9f651b191950010ce118eb78

diff --git a/ao_write.c b/ao_write.c
index 52c4b11e..5c14aa71 100644
--- a/ao_write.c
+++ b/ao_write.c
@@ -28,6 +28,7 @@ struct private_aow_data {
 
 	pthread_t thread;
 	pthread_attr_t attr;
+	/* The mutex and the condition variable serialize access to ->btrn */
 	pthread_mutex_t mutex;
 	pthread_cond_t data_available;
 	struct btr_node *thread_btrn;
@@ -39,6 +40,10 @@ static void aow_close(struct writer_node *wn)
 
 	if (!pawd)
 		return;
+	if (pawd->thread_btrn) {
+		pthread_cancel(pawd->thread);
+		pthread_join(pawd->thread, NULL);
+	}
 	ao_close(pawd->dev);
 	free(pawd);
 	wn->private_data = NULL;
@@ -51,14 +56,34 @@ static void aow_pre_select(struct sched *s, struct task *t)
 	struct private_aow_data *pawd = wn->private_data;
 	int ret;
 
-	if (pawd)
-		pthread_mutex_lock(&pawd->mutex);
+	if (!pawd) { /* not yet started */
+		assert(wn->btrn);
+		ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
+		if (ret != 0)
+			goto min_delay;
+		return; /* no data available */
+	}
+	if (!wn->btrn) { /* EOF */
+		if (!pawd->thread_btrn) /* ready to exit */
+			goto min_delay;
+		/* wait for the play thread to terminate */
+		goto timeout;
+	}
+	pthread_mutex_lock(&pawd->mutex);
 	ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
-	if (pawd)
-		pthread_mutex_unlock(&pawd->mutex);
-
-	if (ret == 0)
-		return;
+	pthread_mutex_unlock(&pawd->mutex);
+	if (ret != 0)
+		goto min_delay;
+	/*
+	 * Even though the node status is zero, we might have data available,
+	 * but the output buffer is full. If we don't set a timeout here, we
+	 * are woken up only if new data arrives, which might be too late and
+	 * result in a buffer underrun in the playing thread. To avoid this we
+	 * never sleep longer than the (default) buffer time.
+	 */
+timeout:
+	return sched_request_timeout_ms(20, s);
+min_delay:
 	sched_min_delay(s);
 }
 
@@ -200,10 +225,6 @@ __noreturn static void *aow_play(void *priv)
 	int ret;
 
 	for (;;) {
-		/*
-		 * Lock mutex and wait for signal. pthread_cond_wait() will
-		 * automatically and atomically unlock mutex while it waits.
-		 */
 		pthread_mutex_lock(&pawd->mutex);
 		for (;;) {
 			ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
@@ -219,10 +240,16 @@ __noreturn static void *aow_play(void *priv)
 				ret = -E_WRITE_COMMON_EOF;
 				goto unlock;
 			}
-			//PARA_CRIT_LOG("waiting for data\n");
-			//usleep(1000);
-			//pthread_mutex_unlock(&pawd->mutex);
-			pthread_cond_wait(&pawd->data_available, &pawd->mutex);
+			/*
+			 * No data available, go to sleep and wait for the main
+			 * thread to wake us up. pthread_cond_wait() unlocks
+			 * the mutex while it waits and locks it again upon
+			 * return.
+			 */
+			ret = pthread_cond_wait(&pawd->data_available,
+				&pawd->mutex);
+			/* pthread_cond_wait() can never fail here */
+			assert(ret == 0);
 		}
 		pthread_mutex_unlock(&pawd->mutex);
 		assert(frames > 0);
@@ -239,6 +266,7 @@ unlock:
 out:
 	assert(ret < 0);
 	PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
+	btr_remove_node(&pawd->thread_btrn);
 	pthread_exit(NULL);
 }
 
@@ -323,21 +351,30 @@ static int aow_post_select(__a_unused struct sched *s,
 			goto remove_thread_btrn;
 		return 0;
 	}
+	if (!wn->btrn) {
+		if (!pawd->thread_btrn)
+			return -E_AO_EOF;
+		PARA_INFO_LOG("waiting for play thread to terminate\n");
+		return 0;
+	}
 	pthread_mutex_lock(&pawd->mutex);
 	ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
 	if (ret > 0) {
 		btr_pushdown(wn->btrn);
-		pthread_cond_signal(&pawd->data_available);
+		if (pthread_cond_signal(&pawd->data_available) != 0) {
+			ret = -E_AO_PTHREAD;
+			PARA_ERROR_LOG("pthread_cond_signal() failed\n");
+			goto remove_thread_btrn;
+		}
 	}
-	pthread_mutex_unlock(&pawd->mutex);
-	if (ret >= 0)
+	if (ret >= 0) {
+		pthread_mutex_unlock(&pawd->mutex);
 		goto out;
-	pthread_mutex_lock(&pawd->mutex);
+	}
 	btr_remove_node(&wn->btrn);
-	PARA_INFO_LOG("waiting for thread to terminate\n");
 	pthread_cond_signal(&pawd->data_available);
 	pthread_mutex_unlock(&pawd->mutex);
-	pthread_join(pawd->thread, NULL);
+	return 0;
 remove_thread_btrn:
 	btr_remove_node(&pawd->thread_btrn);
 remove_btrn: