X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=write_common.c;h=2dca309c622eb53f198bb8ab7d287a9ade33c2cc;hp=476df8f0ec7b4f6ea7c3388795f9272d1e02fd8b;hb=3bbec8ac8ab1879d24acbff447850c0e3872daa7;hpb=09bf3971a58fd1044c145b25429c4886966c7d2a

diff --git a/write_common.c b/write_common.c
index 476df8f0..2dca309c 100644
--- a/write_common.c
+++ b/write_common.c
@@ -20,7 +20,7 @@ const char *writer_names[] ={WRITER_NAMES};
 /** the array of supported writers */
 struct writer writers[NUM_SUPPORTED_WRITERS] = {WRITER_ARRAY};
 
-static void wng_pre_select(__a_unused struct sched *s, struct task *t)
+static void wng_pre_select(struct sched *s, struct task *t)
 {
 	struct writer_node_group *g = container_of(t, struct writer_node_group, task);
 	int i;
@@ -34,13 +34,25 @@ static void wng_pre_select(__a_unused struct sched *s, struct task *t)
 		if (t->error < 0)
 			return;
 	}
+	/*
+	 * Force a minimal delay if something was written during the previous
+	 * call to wng_post_select(). This is necessary because the filter
+	 * chain might still have data for us which it couldn't convert during
+	 * the previous run due to its buffer size constraints. In this case we
+	 * do not want to wait until the next input data arrives as this could
+	 * lead to buffer underruns.
+	 */
+	if (g->last_written == 0)
+		return;
+	s->timeout.tv_sec = 0;
+	s->timeout.tv_usec = 1;
 }
 
 static void wng_post_select(struct sched *s, struct task *t)
 {
 	struct writer_node_group *g = container_of(t, struct writer_node_group, task);
 	int i;
-	size_t min_written = 0;
+	size_t min_written = 0, max_written = 0;
 
 	FOR_EACH_WRITER_NODE(i, g) {
 		struct writer_node *wn = &g->writer_nodes[i];
@@ -52,7 +64,9 @@ static void wng_post_select(struct sched *s, struct task *t)
 			min_written = wn->written;
 		else
 			min_written = PARA_MIN(min_written, wn->written);
+		max_written = PARA_MAX(max_written, wn->written);
 	}
+	g->last_written = max_written;
 	//PARA_INFO_LOG("loaded: %zd, min_written: %zd bytes\n", *g->loaded, min_written);
 	if (min_written) {
 		*g->loaded -= min_written;