til_stream: introduce a per-stream frame counter

This adds til_stream_start_frame() which advances a per-stream
counter.

Subsequent commits will make use of this for implementing a
pre-frame competition for pipe ownership.

2 files changed, 10 insertions, 0 deletions

diff --git a/src/til_stream.c b/src/til_stream.c
index 247dbf3..c508e35 100644
--- a/src/til_stream.c
+++ b/src/til_stream.c
@@ -92,6 +92,7 @@ struct til_stream_module_context_t {
 typedef struct til_stream_t {
 	pthread_mutex_t			mutex;
 	volatile int			ended;
+	unsigned			frame;
 	const til_stream_hooks_t	*hooks;
 	void				*hooks_context;
 	til_stream_pipe_t		*pipe_buckets[TIL_STREAM_PIPE_BUCKETS_COUNT];
@@ -129,6 +130,14 @@ int til_stream_active(til_stream_t *stream)
 }
 
 
+void til_stream_start_frame(til_stream_t *stream)
+{
+	assert(stream);
+
+	stream->frame++;
+}
+
+
 til_stream_t * til_stream_free(til_stream_t *stream)
 {
 	unsigned	leaked;
diff --git a/src/til_stream.h b/src/til_stream.h
index f9717af..54bbdc5 100644
--- a/src/til_stream.h
+++ b/src/til_stream.h
@@ -48,6 +48,7 @@ til_stream_t * til_stream_new(void);
 til_stream_t * til_stream_free(til_stream_t *stream);
 void til_stream_end(til_stream_t *stream);
 int til_stream_active(til_stream_t *stream);
+void til_stream_start_frame(til_stream_t *stream);
 int til_stream_set_hooks(til_stream_t *stream, const til_stream_hooks_t *hooks, void *context);
 int til_stream_unset_hooks(til_stream_t *stream, const til_stream_hooks_t *hooks);