From 9b0a880afb76ceb032b1ea4e7640839aafa01462 Mon Sep 17 00:00:00 2001
From: Wim Taymans <wtaymans@redhat.com>
Date: Fri, 16 Mar 2018 16:55:25 +0100
Subject: [PATCH] simplify things with just 1 process function

Make just one process function in spa node. With the io area states
we can do more complicated io patterns.
---
 meson.build                                  |  4 +-
 spa/include/spa/graph/graph-scheduler2.h     | 30 +++++--
 spa/include/spa/graph/graph.h                | 56 +++++++------
 spa/include/spa/node/node.h                  | 83 +++-----------------
 spa/plugins/alsa/alsa-sink.c                 | 20 ++---
 spa/plugins/alsa/alsa-utils.c                |  2 -
 spa/plugins/v4l2/v4l2-source.c               | 32 +++++---
 spa/plugins/v4l2/v4l2-utils.c                | 11 +--
 spa/tests/test-perf.c                        |  8 +-
 spa/tests/test-ringbuffer.c                  |  8 +-
 spa/tests/test-v4l2.c                        |  2 +-
 src/examples/export-sink.c                   |  4 +-
 src/examples/export-source.c                 |  4 +-
 src/examples/local-v4l2.c                    |  4 +-
 src/modules/module-audio-dsp.c               | 65 +--------------
 src/modules/module-client-node/client-node.c | 71 ++---------------
 src/pipewire/link.c                          | 42 ++++++++--
 src/pipewire/mem.c                           |  2 +-
 src/pipewire/node.c                          | 12 ++-
 src/pipewire/port.c                          | 51 ++----------
 src/pipewire/stream.c                        | 50 ++++++------
 21 files changed, 202 insertions(+), 359 deletions(-)

diff --git a/meson.build b/meson.build
index 9c9210e64..f3ceee9c3 100644
--- a/meson.build
+++ b/meson.build
@@ -165,8 +165,8 @@ endif
 subdir('spa')
 subdir('src')
 subdir('pkgconfig')
-#subdir('pipewire-jack')
-#subdir('alsa-plugins')
+subdir('pipewire-jack')
+subdir('alsa-plugins')
 
 if get_option('enable_docs')
   doxygen = find_program('doxygen', required : false)
diff --git a/spa/include/spa/graph/graph-scheduler2.h b/spa/include/spa/graph/graph-scheduler2.h
index 6a8134b09..8d67664e0 100644
--- a/spa/include/spa/graph/graph-scheduler2.h
+++ b/spa/include/spa/graph/graph-scheduler2.h
@@ -136,21 +136,35 @@ static inline int spa_graph_impl_have_output(void *data, struct spa_graph_node *
 	return 0;
 }
 
+static inline void spa_graph_impl_add_graph(struct spa_graph *g, struct spa_list *pending)
+{
+	struct spa_graph_node *n;
+	struct spa_graph *sg;
+
+	spa_list_for_each(n, &g->nodes, link) {
+		n->state->pending = n->state->required + 1;
+		spa_debug("graph %p node %p: add %d %d status %d", g, n,
+			n->state->pending, n->state->required, n->state->status);
+		spa_list_append(pending, &n->sched_link);
+	}
+	spa_list_for_each(sg, &g->subgraphs, link)
+		spa_graph_impl_add_graph(sg, pending);
+}
+
 static inline int spa_graph_impl_run(void *data)
 {
 	struct spa_graph_data *d = (struct spa_graph_data *) data;
 	struct spa_graph *g = d->graph;
-	struct spa_graph_node *n;
+	struct spa_graph_node *n, *tmp;
+	struct spa_list pending;
 
 	spa_debug("graph %p run", d->graph);
 
-	spa_list_for_each(n, &g->nodes, link) {
-		n->state->pending = n->state->required + 1;
-                spa_debug("node %p: add %d %d status %d", n,
-                                n->state->pending, n->state->required,
-                                n->state->status);
-	}
-	spa_list_for_each(n, &g->nodes, link)
+	spa_list_init(&pending);
+
+	spa_graph_impl_add_graph(g, &pending);
+
+	spa_list_for_each_safe(n, tmp, &pending, sched_link)
 		spa_graph_trigger(d->graph, n);
 
 	return 0;
diff --git a/spa/include/spa/graph/graph.h b/spa/include/spa/graph/graph.h
index 4c34deab5..9f2710acf 100644
--- a/spa/include/spa/graph/graph.h
+++ b/spa/include/spa/graph/graph.h
@@ -48,6 +48,8 @@ struct spa_graph_callbacks {
 
 struct spa_graph {
 	struct spa_list link;		/* link for subgraph */
+#define SPA_GRAPH_FLAG_DRIVER		(1 << 0)
+	uint32_t flags;			/* flags */
 	struct spa_graph *parent;	/* parent graph or NULL when driver */
 	struct spa_list nodes;		/* list of nodes of this graph */
 	struct spa_list subgraphs;	/* list of subgraphs */
@@ -55,25 +57,6 @@ struct spa_graph {
 	void *callbacks_data;
 };
 
-static inline struct spa_graph * spa_graph_find_root(struct spa_graph *graph)
-{
-	while (graph->parent)
-		graph = graph->parent;
-	return graph;
-}
-
-static inline void spa_graph_add_subgraph(struct spa_graph *graph, struct spa_graph *subgraph)
-{
-	subgraph->parent = graph;
-	spa_list_append(&graph->subgraphs, &subgraph->link);
-}
-
-static inline void spa_graph_remove_subgraph(struct spa_graph *subgraph)
-{
-	subgraph->parent = NULL;
-	spa_list_remove(&subgraph->link);
-}
-
 #define spa_graph_need_input(g,n)	((g)->callbacks->need_input((g)->callbacks_data, (n)))
 #define spa_graph_have_output(g,n)	((g)->callbacks->have_output((g)->callbacks_data, (n)))
 #define spa_graph_run(g)		((g)->callbacks->run((g)->callbacks_data))
@@ -124,6 +107,8 @@ static inline void spa_graph_init(struct spa_graph *graph)
 {
 	spa_list_init(&graph->nodes);
 	spa_list_init(&graph->subgraphs);
+	graph->flags = 0;
+	spa_debug("graph %p init", graph);
 }
 
 static inline void
@@ -135,6 +120,27 @@ spa_graph_set_callbacks(struct spa_graph *graph,
 	graph->callbacks_data = data;
 }
 
+static inline struct spa_graph *spa_graph_find_root(struct spa_graph *graph)
+{
+	while (graph->parent)
+		graph = graph->parent;
+	return graph;
+}
+
+static inline void spa_graph_add_subgraph(struct spa_graph *graph, struct spa_graph *subgraph)
+{
+	subgraph->parent = graph;
+	spa_list_append(&graph->subgraphs, &subgraph->link);
+	spa_debug("graph %p add subgraph %p", graph, subgraph);
+}
+
+static inline void spa_graph_remove_subgraph(struct spa_graph *subgraph)
+{
+	subgraph->parent = NULL;
+	spa_list_remove(&subgraph->link);
+	spa_debug("graph %p remove subgraph", subgraph);
+}
+
 static inline void
 spa_graph_node_init(struct spa_graph_node *node, struct spa_graph_state *state)
 {
@@ -163,7 +169,7 @@ spa_graph_node_add(struct spa_graph *graph,
 	node->graph = graph;
 	node->sched_link.next = NULL;
 	spa_list_append(&graph->nodes, &node->link);
-	spa_debug("node %p add", node);
+	spa_debug("node %p add to graph %p", node, graph);
 }
 
 static inline void
@@ -241,15 +247,9 @@ static inline int spa_graph_node_impl_process(void *data, struct spa_graph_node
 {
 	struct spa_graph *g = node->graph;
 	struct spa_node *n = data;
-	//int old = node->state->status, res = 0;
 	int res = 0;
 
-//	if (old == SPA_STATUS_NEED_BUFFER && n->process_input &&
-	if (n->process_input &&
-	    !spa_list_is_empty(&node->ports[SPA_DIRECTION_INPUT]))
-		res = spa_node_process_input(n);
-	else
-		res = spa_node_process_output(n);
+	res = spa_node_process(n);
 
 	spa_debug("node %p: process %d", node, res);
 
@@ -258,8 +258,6 @@ static inline int spa_graph_node_impl_process(void *data, struct spa_graph_node
 	if (res == SPA_STATUS_HAVE_BUFFER)
 		spa_graph_have_output(g, node);
 
-	spa_debug("node %p: end %d", node, res);
-
         return res;
 }
 
diff --git a/spa/include/spa/node/node.h b/spa/include/spa/node/node.h
index 4d9c68171..c08e49324 100644
--- a/spa/include/spa/node/node.h
+++ b/spa/include/spa/node/node.h
@@ -479,81 +479,21 @@ struct spa_node {
 				  uint32_t port_id,
 				  const struct spa_command *command);
 	/**
-	 * Process the input area of the node.
+	 * Process the node
 	 *
-	 * For synchronous nodes, this function is called to start processing data
-	 * or when process_output returned SPA_STATUS_NEED_BUFFER
+	 * Output io areas with SPA_STATUS_NEED_BUFFER will recycle the
+	 * buffers if any.
 	 *
-	 * For Asynchronous nodes, this function is called when a need_input event
-	 * is received from the node.
+	 * Input areas with SPA_STATUS_HAVE_BUFFER are consumed if possible
+	 * and the status is set to SPA_STATUS_NEED_BUFFER or SPA_STATUS_OK.
 	 *
-	 * Before calling this function, you must configure spa_port_io structures
-	 * on the input ports you want to process data on.
+	 * When the node has new output buffers, SPA_STATUS_HAVE_BUFFER
+	 * is returned.
 	 *
-	 * The node will loop through all spa_port_io structures and will
-	 * process the buffers. For each port, the port io will be used as:
-	 *
-	 *  - if status is set to SPA_STATUS_HAVE_BUFFER, buffer_id is read and processed.
-	 *
-	 * The spa_port_io of the port is then updated as follows.
-	 *
-	 *  - buffer_id is set to a buffer id that should be reused. SPA_ID_INVALID
-	 *    is set when there is no buffer to reuse
-	 *
-	 *  - status is set to SPA_STATUS_OK when no new buffer is needed on the port
-	 *
-	 *  - status is set to SPA_STATUS_NEED_BUFFER when a new buffer is needed
-	 *    on the port.
-	 *
-	 *  - status is set to a negative errno style error code when the buffer_id
-	 *    was invalid or any processing error happened on the port.
-	 *
-	 * This function must be called from the data thread.
-	 *
-	 * \param node a spa_node
-	 * \return SPA_STATUS_OK on success or when the node is asynchronous
-	 *         SPA_STATUS_HAVE_BUFFER for synchronous nodes when output
-	 *                                  can be consumed.
-	 *	   < 0 for errno style errors. One or more of the spa_port_io
-	 *	     areas has an error.
+	 * When no new output could be produced, SPA_STATUS_NEED_BUFFER is
+	 * returned.
 	 */
-	int (*process_input) (struct spa_node *node);
-
-	/**
-	 * Tell the node that output is consumed.
-	 *
-	 * For synchronous nodes, this function can be called when process_input
-	 * returned SPA_STATUS_HAVE_BUFFER and the output on the spa_port_io
-	 * areas has been consumed.
-	 *
-	 * For Asynchronous node, this function is called when a have_output event
-	 * is received from the node.
-	 *
-	 * Before calling this function you must process the buffers
-	 * in each of the output ports spa_port_io structure as follows:
-	 *
-	 * - use the buffer_id from the io for all the ports where the status is
-	 *   SPA_STATUS_HAVE_BUFFER
-	 *
-	 * - set buffer_id to a buffer_id you would like to reuse or SPA_ID_INVALID
-	 *   when no buffer is to be reused.
-	 *
-	 * - set the status to SPA_STATUS_NEED_BUFFER for all port you want more
-	 *   output from
-	 *
-	 * - set the status to SPA_STATUS_OK for the port you don't want more
-	 *   buffers from.
-	 *
-	 * This function must be called from the data thread.
-	 *
-	 * \param node a spa_node
-	 * \return SPA_STATUS_OK on success or when the node is asynchronous
-	 *         SPA_STATUS_NEED_BUFFER for synchronous nodes when input
-	 *                                 is needed.
-	 *	   < 0 for errno style errors. One or more of the spa_port_io
-	 *	     areas has an error.
-	 */
-	int (*process_output) (struct spa_node *node);
+	int (*process) (struct spa_node *node);
 };
 
 #define spa_node_enum_params(n,...)		(n)->enum_params((n),__VA_ARGS__)
@@ -572,8 +512,7 @@ struct spa_node {
 #define spa_node_port_set_io(n,...)		(n)->port_set_io((n),__VA_ARGS__)
 #define spa_node_port_reuse_buffer(n,...)	(n)->port_reuse_buffer((n),__VA_ARGS__)
 #define spa_node_port_send_command(n,...)	(n)->port_send_command((n),__VA_ARGS__)
-#define spa_node_process_input(n)		(n)->process_input((n))
-#define spa_node_process_output(n)		(n)->process_output((n))
+#define spa_node_process(n)			(n)->process((n))
 
 #ifdef __cplusplus
 }  /* extern "C" */
diff --git a/spa/plugins/alsa/alsa-sink.c b/spa/plugins/alsa/alsa-sink.c
index 0f27d87ce..3a6c8e0dd 100644
--- a/spa/plugins/alsa/alsa-sink.c
+++ b/spa/plugins/alsa/alsa-sink.c
@@ -571,7 +571,7 @@ impl_node_port_send_command(struct spa_node *node,
 	return -ENOTSUP;
 }
 
-static int impl_node_process_input(struct spa_node *node)
+static int impl_node_process(struct spa_node *node)
 {
 	struct state *this;
 	struct spa_io_buffers *input;
@@ -582,13 +582,15 @@ static int impl_node_process_input(struct spa_node *node)
 	input = this->io;
 	spa_return_val_if_fail(input != NULL, -EIO);
 
-	spa_log_trace(this->log, NAME " %p: process input %d %d", this, input->status, input->buffer_id);
+	spa_log_trace(this->log, NAME " %p: process %d %d", this, input->status, input->buffer_id);
 
-	if (input->status == SPA_STATUS_HAVE_BUFFER && input->buffer_id < this->n_buffers) {
+	if (input->status == SPA_STATUS_HAVE_BUFFER &&
+	    input->buffer_id < this->n_buffers) {
 		struct buffer *b = &this->buffers[input->buffer_id];
 
 		if (!SPA_FLAG_CHECK(b->flags, BUFFER_FLAG_OUT)) {
-			spa_log_warn(this->log, NAME " %p: buffer %u in use", this, input->buffer_id);
+			spa_log_warn(this->log, NAME " %p: buffer %u in use",
+					this, input->buffer_id);
 			input->status = -EINVAL;
 			return -EINVAL;
 		}
@@ -599,17 +601,12 @@ static int impl_node_process_input(struct spa_node *node)
 
 		input->status = SPA_STATUS_OK;
 	}
-
 	return SPA_STATUS_OK;
 }
 
-static int impl_node_process_output(struct spa_node *node)
-{
-	return -ENOTSUP;
-}
-
 static const struct spa_dict_item node_info_items[] = {
 	{ "media.class", "Audio/Sink" },
+	{ "node.driver", "true" },
 };
 
 static const struct spa_dict node_info = {
@@ -636,8 +633,7 @@ static const struct spa_node impl_node = {
 	impl_node_port_set_io,
 	impl_node_port_reuse_buffer,
 	impl_node_port_send_command,
-	impl_node_process_input,
-	impl_node_process_output,
+	impl_node_process,
 };
 
 static int impl_get_interface(struct spa_handle *handle, uint32_t interface_id, void **interface)
diff --git a/spa/plugins/alsa/alsa-utils.c b/spa/plugins/alsa/alsa-utils.c
index e8897e1c7..19f597292 100644
--- a/spa/plugins/alsa/alsa-utils.c
+++ b/spa/plugins/alsa/alsa-utils.c
@@ -343,8 +343,6 @@ static inline void try_pull(struct state *state, snd_pcm_uframes_t frames,
 	if (spa_list_is_empty(&state->ready) && do_pull) {
 		spa_log_trace(state->log, "alsa-util %p: %d %lu", state, io->status,
 				state->filled + written);
-		if (io->status == SPA_STATUS_NEED_BUFFER)
-			return;
 		io->status = SPA_STATUS_NEED_BUFFER;
 		if (state->range) {
 			state->range->offset = state->sample_count * state->frame_size;
diff --git a/spa/plugins/v4l2/v4l2-source.c b/spa/plugins/v4l2/v4l2-source.c
index 731d92f16..112ea7ae3 100644
--- a/spa/plugins/v4l2/v4l2-source.c
+++ b/spa/plugins/v4l2/v4l2-source.c
@@ -61,6 +61,7 @@ static void reset_props(struct props *props)
 #define BUFFER_FLAG_MAPPED	(1<<2)
 
 struct buffer {
+	struct spa_list link;
 	struct spa_buffer *outbuf;
 	struct spa_meta_header *h;
 	uint32_t flags;
@@ -174,6 +175,7 @@ struct port {
 
 	struct buffer buffers[MAX_BUFFERS];
 	uint32_t n_buffers;
+	struct spa_list queue;
 
 	struct spa_source source;
 
@@ -810,17 +812,13 @@ static int impl_node_port_send_command(struct spa_node *node,
 	return -ENOTSUP;
 }
 
-static int impl_node_process_input(struct spa_node *node)
-{
-	return -ENOTSUP;
-}
-
-static int impl_node_process_output(struct spa_node *node)
+static int impl_node_process(struct spa_node *node)
 {
 	struct impl *this;
-	int i, res = SPA_STATUS_OK;
+	int i, res;
 	struct spa_io_buffers *io;
 	struct port *port;
+	struct buffer *b;
 
 	spa_return_val_if_fail(node != NULL, -EINVAL);
 
@@ -834,7 +832,9 @@ static int impl_node_process_output(struct spa_node *node)
 		return SPA_STATUS_HAVE_BUFFER;
 
 	if (io->buffer_id < port->n_buffers) {
-		res = spa_v4l2_buffer_recycle(this, io->buffer_id);
+		if ((res = spa_v4l2_buffer_recycle(this, io->buffer_id)) < 0)
+			return res;
+
 		io->buffer_id = SPA_ID_INVALID;
 	}
 	for (i = 0; i < port->n_controls; i++) {
@@ -856,7 +856,16 @@ static int impl_node_process_output(struct spa_node *node)
 			control->value = *control->io = c.value;
 		}
 	}
-	return res;
+	if (spa_list_is_empty(&port->queue))
+		return -EPIPE;
+
+	b = spa_list_first(&port->queue, struct buffer, link);
+	spa_list_remove(&b->link);
+
+	io->buffer_id = b->outbuf->id;
+	io->status = SPA_STATUS_HAVE_BUFFER;
+
+	return SPA_STATUS_HAVE_BUFFER;
 }
 
 static const struct spa_dict_item info_items[] = {
@@ -889,8 +898,7 @@ static const struct spa_node impl_node = {
 	impl_node_port_set_io,
 	impl_node_port_reuse_buffer,
 	impl_node_port_send_command,
-	impl_node_process_input,
-	impl_node_process_output,
+	impl_node_process,
 };
 
 static int impl_clock_enum_params(struct spa_clock *clock, uint32_t id, uint32_t *index,
@@ -1012,6 +1020,8 @@ impl_init(const struct spa_handle_factory *factory,
 
 	reset_props(&this->props);
 
+	spa_list_init(&port->queue);
+
 	port->log = this->log;
 	port->info.flags = SPA_PORT_INFO_FLAG_LIVE |
 			   SPA_PORT_INFO_FLAG_PHYSICAL |
diff --git a/spa/plugins/v4l2/v4l2-utils.c b/spa/plugins/v4l2/v4l2-utils.c
index 56e2c9bb9..7a0803920 100644
--- a/spa/plugins/v4l2/v4l2-utils.c
+++ b/spa/plugins/v4l2/v4l2-utils.c
@@ -118,6 +118,7 @@ static int spa_v4l2_buffer_recycle(struct impl *this, uint32_t buffer_id)
 		spa_log_error(port->log, "VIDIOC_QBUF: %m");
 		return -err;
 	}
+
 	return 0;
 }
 
@@ -1145,7 +1146,6 @@ static int mmap_read(struct impl *this)
 	struct buffer *b;
 	struct spa_data *d;
 	int64_t pts;
-	struct spa_io_buffers *io = port->io;
 
 	spa_zero(buf);
 	buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
@@ -1178,10 +1178,9 @@ static int mmap_read(struct impl *this)
 	d[0].chunk->stride = port->fmt.fmt.pix.bytesperline;
 
 	SPA_FLAG_SET(b->flags, BUFFER_FLAG_OUTSTANDING);
-	io->buffer_id = b->outbuf->id;
-	io->status = SPA_STATUS_HAVE_BUFFER;
+	spa_list_append(&port->queue, &b->link);
 
-	spa_log_trace(port->log, "v4l2 %p: have output %d", this, io->buffer_id);
+	spa_log_trace(port->log, "v4l2 %p: have output %d", this, buf.index);
 	this->callbacks->have_output(this->callbacks_data);
 
 	return 0;
@@ -1499,10 +1498,12 @@ static int spa_v4l2_stream_off(struct impl *this)
 		struct buffer *b;
 
 		b = &port->buffers[i];
-		if (!SPA_FLAG_CHECK(b->flags, BUFFER_FLAG_OUTSTANDING))
+		if (!SPA_FLAG_CHECK(b->flags, BUFFER_FLAG_OUTSTANDING)) {
 			if (xioctl(port->fd, VIDIOC_QBUF, &b->v4l2_buffer) < 0)
 				spa_log_warn(this->log, "VIDIOC_QBUF: %s", strerror(errno));
+		}
 	}
+	spa_list_init(&port->queue);
 	port->started = false;
 
 	return 0;
diff --git a/spa/tests/test-perf.c b/spa/tests/test-perf.c
index bc546270a..fa0174aa4 100644
--- a/spa/tests/test-perf.c
+++ b/spa/tests/test-perf.c
@@ -229,8 +229,8 @@ static void on_sink_pull(struct data *data)
 {
 	spa_log_trace(data->log, "do sink pull");
 	if (data->mode & MODE_DIRECT) {
-		spa_node_process_output(data->source);
-		spa_node_process_input(data->sink);
+		spa_node_process(data->source);
+		spa_node_process(data->sink);
 	} else {
 		spa_graph_need_input(&data->graph, &data->sink_node);
 	}
@@ -240,8 +240,8 @@ static void on_source_push(struct data *data)
 {
 	spa_log_trace(data->log, "do source push");
 	if (data->mode & MODE_DIRECT) {
-		spa_node_process_output(data->source);
-		spa_node_process_input(data->sink);
+		spa_node_process(data->source);
+		spa_node_process(data->sink);
 	} else {
 		spa_graph_have_output(&data->graph, &data->source_node);
 	}
diff --git a/spa/tests/test-ringbuffer.c b/spa/tests/test-ringbuffer.c
index 8ba40bb45..30d911588 100644
--- a/spa/tests/test-ringbuffer.c
+++ b/spa/tests/test-ringbuffer.c
@@ -219,12 +219,12 @@ static void on_sink_need_input(void *_data)
 	struct data *data = _data;
 	int res;
 
-	res = spa_node_process_output(data->source);
+	res = spa_node_process(data->source);
 	if (res != SPA_STATUS_HAVE_BUFFER)
-		printf("got process_output error from source %d\n", res);
+		printf("got process error from source %d\n", res);
 
-	if ((res = spa_node_process_input(data->sink)) < 0)
-		printf("got process_input error from sink %d\n", res);
+	if ((res = spa_node_process(data->sink)) < 0)
+		printf("got process error from sink %d\n", res);
 }
 
 static void
diff --git a/spa/tests/test-v4l2.c b/spa/tests/test-v4l2.c
index d7e8bdabe..5cba59be7 100644
--- a/spa/tests/test-v4l2.c
+++ b/spa/tests/test-v4l2.c
@@ -276,7 +276,7 @@ static void on_source_have_output(void *_data)
 
 	io->status = SPA_STATUS_NEED_BUFFER;
 
-	if ((res = spa_node_process_output(data->source)) < 0)
+	if ((res = spa_node_process(data->source)) < 0)
 		printf("got pull error %d\n", res);
 }
 
diff --git a/src/examples/export-sink.c b/src/examples/export-sink.c
index db482df2f..6afc1e118 100644
--- a/src/examples/export-sink.c
+++ b/src/examples/export-sink.c
@@ -539,7 +539,7 @@ static int do_render(struct spa_loop *loop, bool async, uint32_t seq,
 	return 0;
 }
 
-static int impl_node_process_input(struct spa_node *node)
+static int impl_node_process(struct spa_node *node)
 {
 	struct data *d = SPA_CONTAINER_OF(node, struct data, impl_node);
 	struct spa_buffer *buf;
@@ -574,7 +574,7 @@ static const struct spa_node impl_node = {
 	.port_enum_params = impl_port_enum_params,
 	.port_set_param = impl_port_set_param,
 	.port_use_buffers = impl_port_use_buffers,
-	.process_input = impl_node_process_input,
+	.process = impl_node_process,
 };
 
 static void make_node(struct data *data)
diff --git a/src/examples/export-source.c b/src/examples/export-source.c
index 5dc20bb75..eb2c4c370 100644
--- a/src/examples/export-source.c
+++ b/src/examples/export-source.c
@@ -467,7 +467,7 @@ static void fill_s16(struct data *d, void *dest, int avail)
         }
 }
 
-static int impl_node_process_output(struct spa_node *node)
+static int impl_node_process(struct spa_node *node)
 {
 	struct data *d = SPA_CONTAINER_OF(node, struct data, impl_node);
 	struct buffer *b;
@@ -529,7 +529,7 @@ static const struct spa_node impl_node = {
 	.port_set_param = impl_port_set_param,
 	.port_use_buffers = impl_port_use_buffers,
 	.port_reuse_buffer = impl_port_reuse_buffer,
-	.process_output = impl_node_process_output,
+	.process = impl_node_process,
 };
 
 static void make_node(struct data *data)
diff --git a/src/examples/local-v4l2.c b/src/examples/local-v4l2.c
index b071af43a..387d2a356 100644
--- a/src/examples/local-v4l2.c
+++ b/src/examples/local-v4l2.c
@@ -433,7 +433,7 @@ static int do_render(struct spa_loop *loop, bool async, uint32_t seq,
 	return 0;
 }
 
-static int impl_node_process_input(struct spa_node *node)
+static int impl_node_process(struct spa_node *node)
 {
 	struct data *d = SPA_CONTAINER_OF(node, struct data, impl_node);
 	int res;
@@ -461,7 +461,7 @@ static const struct spa_node impl_node = {
 	.port_enum_params = impl_port_enum_params,
 	.port_set_param = impl_port_set_param,
 	.port_use_buffers = impl_port_use_buffers,
-	.process_input = impl_node_process_input,
+	.process = impl_node_process,
 };
 
 static void make_nodes(struct data *data)
diff --git a/src/modules/module-audio-dsp.c b/src/modules/module-audio-dsp.c
index baa7b4430..1c8eec6a9 100644
--- a/src/modules/module-audio-dsp.c
+++ b/src/modules/module-audio-dsp.c
@@ -279,7 +279,7 @@ static void dequeue_buffer(struct node *n, struct buffer *b)
 	SPA_FLAG_SET(b->flags, BUFFER_FLAG_OUT);
 }
 
-static int node_process_input(struct spa_node *node)
+static int node_process(struct spa_node *node)
 {
 	struct node *n = SPA_CONTAINER_OF(node, struct node, node_impl);
 	struct pw_node *this = n->node;
@@ -311,43 +311,6 @@ static int node_process_input(struct spa_node *node)
 	return outio->status;
 }
 
-static int node_process_output(struct spa_node *node)
-{
-	struct node *n = SPA_CONTAINER_OF(node, struct node, node_impl);
-	struct pw_node *this = n->node;
-	struct port *outp = GET_OUT_PORT(n, 0);
-	struct spa_io_buffers *outio = outp->io;
-	int i;
-
-	pw_log_trace(NAME " %p: process output %d", this, outio->status);
-
-        if (outio->status == SPA_STATUS_HAVE_BUFFER)
-		return SPA_STATUS_HAVE_BUFFER;
-
-	if (outio->buffer_id < outp->n_buffers) {
-		recycle_buffer(n, outp, outio->buffer_id);
-		outio->buffer_id = SPA_ID_INVALID;
-	}
-	if (n->n_in_ports == 0) {
-		outio->buffer_id = SPA_ID_INVALID;
-		outio->status = SPA_STATUS_HAVE_BUFFER;
-	}
-	else {
-		for (i = 0; i < n->n_in_ports; i++) {
-			struct port *inp = GET_IN_PORT(n, i);
-			struct spa_io_buffers *inio = inp->io;
-
-			if (inio == NULL)
-				continue;
-
-			inio->status = SPA_STATUS_NEED_BUFFER;
-			pw_log_trace(NAME " %p: port %d %d", this, i, inio->buffer_id);
-		}
-		outio->status = SPA_STATUS_NEED_BUFFER;
-	}
-	return outio->status;
-}
-
 static int port_set_io(struct spa_node *node,
 		       enum spa_direction direction, uint32_t port_id,
 		       uint32_t id, void *data, size_t size)
@@ -623,12 +586,11 @@ static const struct spa_node node_impl = {
 	.port_set_io = port_set_io,
 	.port_reuse_buffer = port_reuse_buffer,
 	.port_send_command = port_send_command,
-	.process_input = node_process_input,
-	.process_output = node_process_output,
+	.process = node_process,
 };
 
 
-static int schedule_mix_input(struct spa_node *_node)
+static int schedule_mix(struct spa_node *_node)
 {
 	struct pw_port *port = SPA_CONTAINER_OF(_node, struct pw_port, mix_node);
 	struct port *p = port->owner_data;
@@ -678,24 +640,6 @@ static int schedule_mix_input(struct spa_node *_node)
 	return SPA_STATUS_HAVE_BUFFER;
 }
 
-static int schedule_mix_output(struct spa_node *_node)
-{
-	struct pw_port *port = SPA_CONTAINER_OF(_node, struct pw_port, mix_node);
-	struct spa_graph_node *node = &port->rt.mix_node;
-	struct spa_graph_port *gp;
-	struct spa_io_buffers *io = port->rt.mix_port.io;
-
-	pw_log_trace("port %p", port);
-
-	spa_list_for_each(gp, &node->ports[SPA_DIRECTION_INPUT], link) {
-		pw_log_trace("port %p: port %d %d %p->%p %d %d", port,
-				gp->port_id, gp->flags, io, gp->io, io->status, io->buffer_id);
-		gp->io->status = io->status;
-	}
-	io->status =  SPA_STATUS_HAVE_BUFFER;
-	return io->status;
-}
-
 static int schedule_mix_use_buffers(struct spa_node *_node,
 				    enum spa_direction direction,
 				    uint32_t port_id,
@@ -720,8 +664,7 @@ static const struct spa_node schedule_mix_node = {
 	SPA_VERSION_NODE,
 	NULL,
 	.port_use_buffers = schedule_mix_use_buffers,
-	.process_input = schedule_mix_input,
-	.process_output = schedule_mix_output,
+	.process = schedule_mix,
 };
 
 static void port_free(void *data)
diff --git a/src/modules/module-client-node/client-node.c b/src/modules/module-client-node/client-node.c
index 01c22aae9..b9fdfdfdf 100644
--- a/src/modules/module-client-node/client-node.c
+++ b/src/modules/module-client-node/client-node.c
@@ -842,63 +842,18 @@ impl_node_port_send_command(struct spa_node *node,
 	return 0;
 }
 
-static int impl_node_process_input(struct spa_node *node)
+static int impl_node_process(struct spa_node *node)
 {
 	struct node *this = SPA_CONTAINER_OF(node, struct node, node);
 	struct impl *impl = this->impl;
-	struct spa_graph_node *n = &impl->this.node->rt.node;
-	bool client_reuse = impl->client_reuse;
-	struct spa_graph_port *p, *pp;
 	int res;
 
-	if (impl->input_ready == 0) {
-		/* the client is not ready to receive our buffers, recycle them */
-		pw_log_trace("node not ready, recycle buffers");
-		spa_list_for_each(p, &n->ports[SPA_DIRECTION_INPUT], link)
-			p->io->status = SPA_STATUS_NEED_BUFFER;
-		res = SPA_STATUS_NEED_BUFFER;
-	}
-	else {
-		spa_list_for_each(p, &n->ports[SPA_DIRECTION_INPUT], link) {
-			struct spa_io_buffers *io = p->io;
-
-			pw_log_trace("set io status to %d %d", io->status, io->buffer_id);
-
-			/* explicitly recycle buffers when the client is not going to do it */
-			if (!client_reuse && (pp = p->peer))
-		                spa_graph_node_reuse_buffer(pp->node,
-						pp->port_id, io->buffer_id);
-		}
-		pw_log_trace("client-node %p: send process input", this);
-		pw_client_node_transport_add_message(impl->transport,
-			       &PW_CLIENT_NODE_MESSAGE_INIT(PW_CLIENT_NODE_MESSAGE_PROCESS_INPUT));
-		do_flush(this);
-
-		impl->input_ready--;
-		res = SPA_STATUS_OK;
-	}
-	return res;
-}
-
-static int impl_node_process_output(struct spa_node *node)
-{
-	struct node *this;
-	struct impl *impl;
-
-	this = SPA_CONTAINER_OF(node, struct node, node);
-	impl = this->impl;
-
-	pw_log_trace("client-node %p: process output %d", this, impl->out_pending);
-	if (impl->out_pending)
-		return SPA_STATUS_OK;
-
-	impl->out_pending = true;
-
+	pw_log_trace("client-node %p: send process input", this);
 	pw_client_node_transport_add_message(impl->transport,
-			       &PW_CLIENT_NODE_MESSAGE_INIT(PW_CLIENT_NODE_MESSAGE_PROCESS_OUTPUT));
+		       &PW_CLIENT_NODE_MESSAGE_INIT(PW_CLIENT_NODE_MESSAGE_PROCESS_INPUT));
 	do_flush(this);
-
-	return SPA_STATUS_OK;
+	res = SPA_STATUS_OK;
+	return res;
 }
 
 static int handle_node_message(struct node *this, struct pw_client_node_message *message)
@@ -1082,8 +1037,7 @@ static const struct spa_node impl_node = {
 	impl_node_port_set_io,
 	impl_node_port_reuse_buffer,
 	impl_node_port_send_command,
-	impl_node_process_input,
-	impl_node_process_output,
+	impl_node_process,
 };
 
 static int
@@ -1285,7 +1239,7 @@ static int mix_port_set_io(struct spa_node *node,
 			      id, data, size);
 }
 
-static int mix_port_process_input(struct spa_node *data)
+static int mix_port_process(struct spa_node *data)
 {
 	struct pw_port *p = SPA_CONTAINER_OF(data, struct pw_port, mix_node);
 	struct spa_io_buffers *io = p->rt.mix_port.io;
@@ -1293,22 +1247,13 @@ static int mix_port_process_input(struct spa_node *data)
 	return SPA_STATUS_HAVE_BUFFER;
 }
 
-static int mix_port_process_output(struct spa_node *data)
-{
-	struct pw_port *p = SPA_CONTAINER_OF(data, struct pw_port, mix_node);
-	struct spa_io_buffers *io = p->rt.mix_port.io;
-	pw_log_trace("client-node %p: pass %d %d", data, io->status, io->buffer_id);
-	return SPA_STATUS_NEED_BUFFER;
-}
-
 static void node_port_added(void *data, struct pw_port *port)
 {
 	struct impl *impl = data;
 
 	pw_log_debug("client-node %p: port %p added", &impl->this, port);
 	port->mix_node.port_set_io = mix_port_set_io;
-	port->mix_node.process_input = mix_port_process_input;
-	port->mix_node.process_output = mix_port_process_output;
+	port->mix_node.process = mix_port_process;
 
 	port->implementation = &port_impl;
 	port->implementation_data = impl;
diff --git a/src/pipewire/link.c b/src/pipewire/link.c
index 2c59a062f..d2508e298 100644
--- a/src/pipewire/link.c
+++ b/src/pipewire/link.c
@@ -1154,6 +1154,30 @@ static const struct pw_node_events output_node_events = {
 	.async_complete = output_node_async_complete,
 };
 
+static int
+do_join_graphs(struct spa_loop *loop,
+		bool async, uint32_t seq, const void *data, size_t size, void *user_data)
+{
+        struct pw_link *this = user_data;
+	struct spa_graph *in_graph, *out_graph;
+	struct spa_graph *in_root, *out_root;
+
+	in_graph = this->input->node->rt.node.graph;
+	out_graph = this->output->node->rt.node.graph;
+
+	in_root = spa_graph_find_root(in_graph);
+	out_root = spa_graph_find_root(out_graph);
+
+	if (out_root == in_root)
+		return 0;
+
+	if (SPA_FLAG_CHECK(in_root->flags, SPA_GRAPH_FLAG_DRIVER))
+		spa_graph_add_subgraph(in_root, out_root);
+	else
+		spa_graph_add_subgraph(out_root, in_root);
+	return 0;
+}
+
 struct pw_link *pw_link_new(struct pw_core *core,
 			    struct pw_port *output,
 			    struct pw_port *input,
@@ -1166,6 +1190,7 @@ struct pw_link *pw_link_new(struct pw_core *core,
 	struct pw_link *this;
 	struct pw_node *input_node, *output_node;
 	struct spa_graph *in_graph, *out_graph;
+	struct spa_graph *in_root, *out_root;
 
 	if (output == input)
 		goto same_ports;
@@ -1179,7 +1204,16 @@ struct pw_link *pw_link_new(struct pw_core *core,
 	in_graph = input_node->rt.node.graph;
 	out_graph = output_node->rt.node.graph;
 
-	if (in_graph != NULL && out_graph != NULL && in_graph != out_graph)
+	pw_log_debug("link new %p %p", in_graph, out_graph);
+
+	in_root = spa_graph_find_root(in_graph);
+	out_root = spa_graph_find_root(out_graph);
+
+	pw_log_debug("link new %p %p", in_root, out_root);
+
+	if (SPA_FLAG_CHECK(in_root->flags, SPA_GRAPH_FLAG_DRIVER) &&
+	    SPA_FLAG_CHECK(out_root->flags, SPA_GRAPH_FLAG_DRIVER) &&
+	    in_root != out_root)
 		goto link_not_supported;
 
 	impl = calloc(1, sizeof(struct impl) + user_data_size);
@@ -1243,10 +1277,8 @@ struct pw_link *pw_link_new(struct pw_core *core,
 		     output_node, output->port_id, this->rt.mix[SPA_DIRECTION_OUTPUT].port.port_id,
 		     input_node, input->port_id, this->rt.mix[SPA_DIRECTION_INPUT].port.port_id);
 
-	if (out_graph != NULL)
-		pw_node_join_graph(input_node, out_graph);
-	else if (in_graph != NULL)
-		pw_node_join_graph(output_node, in_graph);
+	pw_loop_invoke(output->node->data_loop,
+		       do_join_graphs, SPA_ID_INVALID, NULL, 0, false, this);
 
 	spa_hook_list_call(&output->listener_list, struct pw_port_events, link_added, this);
 	spa_hook_list_call(&input->listener_list, struct pw_port_events, link_added, this);
diff --git a/src/pipewire/mem.c b/src/pipewire/mem.c
index 80e6886b2..94cdfa15f 100644
--- a/src/pipewire/mem.c
+++ b/src/pipewire/mem.c
@@ -257,7 +257,7 @@ void pw_memblock_free(struct pw_memblock *mem)
 	if (mem == NULL)
 		return;
 
-	pw_log_debug("mem %p: free", mem);
+	pw_log_debug("mem %p: free %p %d", mem, mem->ptr, mem->fd);
 	if (mem->flags & PW_MEMBLOCK_FLAG_WITH_FD) {
 		if (mem->ptr)
 			munmap(mem->ptr, mem->size);
diff --git a/src/pipewire/node.c b/src/pipewire/node.c
index 8b17cc388..f71b009ce 100644
--- a/src/pipewire/node.c
+++ b/src/pipewire/node.c
@@ -392,6 +392,11 @@ static void check_properties(struct pw_node *node)
 		node->driver = pw_properties_parse_bool(str);
 	else
 		node->driver = false;
+
+	if (node->driver)
+		SPA_FLAG_SET(impl->graph.flags, SPA_GRAPH_FLAG_DRIVER);
+	else
+		SPA_FLAG_UNSET(impl->graph.flags, SPA_GRAPH_FLAG_DRIVER);
 }
 
 static int
@@ -458,7 +463,7 @@ struct pw_node *pw_node_new(struct pw_core *core,
 	this->rt.activation = &impl->activation;
 	spa_graph_node_init(&this->rt.node, &this->rt.activation->state);
 
-	pw_loop_invoke(this->data_loop, do_node_join, 1, NULL, 0, false, this);
+	pw_loop_invoke(this->data_loop, do_node_join, 1, NULL, 0, true, this);
 
 	spa_list_init(&this->rt.links[SPA_DIRECTION_INPUT]);
 	spa_list_init(&this->rt.links[SPA_DIRECTION_OUTPUT]);
@@ -628,7 +633,12 @@ do_node_remove(struct spa_loop *loop,
 	       bool async, uint32_t seq, const void *data, size_t size, void *user_data)
 {
 	struct pw_node *this = user_data;
+	struct impl *impl = SPA_CONTAINER_OF(this, struct impl, this);
+
+	if (impl->graph.parent)
+		spa_graph_remove_subgraph(&impl->graph);
 	spa_graph_node_remove(&this->rt.node);
+
 	return 0;
 }
 
diff --git a/src/pipewire/port.c b/src/pipewire/port.c
index 1eb8d4ce1..451922f6e 100644
--- a/src/pipewire/port.c
+++ b/src/pipewire/port.c
@@ -64,23 +64,8 @@ static int schedule_tee_input(struct spa_node *data)
 			*p->io = *io;
 		}
 	}
-        return io->status;
-}
-static int schedule_tee_output(struct spa_node *data)
-{
-	struct pw_port *this = SPA_CONTAINER_OF(data, struct pw_port, mix_node);
-	struct spa_graph_node *node = &this->rt.mix_node;
-	struct spa_graph_port *p;
-	struct spa_io_buffers *io = this->rt.mix_port.io;
-
-	spa_list_for_each(p, &node->ports[SPA_DIRECTION_OUTPUT], link) {
-		pw_log_trace("port %p: port %d %d %p->%p %d %d",
-				this, p->port_id, p->flags, p->io, io,
-				p->io->status, p->io->buffer_id);
-		*io = *p->io;
-	}
-	pw_log_trace("port %p: tee output %d %d", this, io->status, io->buffer_id);
-	return io->status;
+	io->status = SPA_STATUS_NEED_BUFFER;
+        return SPA_STATUS_HAVE_BUFFER;
 }
 
 static int schedule_tee_reuse_buffer(struct spa_node *data, uint32_t port_id, uint32_t buffer_id)
@@ -98,8 +83,7 @@ static int schedule_tee_reuse_buffer(struct spa_node *data, uint32_t port_id, ui
 static const struct spa_node schedule_tee_node = {
 	SPA_VERSION_NODE,
 	NULL,
-	.process_input = schedule_tee_input,
-	.process_output = schedule_tee_output,
+	.process = schedule_tee_input,
 	.port_reuse_buffer = schedule_tee_reuse_buffer,
 };
 
@@ -119,24 +103,6 @@ static int schedule_mix_input(struct spa_node *data)
 	return io->status;
 }
 
-static int schedule_mix_output(struct spa_node *data)
-{
-	struct pw_port *this = SPA_CONTAINER_OF(data, struct pw_port, mix_node);
-	struct spa_graph_node *node = &this->rt.mix_node;
-	struct spa_graph_port *p;
-	struct spa_io_buffers *io = this->rt.mix_port.io;
-
-	if (!spa_list_is_empty(&node->ports[SPA_DIRECTION_INPUT])) {
-		spa_list_for_each(p, &node->ports[SPA_DIRECTION_INPUT], link) {
-			pw_log_trace("port %p: port %d %d %p->%p", this,
-					p->port_id, p->flags, io, p->io);
-			*p->io = *io;
-		}
-	}
-	pw_log_trace("port %p: output %d %d", this, io->status, io->buffer_id);
-	return io->status;
-}
-
 static int schedule_mix_reuse_buffer(struct spa_node *data, uint32_t port_id, uint32_t buffer_id)
 {
 	struct pw_port *this = SPA_CONTAINER_OF(data, struct pw_port, mix_node);
@@ -155,8 +121,7 @@ static int schedule_mix_reuse_buffer(struct spa_node *data, uint32_t port_id, ui
 static const struct spa_node schedule_mix_node = {
 	SPA_VERSION_NODE,
 	NULL,
-	.process_input = schedule_mix_input,
-	.process_output = schedule_mix_output,
+	.process = schedule_mix_input,
 	.port_reuse_buffer = schedule_mix_reuse_buffer,
 };
 
@@ -335,9 +300,7 @@ static int do_add_port(struct spa_loop *loop,
 	spa_graph_port_add(&this->node->rt.node, &this->rt.port);
 	spa_graph_port_add(&this->rt.mix_node, &this->rt.mix_port);
 	spa_graph_port_link(&this->rt.port, &this->rt.mix_port);
-
-	if (this->rt.mix_node.graph)
-		spa_graph_node_add(this->rt.mix_node.graph, &this->rt.mix_node);
+	spa_graph_node_add(this->node->rt.node.graph, &this->rt.mix_node);
 
 	return 0;
 }
@@ -549,9 +512,7 @@ static int do_remove_port(struct spa_loop *loop,
 		spa_graph_port_remove(p);
 
 	spa_graph_port_remove(&this->rt.mix_port);
-	if (this->rt.mix_node.graph)
-		spa_graph_node_remove(&this->rt.mix_node);
-	this->rt.mix_node.graph = NULL;
+	spa_graph_node_remove(&this->rt.mix_node);
 
 	return 0;
 }
diff --git a/src/pipewire/stream.c b/src/pipewire/stream.c
index da02bb146..ac04d5689 100644
--- a/src/pipewire/stream.c
+++ b/src/pipewire/stream.c
@@ -612,41 +612,37 @@ static void handle_rtnode_message(struct pw_stream *stream, struct pw_client_nod
 		struct buffer *b;
 		uint32_t buffer_id;
 
-		buffer_id = io->buffer_id;
+		if (impl->direction == SPA_DIRECTION_INPUT) {
+			buffer_id = io->buffer_id;
 
-		pw_log_trace("stream %p: process input %d %d", stream, io->status,
+			pw_log_trace("stream %p: process input %d %d", stream, io->status,
 			     buffer_id);
 
-		if ((b = find_buffer(stream, buffer_id)) == NULL)
-			return;
+			if ((b = find_buffer(stream, buffer_id)) == NULL)
+				return;
 
-		if (impl->client_reuse)
+			if (impl->client_reuse)
+				io->buffer_id = SPA_ID_INVALID;
+
+			if (io->status == SPA_STATUS_HAVE_BUFFER) {
+		                SPA_FLAG_SET(b->flags, BUFFER_FLAG_OUT);
+
+				impl->in_new_buffer = true;
+				spa_hook_list_call(&stream->listener_list, struct pw_stream_events,
+					 new_buffer, buffer_id);
+				impl->in_new_buffer = false;
+			}
+			io->status = SPA_STATUS_NEED_BUFFER;
+		} else {
+			reuse_buffer(stream, io->buffer_id);
 			io->buffer_id = SPA_ID_INVALID;
 
-		if (io->status == SPA_STATUS_HAVE_BUFFER) {
-	                SPA_FLAG_SET(b->flags, BUFFER_FLAG_OUT);
-
-			impl->in_new_buffer = true;
+			pw_log_trace("stream %p: process output", stream);
+			impl->in_need_buffer = true;
 			spa_hook_list_call(&stream->listener_list, struct pw_stream_events,
-				 new_buffer, buffer_id);
-			impl->in_new_buffer = false;
+					need_buffer);
+			impl->in_need_buffer = false;
 		}
-
-		io->status = SPA_STATUS_NEED_BUFFER;
-		send_need_input(stream);
-		break;
-	}
-	case PW_CLIENT_NODE_MESSAGE_PROCESS_OUTPUT:
-	{
-		struct spa_io_buffers *io = impl->io;
-
-		reuse_buffer(stream, io->buffer_id);
-		io->buffer_id = SPA_ID_INVALID;
-
-		pw_log_trace("stream %p: process output", stream);
-		impl->in_need_buffer = true;
-		spa_hook_list_call(&stream->listener_list, struct pw_stream_events, need_buffer);
-		impl->in_need_buffer = false;
 		break;
 	}
 	case PW_CLIENT_NODE_MESSAGE_PORT_REUSE_BUFFER: