interfaces: improve remote API

Add return values to events and method callbacks. This makes it
possible to pass any error or async return value.
Add sync/done/error in both directions so that both proxy and resource
and perform/reply sync and produce errors.
Return a SPA_ASYNC from remote method calls (and events), keep the
sequence number in the connection.
With the core sync/done we can remove the client-node done method and
it's internal sequence number along with the seq number in method calls.
We can also use the method/event async return value to perform a sync
with as the unique sequence number for this method.
Add sync method and done/error event to proxy and resource.

pipewire-jack

@@ -1 +1 @@
-Subproject commit 1108c5d83d2f105f6976a6edd79efa348b688d23
+Subproject commit af96643eaa5d3d9df727629e96a0b1f101a16664

pipewire-pulseaudio

@@ -1 +1 @@
-Subproject commit 5f9200d9ee58271e60ff24e91e07fa340d71d494
+Subproject commit 61edd78bf4a3bba5edab0ba0c10a7d7f12ff3f7a

spa/examples/example-control.c

@@ -184,16 +184,6 @@ static int make_node(struct data *data, struct spa_node **node, const char *lib,
 	return -EBADF;
 }
 
-static void on_sink_done(void *data, int seq, int res)
-{
-	printf("got done %d %d\n", seq, res);
-}
-
-static void on_sink_event(void *data, struct spa_event *event)
-{
-	printf("got event %d\n", SPA_EVENT_TYPE(event));
-}
-
 static void update_props(struct data *data)
 {
 	struct spa_pod_builder b;
@@ -233,7 +223,7 @@ static void update_props(struct data *data)
 		data->volume_accum -= M_PI_M2;
 }
 
-static void on_sink_ready(void *_data, int status)
+static int on_sink_ready(void *_data, int status)
 {
 	struct data *data = _data;
 
@@ -241,20 +231,20 @@ static void on_sink_ready(void *_data, int status)
 
 	spa_graph_node_process(&data->source_node);
 	spa_graph_node_process(&data->sink_node);
+	return 0;
 }
 
-static void
+static int
 on_sink_reuse_buffer(void *_data, uint32_t port_id, uint32_t buffer_id)
 {
 	struct data *data = _data;
 
 	data->source_sink_io[0].buffer_id = buffer_id;
+	return 0;
 }
 
 static const struct spa_node_callbacks sink_callbacks = {
 	SPA_VERSION_NODE_CALLBACKS,
-	.done = on_sink_done,
-	.event = on_sink_event,
 	.ready = on_sink_ready,
 	.reuse_buffer = on_sink_reuse_buffer
 };

spa/examples/local-v4l2.c

@@ -145,21 +145,7 @@ static void handle_events(struct data *data)
 	}
 }
 
-static void on_source_done(void *data, int seq, int res)
-{
-	printf("got done %d %d\n", seq, res);
-}
-
-static void on_source_event(void *_data, struct spa_event *event)
-{
-	struct data *data = _data;
-
-	handle_events(data);
-
-	printf("got event %d\n", SPA_EVENT_TYPE(event));
-}
-
-static void on_source_ready(void *_data, int status)
+static int on_source_ready(void *_data, int status)
 {
 	struct data *data = _data;
 	int res;
@@ -177,7 +163,7 @@ static void on_source_ready(void *_data, int status)
 		printf("got process error %d\n", res);
 
 	if (io->buffer_id > MAX_BUFFERS)
-		return;
+		return -EINVAL;
 
 	b = &data->buffers[io->buffer_id];
 
@@ -194,26 +180,28 @@ static void on_source_ready(void *_data, int status)
 
 		if (SDL_LockTexture(texture, NULL, &sdata, &sstride) < 0) {
 			fprintf(stderr, "Couldn't lock texture: %s\n", SDL_GetError());
-			return;
+			return -EIO;
 		}
 	} else {
 		uint8_t *map;
 
 		if (SDL_LockTexture(data->texture, NULL, &ddata, &dstride) < 0) {
 			fprintf(stderr, "Couldn't lock texture: %s\n", SDL_GetError());
-			return;
+			return -EIO;
 		}
 		sdata = datas[0].data;
 		if (datas[0].type == SPA_DATA_MemFd ||
 		    datas[0].type == SPA_DATA_DmaBuf) {
 			map = mmap(NULL, datas[0].maxsize + datas[0].mapoffset, PROT_READ,
 				   MAP_PRIVATE, datas[0].fd, 0);
+			if (map == MAP_FAILED)
+				return -errno;
 			sdata = SPA_MEMBER(map, datas[0].mapoffset, uint8_t);
 		} else if (datas[0].type == SPA_DATA_MemPtr) {
 			map = NULL;
 			sdata = datas[0].data;
 		} else
-			return;
+			return -EIO;
 
 		sstride = datas[0].chunk->stride;
 
@@ -233,12 +221,11 @@ static void on_source_ready(void *_data, int status)
 	}
 
 	io->status = SPA_STATUS_NEED_BUFFER;
+	return 0;
 }
 
 static const struct spa_node_callbacks source_callbacks = {
 	SPA_VERSION_NODE_CALLBACKS,
-	.done = on_source_done,
-	.event = on_source_event,
 	.ready = on_source_ready
 };
 

spa/include/spa/monitor/device.h

@@ -74,15 +74,15 @@ struct spa_device_callbacks {
 	uint32_t version;
 
 	/** notify extra information about the device */
-	void (*info) (void *data, const struct spa_device_info *info);
+	int (*info) (void *data, const struct spa_device_info *info);
 
 	/** a device event */
-	void (*event) (void *data, struct spa_event *event);
+	int (*event) (void *data, struct spa_event *event);
 
 	/** info changed for an object managed by the device, info is NULL when
 	 * the object is removed */
-	void (*object_info) (void *data, uint32_t id,
-			     const struct spa_device_object_info *info);
+	int (*object_info) (void *data, uint32_t id,
+		const struct spa_device_object_info *info);
 };
 
 /**

spa/include/spa/monitor/monitor.h

@@ -80,10 +80,10 @@ struct spa_monitor_callbacks {
 	uint32_t version;
 
 	/** receive extra information about the monitor */
-	void (*info) (void *data, const struct spa_dict *info);
+	int (*info) (void *data, const struct spa_dict *info);
 
 	/** an item is added/removed/changed on the monitor */
-	void (*event) (void *data, struct spa_event *event);
+	int (*event) (void *data, struct spa_event *event);
 };
 
 /**

spa/include/spa/node/node.h

@@ -97,18 +97,22 @@ struct spa_node_callbacks {
 #define SPA_VERSION_NODE_CALLBACKS	0
 	uint32_t version;	/**< version of this structure */
 
-	/** Emited when info changes */
-	void (*info) (void *data, const struct spa_node_info *info);
-
-	/** Emited when port info changes, NULL when port is removed */
-	void (*port_info) (void *data,
-		           enum spa_direction direction, uint32_t port,
-			   const struct spa_port_info *info);
-
-	/** Emited when an async operation completed.
+	/** Emited as a reply to a sync method with \a seq.
 	 *
 	 * Will be called from the main thread. */
-	void (*done) (void *data, int seq, int res);
+	int (*done) (void *data, uint32_t seq);
+
+	/** an asynchronous error occured */
+	int (*error) (void *data, int res, const char *message);
+
+	/** Emited when info changes */
+	int (*info) (void *data, const struct spa_node_info *info);
+
+	/** Emited when port info changes, NULL when port is removed */
+	int (*port_info) (void *data,
+			enum spa_direction direction, uint32_t port,
+			const struct spa_port_info *info);
+
 	/**
 	 * \param node a spa_node
 	 * \param event the event that was emited
@@ -116,7 +120,7 @@ struct spa_node_callbacks {
 	 * This will be called when an out-of-bound event is notified
 	 * on \a node. The callback will be called from the main thread.
 	 */
-	void (*event) (void *data, struct spa_event *event);
+	int (*event) (void *data, struct spa_event *event);
 
 	/**
 	 * \param node a spa_node
@@ -127,7 +131,7 @@ struct spa_node_callbacks {
 	 * When this function is NULL, synchronous operation is requested
 	 * on the ports.
 	 */
-	void (*ready) (void *data, int state);
+	int (*ready) (void *data, int state);
 
 	/**
 	 * \param node a spa_node
@@ -140,9 +144,9 @@ struct spa_node_callbacks {
 	 * When this function is NULL, the buffers to reuse will be set in
 	 * the io area of the input ports.
 	 */
-	void (*reuse_buffer) (void *data,
-			      uint32_t port_id,
-			      uint32_t buffer_id);
+	int (*reuse_buffer) (void *data,
+			     uint32_t port_id,
+			     uint32_t buffer_id);
 
 };
 
@@ -160,6 +164,32 @@ struct spa_node {
 	 * structure in the future */
 #define SPA_VERSION_NODE	0
 	uint32_t version;
+
+	/**
+	 * Set callbacks to receive events and scheduling callbacks from \a node.
+	 * if \a callbacks is NULL, the current callbacks are removed.
+	 *
+	 * This function must be called from the main thread.
+	 *
+	 * \param node a spa_node
+	 * \param callbacks callbacks to set
+	 * \return 0 on success
+	 *         -EINVAL when node is NULL
+	 */
+	int (*set_callbacks) (struct spa_node *node,
+			      const struct spa_node_callbacks *callbacks,
+			      void *data);
+	/**
+	 * Perform a sync operation.
+	 *
+	 * Calling this method will emit the done event or -EIO when
+	 * no callbacks are installed.
+	 *
+	 * Because all methods are serialized in the node, this can be used
+	 * to wait for completion of all previous method calls.
+	 */
+	int (*sync) (struct spa_node *node, uint32_t seq);
+
 	/**
 	 * Enumerate the parameters of a node.
 	 *
@@ -251,20 +281,6 @@ struct spa_node {
 	 */
 	int (*send_command) (struct spa_node *node, const struct spa_command *command);
 
-	/**
-	 * Set callbacks to receive events and scheduling callbacks from \a node.
-	 * if \a callbacks is NULL, the current callbacks are removed.
-	 *
-	 * This function must be called from the main thread.
-	 *
-	 * \param node a spa_node
-	 * \param callbacks callbacks to set
-	 * \return 0 on success
-	 *         -EINVAL when node is NULL
-	 */
-	int (*set_callbacks) (struct spa_node *node,
-			      const struct spa_node_callbacks *callbacks,
-			      void *data);
 	/**
 	 * Make a new port with \a port_id. The caller should use get_port_ids() to
 	 * find an unused id for the given \a direction.
@@ -477,11 +493,12 @@ struct spa_node {
 	int (*process) (struct spa_node *node);
 };
 
+#define spa_node_set_callbacks(n,...)		(n)->set_callbacks((n),__VA_ARGS__)
+#define spa_node_sync(n,...)			(n)->sync((n),__VA_ARGS__)
 #define spa_node_enum_params(n,...)		(n)->enum_params((n),__VA_ARGS__)
 #define spa_node_set_param(n,...)		(n)->set_param((n),__VA_ARGS__)
 #define spa_node_set_io(n,...)			(n)->set_io((n),__VA_ARGS__)
 #define spa_node_send_command(n,...)		(n)->send_command((n),__VA_ARGS__)
-#define spa_node_set_callbacks(n,...)		(n)->set_callbacks((n),__VA_ARGS__)
 #define spa_node_add_port(n,...)		(n)->add_port((n),__VA_ARGS__)
 #define spa_node_remove_port(n,...)		(n)->remove_port((n),__VA_ARGS__)
 #define spa_node_port_enum_params(n,...)	(n)->port_enum_params((n),__VA_ARGS__)

spa/plugins/alsa/alsa-sink.c

@@ -264,6 +264,20 @@ static void emit_port_info(struct state *this)
 	}
 }
 
+static int
+impl_node_sync(struct spa_node *node, uint32_t seq)
+{
+	struct state *this;
+
+	spa_return_val_if_fail(node != NULL, -EINVAL);
+	this = SPA_CONTAINER_OF(node, struct state, node);
+
+	spa_return_val_if_fail(this->callbacks && this->callbacks->done, -EIO);
+
+	this->callbacks->done(this->callbacks_data, seq);
+	return 0;
+}
+
 static int
 impl_node_set_callbacks(struct spa_node *node,
 			const struct spa_node_callbacks *callbacks,
@@ -637,11 +651,12 @@ static int impl_node_process(struct spa_node *node)
 
 static const struct spa_node impl_node = {
 	SPA_VERSION_NODE,
+	.set_callbacks = impl_node_set_callbacks,
+	.sync = impl_node_sync,
 	.enum_params = impl_node_enum_params,
 	.set_param = impl_node_set_param,
 	.set_io = impl_node_set_io,
 	.send_command = impl_node_send_command,
-	.set_callbacks = impl_node_set_callbacks,
 	.add_port = impl_node_add_port,
 	.remove_port = impl_node_remove_port,
 	.port_enum_params = impl_node_port_enum_params,

spa/plugins/audioconvert/audioconvert.c

@@ -550,16 +550,17 @@ static void emit_port_info(struct impl *this,
 }
 
 
-static void fmt_input_port_info(void *data,
+static int fmt_input_port_info(void *data,
 		enum spa_direction direction, uint32_t port,
 		const struct spa_port_info *info)
 {
 	struct impl *this = data;
 
 	if (direction != SPA_DIRECTION_INPUT)
-		return;
+		return 0;
 
 	emit_port_info(this, direction, port, info);
+	return 0;
 }
 
 static struct spa_node_callbacks fmt_input_callbacks = {
@@ -567,16 +568,17 @@ static struct spa_node_callbacks fmt_input_callbacks = {
 	.port_info = fmt_input_port_info
 };
 
-static void fmt_output_port_info(void *data,
+static int fmt_output_port_info(void *data,
 		enum spa_direction direction, uint32_t port,
 		const struct spa_port_info *info)
 {
 	struct impl *this = data;
 
 	if (direction != SPA_DIRECTION_OUTPUT)
-		return;
+		return 0;
 
 	emit_port_info(this, direction, port, info);
+	return 0;
 }
 
 static struct spa_node_callbacks fmt_output_callbacks = {

spa/tools/spa-inspect.c

@@ -136,7 +136,7 @@ inspect_port_params(struct data *data, struct spa_node *node,
 	}
 }
 
-static void node_info(void *_data, const struct spa_node_info *info)
+static int node_info(void *_data, const struct spa_node_info *info)
 {
 	struct data *data = _data;
 
@@ -148,9 +148,10 @@ static void node_info(void *_data, const struct spa_node_info *info)
 		spa_debug_dict(2, info->props);
 	}
 	inspect_node_params(data, data->node);
+	return 0;
 }
 
-static void node_port_info(void *_data, enum spa_direction direction, uint32_t id,
+static int node_port_info(void *_data, enum spa_direction direction, uint32_t id,
 		const struct spa_port_info *info)
 {
 	struct data *data = _data;
@@ -164,6 +165,7 @@ static void node_port_info(void *_data, enum spa_direction direction, uint32_t i
 				id);
 		inspect_port_params(data, data->node, direction, id);
 	}
+	return 0;
 }
 
 static const struct spa_node_callbacks node_callbacks =

spa/tools/spa-monitor.c

@@ -61,12 +61,13 @@ static void inspect_item(struct data *data, struct spa_pod *item)
 	spa_debug_pod(0, NULL, item);
 }
 
-static void on_monitor_info(void *_data, const struct spa_dict *info)
+static int on_monitor_info(void *_data, const struct spa_dict *info)
 {
 	spa_debug_dict(0, info);
+	return 0;
 }
 
-static void on_monitor_event(void *_data, struct spa_event *event)
+static int on_monitor_event(void *_data, struct spa_event *event)
 {
 	struct data *data = _data;
 
@@ -84,6 +85,7 @@ static void on_monitor_event(void *_data, struct spa_event *event)
 		inspect_item(data, SPA_POD_CONTENTS(struct spa_event, event));
 		break;
 	}
+	return 0;
 }
 
 static int do_add_source(struct spa_loop *loop, struct spa_source *source)

src/examples/media-session.c

@@ -193,7 +193,7 @@ static void *find_object(struct impl *impl, uint32_t id)
 static void schedule_rescan(struct impl *impl)
 {
 	if (impl->core_proxy)
-		pw_core_proxy_sync(impl->core_proxy, ++impl->seq);
+		pw_core_proxy_sync(impl->core_proxy, 0, ++impl->seq);
 }
 
 static void remove_idle_timeout(struct session *sess)
@@ -344,7 +344,7 @@ static int on_node_running(struct impl *impl, struct node *node)
 	return 0;
 }
 
-static void node_event_info(void *object, const struct pw_node_info *info)
+static int node_event_info(void *object, const struct pw_node_info *info)
 {
 	struct node *n = object;
 	struct impl *impl = n->obj.impl;
@@ -364,10 +364,10 @@ static void node_event_info(void *object, const struct pw_node_info *info)
 	default:
 		break;
 	}
-
+	return 0;
 }
 
-static void node_event_param(void *object,
+static int node_event_param(void *object,
                        uint32_t id, uint32_t index, uint32_t next,
                        const struct spa_pod *param)
 {
@@ -385,7 +385,7 @@ static void node_event_param(void *object,
 
 	if (n->media_type != SPA_MEDIA_TYPE_audio ||
 	    n->media_subtype != SPA_MEDIA_SUBTYPE_raw)
-		return;
+		return 0;
 
 	spa_pod_object_fixate((struct spa_pod_object*)param);
 
@@ -393,12 +393,12 @@ static void node_event_param(void *object,
 		goto error;
 
 	n->format = info;
-	return;
+	return 0;
 
       error:
 	pw_log_warn("unhandled param:");
 	spa_debug_pod(2, NULL, param);
-	return;
+	return -EINVAL;
 }
 
 static const struct pw_node_proxy_events node_events = {
@@ -579,14 +579,15 @@ handle_node(struct impl *impl, uint32_t id, uint32_t parent_id,
 	return 1;
 }
 
-static void port_event_info(void *object, const struct pw_port_info *info)
+static int port_event_info(void *object, const struct pw_port_info *info)
 {
 	struct port *p = object;
 	pw_log_debug(NAME" %p: info for port %d", p->obj.impl, p->obj.id);
 	p->info = pw_port_info_update(p->info, info);
+	return 0;
 }
 
-static void port_event_param(void *object,
+static int port_event_param(void *object,
                        uint32_t id, uint32_t index, uint32_t next,
                        const struct spa_pod *param)
 {
@@ -597,28 +598,29 @@ static void port_event_param(void *object,
 	pw_log_debug(NAME" %p: param for port %d", p->obj.impl, p->obj.id);
 
 	if (node == NULL)
-		return;
+		return 0;
 
 	if (id != SPA_PARAM_EnumFormat)
-		return;
+		return 0;
 
 	if (node->manager)
 		node->manager->enabled = true;
 
 	if (spa_format_parse(param, &node->media_type, &node->media_subtype) < 0)
-		return;
+		return 0;
 
 	if (node->media_type != SPA_MEDIA_TYPE_audio ||
 	    node->media_subtype != SPA_MEDIA_SUBTYPE_raw)
-		return;
+		return 0;
 
 	spa_pod_fixate((struct spa_pod*)param);
 
 	if (spa_format_audio_raw_parse(param, &info) < 0)
-		return;
+		return -EINVAL;
 
 	if (info.channels > node->format.channels)
 		node->format = info;
+	return 0;
 }
 
 static const struct pw_port_proxy_events port_events = {
@@ -697,7 +699,7 @@ handle_port(struct impl *impl, uint32_t id, uint32_t parent_id, uint32_t type,
 	return 0;
 }
 
-static void client_event_info(void *object, const struct pw_client_info *info)
+static int client_event_info(void *object, const struct pw_client_info *info)
 {
 	struct client *c = object;
 	uint32_t i;
@@ -708,7 +710,7 @@ static void client_event_info(void *object, const struct pw_client_info *info)
 		pw_log_debug(NAME" %p:  %s = %s", c,
 				info->props->items[i].key,
 				info->props->items[i].value);
-
+	return 0;
 }
 
 static const struct pw_client_proxy_events client_events = {
@@ -772,7 +774,7 @@ handle_client(struct impl *impl, uint32_t id, uint32_t parent_id,
 	return 0;
 }
 
-static void
+static int
 registry_global(void *data,uint32_t id, uint32_t parent_id,
 		uint32_t permissions, uint32_t type, uint32_t version,
 		const struct spa_dict *props)
@@ -804,9 +806,11 @@ registry_global(void *data,uint32_t id, uint32_t parent_id,
 	}
 	else
 		schedule_rescan(impl);
+
+	return res;
 }
 
-static void
+static int
 registry_global_remove(void *data, uint32_t id)
 {
 	struct impl *impl = data;
@@ -815,7 +819,7 @@ registry_global_remove(void *data, uint32_t id)
 	pw_log_debug(NAME " %p: remove global '%d'", impl, id);
 
 	if ((obj = find_object(impl, id)) == NULL)
-		return;
+		return 0;
 
 	switch (obj->type) {
 	case PW_TYPE_INTERFACE_Node:
@@ -825,13 +829,13 @@ registry_global_remove(void *data, uint32_t id)
 			remove_session(impl, node->manager);
 		node->manager = NULL;
 		break;
-
 	}
 	default:
 		break;
 	}
 	remove_object(impl, obj);
 	schedule_rescan(impl);
+	return 0;
 }
 
 static const struct pw_registry_proxy_events registry_events = {
@@ -1196,13 +1200,13 @@ do_link:
         return 1;
 }
 
-static void dsp_node_event_info(void *object, const struct pw_node_info *info)
+static int dsp_node_event_info(void *object, const struct pw_node_info *info)
 {
 	struct session *s = object;
 	struct node *dsp;
 
 	if ((dsp = find_object(s->impl, info->id)) == NULL)
-		return;
+		return 0;
 
 	pw_log_debug(NAME" %p: dsp node session %d id %d", dsp->obj.impl, s->id, info->id);
 
@@ -1217,6 +1221,7 @@ static void dsp_node_event_info(void *object, const struct pw_node_info *info)
 	dsp->format = s->node->format;
 	dsp->profile_format = dsp->format;
 	dsp->profile_format.format = SPA_AUDIO_FORMAT_F32P;
+	return 0;
 }
 
 static const struct pw_node_proxy_events dsp_node_events = {
@@ -1292,11 +1297,12 @@ static void do_rescan(struct impl *impl)
 		rescan_node(impl, node);
 }
 
-static void core_done(void *data, uint32_t seq)
+static int core_done(void *data, uint32_t id, uint32_t seq)
 {
 	struct impl *impl = data;
 	if (impl->seq == seq)
 		do_rescan(impl);
+	return 0;
 }
 
 static const struct pw_core_proxy_events core_events = {

src/extensions/client-node.h

@@ -48,21 +48,17 @@ struct pw_client_node_buffer {
 	struct spa_buffer *buffer;	/**< buffer describing metadata and buffer memory */
 };
 
-#define PW_CLIENT_NODE_PROXY_METHOD_DONE		0
-#define PW_CLIENT_NODE_PROXY_METHOD_UPDATE		1
-#define PW_CLIENT_NODE_PROXY_METHOD_PORT_UPDATE		2
-#define PW_CLIENT_NODE_PROXY_METHOD_SET_ACTIVE		3
-#define PW_CLIENT_NODE_PROXY_METHOD_EVENT		4
-#define PW_CLIENT_NODE_PROXY_METHOD_NUM			5
+#define PW_CLIENT_NODE_PROXY_METHOD_UPDATE		0
+#define PW_CLIENT_NODE_PROXY_METHOD_PORT_UPDATE		1
+#define PW_CLIENT_NODE_PROXY_METHOD_SET_ACTIVE		2
+#define PW_CLIENT_NODE_PROXY_METHOD_EVENT		3
+#define PW_CLIENT_NODE_PROXY_METHOD_NUM			4
 
 /** \ref pw_client_node methods */
 struct pw_client_node_proxy_methods {
 #define PW_VERSION_CLIENT_NODE_PROXY_METHODS		0
 	uint32_t version;
 
-	/** Complete an async operation */
-	void (*done) (void *object, int seq, int res);
-
 	/**
 	 * Update the node ports and properties
 	 *
@@ -73,7 +69,7 @@ struct pw_client_node_proxy_methods {
 	 * \param max_output_ports new max output ports
 	 * \param params new params
 	 */
-	void (*update) (void *object,
+	int (*update) (void *object,
 #define PW_CLIENT_NODE_UPDATE_MAX_INPUTS   (1 << 0)
 #define PW_CLIENT_NODE_UPDATE_MAX_OUTPUTS  (1 << 1)
 #define PW_CLIENT_NODE_UPDATE_PARAMS       (1 << 2)
@@ -96,7 +92,7 @@ struct pw_client_node_proxy_methods {
 	 * \param params array of port parameters
 	 * \param info port information
 	 */
-	void (*port_update) (void *object,
+	int (*port_update) (void *object,
 			     enum spa_direction direction,
 			     uint32_t port_id,
 #define PW_CLIENT_NODE_PORT_UPDATE_PARAMS            (1 << 0)
@@ -108,21 +104,15 @@ struct pw_client_node_proxy_methods {
 	/**
 	 * Activate or deactivate the node
 	 */
-	void (*set_active) (void *object, bool active);
+	int (*set_active) (void *object, bool active);
 	/**
 	 * Send an event to the node
 	 * \param event the event to send
 	 */
-	void (*event) (void *object, struct spa_event *event);
+	int (*event) (void *object, struct spa_event *event);
 };
 
-static inline void
-pw_client_node_proxy_done(struct pw_client_node_proxy *p, int seq, int res)
-{
-        pw_proxy_do((struct pw_proxy*)p, struct pw_client_node_proxy_methods, done, seq, res);
-}
-
-static inline void
+static inline int
 pw_client_node_proxy_update(struct pw_client_node_proxy *p,
 			    uint32_t change_mask,
 			    uint32_t max_input_ports,
@@ -131,13 +121,13 @@ pw_client_node_proxy_update(struct pw_client_node_proxy *p,
 			    const struct spa_pod **params,
 			    const struct spa_dict *props)
 {
-        pw_proxy_do((struct pw_proxy*)p, struct pw_client_node_proxy_methods, update, change_mask,
+        return pw_proxy_do((struct pw_proxy*)p, struct pw_client_node_proxy_methods, update, change_mask,
 							      max_input_ports,
 							      max_output_ports,
 							      n_params, params, props);
 }
 
-static inline void
+static inline int
 pw_client_node_proxy_port_update(struct pw_client_node_proxy *p,
 				 enum spa_direction direction,
 				 uint32_t port_id,
@@ -146,7 +136,7 @@ pw_client_node_proxy_port_update(struct pw_client_node_proxy *p,
 				 const struct spa_pod **params,
 				 const struct spa_port_info *info)
 {
-        pw_proxy_do((struct pw_proxy*)p, struct pw_client_node_proxy_methods, port_update, direction,
+        return pw_proxy_do((struct pw_proxy*)p, struct pw_client_node_proxy_methods, port_update, direction,
 								   port_id,
 								   change_mask,
 								   n_params,
@@ -154,16 +144,16 @@ pw_client_node_proxy_port_update(struct pw_client_node_proxy *p,
 								   info);
 }
 
-static inline void
+static inline int
 pw_client_node_proxy_set_active(struct pw_client_node_proxy *p, bool active)
 {
-        pw_proxy_do((struct pw_proxy*)p, struct pw_client_node_proxy_methods, set_active, active);
+	return pw_proxy_do((struct pw_proxy*)p, struct pw_client_node_proxy_methods, set_active, active);
 }
 
-static inline void
+static inline int
 pw_client_node_proxy_event(struct pw_client_node_proxy *p, struct spa_event *event)
 {
-        pw_proxy_do((struct pw_proxy*)p, struct pw_client_node_proxy_methods, event, event);
+	return pw_proxy_do((struct pw_proxy*)p, struct pw_client_node_proxy_methods, event, event);
 }
 
 #define PW_CLIENT_NODE_PROXY_EVENT_ADD_MEM		0
@@ -201,11 +191,11 @@ struct pw_client_node_proxy_events {
 	 * \param memfd the fd of the memory
 	 * \param flags flags for the \a memfd
 	 */
-	void (*add_mem) (void *object,
-			 uint32_t mem_id,
-			 uint32_t type,
-			 int memfd,
-			 uint32_t flags);
+	int (*add_mem) (void *object,
+			uint32_t mem_id,
+			uint32_t type,
+			int memfd,
+			uint32_t flags);
 	/**
 	 * Notify of a new transport area
 	 *
@@ -215,24 +205,23 @@ struct pw_client_node_proxy_events {
 	 * \param readfd fd for signal data can be read
 	 * \param writefd fd for signal data can be written
 	 */
-	void (*transport) (void *object,
-			   uint32_t node_id,
-			   int readfd,
-			   int writefd);
+	int (*transport) (void *object,
+			  uint32_t node_id,
+			  int readfd,
+			  int writefd);
 	/**
 	 * Notify of a property change
 	 *
 	 * When the server configures the properties on the node
 	 * this event is sent
 	 *
-	 * \param seq a sequence number
 	 * \param id the id of the parameter
 	 * \param flags parameter flags
 	 * \param param the param to set
 	 */
-	void (*set_param) (void *object, uint32_t seq,
-			   uint32_t id, uint32_t flags,
-			   const struct spa_pod *param);
+	int (*set_param) (void *object,
+			  uint32_t id, uint32_t flags,
+			  const struct spa_pod *param);
 	/**
 	 * Configure an IO area for the client
 	 *
@@ -244,7 +233,7 @@ struct pw_client_node_proxy_events {
 	 * \param offset offset of io area in memory
 	 * \param size size of the io area
 	 */
-	void (*set_io) (void *object,
+	int (*set_io) (void *object,
 			uint32_t id,
 			uint32_t mem_id,
 			uint32_t offset,
@@ -252,51 +241,44 @@ struct pw_client_node_proxy_events {
 	/**
 	 * Receive an event from the client node
 	 * \param event the received event */
-	void (*event) (void *object, const struct spa_event *event);
+	int (*event) (void *object, const struct spa_event *event);
 	/**
 	 * Notify of a new node command
 	 *
-	 * \param seq a sequence number
 	 * \param command the command
 	 */
-	void (*command) (void *object, uint32_t seq, const struct spa_command *command);
+	int (*command) (void *object, const struct spa_command *command);
 	/**
 	 * A new port was added to the node
 	 *
 	 * The server can at any time add a port to the node when there
 	 * are free ports available.
 	 *
-	 * \param seq a sequence number
 	 * \param direction the direction of the port
 	 * \param port_id the new port id
 	 */
-	void (*add_port) (void *object,
-			  uint32_t seq,
+	int (*add_port) (void *object,
 			  enum spa_direction direction,
 			  uint32_t port_id);
 	/**
 	 * A port was removed from the node
 	 *
-	 * \param seq a sequence number
 	 * \param direction a port direction
 	 * \param port_id the remove port id
 	 */
-	void (*remove_port) (void *object,
-			     uint32_t seq,
+	int (*remove_port) (void *object,
 			     enum spa_direction direction,
 			     uint32_t port_id);
 	/**
 	 * A parameter was configured on the port
 	 *
-	 * \param seq a sequence number
 	 * \param direction a port direction
 	 * \param port_id the port id
 	 * \param id the id of the parameter
 	 * \param flags flags used when setting the param
 	 * \param param the new param
 	 */
-	void (*port_set_param) (void *object,
-				uint32_t seq,
+	int (*port_set_param) (void *object,
 				enum spa_direction direction,
 				uint32_t port_id,
 				uint32_t id, uint32_t flags,
@@ -304,15 +286,13 @@ struct pw_client_node_proxy_events {
 	/**
 	 * Notify the port of buffers
 	 *
-	 * \param seq a sequence number
 	 * \param direction a port direction
 	 * \param port_id the port id
 	 * \param mix_id the mixer port id
 	 * \param n_buffer the number of buffers
 	 * \param buffers and array of buffer descriptions
 	 */
-	void (*port_use_buffers) (void *object,
-				  uint32_t seq,
+	int (*port_use_buffers) (void *object,
 				  enum spa_direction direction,
 				  uint32_t port_id,
 				  uint32_t mix_id,
@@ -321,7 +301,6 @@ struct pw_client_node_proxy_events {
 	/**
 	 * Configure the io area with \a id of \a port_id.
 	 *
-	 * \param seq a sequence number
 	 * \param direction the direction of the port
 	 * \param port_id the port id
 	 * \param mix_id the mixer port id
@@ -330,8 +309,7 @@ struct pw_client_node_proxy_events {
 	 * \param offset offset of io area in memory
 	 * \param size size of the io area
 	 */
-	void (*port_set_io) (void *object,
-			     uint32_t seq,
+	int (*port_set_io) (void *object,
 			     enum spa_direction direction,
 			     uint32_t port_id,
 			     uint32_t mix_id,
@@ -340,7 +318,7 @@ struct pw_client_node_proxy_events {
 			     uint32_t offset,
 			     uint32_t size);
 
-	void (*set_activation) (void *object,
+	int (*set_activation) (void *object,
 				uint32_t node_id,
 				int signalfd,
 				uint32_t mem_id,

src/extensions/protocol-native.h

@@ -51,8 +51,8 @@ struct pw_protocol_native_ext {
 	uint32_t (*add_proxy_fd) (struct pw_proxy *proxy, int fd);
 	int (*get_proxy_fd) (struct pw_proxy *proxy, uint32_t index);
 
-	void (*end_proxy) (struct pw_proxy *proxy,
-			   struct spa_pod_builder *builder);
+	int (*end_proxy) (struct pw_proxy *proxy,
+			  struct spa_pod_builder *builder);
 
 	struct spa_pod_builder * (*begin_resource) (struct pw_resource *resource,
 						    uint8_t opcode);
@@ -60,8 +60,8 @@ struct pw_protocol_native_ext {
 	uint32_t (*add_resource_fd) (struct pw_resource *resource, int fd);
 	int (*get_resource_fd) (struct pw_resource *resource, uint32_t index);
 
-	void (*end_resource) (struct pw_resource *resource,
-			      struct spa_pod_builder *builder);
+	int (*end_resource) (struct pw_resource *resource,
+			     struct spa_pod_builder *builder);
 
 };
 

src/gst/gstpipewiredeviceprovider.c

@@ -281,7 +281,7 @@ static void add_pending(GstPipeWireDeviceProvider *self, struct pending *p,
   p->data = data;
   p->seq = ++self->seq;
   pw_log_debug("add pending %d", p->seq);
-  pw_core_proxy_sync(self->core_proxy, p->seq);
+  pw_core_proxy_sync(self->core_proxy, 0, p->seq);
 }
 
 static void remove_pending(struct pending *p)
@@ -293,7 +293,7 @@ static void remove_pending(struct pending *p)
   }
 }
 
-static void
+static int
 on_core_info (void *data, const struct pw_core_info *info)
 {
   GstPipeWireDeviceProvider *self = data;
@@ -301,7 +301,7 @@ on_core_info (void *data, const struct pw_core_info *info)
   const gchar *value;
 
   if (info == NULL || info->props == NULL)
-    return;
+    return -EINVAL;
 
   value = spa_dict_lookup (info->props, "monitors");
   if (value) {
@@ -318,10 +318,11 @@ on_core_info (void *data, const struct pw_core_info *info)
     }
     g_strfreev (monitors);
   }
+  return 0;
 }
 
-static void
-on_core_done (void *data, uint32_t seq)
+static int
+on_core_done (void *data, uint32_t id, uint32_t seq)
 {
   GstPipeWireDeviceProvider *self = data;
   struct pending *p, *t;
@@ -339,6 +340,7 @@ on_core_done (void *data, uint32_t seq)
     if (self->main_loop)
       pw_thread_loop_signal (self->main_loop, FALSE);
   }
+  return 0;
 }
 
 static const struct pw_core_proxy_events core_events = {
@@ -371,13 +373,14 @@ on_state_changed (void *data, enum pw_remote_state old, enum pw_remote_state sta
     pw_thread_loop_signal (self->main_loop, FALSE);
 }
 
-static void port_event_info(void *data, const struct pw_port_info *info)
+static int port_event_info(void *data, const struct pw_port_info *info)
 {
   struct port_data *port_data = data;
   pw_log_debug("%p", port_data);
+  return 0;
 }
 
-static void port_event_param(void *data, uint32_t id, uint32_t index, uint32_t next,
+static int port_event_param(void *data, uint32_t id, uint32_t index, uint32_t next,
                 const struct spa_pod *param)
 {
   struct port_data *port_data = data;
@@ -389,7 +392,7 @@ static void port_event_param(void *data, uint32_t id, uint32_t index, uint32_t n
   c1 = gst_caps_from_format (param);
   if (c1 && node_data->caps)
       gst_caps_append (node_data->caps, c1);
-
+  return 0;
 }
 
 static const struct pw_port_proxy_events port_events = {
@@ -398,11 +401,12 @@ static const struct pw_port_proxy_events port_events = {
   .param = port_event_param
 };
 
-static void node_event_info(void *data, const struct pw_node_info *info)
+static int node_event_info(void *data, const struct pw_node_info *info)
 {
   struct node_data *node_data = data;
   pw_log_debug("%p", node_data);
   node_data->info = pw_node_info_update(node_data->info, info);
+  return 0;
 }
 
 static const struct pw_node_proxy_events node_events = {
@@ -451,9 +455,9 @@ static const struct pw_proxy_events proxy_port_events = {
         .destroy = destroy_port_proxy,
 };
 
-static void registry_event_global(void *data, uint32_t id, uint32_t parent_id, uint32_t permissions,
-				  uint32_t type, uint32_t version,
-				  const struct spa_dict *props)
+static int registry_event_global(void *data, uint32_t id, uint32_t parent_id, uint32_t permissions,
+				 uint32_t type, uint32_t version,
+				 const struct spa_dict *props)
 {
   struct remote_data *rd = data;
   GstPipeWireDeviceProvider *self = rd->self;
@@ -484,7 +488,7 @@ static void registry_event_global(void *data, uint32_t id, uint32_t parent_id, u
     struct port_data *pd;
 
     if ((nd = find_node_data(rd, parent_id)) == NULL)
-      return;
+      return -EINVAL;
 
     port = pw_registry_proxy_bind(rd->registry,
 		    id, PW_TYPE_INTERFACE_Port,
@@ -504,15 +508,16 @@ static void registry_event_global(void *data, uint32_t id, uint32_t parent_id, u
     add_pending(self, &pd->pending, do_add_node, pd);
   }
 
-  return;
+  return 0;
 
 no_mem:
   GST_ERROR_OBJECT(self, "failed to create proxy");
-  return;
+  return -ENOMEM;
 }
 
-static void registry_event_global_remove(void *data, uint32_t id)
+static int registry_event_global_remove(void *data, uint32_t id)
 {
+	return 0;
 }
 
 static const struct pw_registry_proxy_events registry_events = {
@@ -586,7 +591,7 @@ gst_pipewire_device_provider_probe (GstDeviceProvider * provider)
   data->registry = pw_core_proxy_get_registry(self->core_proxy,
 		  PW_TYPE_INTERFACE_Registry, PW_VERSION_REGISTRY, 0);
   pw_registry_proxy_add_listener(data->registry, &data->registry_listener, &registry_events, data);
-  pw_core_proxy_sync(self->core_proxy, ++self->seq);
+  pw_core_proxy_sync(self->core_proxy, 0, ++self->seq);
 
   for (;;) {
     if (pw_remote_get_state(r, NULL) <= 0)
@@ -676,7 +681,7 @@ gst_pipewire_device_provider_start (GstDeviceProvider * provider)
   data->registry = self->registry;
 
   pw_registry_proxy_add_listener(self->registry, &data->registry_listener, &registry_events, data);
-  pw_core_proxy_sync(self->core_proxy, ++self->seq);
+  pw_core_proxy_sync(self->core_proxy, 0, ++self->seq);
 
   for (;;) {
     if (self->end)

src/modules/module-client-node/client-node.c

@@ -146,8 +146,6 @@ struct node {
 
 	uint32_t n_params;
 	struct spa_pod **params;
-
-	uint32_t seq;
 };
 
 struct impl {
@@ -396,9 +394,7 @@ static int impl_node_set_param(struct spa_node *node, uint32_t id, uint32_t flag
 	if (this->resource == NULL)
 		return 0;
 
-	pw_client_node_resource_set_param(this->resource, this->seq, id, flags, param);
-
-	return SPA_RESULT_RETURN_ASYNC(this->seq++);
+	return pw_client_node_resource_set_param(this->resource, id, flags, param);
 }
 
 static int impl_node_set_io(struct spa_node *node, uint32_t id, void *data, size_t size)
@@ -448,7 +444,6 @@ static int impl_node_set_io(struct spa_node *node, uint32_t id, void *data, size
 static int impl_node_send_command(struct spa_node *node, const struct spa_command *command)
 {
 	struct node *this;
-	int res = 0;
 
 	spa_return_val_if_fail(node != NULL, -EINVAL);
 	spa_return_val_if_fail(command != NULL, -EINVAL);
@@ -458,10 +453,8 @@ static int impl_node_send_command(struct spa_node *node, const struct spa_comman
 	if (this->resource == NULL)
 		return 0;
 
-	pw_client_node_resource_command(this->resource, this->seq, command);
-	res = SPA_RESULT_RETURN_ASYNC(this->seq++);
-
-	return res;
+	pw_log_debug("client-node %p: send command %d", node, SPA_COMMAND_TYPE(command));
+	return pw_client_node_resource_command(this->resource, command);
 }
 
 
@@ -497,6 +490,16 @@ impl_node_set_callbacks(struct spa_node *node,
 	return 0;
 }
 
+static int
+impl_node_sync(struct spa_node *node, uint32_t seq)
+{
+	struct node *this;
+	spa_return_val_if_fail(node != NULL, -EINVAL);
+	this = SPA_CONTAINER_OF(node, struct node, node);
+	pw_log_debug("client-node %p: sync %u", node, seq);
+	return pw_resource_sync(this->resource, seq);
+}
+
 static void
 do_update_port(struct node *this,
 	       struct port *port,
@@ -585,11 +588,7 @@ impl_node_add_port(struct spa_node *node, enum spa_direction direction, uint32_t
 
 	spa_return_val_if_fail(CHECK_FREE_PORT(this, direction, port_id), -EINVAL);
 
-	pw_client_node_resource_add_port(this->resource,
-					 this->seq,
-					 direction, port_id);
-
-	return SPA_RESULT_RETURN_ASYNC(this->seq++);
+	return pw_client_node_resource_add_port(this->resource, direction, port_id);
 }
 
 static int
@@ -602,11 +601,7 @@ impl_node_remove_port(struct spa_node *node, enum spa_direction direction, uint3
 
 	spa_return_val_if_fail(CHECK_PORT(this, direction, port_id), -EINVAL);
 
-	pw_client_node_resource_remove_port(this->resource,
-					    this->seq,
-					    direction, port_id);
-
-	return SPA_RESULT_RETURN_ASYNC(this->seq++);
+	return pw_client_node_resource_remove_port(this->resource, direction, port_id);
 }
 
 static int
@@ -667,13 +662,14 @@ impl_node_port_set_param(struct spa_node *node,
 	if (this->resource == NULL)
 		return 0;
 
-	pw_client_node_resource_port_set_param(this->resource,
-					       this->seq,
+	pw_log_debug("node %p: port %d.%d add param %s %d", this,
+			direction, port_id,
+			spa_debug_type_find_name(spa_type_param, id), id);
+
+	return pw_client_node_resource_port_set_param(this->resource,
 					       direction, port_id,
 					       id, flags,
 					       param);
-
-	return SPA_RESULT_RETURN_ASYNC(this->seq++);
 }
 
 static int do_port_set_io(struct impl *impl,
@@ -722,15 +718,12 @@ static int do_port_set_io(struct impl *impl,
 
 	update_io(this, mix->ios, id, memid);
 
-	pw_client_node_resource_port_set_io(this->resource,
-					    this->seq,
+	return pw_client_node_resource_port_set_io(this->resource,
 					    direction, port_id,
 					    mix_id,
 					    id,
 					    memid,
 					    mem_offset, mem_size);
-
-	return SPA_RESULT_RETURN_ASYNC(this->seq++);
 }
 
 static int
@@ -855,12 +848,9 @@ do_port_use_buffers(struct impl *impl,
 		}
 	}
 
-	pw_client_node_resource_port_use_buffers(this->resource,
-						 this->seq,
+	return pw_client_node_resource_port_use_buffers(this->resource,
 						 direction, port_id, mix_id,
 						 n_buffers, mb);
-
-	return SPA_RESULT_RETURN_ASYNC(this->seq++);
 }
 
 static int
@@ -946,16 +936,7 @@ static int impl_node_process(struct spa_node *node)
 	return SPA_STATUS_OK;
 }
 
-static void
-client_node_done(void *data, int seq, int res)
-{
-	struct impl *impl = data;
-	struct node *this = &impl->node;
-	if (this->callbacks && this->callbacks->done)
-		this->callbacks->done(this->callbacks_data, seq, res);
-}
-
-static void
+static int
 client_node_update(void *data,
 		   uint32_t change_mask,
 		   uint32_t max_input_ports,
@@ -988,9 +969,10 @@ client_node_update(void *data,
 	}
 	spa_log_debug(this->log, "node %p: got node update max_in %u, max_out %u", this,
 		     this->max_inputs, this->max_outputs);
+	return 0;
 }
 
-static void
+static int
 client_node_port_update(void *data,
 			enum spa_direction direction,
 			uint32_t port_id,
@@ -1006,7 +988,7 @@ client_node_port_update(void *data,
 
 	spa_log_debug(this->log, "node %p: got port update", this);
 	if (!CHECK_PORT_ID(this, direction, port_id))
-		return;
+		return -EINVAL;
 
 	remove = (change_mask == 0);
 
@@ -1033,25 +1015,26 @@ client_node_port_update(void *data,
 		    info && (change_mask & PW_CLIENT_NODE_PORT_UPDATE_INFO))
 			this->callbacks->port_info(this->callbacks_data, direction, port_id, info);
 	}
+	return 0;
 }
 
-static void client_node_set_active(void *data, bool active)
+static int client_node_set_active(void *data, bool active)
 {
 	struct impl *impl = data;
-	pw_node_set_active(impl->this.node, active);
+	return pw_node_set_active(impl->this.node, active);
 }
 
-static void client_node_event(void *data, struct spa_event *event)
+static int client_node_event(void *data, struct spa_event *event)
 {
 	struct impl *impl = data;
 	struct node *this = &impl->node;
 	if (this->callbacks && this->callbacks->event)
 		this->callbacks->event(this->callbacks_data, event);
+	return 0;
 }
 
 static struct pw_client_node_proxy_methods client_node_methods = {
 	PW_VERSION_CLIENT_NODE_PROXY_METHODS,
-	.done = client_node_done,
 	.update = client_node_update,
 	.port_update = client_node_port_update,
 	.set_active = client_node_set_active,
@@ -1082,11 +1065,12 @@ static void node_on_data_fd_events(struct spa_source *source)
 static const struct spa_node impl_node = {
 	SPA_VERSION_NODE,
 	NULL,
+	.set_callbacks = impl_node_set_callbacks,
+	.sync = impl_node_sync,
 	.enum_params = impl_node_enum_params,
 	.set_param = impl_node_set_param,
 	.set_io = impl_node_set_io,
 	.send_command = impl_node_send_command,
-	.set_callbacks = impl_node_set_callbacks,
 	.add_port = impl_node_add_port,
 	.remove_port = impl_node_remove_port,
 	.port_enum_params = impl_node_port_enum_params,
@@ -1133,9 +1117,7 @@ node_init(struct node *this,
 	this->data_source.mask = SPA_IO_IN | SPA_IO_ERR | SPA_IO_HUP;
 	this->data_source.rmask = 0;
 
-	this->seq = 1;
-
-	return SPA_RESULT_RETURN_ASYNC(this->seq++);
+	return 0;
 }
 
 static int node_clear(struct node *this)
@@ -1186,6 +1168,25 @@ static void client_node_resource_destroy(void *data)
 	pw_node_destroy(this->node);
 }
 
+static void client_node_resource_error(void *data, int res, const char *message)
+{
+	struct impl *impl = data;
+	struct node *this = &impl->node;
+	pw_log_error("client-node %p: error %d: %s", this, res, message);
+	if (this->callbacks && this->callbacks->error)
+		this->callbacks->error(this->callbacks_data, res, message);
+}
+
+static void client_node_resource_done(void *data, uint32_t seq)
+{
+	struct impl *impl = data;
+	struct node *this = &impl->node;
+
+	pw_log_debug("client-node %p: done %d", this, seq);
+	if (this->callbacks && this->callbacks->done)
+		this->callbacks->done(this->callbacks_data, SPA_RESULT_ASYNC_SEQ(seq));
+}
+
 void pw_client_node_registered(struct pw_client_node *this, uint32_t node_id)
 {
 	struct impl *impl = SPA_CONTAINER_OF(this, struct impl, this);
@@ -1541,6 +1542,8 @@ static const struct pw_node_events node_events = {
 static const struct pw_resource_events resource_events = {
 	PW_VERSION_RESOURCE_EVENTS,
 	.destroy = client_node_resource_destroy,
+	.error = client_node_resource_error,
+	.done = client_node_resource_done,
 };
 
 static int root_impl_process(void *data, struct spa_graph_node *node)
@@ -1630,6 +1633,8 @@ struct pw_client_node *pw_client_node_new(struct pw_resource *resource,
 
 	pw_node_add_listener(this->node, &impl->node_listener, &node_events, impl);
 
+	pw_resource_sync(this->resource, 0);
+
 	return this;
 
       error_no_node:

src/modules/module-client-node/client-stream.c

@@ -281,11 +281,10 @@ static int impl_node_send_command(struct spa_node *node, const struct spa_comman
 		if ((res = spa_node_send_command(impl->cnode, command)) < 0)
 			return res;
 	}
-
-	return 0;
+	return res;
 }
 
-static void adapter_port_info(void *data,
+static int adapter_port_info(void *data,
 		enum spa_direction direction, uint32_t port_id,
 		const struct spa_port_info *info)
 {
@@ -297,6 +296,7 @@ static void adapter_port_info(void *data,
 			this->callbacks->port_info(this->callbacks_data, direction, port_id, info);
 		}
 	}
+	return 0;
 }
 
 static const struct spa_node_callbacks adapter_node_callbacks = {
@@ -326,6 +326,20 @@ impl_node_set_callbacks(struct spa_node *node,
 	return 0;
 }
 
+static int
+impl_node_sync(struct spa_node *node, uint32_t seq)
+{
+	struct node *this;
+	struct impl *impl;
+
+	spa_return_val_if_fail(node != NULL, -EINVAL);
+
+	this = SPA_CONTAINER_OF(node, struct node, node);
+	impl = this->impl;
+
+	return spa_node_sync(impl->cnode, seq);
+}
+
 static int
 impl_node_add_port(struct spa_node *node, enum spa_direction direction, uint32_t port_id)
 {
@@ -816,11 +830,12 @@ static int impl_node_process(struct spa_node *node)
 
 static const struct spa_node impl_node = {
 	SPA_VERSION_NODE,
+	.set_callbacks = impl_node_set_callbacks,
+	.sync = impl_node_sync,
 	.enum_params = impl_node_enum_params,
 	.set_param = impl_node_set_param,
 	.set_io = impl_node_set_io,
 	.send_command = impl_node_send_command,
-	.set_callbacks = impl_node_set_callbacks,
 	.add_port = impl_node_add_port,
 	.remove_port = impl_node_remove_port,
 	.port_enum_params = impl_node_port_enum_params,
@@ -1077,7 +1092,7 @@ static void client_node_async_complete(void *data, uint32_t seq, int res)
 	struct node *node = &impl->node;
 
 	pw_log_debug("client-stream %p: async complete %d %d", &impl->this, seq, res);
-	node->callbacks->done(node->callbacks_data, seq, res);
+	node->callbacks->done(node->callbacks_data, seq);
 }
 
 static void client_node_active_changed(void *data, bool active)

src/modules/module-client-node/protocol-native.c

@@ -31,23 +31,7 @@
 #include <extensions/protocol-native.h>
 #include <extensions/client-node.h>
 
-static void
-client_node_marshal_done(void *object, int seq, int res)
-{
-	struct pw_proxy *proxy = object;
-	struct spa_pod_builder *b;
-
-	b = pw_protocol_native_begin_proxy(proxy, PW_CLIENT_NODE_PROXY_METHOD_DONE);
-
-	spa_pod_builder_add_struct(b,
-			       SPA_POD_Int(seq),
-			       SPA_POD_Int(res));
-
-	pw_protocol_native_end_proxy(proxy, b);
-}
-
-
-static void
+static int
 client_node_marshal_update(void *object,
 			   uint32_t change_mask,
 			   uint32_t max_input_ports,
@@ -83,10 +67,10 @@ client_node_marshal_update(void *object,
 	}
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
-static void
+static int
 client_node_marshal_port_update(void *object,
 				enum spa_direction direction,
 				uint32_t port_id,
@@ -133,10 +117,10 @@ client_node_marshal_port_update(void *object,
 	}
 	spa_pod_builder_pop(b, &f[0]);
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
-static void client_node_marshal_set_active(void *object, bool active)
+static int client_node_marshal_set_active(void *object, bool active)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_builder *b;
@@ -146,10 +130,10 @@ static void client_node_marshal_set_active(void *object, bool active)
 	spa_pod_builder_add_struct(b,
 			SPA_POD_Bool(active));
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
-static void client_node_marshal_event_method(void *object, struct spa_event *event)
+static int client_node_marshal_event_method(void *object, struct spa_event *event)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_builder *b;
@@ -159,7 +143,7 @@ static void client_node_marshal_event_method(void *object, struct spa_event *eve
 	spa_pod_builder_add_struct(b,
 			SPA_POD_Pod(event));
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
 static int client_node_demarshal_add_mem(void *object, void *data, size_t size)
@@ -215,18 +199,17 @@ static int client_node_demarshal_set_param(void *object, void *data, size_t size
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_parser prs;
-	uint32_t seq, id, flags;
+	uint32_t id, flags;
 	const struct spa_pod *param = NULL;
 
 	spa_pod_parser_init(&prs, data, size);
 	if (spa_pod_parser_get_struct(&prs,
-			SPA_POD_Int(&seq),
 			SPA_POD_Id(&id),
 			SPA_POD_Int(&flags),
 			SPA_POD_PodObject(&param)) < 0)
 		return -EINVAL;
 
-	pw_proxy_notify(proxy, struct pw_client_node_proxy_events, set_param, 0, seq, id, flags, param);
+	pw_proxy_notify(proxy, struct pw_client_node_proxy_events, set_param, 0, id, flags, param);
 	return 0;
 }
 
@@ -250,15 +233,13 @@ static int client_node_demarshal_command(void *object, void *data, size_t size)
 	struct pw_proxy *proxy = object;
 	struct spa_pod_parser prs;
 	const struct spa_command *command;
-	uint32_t seq;
 
 	spa_pod_parser_init(&prs, data, size);
 	if (spa_pod_parser_get_struct(&prs,
-			SPA_POD_Int(&seq),
 			SPA_POD_PodObject(&command)) < 0)
 		return -EINVAL;
 
-	pw_proxy_notify(proxy, struct pw_client_node_proxy_events, command, 0, seq, command);
+	pw_proxy_notify(proxy, struct pw_client_node_proxy_events, command, 0, command);
 	return 0;
 }
 
@@ -266,16 +247,15 @@ static int client_node_demarshal_add_port(void *object, void *data, size_t size)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_parser prs;
-	int32_t seq, direction, port_id;
+	int32_t direction, port_id;
 
 	spa_pod_parser_init(&prs, data, size);
 	if (spa_pod_parser_get_struct(&prs,
-			SPA_POD_Int(&seq),
 			SPA_POD_Int(&direction),
 			SPA_POD_Int(&port_id)) < 0)
 		return -EINVAL;
 
-	pw_proxy_notify(proxy, struct pw_client_node_proxy_events, add_port, 0, seq, direction, port_id);
+	pw_proxy_notify(proxy, struct pw_client_node_proxy_events, add_port, 0, direction, port_id);
 	return 0;
 }
 
@@ -283,16 +263,15 @@ static int client_node_demarshal_remove_port(void *object, void *data, size_t si
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_parser prs;
-	int32_t seq, direction, port_id;
+	int32_t direction, port_id;
 
 	spa_pod_parser_init(&prs, data, size);
 	if (spa_pod_parser_get_struct(&prs,
-			SPA_POD_Int(&seq),
 			SPA_POD_Int(&direction),
 			SPA_POD_Int(&port_id)) < 0)
 		return -EINVAL;
 
-	pw_proxy_notify(proxy, struct pw_client_node_proxy_events, remove_port, 0, seq, direction, port_id);
+	pw_proxy_notify(proxy, struct pw_client_node_proxy_events, remove_port, 0, direction, port_id);
 	return 0;
 }
 
@@ -300,12 +279,11 @@ static int client_node_demarshal_port_set_param(void *object, void *data, size_t
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_parser prs;
-	uint32_t seq, direction, port_id, id, flags;
+	uint32_t direction, port_id, id, flags;
 	const struct spa_pod *param = NULL;
 
 	spa_pod_parser_init(&prs, data, size);
 	if (spa_pod_parser_get_struct(&prs,
-			SPA_POD_Int(&seq),
 			SPA_POD_Int(&direction),
 			SPA_POD_Int(&port_id),
 			SPA_POD_Id(&id),
@@ -314,7 +292,7 @@ static int client_node_demarshal_port_set_param(void *object, void *data, size_t
 		return -EINVAL;
 
 	pw_proxy_notify(proxy, struct pw_client_node_proxy_events, port_set_param, 0,
-			seq, direction, port_id, id, flags, param);
+			direction, port_id, id, flags, param);
 	return 0;
 }
 
@@ -323,14 +301,13 @@ static int client_node_demarshal_port_use_buffers(void *object, void *data, size
 	struct pw_proxy *proxy = object;
 	struct spa_pod_parser prs;
 	struct spa_pod_frame f;
-	uint32_t seq, direction, port_id, mix_id, n_buffers, data_id;
+	uint32_t direction, port_id, mix_id, n_buffers, data_id;
 	struct pw_client_node_buffer *buffers;
 	uint32_t i, j;
 
 	spa_pod_parser_init(&prs, data, size);
 	if (spa_pod_parser_push_struct(&prs, &f) < 0 ||
 	    spa_pod_parser_get(&prs,
-			SPA_POD_Int(&seq),
 			SPA_POD_Int(&direction),
 			SPA_POD_Int(&port_id),
 			SPA_POD_Int(&mix_id),
@@ -376,7 +353,7 @@ static int client_node_demarshal_port_use_buffers(void *object, void *data, size
 			d->data = SPA_UINT32_TO_PTR(data_id);
 		}
 	}
-	pw_proxy_notify(proxy, struct pw_client_node_proxy_events, port_use_buffers, 0, seq,
+	pw_proxy_notify(proxy, struct pw_client_node_proxy_events, port_use_buffers, 0,
 									  direction,
 									  port_id,
 									  mix_id,
@@ -388,11 +365,10 @@ static int client_node_demarshal_port_set_io(void *object, void *data, size_t si
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_parser prs;
-	uint32_t seq, direction, port_id, mix_id, id, memid, off, sz;
+	uint32_t direction, port_id, mix_id, id, memid, off, sz;
 
 	spa_pod_parser_init(&prs, data, size);
 	if (spa_pod_parser_get_struct(&prs,
-			SPA_POD_Int(&seq),
 			SPA_POD_Int(&direction),
 			SPA_POD_Int(&port_id),
 			SPA_POD_Int(&mix_id),
@@ -403,7 +379,6 @@ static int client_node_demarshal_port_set_io(void *object, void *data, size_t si
 		return -EINVAL;
 
 	pw_proxy_notify(proxy, struct pw_client_node_proxy_events, port_set_io, 0,
-							seq,
 							direction, port_id, mix_id,
 							id, memid,
 							off, sz);
@@ -457,7 +432,7 @@ static int client_node_demarshal_set_io(void *object, void *data, size_t size)
 	return 0;
 }
 
-static void
+static int
 client_node_marshal_add_mem(void *object,
 			    uint32_t mem_id,
 			    uint32_t type,
@@ -474,10 +449,10 @@ client_node_marshal_add_mem(void *object,
 		       SPA_POD_Int(pw_protocol_native_add_resource_fd(resource, memfd)),
 		       SPA_POD_Int(flags));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void client_node_marshal_transport(void *object, uint32_t node_id, int readfd, int writefd)
+static int client_node_marshal_transport(void *object, uint32_t node_id, int readfd, int writefd)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -489,11 +464,11 @@ static void client_node_marshal_transport(void *object, uint32_t node_id, int re
 			       SPA_POD_Int(pw_protocol_native_add_resource_fd(resource, readfd)),
 			       SPA_POD_Int(pw_protocol_native_add_resource_fd(resource, writefd)));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void
-client_node_marshal_set_param(void *object, uint32_t seq, uint32_t id, uint32_t flags,
+static int
+client_node_marshal_set_param(void *object, uint32_t id, uint32_t flags,
 			      const struct spa_pod *param)
 {
 	struct pw_resource *resource = object;
@@ -502,15 +477,14 @@ client_node_marshal_set_param(void *object, uint32_t seq, uint32_t id, uint32_t
 	b = pw_protocol_native_begin_resource(resource, PW_CLIENT_NODE_PROXY_EVENT_SET_PARAM);
 
 	spa_pod_builder_add_struct(b,
-			       SPA_POD_Int(seq),
 			       SPA_POD_Id(id),
 			       SPA_POD_Int(flags),
 			       SPA_POD_Pod(param));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void client_node_marshal_event_event(void *object, const struct spa_event *event)
+static int client_node_marshal_event_event(void *object, const struct spa_event *event)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -520,11 +494,11 @@ static void client_node_marshal_event_event(void *object, const struct spa_event
 	spa_pod_builder_add_struct(b,
 			SPA_POD_Pod(event));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void
-client_node_marshal_command(void *object, uint32_t seq, const struct spa_command *command)
+static int
+client_node_marshal_command(void *object, const struct spa_command *command)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -532,15 +506,14 @@ client_node_marshal_command(void *object, uint32_t seq, const struct spa_command
 	b = pw_protocol_native_begin_resource(resource, PW_CLIENT_NODE_PROXY_EVENT_COMMAND);
 
 	spa_pod_builder_add_struct(b,
-			SPA_POD_Int(seq),
 			SPA_POD_Pod(command));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void
+static int
 client_node_marshal_add_port(void *object,
-			     uint32_t seq, enum spa_direction direction, uint32_t port_id)
+			     enum spa_direction direction, uint32_t port_id)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -548,16 +521,15 @@ client_node_marshal_add_port(void *object,
 	b = pw_protocol_native_begin_resource(resource, PW_CLIENT_NODE_PROXY_EVENT_ADD_PORT);
 
 	spa_pod_builder_add_struct(b,
-			       SPA_POD_Int(seq),
 			       SPA_POD_Int(direction),
 			       SPA_POD_Int(port_id));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void
+static int
 client_node_marshal_remove_port(void *object,
-				uint32_t seq, enum spa_direction direction, uint32_t port_id)
+				enum spa_direction direction, uint32_t port_id)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -565,16 +537,14 @@ client_node_marshal_remove_port(void *object,
 	b = pw_protocol_native_begin_resource(resource, PW_CLIENT_NODE_PROXY_EVENT_REMOVE_PORT);
 
 	spa_pod_builder_add_struct(b,
-			       SPA_POD_Int(seq),
 			       SPA_POD_Int(direction),
 			       SPA_POD_Int(port_id));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void
+static int
 client_node_marshal_port_set_param(void *object,
-				   uint32_t seq,
 				   enum spa_direction direction,
 				   uint32_t port_id,
 				   uint32_t id,
@@ -587,19 +557,17 @@ client_node_marshal_port_set_param(void *object,
 	b = pw_protocol_native_begin_resource(resource, PW_CLIENT_NODE_PROXY_EVENT_PORT_SET_PARAM);
 
 	spa_pod_builder_add_struct(b,
-			       SPA_POD_Int(seq),
 			       SPA_POD_Int(direction),
 			       SPA_POD_Int(port_id),
 			       SPA_POD_Id(id),
 			       SPA_POD_Int(flags),
 			       SPA_POD_Pod(param));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void
+static int
 client_node_marshal_port_use_buffers(void *object,
-				     uint32_t seq,
 				     enum spa_direction direction,
 				     uint32_t port_id,
 				     uint32_t mix_id,
@@ -614,7 +582,6 @@ client_node_marshal_port_use_buffers(void *object,
 
 	spa_pod_builder_push_struct(b, &f);
 	spa_pod_builder_add(b,
-			    SPA_POD_Int(seq),
 			    SPA_POD_Int(direction),
 			    SPA_POD_Int(port_id),
 			    SPA_POD_Int(mix_id),
@@ -649,12 +616,11 @@ client_node_marshal_port_use_buffers(void *object,
 	}
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void
+static int
 client_node_marshal_port_set_io(void *object,
-				uint32_t seq,
 				uint32_t direction,
 				uint32_t port_id,
 				uint32_t mix_id,
@@ -669,7 +635,6 @@ client_node_marshal_port_set_io(void *object,
 	b = pw_protocol_native_begin_resource(resource, PW_CLIENT_NODE_PROXY_EVENT_PORT_SET_IO);
 
 	spa_pod_builder_add_struct(b,
-			       SPA_POD_Int(seq),
 			       SPA_POD_Int(direction),
 			       SPA_POD_Int(port_id),
 			       SPA_POD_Int(mix_id),
@@ -678,10 +643,10 @@ client_node_marshal_port_set_io(void *object,
 			       SPA_POD_Int(offset),
 			       SPA_POD_Int(size));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void
+static int
 client_node_marshal_set_activation(void *object,
 				uint32_t node_id,
 				int signalfd,
@@ -701,10 +666,10 @@ client_node_marshal_set_activation(void *object,
 			       SPA_POD_Int(offset),
 			       SPA_POD_Int(size));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void
+static int
 client_node_marshal_set_io(void *object,
 			   uint32_t id,
 			   uint32_t memid,
@@ -720,23 +685,7 @@ client_node_marshal_set_io(void *object,
 			       SPA_POD_Int(memid),
 			       SPA_POD_Int(offset),
 			       SPA_POD_Int(size));
-	pw_protocol_native_end_resource(resource, b);
-}
-
-static int client_node_demarshal_done(void *object, void *data, size_t size)
-{
-	struct pw_resource *resource = object;
-	struct spa_pod_parser prs;
-	uint32_t seq, res;
-
-	spa_pod_parser_init(&prs, data, size);
-	if (spa_pod_parser_get_struct(&prs,
-			SPA_POD_Int(&seq),
-			SPA_POD_Int(&res)) < 0)
-		return -EINVAL;
-
-	pw_resource_do(resource, struct pw_client_node_proxy_methods, done, 0, seq, res);
-	return 0;
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int client_node_demarshal_update(void *object, void *data, size_t size)
@@ -882,7 +831,6 @@ static int client_node_demarshal_event_method(void *object, void *data, size_t s
 
 static const struct pw_client_node_proxy_methods pw_protocol_native_client_node_method_marshal = {
 	PW_VERSION_CLIENT_NODE_PROXY_METHODS,
-	&client_node_marshal_done,
 	&client_node_marshal_update,
 	&client_node_marshal_port_update,
 	&client_node_marshal_set_active,
@@ -890,7 +838,6 @@ static const struct pw_client_node_proxy_methods pw_protocol_native_client_node_
 };
 
 static const struct pw_protocol_native_demarshal pw_protocol_native_client_node_method_demarshal[] = {
-	{ &client_node_demarshal_done, 0 },
 	{ &client_node_demarshal_update, 0 },
 	{ &client_node_demarshal_port_update, 0 },
 	{ &client_node_demarshal_set_active, 0 },

src/modules/module-client-node/remote-node.c

@@ -343,9 +343,9 @@ static struct mix *ensure_mix(struct node_data *data,
 	return mix;
 }
 
-static void client_node_add_mem(void *object,
-				uint32_t mem_id,
-				uint32_t type, int memfd, uint32_t flags)
+static int client_node_add_mem(void *object,
+			uint32_t mem_id,
+			uint32_t type, int memfd, uint32_t flags)
 {
 	struct pw_proxy *proxy = object;
 	struct node_data *data = proxy->user_data;
@@ -355,7 +355,7 @@ static void client_node_add_mem(void *object,
 	if (m) {
 		pw_log_warn("duplicate mem %u, fd %d, flags %d",
 			     mem_id, memfd, flags);
-		return;
+		return -EINVAL;
 	}
 
 	m = pw_array_add(&data->mems, sizeof(struct mem));
@@ -367,10 +367,11 @@ static void client_node_add_mem(void *object,
 	m->ref = 0;
 	m->map.map = PW_MAP_RANGE_INIT;
 	m->map.ptr = NULL;
+	return 0;
 }
 
-static void client_node_transport(void *object, uint32_t node_id,
-                                  int readfd, int writefd)
+static int client_node_transport(void *object, uint32_t node_id,
+			int readfd, int writefd)
 {
 	struct pw_proxy *proxy = object;
 	struct node_data *data = proxy->user_data;
@@ -392,14 +393,16 @@ static void client_node_transport(void *object, uint32_t node_id,
 		pw_client_node_proxy_set_active(data->node_proxy, true);
 
 	pw_remote_events_exported(remote, proxy->id, node_id);
+	return 0;
 }
 
-static void add_port_update(struct pw_proxy *proxy, struct pw_port *port, uint32_t change_mask)
+static int add_port_update(struct pw_proxy *proxy, struct pw_port *port, uint32_t change_mask)
 {
 	struct node_data *data = proxy->user_data;
 	struct spa_port_info pi = SPA_PORT_INFO_INIT();
 	uint32_t n_params = 0;
 	struct spa_pod **params = NULL;
+	int res;
 
 	if (change_mask & PW_CLIENT_NODE_PORT_UPDATE_PARAMS) {
 		uint32_t idx1, idx2, id;
@@ -446,7 +449,7 @@ static void add_port_update(struct pw_proxy *proxy, struct pw_port *port, uint32
 		pi.flags &= ~SPA_PORT_FLAG_CAN_ALLOC_BUFFERS;
 	}
 
-        pw_client_node_proxy_port_update(data->node_proxy,
+	res = pw_client_node_proxy_port_update(data->node_proxy,
                                          port->direction,
                                          port->port_id,
                                          change_mask,
@@ -458,17 +461,19 @@ static void add_port_update(struct pw_proxy *proxy, struct pw_port *port, uint32
 			free(params[--n_params]);
 		free(params);
 	}
+	return res;
 }
 
-static void
-client_node_set_param(void *object, uint32_t seq, uint32_t id, uint32_t flags,
+static int
+client_node_set_param(void *object, uint32_t id, uint32_t flags,
 		      const struct spa_pod *param)
 {
 	pw_log_warn("set param not implemented");
+	return -ENOTSUP;
 }
 
 
-static void
+static int
 client_node_set_io(void *object,
 		   uint32_t id,
 		   uint32_t memid,
@@ -488,12 +493,12 @@ client_node_set_io(void *object,
 		m = find_mem(data, memid);
 		if (m == NULL) {
 			pw_log_warn("unknown memory id %u", memid);
-			return;
+			return -EINVAL;
 		}
 		ptr = mem_map(data, &m->map, m->fd,
 			PROT_READ|PROT_WRITE, offset, size);
 		if (ptr == NULL)
-			return;
+			return -errno;
 		m->ref++;
 	}
 
@@ -508,12 +513,13 @@ client_node_set_io(void *object,
 		}
 		data->position = ptr;
 	}
-	spa_node_set_io(data->node->node, id, ptr, size);
+	return spa_node_set_io(data->node->node, id, ptr, size);
 }
 
-static void client_node_event(void *object, const struct spa_event *event)
+static int client_node_event(void *object, const struct spa_event *event)
 {
 	pw_log_warn("unhandled node event %d", SPA_EVENT_TYPE(event));
+	return -ENOTSUP;
 }
 
 static int
@@ -527,7 +533,7 @@ do_pause_source(struct spa_loop *loop,
         return 0;
 }
 
-static void client_node_command(void *object, uint32_t seq, const struct spa_command *command)
+static int client_node_command(void *object, const struct spa_command *command)
 {
 	struct pw_proxy *proxy = object;
 	struct node_data *data = proxy->user_data;
@@ -536,50 +542,58 @@ static void client_node_command(void *object, uint32_t seq, const struct spa_com
 
 	switch (SPA_NODE_COMMAND_ID(command)) {
 	case SPA_NODE_COMMAND_Pause:
-		pw_log_debug("node %p: pause %d", proxy, seq);
+		pw_log_debug("node %p: pause", proxy);
 
 		if (data->rtsocket_source) {
 			pw_loop_invoke(data->core->data_loop,
 				do_pause_source, 1, NULL, 0, true, data);
 		}
-		if ((res = pw_node_set_state(data->node, PW_NODE_STATE_IDLE)) < 0)
+		if ((res = pw_node_set_state(data->node, PW_NODE_STATE_IDLE)) < 0) {
 			pw_log_warn("node %p: pause failed", proxy);
+			pw_proxy_error(proxy, res, "pause failed");
+		}
 
-		pw_client_node_proxy_done(data->node_proxy, seq, res);
 		break;
 	case SPA_NODE_COMMAND_Start:
-		pw_log_debug("node %p: start %d", proxy, seq);
+		pw_log_debug("node %p: start", proxy);
 
 		if ((res = pw_node_set_state(data->node, PW_NODE_STATE_RUNNING)) < 0) {
 			pw_log_warn("node %p: start failed", proxy);
+			pw_proxy_error(proxy, res, "start failed");
 		}
 		else if (data->rtsocket_source) {
 			pw_loop_update_io(remote->core->data_loop,
 				  data->rtsocket_source,
 				  SPA_IO_IN | SPA_IO_ERR | SPA_IO_HUP);
 		}
-
-		pw_client_node_proxy_done(data->node_proxy, seq, res);
 		break;
 	default:
 		pw_log_warn("unhandled node command %d", SPA_NODE_COMMAND_ID(command));
-		pw_client_node_proxy_done(data->node_proxy, seq, -ENOTSUP);
+		res = -ENOTSUP;
+		pw_proxy_error(proxy, res, "command %d not supported", SPA_NODE_COMMAND_ID(command));
 	}
+	return res;
 }
 
-static void
-client_node_add_port(void *object, uint32_t seq, enum spa_direction direction, uint32_t port_id)
+static int
+client_node_add_port(void *object, enum spa_direction direction, uint32_t port_id)
 {
+	struct pw_proxy *proxy = object;
 	pw_log_warn("add port not supported");
+	pw_proxy_error(proxy, -ENOTSUP, "add port not supported");
+	return -ENOTSUP;
 }
 
-static void
-client_node_remove_port(void *object, uint32_t seq, enum spa_direction direction, uint32_t port_id)
+static int
+client_node_remove_port(void *object, enum spa_direction direction, uint32_t port_id)
 {
+	struct pw_proxy *proxy = object;
 	pw_log_warn("remove port not supported");
+	pw_proxy_error(proxy, -ENOTSUP, "remove port not supported");
+	return -ENOTSUP;
 }
 
-static void clear_buffers(struct node_data *data, struct mix *mix)
+static int clear_buffers(struct node_data *data, struct mix *mix)
 {
 	struct pw_port *port = mix->port;
         struct buffer *b;
@@ -589,7 +603,7 @@ static void clear_buffers(struct node_data *data, struct mix *mix)
         pw_log_debug("port %p: clear buffers %d", port, mix->mix_id);
 	if ((res = pw_port_use_buffers(port, mix->mix_id, NULL, 0)) < 0) {
 		pw_log_error("port %p: error clear buffers %s", port, spa_strerror(res));
-		return;
+		return res;
 	}
 
         pw_array_for_each(b, &mix->buffers) {
@@ -608,11 +622,11 @@ static void clear_buffers(struct node_data *data, struct mix *mix)
                 free(b->buf);
         }
 	mix->buffers.size = 0;
+	return 0;
 }
 
-static void
+static int
 client_node_port_set_param(void *object,
-			   uint32_t seq,
 			   enum spa_direction direction, uint32_t port_id,
 			   uint32_t id, uint32_t flags,
 			   const struct spa_pod *param)
@@ -625,6 +639,7 @@ client_node_port_set_param(void *object,
 	port = pw_node_find_port(data->node, direction, port_id);
 	if (port == NULL) {
 		res = -EINVAL;
+		pw_proxy_error(proxy, res, "unknown port");
 		goto done;
 	}
 
@@ -639,20 +654,22 @@ client_node_port_set_param(void *object,
 	}
 
 	res = pw_port_set_param(port, SPA_ID_INVALID, id, flags, param);
-	if (res < 0)
+	if (res < 0) {
+		pw_proxy_error(proxy, res, "can't set port param: %s", spa_strerror(res));
 		goto done;
+	}
 
-	add_port_update(proxy, port,
+	if ((res = add_port_update(proxy, port,
 			PW_CLIENT_NODE_PORT_UPDATE_PARAMS |
-			PW_CLIENT_NODE_PORT_UPDATE_INFO);
+			PW_CLIENT_NODE_PORT_UPDATE_INFO)) < 0)
+		pw_proxy_error(proxy, res, "can't add port update");
 
       done:
-	pw_client_node_proxy_done(data->node_proxy, seq, res);
+	return res;
 }
 
-static void
+static int
 client_node_port_use_buffers(void *object,
-			     uint32_t seq,
 			     enum spa_direction direction, uint32_t port_id, uint32_t mix_id,
 			     uint32_t n_buffers, struct pw_client_node_buffer *buffers)
 {
@@ -667,6 +684,7 @@ client_node_port_use_buffers(void *object,
 	mix = ensure_mix(data, direction, port_id, mix_id);
 	if (mix == NULL) {
 		res = -EINVAL;
+		pw_proxy_error(proxy, res, "can add mix");
 		goto done;
 	}
 
@@ -687,6 +705,7 @@ client_node_port_use_buffers(void *object,
 		if (m == NULL) {
 			pw_log_error("unknown memory id %u", buffers[i].mem_id);
 			res = -EINVAL;
+			pw_proxy_error(proxy, res, "unknown memory %u", buffers[i].mem_id);
 			goto cleanup;
 		}
 
@@ -698,6 +717,7 @@ client_node_port_use_buffers(void *object,
 				buffers[i].offset, buffers[i].size);
 		if (bmem.map.ptr == NULL) {
 			res = -errno;
+			pw_proxy_error(proxy, res, "can't mmap memory: %s", spa_strerror(res));
 			goto cleanup;
 		}
 		if (mlock(bmem.map.ptr, bmem.map.map.size) < 0)
@@ -716,6 +736,7 @@ client_node_port_use_buffers(void *object,
 		b = bid->buf = malloc(size);
 		if (b == NULL) {
 			res = -ENOMEM;
+			pw_proxy_error(proxy, res, "can't alloc memory: %s", spa_strerror(res));
 			goto cleanup;
 		}
 		memcpy(b, buffers[i].buffer, sizeof(struct spa_buffer));
@@ -757,6 +778,7 @@ client_node_port_use_buffers(void *object,
 				if (bm == NULL) {
 					pw_log_error("unknown buffer mem %u", mem_id);
 					res = -EINVAL;
+					pw_proxy_error(proxy, res, "unknown buffer mem %u", mem_id);
 					goto cleanup;
 				}
 
@@ -783,11 +805,11 @@ client_node_port_use_buffers(void *object,
 		bufs[i] = b;
 	}
 
-	res = pw_port_use_buffers(mix->port, mix->mix_id, bufs, n_buffers);
+	if ((res = pw_port_use_buffers(mix->port, mix->mix_id, bufs, n_buffers)) < 0)
+		pw_proxy_error(proxy, res, "can't use buffers: %s", spa_strerror(res));
 
       done:
-	pw_client_node_proxy_done(data->node_proxy, seq, res);
-	return;
+	return res;
 
      cleanup:
 	clear_buffers(data, mix);
@@ -795,9 +817,8 @@ client_node_port_use_buffers(void *object,
 
 }
 
-static void
+static int
 client_node_port_set_io(void *object,
-                        uint32_t seq,
                         uint32_t direction,
                         uint32_t port_id,
                         uint32_t mix_id,
@@ -811,10 +832,14 @@ client_node_port_set_io(void *object,
 	struct mix *mix;
 	struct mem *m;
 	void *ptr;
+	int res = 0;
 
 	mix = ensure_mix(data, direction, port_id, mix_id);
-	if (mix == NULL)
-		return;
+	if (mix == NULL) {
+		res = -EINVAL;
+		pw_proxy_error(proxy, res, "can't get mixer: %s", spa_strerror(res));
+		return res;
+	}
 
 	if (memid == SPA_ID_INVALID) {
 		ptr = NULL;
@@ -824,12 +849,17 @@ client_node_port_set_io(void *object,
 		m = find_mem(data, memid);
 		if (m == NULL) {
 			pw_log_warn("unknown memory id %u", memid);
-			return;
+			res = -EINVAL;
+			pw_proxy_error(proxy, res, "unknown memory id %u", memid);
+			return res;
 		}
 		ptr = mem_map(data, &m->map, m->fd,
 			PROT_READ|PROT_WRITE, offset, size);
-		if (ptr == NULL)
-			return;
+		if (ptr == NULL) {
+			res = -errno;
+			pw_proxy_error(proxy, res, "mmap failed: %s", spa_strerror(res));
+			return res;
+		}
 
 		m->ref++;
 	}
@@ -848,12 +878,14 @@ client_node_port_set_io(void *object,
 		if (ptr)
 			activate_mix(data, mix);
 	} else {
-		spa_node_port_set_io(mix->port->node->node,
+		if ((res = spa_node_port_set_io(mix->port->node->node,
 				     direction, port_id,
 				     id,
 				     ptr,
-				     size);
+				     size)) < 0)
+			pw_proxy_error(proxy, res, "set_io failed: %s", spa_strerror(res));
 	}
+	return res;
 }
 
 #if 0
@@ -868,7 +900,7 @@ static int link_signal_func(void *user_data)
 }
 #endif
 
-static void
+static int
 client_node_set_activation(void *object,
                         uint32_t node_id,
                         int signalfd,
@@ -881,6 +913,7 @@ client_node_set_activation(void *object,
 	struct pw_node *node = data->node;
 	struct mem *m;
 	struct pw_node_activation *ptr;
+	int res = 0;
 
 	if (memid == SPA_ID_INVALID) {
 		ptr = NULL;
@@ -890,12 +923,17 @@ client_node_set_activation(void *object,
 		m = find_mem(data, memid);
 		if (m == NULL) {
 			pw_log_warn("unknown memory id %u", memid);
-			return;
+			res = -EINVAL;
+			pw_proxy_error(proxy, res, "unknown memory id %u", memid);
+			return res;
 		}
 		ptr = mem_map(data, &m->map, m->fd,
 			PROT_READ|PROT_WRITE, offset, size);
-		if (ptr == NULL)
-			return;
+		if (ptr == NULL) {
+			res = -errno;
+			pw_proxy_error(proxy, res, "mmap failed: %s", spa_strerror(res));
+			return res;
+		}
 		m->ref++;
 	}
 	pw_log_debug("node %p: set activation %d", node, node_id);
@@ -914,6 +952,7 @@ client_node_set_activation(void *object,
 				link->link.state->pending);
 	}
 #endif
+	return res;
 }
 
 static const struct pw_client_node_proxy_events client_node_events = {
@@ -956,7 +995,6 @@ static void do_node_init(struct pw_proxy *proxy)
 				PW_CLIENT_NODE_PORT_UPDATE_PARAMS |
 				PW_CLIENT_NODE_PORT_UPDATE_INFO);
 	}
-        pw_client_node_proxy_done(data->node_proxy, 0, 0);
 }
 
 static void clear_mix(struct node_data *data, struct mix *mix)

src/modules/module-protocol-native.c

@@ -476,8 +476,7 @@ on_remote_data(void *data, int fd, enum spa_io mask)
 
         if (mask & SPA_IO_IN) {
                 uint8_t opcode;
-                uint32_t id;
-                uint32_t size;
+                uint32_t id, size;
                 void *message;
 
                 while (!impl->disconnecting
@@ -773,11 +772,11 @@ static int impl_ext_get_proxy_fd(struct pw_proxy *proxy, uint32_t index)
 	return pw_protocol_native_connection_get_fd(impl->connection, index);
 }
 
-static void impl_ext_end_proxy(struct pw_proxy *proxy,
+static int impl_ext_end_proxy(struct pw_proxy *proxy,
 			       struct spa_pod_builder *builder)
 {
 	struct client *impl = SPA_CONTAINER_OF(proxy->remote->conn, struct client, this);
-	pw_protocol_native_connection_end(impl->connection, builder);
+	return pw_protocol_native_connection_end(impl->connection, builder);
 }
 
 static struct spa_pod_builder *
@@ -798,11 +797,11 @@ static int impl_ext_get_resource_fd(struct pw_resource *resource, uint32_t index
 	return pw_protocol_native_connection_get_fd(data->connection, index);
 }
 
-static void impl_ext_end_resource(struct pw_resource *resource,
+static int impl_ext_end_resource(struct pw_resource *resource,
 				  struct spa_pod_builder *builder)
 {
 	struct client_data *data = resource->client->user_data;
-	pw_protocol_native_connection_end(data->connection, builder);
+	return pw_protocol_native_connection_end(data->connection, builder);
 }
 
 const static struct pw_protocol_native_ext protocol_ext_impl = {

src/modules/module-protocol-native/connection.c

@@ -65,8 +65,8 @@ struct impl {
 	uint32_t dest_id;
 	uint8_t opcode;
 	struct spa_pod_builder builder;
-
 	struct pw_core *core;
+	uint32_t seq;
 };
 
 /** \endcond */
@@ -398,16 +398,20 @@ pw_protocol_native_connection_begin_proxy(struct pw_protocol_native_connection *
 	return &impl->builder;
 }
 
-void
+int
 pw_protocol_native_connection_end(struct pw_protocol_native_connection *conn,
 				  struct spa_pod_builder *builder)
 {
 	struct impl *impl = SPA_CONTAINER_OF(conn, struct impl, this);
 	uint32_t *p, size = builder->state.offset;
 	struct buffer *buf = &impl->out;
+	uint32_t seq;
 
 	if ((p = connection_ensure_size(conn, buf, 8 + size)) == NULL)
-		return;
+		return -ENOMEM;
+
+	seq = impl->seq;
+	impl->seq = (impl->seq + 1) & SPA_ASYNC_SEQ_MASK;
 
 	*p++ = impl->dest_id;
 	*p++ = (impl->opcode << 24) | (size & 0xffffff);
@@ -418,8 +422,11 @@ pw_protocol_native_connection_end(struct pw_protocol_native_connection *conn,
 		fprintf(stderr, ">>>>>>>>> out: %d %d %d\n", impl->dest_id, impl->opcode, size);
 	        spa_debug_pod(0, NULL, (struct spa_pod *)p);
 	}
+
 	spa_hook_list_call(&conn->listener_list,
 			struct pw_protocol_native_connection_events, need_flush, 0);
+
+	return SPA_RESULT_RETURN_ASYNC(seq);
 }
 
 /** Flush the connection object

src/modules/module-protocol-native/connection.h

@@ -90,7 +90,7 @@ struct spa_pod_builder *
 pw_protocol_native_connection_begin_proxy(struct pw_protocol_native_connection *conn,
                                           struct pw_proxy *proxy,
                                           uint8_t opcode);
-void
+int
 pw_protocol_native_connection_end(struct pw_protocol_native_connection *conn,
                                   struct spa_pod_builder *builder);
 

src/modules/module-protocol-native/protocol-native.c

@@ -32,7 +32,7 @@
 
 #include "connection.h"
 
-static void core_marshal_hello(void *object, uint32_t version)
+static int core_method_marshal_hello(void *object, uint32_t version)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_builder *b;
@@ -42,10 +42,10 @@ static void core_marshal_hello(void *object, uint32_t version)
 	spa_pod_builder_add_struct(b,
 			SPA_POD_Int(version));
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
-static void core_marshal_sync(void *object, uint32_t seq)
+static int core_method_marshal_sync(void *object, uint32_t id, uint32_t seq)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_builder *b;
@@ -53,12 +53,42 @@ static void core_marshal_sync(void *object, uint32_t seq)
 	b = pw_protocol_native_begin_proxy(proxy, PW_CORE_PROXY_METHOD_SYNC);
 
 	spa_pod_builder_add_struct(b,
+			SPA_POD_Int(id),
 			SPA_POD_Int(seq));
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
-static void core_marshal_get_registry(void *object, uint32_t version, uint32_t new_id)
+static int core_method_marshal_done(void *object, uint32_t id, uint32_t seq)
+{
+	struct pw_proxy *proxy = object;
+	struct spa_pod_builder *b;
+
+	b = pw_protocol_native_begin_proxy(proxy, PW_CORE_PROXY_METHOD_DONE);
+
+	spa_pod_builder_add_struct(b,
+			SPA_POD_Int(id),
+			SPA_POD_Int(seq));
+
+	return pw_protocol_native_end_proxy(proxy, b);
+}
+
+static int core_method_marshal_error(void *object, uint32_t id, int res, const char *error)
+{
+	struct pw_proxy *proxy = object;
+	struct spa_pod_builder *b;
+
+	b = pw_protocol_native_begin_proxy(proxy, PW_CORE_PROXY_METHOD_ERROR);
+
+	spa_pod_builder_add_struct(b,
+			       SPA_POD_Int(id),
+			       SPA_POD_Int(res),
+			       SPA_POD_String(error));
+
+	return pw_protocol_native_end_proxy(proxy, b);
+}
+
+static int core_method_marshal_get_registry(void *object, uint32_t version, uint32_t new_id)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_builder *b;
@@ -69,7 +99,7 @@ static void core_marshal_get_registry(void *object, uint32_t version, uint32_t n
 		       SPA_POD_Int(version),
 		       SPA_POD_Int(new_id));
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
 static void push_dict(struct spa_pod_builder *b, const struct spa_dict *dict)
@@ -88,8 +118,8 @@ static void push_dict(struct spa_pod_builder *b, const struct spa_dict *dict)
 	spa_pod_builder_pop(b, &f);
 }
 
-static void
-core_marshal_create_object(void *object,
+static int
+core_method_marshal_create_object(void *object,
 			   const char *factory_name,
 			   uint32_t type, uint32_t version,
 			   const struct spa_dict *props, uint32_t new_id)
@@ -110,11 +140,11 @@ core_marshal_create_object(void *object,
 	spa_pod_builder_int(b, new_id);
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
-static void
-core_marshal_destroy(void *object, uint32_t id)
+static int
+core_method_marshal_destroy(void *object, uint32_t id)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_builder *b;
@@ -124,10 +154,10 @@ core_marshal_destroy(void *object, uint32_t id)
 	spa_pod_builder_add_struct(b,
 			SPA_POD_Int(id));
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
-static int core_demarshal_info(void *object, void *data, size_t size)
+static int core_event_demarshal_info(void *object, void *data, size_t size)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_dict props;
@@ -164,26 +194,40 @@ static int core_demarshal_info(void *object, void *data, size_t size)
 				       NULL) < 0)
 			return -EINVAL;
 	}
-	pw_proxy_notify(proxy, struct pw_core_proxy_events, info, 0, &info);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_core_proxy_events, info, 0, &info);
 }
 
-static int core_demarshal_done(void *object, void *data, size_t size)
+static int core_event_demarshal_done(void *object, void *data, size_t size)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_parser prs;
-	uint32_t seq;
+	uint32_t id, seq;
 
 	spa_pod_parser_init(&prs, data, size);
 	if (spa_pod_parser_get_struct(&prs,
+				SPA_POD_Int(&id),
 				SPA_POD_Int(&seq)) < 0)
 		return -EINVAL;
 
-	pw_proxy_notify(proxy, struct pw_core_proxy_events, done, 0, seq);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_core_proxy_events, done, 0, id, seq);
 }
 
-static int core_demarshal_error(void *object, void *data, size_t size)
+static int core_event_demarshal_sync(void *object, void *data, size_t size)
+{
+	struct pw_proxy *proxy = object;
+	struct spa_pod_parser prs;
+	uint32_t id, seq;
+
+	spa_pod_parser_init(&prs, data, size);
+	if (spa_pod_parser_get_struct(&prs,
+				SPA_POD_Int(&id),
+				SPA_POD_Int(&seq)) < 0)
+		return -EINVAL;
+
+	return pw_proxy_notify(proxy, struct pw_core_proxy_events, sync, 0, id, seq);
+}
+
+static int core_event_demarshal_error(void *object, void *data, size_t size)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_parser prs;
@@ -197,11 +241,10 @@ static int core_demarshal_error(void *object, void *data, size_t size)
 			SPA_POD_String(&error)) < 0)
 		return -EINVAL;
 
-	pw_proxy_notify(proxy, struct pw_core_proxy_events, error, 0, id, res, error);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_core_proxy_events, error, 0, id, res, error);
 }
 
-static int core_demarshal_remove_id(void *object, void *data, size_t size)
+static int core_event_demarshal_remove_id(void *object, void *data, size_t size)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_parser prs;
@@ -211,11 +254,10 @@ static int core_demarshal_remove_id(void *object, void *data, size_t size)
 	if (spa_pod_parser_get_struct(&prs, SPA_POD_Int(&id)) < 0)
 		return -EINVAL;
 
-	pw_proxy_notify(proxy, struct pw_core_proxy_events, remove_id, 0, id);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_core_proxy_events, remove_id, 0, id);
 }
 
-static void core_marshal_info(void *object, const struct pw_core_info *info)
+static int core_event_marshal_info(void *object, const struct pw_core_info *info)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -236,10 +278,10 @@ static void core_marshal_info(void *object, const struct pw_core_info *info)
 	push_dict(b, info->props);
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void core_marshal_done(void *object, uint32_t seq)
+static int core_event_marshal_done(void *object, uint32_t id, uint32_t seq)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -247,12 +289,27 @@ static void core_marshal_done(void *object, uint32_t seq)
 	b = pw_protocol_native_begin_resource(resource, PW_CORE_PROXY_EVENT_DONE);
 
 	spa_pod_builder_add_struct(b,
+			SPA_POD_Int(id),
 			SPA_POD_Int(seq));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void core_marshal_error(void *object, uint32_t id, int res, const char *error)
+static int core_event_marshal_sync(void *object, uint32_t id, uint32_t seq)
+{
+	struct pw_resource *resource = object;
+	struct spa_pod_builder *b;
+
+	b = pw_protocol_native_begin_resource(resource, PW_CORE_PROXY_EVENT_SYNC);
+
+	spa_pod_builder_add_struct(b,
+			SPA_POD_Int(id),
+			SPA_POD_Int(seq));
+
+	return pw_protocol_native_end_resource(resource, b);
+}
+
+static int core_event_marshal_error(void *object, uint32_t id, int res, const char *error)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -264,10 +321,10 @@ static void core_marshal_error(void *object, uint32_t id, int res, const char *e
 			       SPA_POD_Int(res),
 			       SPA_POD_String(error));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void core_marshal_remove_id(void *object, uint32_t id)
+static int core_event_marshal_remove_id(void *object, uint32_t id)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -277,10 +334,10 @@ static void core_marshal_remove_id(void *object, uint32_t id)
 	spa_pod_builder_add_struct(b,
 			SPA_POD_Int(id));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static int core_demarshal_hello(void *object, void *data, size_t size)
+static int core_method_demarshal_hello(void *object, void *data, size_t size)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_parser prs;
@@ -291,26 +348,57 @@ static int core_demarshal_hello(void *object, void *data, size_t size)
 				SPA_POD_Int(&version)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_core_proxy_methods, hello, 0, version);
-	return 0;
+	return pw_resource_do(resource, struct pw_core_proxy_methods, hello, 0, version);
 }
 
-static int core_demarshal_sync(void *object, void *data, size_t size)
+static int core_method_demarshal_sync(void *object, void *data, size_t size)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_parser prs;
-	uint32_t seq;
+	uint32_t id, seq;
 
 	spa_pod_parser_init(&prs, data, size);
 	if (spa_pod_parser_get_struct(&prs,
+				SPA_POD_Int(&id),
 				SPA_POD_Int(&seq)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_core_proxy_methods, sync, 0, seq);
-	return 0;
+	return pw_resource_do(resource, struct pw_core_proxy_methods, sync, 0, id, seq);
 }
 
-static int core_demarshal_get_registry(void *object, void *data, size_t size)
+static int core_method_demarshal_done(void *object, void *data, size_t size)
+{
+	struct pw_resource *resource = object;
+	struct spa_pod_parser prs;
+	uint32_t id, seq;
+
+	spa_pod_parser_init(&prs, data, size);
+	if (spa_pod_parser_get_struct(&prs,
+				SPA_POD_Int(&id),
+				SPA_POD_Int(&seq)) < 0)
+		return -EINVAL;
+
+	return pw_resource_do(resource, struct pw_core_proxy_methods, done, 0, id, seq);
+}
+
+static int core_method_demarshal_error(void *object, void *data, size_t size)
+{
+	struct pw_resource *resource = object;
+	struct spa_pod_parser prs;
+	uint32_t id, res;
+	const char *error;
+
+	spa_pod_parser_init(&prs, data, size);
+	if (spa_pod_parser_get_struct(&prs,
+			SPA_POD_Int(&id),
+			SPA_POD_Int(&res),
+			SPA_POD_String(&error)) < 0)
+		return -EINVAL;
+
+	return pw_resource_do(resource, struct pw_core_proxy_methods, error, 0, id, res, error);
+}
+
+static int core_method_demarshal_get_registry(void *object, void *data, size_t size)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_parser prs;
@@ -322,11 +410,10 @@ static int core_demarshal_get_registry(void *object, void *data, size_t size)
 				SPA_POD_Int(&new_id)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_core_proxy_methods, get_registry, 0, version, new_id);
-	return 0;
+	return pw_resource_do(resource, struct pw_core_proxy_methods, get_registry, 0, version, new_id);
 }
 
-static int core_demarshal_create_object(void *object, void *data, size_t size)
+static int core_method_demarshal_create_object(void *object, void *data, size_t size)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_parser prs;
@@ -362,13 +449,12 @@ static int core_demarshal_create_object(void *object, void *data, size_t size)
 			SPA_POD_Int(&new_id), NULL) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_core_proxy_methods, create_object, 0, factory_name,
+	return pw_resource_do(resource, struct pw_core_proxy_methods, create_object, 0, factory_name,
 								      type, version,
 								      &props, new_id);
-	return 0;
 }
 
-static int core_demarshal_destroy(void *object, void *data, size_t size)
+static int core_method_demarshal_destroy(void *object, void *data, size_t size)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_parser prs;
@@ -379,11 +465,10 @@ static int core_demarshal_destroy(void *object, void *data, size_t size)
 			SPA_POD_Int(&id)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_core_proxy_methods, destroy, 0, id);
-	return 0;
+	return pw_resource_do(resource, struct pw_core_proxy_methods, destroy, 0, id);
 }
 
-static void registry_marshal_global(void *object, uint32_t id, uint32_t parent_id, uint32_t permissions,
+static int registry_marshal_global(void *object, uint32_t id, uint32_t parent_id, uint32_t permissions,
 				    uint32_t type, uint32_t version, const struct spa_dict *props)
 {
 	struct pw_resource *resource = object;
@@ -403,10 +488,10 @@ static void registry_marshal_global(void *object, uint32_t id, uint32_t parent_i
 	push_dict(b, props);
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
-static void registry_marshal_global_remove(void *object, uint32_t id)
+static int registry_marshal_global_remove(void *object, uint32_t id)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -415,7 +500,7 @@ static void registry_marshal_global_remove(void *object, uint32_t id)
 
 	spa_pod_builder_add_struct(b, SPA_POD_Int(id));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int registry_demarshal_bind(void *object, void *data, size_t size)
@@ -432,8 +517,7 @@ static int registry_demarshal_bind(void *object, void *data, size_t size)
 			SPA_POD_Int(&new_id)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_registry_proxy_methods, bind, 0, id, type, version, new_id);
-	return 0;
+	return pw_resource_do(resource, struct pw_registry_proxy_methods, bind, 0, id, type, version, new_id);
 }
 
 static int registry_demarshal_destroy(void *object, void *data, size_t size)
@@ -447,11 +531,10 @@ static int registry_demarshal_destroy(void *object, void *data, size_t size)
 			SPA_POD_Int(&id)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_registry_proxy_methods, destroy, 0, id);
-	return 0;
+	return pw_resource_do(resource, struct pw_registry_proxy_methods, destroy, 0, id);
 }
 
-static void module_marshal_info(void *object, const struct pw_module_info *info)
+static int module_marshal_info(void *object, const struct pw_module_info *info)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -470,7 +553,7 @@ static void module_marshal_info(void *object, const struct pw_module_info *info)
 	push_dict(b, info->props);
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int module_demarshal_info(void *object, void *data, size_t size)
@@ -505,11 +588,10 @@ static int module_demarshal_info(void *object, void *data, size_t size)
 				    SPA_POD_String(&props.items[i].value), NULL) < 0)
 			return -EINVAL;
 	}
-	pw_proxy_notify(proxy, struct pw_module_proxy_events, info, 0, &info);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_module_proxy_events, info, 0, &info);
 }
 
-static void device_marshal_info(void *object, const struct pw_device_info *info)
+static int device_marshal_info(void *object, const struct pw_device_info *info)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -526,7 +608,7 @@ static void device_marshal_info(void *object, const struct pw_device_info *info)
 	push_dict(b, info->props);
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int device_demarshal_info(void *object, void *data, size_t size)
@@ -559,11 +641,10 @@ static int device_demarshal_info(void *object, void *data, size_t size)
 				    SPA_POD_String(&props.items[i].value), NULL) < 0)
 			return -EINVAL;
 	}
-	pw_proxy_notify(proxy, struct pw_device_proxy_events, info, 0, &info);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_device_proxy_events, info, 0, &info);
 }
 
-static void device_marshal_param(void *object, uint32_t id, uint32_t index, uint32_t next,
+static int device_marshal_param(void *object, uint32_t id, uint32_t index, uint32_t next,
 		const struct spa_pod *param)
 {
 	struct pw_resource *resource = object;
@@ -577,7 +658,7 @@ static void device_marshal_param(void *object, uint32_t id, uint32_t index, uint
 			SPA_POD_Int(next),
 			SPA_POD_Pod(param));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int device_demarshal_param(void *object, void *data, size_t size)
@@ -595,11 +676,10 @@ static int device_demarshal_param(void *object, void *data, size_t size)
 				SPA_POD_Pod(&param)) < 0)
 		return -EINVAL;
 
-	pw_proxy_notify(proxy, struct pw_device_proxy_events, param, 0, id, index, next, param);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_device_proxy_events, param, 0, id, index, next, param);
 }
 
-static void device_marshal_enum_params(void *object, uint32_t id, uint32_t index, uint32_t num,
+static int device_marshal_enum_params(void *object, uint32_t id, uint32_t index, uint32_t num,
 		const struct spa_pod *filter)
 {
 	struct pw_proxy *proxy = object;
@@ -613,7 +693,7 @@ static void device_marshal_enum_params(void *object, uint32_t id, uint32_t index
 			SPA_POD_Int(num),
 			SPA_POD_Pod(filter));
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
 static int device_demarshal_enum_params(void *object, void *data, size_t size)
@@ -631,11 +711,10 @@ static int device_demarshal_enum_params(void *object, void *data, size_t size)
 				SPA_POD_Pod(&filter)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_device_proxy_methods, enum_params, 0, id, index, num, filter);
-	return 0;
+	return pw_resource_do(resource, struct pw_device_proxy_methods, enum_params, 0, id, index, num, filter);
 }
 
-static void device_marshal_set_param(void *object, uint32_t id, uint32_t flags,
+static int device_marshal_set_param(void *object, uint32_t id, uint32_t flags,
 		const struct spa_pod *param)
 {
 	struct pw_proxy *proxy = object;
@@ -647,7 +726,7 @@ static void device_marshal_set_param(void *object, uint32_t id, uint32_t flags,
 			SPA_POD_Id(id),
 			SPA_POD_Int(flags),
 			SPA_POD_Pod(param));
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
 static int device_demarshal_set_param(void *object, void *data, size_t size)
@@ -664,11 +743,10 @@ static int device_demarshal_set_param(void *object, void *data, size_t size)
 				SPA_POD_Pod(&param)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_device_proxy_methods, set_param, 0, id, flags, param);
-	return 0;
+	return pw_resource_do(resource, struct pw_device_proxy_methods, set_param, 0, id, flags, param);
 }
 
-static void factory_marshal_info(void *object, const struct pw_factory_info *info)
+static int factory_marshal_info(void *object, const struct pw_factory_info *info)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -687,7 +765,7 @@ static void factory_marshal_info(void *object, const struct pw_factory_info *inf
 	push_dict(b, info->props);
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int factory_demarshal_info(void *object, void *data, size_t size)
@@ -722,11 +800,10 @@ static int factory_demarshal_info(void *object, void *data, size_t size)
 				       SPA_POD_String(&props.items[i].value), NULL) < 0)
 			return -EINVAL;
 	}
-	pw_proxy_notify(proxy, struct pw_factory_proxy_events, info, 0, &info);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_factory_proxy_events, info, 0, &info);
 }
 
-static void node_marshal_info(void *object, const struct pw_node_info *info)
+static int node_marshal_info(void *object, const struct pw_node_info *info)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -749,7 +826,7 @@ static void node_marshal_info(void *object, const struct pw_node_info *info)
 	push_dict(b, info->props);
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int node_demarshal_info(void *object, void *data, size_t size)
@@ -788,11 +865,10 @@ static int node_demarshal_info(void *object, void *data, size_t size)
 				       SPA_POD_String(&props.items[i].value), NULL) < 0)
 			return -EINVAL;
 	}
-	pw_proxy_notify(proxy, struct pw_node_proxy_events, info, 0, &info);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_node_proxy_events, info, 0, &info);
 }
 
-static void node_marshal_param(void *object, uint32_t id, uint32_t index, uint32_t next,
+static int node_marshal_param(void *object, uint32_t id, uint32_t index, uint32_t next,
 		const struct spa_pod *param)
 {
 	struct pw_resource *resource = object;
@@ -806,7 +882,7 @@ static void node_marshal_param(void *object, uint32_t id, uint32_t index, uint32
 			SPA_POD_Int(next),
 			SPA_POD_Pod(param));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int node_demarshal_param(void *object, void *data, size_t size)
@@ -824,11 +900,10 @@ static int node_demarshal_param(void *object, void *data, size_t size)
 				SPA_POD_Pod(&param)) < 0)
 		return -EINVAL;
 
-	pw_proxy_notify(proxy, struct pw_node_proxy_events, param, 0, id, index, next, param);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_node_proxy_events, param, 0, id, index, next, param);
 }
 
-static void node_marshal_enum_params(void *object, uint32_t id, uint32_t index, uint32_t num,
+static int node_marshal_enum_params(void *object, uint32_t id, uint32_t index, uint32_t num,
 		const struct spa_pod *filter)
 {
 	struct pw_proxy *proxy = object;
@@ -842,7 +917,7 @@ static void node_marshal_enum_params(void *object, uint32_t id, uint32_t index,
 			SPA_POD_Int(num),
 			SPA_POD_Pod(filter));
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
 static int node_demarshal_enum_params(void *object, void *data, size_t size)
@@ -860,11 +935,10 @@ static int node_demarshal_enum_params(void *object, void *data, size_t size)
 				SPA_POD_Pod(&filter)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_node_proxy_methods, enum_params, 0, id, index, num, filter);
-	return 0;
+	return pw_resource_do(resource, struct pw_node_proxy_methods, enum_params, 0, id, index, num, filter);
 }
 
-static void node_marshal_set_param(void *object, uint32_t id, uint32_t flags,
+static int node_marshal_set_param(void *object, uint32_t id, uint32_t flags,
 		const struct spa_pod *param)
 {
 	struct pw_proxy *proxy = object;
@@ -876,7 +950,7 @@ static void node_marshal_set_param(void *object, uint32_t id, uint32_t flags,
 			SPA_POD_Id(id),
 			SPA_POD_Int(flags),
 			SPA_POD_Pod(param));
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
 static int node_demarshal_set_param(void *object, void *data, size_t size)
@@ -893,11 +967,10 @@ static int node_demarshal_set_param(void *object, void *data, size_t size)
 				SPA_POD_Pod(&param)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_node_proxy_methods, set_param, 0, id, flags, param);
-	return 0;
+	return pw_resource_do(resource, struct pw_node_proxy_methods, set_param, 0, id, flags, param);
 }
 
-static void node_marshal_send_command(void *object, const struct spa_command *command)
+static int node_marshal_send_command(void *object, const struct spa_command *command)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_builder *b;
@@ -905,7 +978,7 @@ static void node_marshal_send_command(void *object, const struct spa_command *co
 	b = pw_protocol_native_begin_proxy(proxy, PW_NODE_PROXY_METHOD_SEND_COMMAND);
 	spa_pod_builder_add_struct(b,
 			SPA_POD_Pod(command));
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
 static int node_demarshal_send_command(void *object, void *data, size_t size)
@@ -919,11 +992,10 @@ static int node_demarshal_send_command(void *object, void *data, size_t size)
 				SPA_POD_Pod(&command)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_node_proxy_methods, send_command, 0, command);
-	return 0;
+	return pw_resource_do(resource, struct pw_node_proxy_methods, send_command, 0, command);
 }
 
-static void port_marshal_info(void *object, const struct pw_port_info *info)
+static int port_marshal_info(void *object, const struct pw_port_info *info)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -940,7 +1012,7 @@ static void port_marshal_info(void *object, const struct pw_port_info *info)
 	push_dict(b, info->props);
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int port_demarshal_info(void *object, void *data, size_t size)
@@ -973,11 +1045,10 @@ static int port_demarshal_info(void *object, void *data, size_t size)
 				       SPA_POD_String(&props.items[i].value), NULL) < 0)
 			return -EINVAL;
 	}
-	pw_proxy_notify(proxy, struct pw_port_proxy_events, info, 0, &info);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_port_proxy_events, info, 0, &info);
 }
 
-static void port_marshal_param(void *object, uint32_t id, uint32_t index, uint32_t next,
+static int port_marshal_param(void *object, uint32_t id, uint32_t index, uint32_t next,
 		const struct spa_pod *param)
 {
 	struct pw_resource *resource = object;
@@ -991,7 +1062,7 @@ static void port_marshal_param(void *object, uint32_t id, uint32_t index, uint32
 			SPA_POD_Int(next),
 			SPA_POD_Pod(param));
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int port_demarshal_param(void *object, void *data, size_t size)
@@ -1009,11 +1080,10 @@ static int port_demarshal_param(void *object, void *data, size_t size)
 				SPA_POD_Pod(&param)) < 0)
 		return -EINVAL;
 
-	pw_proxy_notify(proxy, struct pw_port_proxy_events, param, 0, id, index, next, param);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_port_proxy_events, param, 0, id, index, next, param);
 }
 
-static void port_marshal_enum_params(void *object, uint32_t id, uint32_t index, uint32_t num,
+static int port_marshal_enum_params(void *object, uint32_t id, uint32_t index, uint32_t num,
 		const struct spa_pod *filter)
 {
 	struct pw_proxy *proxy = object;
@@ -1027,7 +1097,7 @@ static void port_marshal_enum_params(void *object, uint32_t id, uint32_t index,
 			SPA_POD_Int(num),
 			SPA_POD_Pod(filter));
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
 static int port_demarshal_enum_params(void *object, void *data, size_t size)
@@ -1045,11 +1115,10 @@ static int port_demarshal_enum_params(void *object, void *data, size_t size)
 				SPA_POD_Pod(&filter)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_port_proxy_methods, enum_params, 0, id, index, num, filter);
-	return 0;
+	return pw_resource_do(resource, struct pw_port_proxy_methods, enum_params, 0, id, index, num, filter);
 }
 
-static void client_marshal_info(void *object, const struct pw_client_info *info)
+static int client_marshal_info(void *object, const struct pw_client_info *info)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -1065,7 +1134,7 @@ static void client_marshal_info(void *object, const struct pw_client_info *info)
 	push_dict(b, info->props);
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int client_demarshal_info(void *object, void *data, size_t size)
@@ -1097,11 +1166,10 @@ static int client_demarshal_info(void *object, void *data, size_t size)
 				       SPA_POD_String(&props.items[i].value), NULL) < 0)
 			return -EINVAL;
 	}
-	pw_proxy_notify(proxy, struct pw_client_proxy_events, info, 0, &info);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_client_proxy_events, info, 0, &info);
 }
 
-static void client_marshal_permissions(void *object, uint32_t index, uint32_t n_permissions,
+static int client_marshal_permissions(void *object, uint32_t index, uint32_t n_permissions,
 		const struct pw_permission *permissions)
 {
 	struct pw_resource *resource = object;
@@ -1130,7 +1198,7 @@ static void client_marshal_permissions(void *object, uint32_t index, uint32_t n_
 	spa_pod_builder_pop(b, &f[1]);
 	spa_pod_builder_pop(b, &f[0]);
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int client_demarshal_permissions(void *object, void *data, size_t size)
@@ -1159,11 +1227,10 @@ static int client_demarshal_permissions(void *object, void *data, size_t size)
 				SPA_POD_Int(&permissions[i].permissions), NULL) < 0)
 			return -EINVAL;
 	}
-	pw_proxy_notify(proxy, struct pw_client_proxy_events, permissions, 0, index, n_permissions, permissions);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_client_proxy_events, permissions, 0, index, n_permissions, permissions);
 }
 
-static void client_marshal_error(void *object, uint32_t id, int res, const char *error)
+static int client_marshal_error(void *object, uint32_t id, int res, const char *error)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_builder *b;
@@ -1173,7 +1240,7 @@ static void client_marshal_error(void *object, uint32_t id, int res, const char
 			       SPA_POD_Int(id),
 			       SPA_POD_Int(res),
 			       SPA_POD_String(error));
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
 static int client_demarshal_error(void *object, void *data, size_t size)
@@ -1190,11 +1257,10 @@ static int client_demarshal_error(void *object, void *data, size_t size)
 				SPA_POD_String(&error)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_client_proxy_methods, error, 0, id, res, error);
-	return 0;
+	return pw_resource_do(resource, struct pw_client_proxy_methods, error, 0, id, res, error);
 }
 
-static void client_marshal_get_permissions(void *object, uint32_t index, uint32_t num)
+static int client_marshal_get_permissions(void *object, uint32_t index, uint32_t num)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_builder *b;
@@ -1205,10 +1271,10 @@ static void client_marshal_get_permissions(void *object, uint32_t index, uint32_
 			SPA_POD_Int(index),
 			SPA_POD_Int(num));
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
-static void client_marshal_update_properties(void *object, const struct spa_dict *props)
+static int client_marshal_update_properties(void *object, const struct spa_dict *props)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_builder *b;
@@ -1220,7 +1286,7 @@ static void client_marshal_update_properties(void *object, const struct spa_dict
 	push_dict(b, props);
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
 static int client_demarshal_update_properties(void *object, void *data, size_t size)
@@ -1245,9 +1311,8 @@ static int client_demarshal_update_properties(void *object, void *data, size_t s
 				SPA_POD_String(&props.items[i].value), NULL) < 0)
 			return -EINVAL;
 	}
-	pw_resource_do(resource, struct pw_client_proxy_methods, update_properties, 0,
+	return pw_resource_do(resource, struct pw_client_proxy_methods, update_properties, 0,
 			&props);
-	return 0;
 }
 
 static int client_demarshal_get_permissions(void *object, void *data, size_t size)
@@ -1262,11 +1327,10 @@ static int client_demarshal_get_permissions(void *object, void *data, size_t siz
 				SPA_POD_Int(&num)) < 0)
 		return -EINVAL;
 
-	pw_resource_do(resource, struct pw_client_proxy_methods, get_permissions, 0, index, num);
-	return 0;
+	return pw_resource_do(resource, struct pw_client_proxy_methods, get_permissions, 0, index, num);
 }
 
-static void client_marshal_update_permissions(void *object, uint32_t n_permissions,
+static int client_marshal_update_permissions(void *object, uint32_t n_permissions,
 		const struct pw_permission *permissions)
 {
 	struct pw_proxy *proxy = object;
@@ -1284,7 +1348,7 @@ static void client_marshal_update_permissions(void *object, uint32_t n_permissio
 	}
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
 static int client_demarshal_update_permissions(void *object, void *data, size_t size)
@@ -1308,12 +1372,11 @@ static int client_demarshal_update_permissions(void *object, void *data, size_t
 				SPA_POD_Int(&permissions[i].permissions), NULL) < 0)
 			return -EINVAL;
 	}
-	pw_resource_do(resource, struct pw_client_proxy_methods, update_permissions, 0,
+	return pw_resource_do(resource, struct pw_client_proxy_methods, update_permissions, 0,
 			n_permissions, permissions);
-	return 0;
 }
 
-static void link_marshal_info(void *object, const struct pw_link_info *info)
+static int link_marshal_info(void *object, const struct pw_link_info *info)
 {
 	struct pw_resource *resource = object;
 	struct spa_pod_builder *b;
@@ -1336,7 +1399,7 @@ static void link_marshal_info(void *object, const struct pw_link_info *info)
 	push_dict(b, info->props);
 	spa_pod_builder_pop(b, &f);
 
-	pw_protocol_native_end_resource(resource, b);
+	return pw_protocol_native_end_resource(resource, b);
 }
 
 static int link_demarshal_info(void *object, void *data, size_t size)
@@ -1375,8 +1438,7 @@ static int link_demarshal_info(void *object, void *data, size_t size)
 				       SPA_POD_String(&props.items[i].value), NULL) < 0)
 			return -EINVAL;
 	}
-	pw_proxy_notify(proxy, struct pw_link_proxy_events, info, 0, &info);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_link_proxy_events, info, 0, &info);
 }
 
 static int registry_demarshal_global(void *object, void *data, size_t size)
@@ -1410,10 +1472,9 @@ static int registry_demarshal_global(void *object, void *data, size_t size)
 			return -EINVAL;
 	}
 
-	pw_proxy_notify(proxy, struct pw_registry_proxy_events,
+	return pw_proxy_notify(proxy, struct pw_registry_proxy_events,
 			global, 0, id, parent_id, permissions, type, version,
 			props.n_items > 0 ? &props : NULL);
-	return 0;
 }
 
 static int registry_demarshal_global_remove(void *object, void *data, size_t size)
@@ -1427,11 +1488,10 @@ static int registry_demarshal_global_remove(void *object, void *data, size_t siz
 				SPA_POD_Int(&id)) < 0)
 		return -EINVAL;
 
-	pw_proxy_notify(proxy, struct pw_registry_proxy_events, global_remove, 0, id);
-	return 0;
+	return pw_proxy_notify(proxy, struct pw_registry_proxy_events, global_remove, 0, id);
 }
 
-static void registry_marshal_bind(void *object, uint32_t id,
+static int registry_marshal_bind(void *object, uint32_t id,
 				  uint32_t type, uint32_t version, uint32_t new_id)
 {
 	struct pw_proxy *proxy = object;
@@ -1445,10 +1505,10 @@ static void registry_marshal_bind(void *object, uint32_t id,
 			       SPA_POD_Int(version),
 			       SPA_POD_Int(new_id));
 
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
-static void registry_marshal_destroy(void *object, uint32_t id)
+static int registry_marshal_destroy(void *object, uint32_t id)
 {
 	struct pw_proxy *proxy = object;
 	struct spa_pod_builder *b;
@@ -1456,39 +1516,45 @@ static void registry_marshal_destroy(void *object, uint32_t id)
 	b = pw_protocol_native_begin_proxy(proxy, PW_REGISTRY_PROXY_METHOD_DESTROY);
 	spa_pod_builder_add_struct(b,
 			       SPA_POD_Int(id));
-	pw_protocol_native_end_proxy(proxy, b);
+	return pw_protocol_native_end_proxy(proxy, b);
 }
 
 static const struct pw_core_proxy_methods pw_protocol_native_core_method_marshal = {
 	PW_VERSION_CORE_PROXY_METHODS,
-	&core_marshal_hello,
-	&core_marshal_sync,
-	&core_marshal_get_registry,
-	&core_marshal_create_object,
-	&core_marshal_destroy,
+	&core_method_marshal_hello,
+	&core_method_marshal_sync,
+	&core_method_marshal_done,
+	&core_method_marshal_error,
+	&core_method_marshal_get_registry,
+	&core_method_marshal_create_object,
+	&core_method_marshal_destroy,
 };
 
 static const struct pw_protocol_native_demarshal pw_protocol_native_core_method_demarshal[PW_CORE_PROXY_METHOD_NUM] = {
-	{ &core_demarshal_hello, 0, },
-	{ &core_demarshal_sync, 0, },
-	{ &core_demarshal_get_registry, 0, },
-	{ &core_demarshal_create_object, 0, },
-	{ &core_demarshal_destroy, 0, }
+	{ &core_method_demarshal_hello, 0, },
+	{ &core_method_demarshal_sync, 0, },
+	{ &core_method_demarshal_done, 0, },
+	{ &core_method_demarshal_error, 0, },
+	{ &core_method_demarshal_get_registry, 0, },
+	{ &core_method_demarshal_create_object, 0, },
+	{ &core_method_demarshal_destroy, 0, }
 };
 
 static const struct pw_core_proxy_events pw_protocol_native_core_event_marshal = {
 	PW_VERSION_CORE_PROXY_EVENTS,
-	&core_marshal_done,
-	&core_marshal_error,
-	&core_marshal_remove_id,
-	&core_marshal_info
+	&core_event_marshal_info,
+	&core_event_marshal_done,
+	&core_event_marshal_sync,
+	&core_event_marshal_error,
+	&core_event_marshal_remove_id,
 };
 
 static const struct pw_protocol_native_demarshal pw_protocol_native_core_event_demarshal[PW_CORE_PROXY_EVENT_NUM] = {
-	{ &core_demarshal_done, 0, },
-	{ &core_demarshal_error, 0, },
-	{ &core_demarshal_remove_id, 0, },
-	{ &core_demarshal_info, 0, },
+	{ &core_event_demarshal_info, 0, },
+	{ &core_event_demarshal_done, 0, },
+	{ &core_event_demarshal_sync, 0, },
+	{ &core_event_demarshal_error, 0, },
+	{ &core_event_demarshal_remove_id, 0, },
 };
 
 static const struct pw_protocol_marshal pw_protocol_native_core_marshal = {

src/modules/spa/spa-monitor.c

@@ -242,7 +242,7 @@ static void change_item(struct pw_spa_monitor *this, struct spa_pod *item, uint6
 	}
 }
 
-static void on_monitor_event(void *data, struct spa_event *event)
+static int on_monitor_event(void *data, struct spa_event *event)
 {
 	struct impl *impl = data;
 	struct pw_spa_monitor *this = &impl->this;
@@ -265,6 +265,7 @@ static void on_monitor_event(void *data, struct spa_event *event)
 		change_item(this, item, now_nsec);
 		break;
 	}
+	return 0;
 }
 
 static void update_monitor(struct pw_core *core, const char *name)

src/pipewire/client.c

@@ -102,7 +102,7 @@ client_permission_func(struct pw_global *global,
 	return p->permissions;
 }
 
-static void client_error(void *object, uint32_t id, int res, const char *error)
+static int client_error(void *object, uint32_t id, int res, const char *error)
 {
 	struct pw_resource *resource = object;
 	struct resource_data *data = pw_resource_get_user_data(resource);
@@ -112,24 +112,25 @@ static void client_error(void *object, uint32_t id, int res, const char *error)
 
 	global = pw_core_find_global(client->core, id);
 	if (global == NULL)
-		return;
+		return -ENOENT;
 
 	spa_list_for_each_safe(r, t, &global->resource_list, link) {
 		if (t->client != client)
 			continue;
 		pw_resource_error(r, res, error);
 	}
+	return 0;
 }
 
-static void client_update_properties(void *object, const struct spa_dict *props)
+static int client_update_properties(void *object, const struct spa_dict *props)
 {
 	struct pw_resource *resource = object;
 	struct resource_data *data = pw_resource_get_user_data(resource);
 	struct pw_client *client = data->client;
-	pw_client_update_properties(client, props);
+	return pw_client_update_properties(client, props);
 }
 
-static void client_get_permissions(void *object, uint32_t index, uint32_t num)
+static int client_get_permissions(void *object, uint32_t index, uint32_t num)
 {
 	struct pw_resource *resource = object;
 	struct resource_data *data = pw_resource_get_user_data(resource);
@@ -143,17 +144,17 @@ static void client_get_permissions(void *object, uint32_t index, uint32_t num)
 	else if ((size_t)index + (size_t)num >= len)
 		num = len - index;
 
-	pw_client_resource_permissions(resource, index,
+	return pw_client_resource_permissions(resource, index,
 			num, pw_array_get_unchecked(&impl->permissions, index, struct pw_permission));
 }
 
-static void client_update_permissions(void *object,
+static int client_update_permissions(void *object,
 		uint32_t n_permissions, const struct pw_permission *permissions)
 {
 	struct pw_resource *resource = object;
 	struct resource_data *data = pw_resource_get_user_data(resource);
 	struct pw_client *client = data->client;
-	pw_client_update_permissions(client, n_permissions, permissions);
+	return pw_client_update_permissions(client, n_permissions, permissions);
 }
 
 static const struct pw_client_proxy_methods client_methods = {

src/pipewire/core.c

@@ -57,8 +57,8 @@ struct resource_data {
 
 /** \endcond */
 
-static void registry_bind(void *object, uint32_t id,
-			  uint32_t type, uint32_t version, uint32_t new_id)
+static int registry_bind(void *object, uint32_t id,
+		uint32_t type, uint32_t version, uint32_t new_id)
 {
 	struct pw_resource *resource = object;
 	struct pw_client *client = resource->client;
@@ -83,7 +83,7 @@ static void registry_bind(void *object, uint32_t id,
 	if (pw_global_bind(global, client, permissions, version, new_id) < 0)
 		goto exit;
 
-	return;
+	return 0;
 
       no_id:
 	pw_log_debug("registry %p: no global with id %u to bind to %u", resource, id, new_id);
@@ -99,9 +99,10 @@ static void registry_bind(void *object, uint32_t id,
 	 * new_id as 'used and freed' */
 	pw_map_insert_at(&client->objects, new_id, NULL);
 	pw_core_resource_remove_id(client->core_resource, new_id);
+	return -EFAULT;
 }
 
-static void registry_destroy(void *object, uint32_t id)
+static int registry_destroy(void *object, uint32_t id)
 {
 	struct pw_resource *resource = object;
 	struct pw_client *client = resource->client;
@@ -120,13 +121,13 @@ static void registry_destroy(void *object, uint32_t id)
 	pw_log_debug("global %p: destroy global id %d", global, id);
 
 	pw_global_destroy(global);
-	return;
+	return 0;
 
       no_id:
 	pw_log_debug("registry %p: no global with id %u to destroy", resource, id);
 	goto exit;
       exit:
-	return;
+	return -EFAULT;
 }
 
 static const struct pw_registry_proxy_methods registry_methods = {
@@ -146,26 +147,56 @@ static const struct pw_resource_events resource_events = {
 	.destroy = destroy_registry_resource
 };
 
-static void core_hello(void *object, uint32_t version)
+static int core_hello(void *object, uint32_t version)
 {
 	struct pw_resource *resource = object;
 	struct pw_core *this = resource->core;
 
-	pw_log_debug("core %p: hello %d from source %p", this, version, resource);
-
+	pw_log_debug("core %p: hello %d from resource %p", this, version, resource);
 	this->info.change_mask = PW_CORE_CHANGE_MASK_ALL;
 	pw_core_resource_info(resource, &this->info);
+	return 0;
 }
 
-static void core_sync(void *object, uint32_t seq)
+static int core_sync(void *object, uint32_t id, uint32_t seq)
 {
 	struct pw_resource *resource = object;
-
-	pw_log_debug("core %p: sync %d from resource %p", resource->core, seq, resource);
-	pw_core_resource_done(resource, seq);
+	pw_log_debug("core %p: sync %d for resource %d", resource->core, seq, id);
+	pw_core_resource_done(resource, id, seq);
+	return 0;
 }
 
-static void core_get_registry(void *object, uint32_t version, uint32_t new_id)
+static int core_done(void *object, uint32_t id, uint32_t seq)
+{
+	struct pw_resource *resource = object;
+	struct pw_client *client = resource->client;
+	struct pw_resource *r;
+
+	pw_log_debug("core %p: done %d for resource %d", resource->core, seq, id);
+
+	if ((r = pw_client_find_resource(client, id)) == NULL)
+		return -EINVAL;
+
+	pw_resource_events_done(r, seq);
+	return 0;
+}
+
+static int core_error(void *object, uint32_t id, int res, const char *message)
+{
+	struct pw_resource *resource = object;
+	struct pw_client *client = resource->client;
+	struct pw_resource *r;
+
+	pw_log_debug("core %p: error %d for resource %d: %s", resource->core, res, id, message);
+
+	if ((r = pw_client_find_resource(client, id)) == NULL)
+		return -EINVAL;
+
+	pw_resource_events_error(r, res, message);
+	return 0;
+}
+
+static int core_get_registry(void *object, uint32_t version, uint32_t new_id)
 {
 	struct pw_resource *resource = object;
 	struct pw_client *client = resource->client;
@@ -209,16 +240,17 @@ static void core_get_registry(void *object, uint32_t version, uint32_t new_id)
 		}
 	}
 
-	return;
+	return 0;
 
       no_mem:
 	pw_log_error("can't create registry resource");
 	pw_core_resource_error(client->core_resource, new_id, -ENOMEM, "no memory");
 	pw_map_insert_at(&client->objects, new_id, NULL);
 	pw_core_resource_remove_id(client->core_resource, new_id);
+	return -ENOMEM;
 }
 
-static void
+static int
 core_create_object(void *object,
 		   const char *factory_name,
 		   uint32_t type,
@@ -231,6 +263,7 @@ core_create_object(void *object,
 	struct pw_factory *factory;
 	void *obj;
 	struct pw_properties *properties;
+	int res;
 
 	factory = pw_core_find_factory(client->core, factory_name);
 	if (factory == NULL || factory->global == NULL)
@@ -255,32 +288,34 @@ core_create_object(void *object,
 	/* error will be posted */
 	obj = pw_factory_create_object(factory, resource, type, version, properties, new_id);
 	if (obj == NULL)
-		goto error;
+		goto create_failed;
 
-	return;
+	return 0;
 
       no_factory:
+	res = -EINVAL;
 	pw_log_error("can't find node factory %s", factory_name);
-	pw_resource_error(resource, -EINVAL, "unknown factory name %s", factory_name);
+	pw_resource_error(resource, res, "unknown factory name %s", factory_name);
 	goto error;
       wrong_version:
       wrong_type:
+	res = -EPROTO;
 	pw_log_error("invalid resource type/version");
-	pw_resource_error(resource, -EINVAL, "wrong resource type/version");
+	pw_resource_error(resource, res, "wrong resource type/version");
 	goto error;
       no_properties:
+	res = -errno;
 	pw_log_error("can't create properties");
-	goto no_mem;
-      no_mem:
-	pw_resource_error(resource, -ENOMEM, "no memory");
-	goto error;
+	pw_resource_error(resource, res, "no memory");
+      create_failed:
+	res = -errno;
       error:
 	pw_map_insert_at(&client->objects, new_id, NULL);
 	pw_core_resource_remove_id(client->core_resource, new_id);
-	return;
+	return res;
 }
 
-static void core_destroy(void *object, uint32_t id)
+static int core_destroy(void *object, uint32_t id)
 {
 	struct pw_resource *resource = object;
 	struct pw_client *client = resource->client;
@@ -292,20 +327,20 @@ static void core_destroy(void *object, uint32_t id)
 		goto no_resource;
 
 	pw_resource_destroy(r);
-
-      done:
-	return;
+	return 0;
 
       no_resource:
 	pw_log_error("can't find resouce %d", id);
 	pw_resource_error(resource, -EINVAL, "unknown resource %d", id);
-	goto done;
+	return -EINVAL;
 }
 
 static const struct pw_core_proxy_methods core_methods = {
 	PW_VERSION_CORE_PROXY_METHODS,
 	.hello = core_hello,
 	.sync = core_sync,
+	.done = core_done,
+	.error = core_error,
 	.get_registry = core_get_registry,
 	.create_object = core_create_object,
 	.destroy = core_destroy,

src/pipewire/device.c

@@ -158,7 +158,7 @@ static int reply_param(void *data, uint32_t id, uint32_t index, uint32_t next, s
 	return 0;
 }
 
-static void device_enum_params(void *object, uint32_t id, uint32_t start, uint32_t num,
+static int device_enum_params(void *object, uint32_t id, uint32_t start, uint32_t num,
                              const struct spa_pod *filter)
 {
 	struct pw_resource *resource = object;
@@ -170,9 +170,10 @@ static void device_enum_params(void *object, uint32_t id, uint32_t start, uint32
 				filter, reply_param, resource)) < 0)
 		pw_core_resource_error(resource->client->core_resource,
 				resource->id, res, spa_strerror(res));
+	return res;
 }
 
-static void device_set_param(void *object, uint32_t id, uint32_t flags,
+static int device_set_param(void *object, uint32_t id, uint32_t flags,
                            const struct spa_pod *param)
 {
 	struct pw_resource *resource = object;
@@ -183,6 +184,7 @@ static void device_set_param(void *object, uint32_t id, uint32_t flags,
 	if ((res = spa_device_set_param(device->implementation, id, flags, param)) < 0)
 		pw_core_resource_error(resource->client->core_resource,
 				resource->id, res, spa_strerror(res));
+	return res;
 }
 
 static const struct pw_device_proxy_methods device_methods = {
@@ -288,11 +290,12 @@ static const struct pw_node_events node_events = {
 };
 
 
-static void device_info(void *data, const struct spa_device_info *info)
+static int device_info(void *data, const struct spa_device_info *info)
 {
 	struct pw_device *device = data;
 	if (info->change_mask & SPA_DEVICE_CHANGE_MASK_INFO)
 		pw_device_update_properties(device, info->info);
+	return 0;
 }
 
 static void device_add(struct pw_device *device, uint32_t id,
@@ -366,7 +369,7 @@ static struct node_data *find_node(struct pw_device *device, uint32_t id)
 	return NULL;
 }
 
-static void device_object_info(void *data, uint32_t id,
+static int device_object_info(void *data, uint32_t id,
 		const struct spa_device_object_info *info)
 {
 	struct pw_device *device = data;
@@ -390,6 +393,7 @@ static void device_object_info(void *data, uint32_t id,
 	else {
 		device_add(device, id, info);
 	}
+	return 0;
 }
 
 

src/pipewire/interfaces.h

@@ -71,10 +71,12 @@ struct pw_link_proxy;
 
 #define PW_CORE_PROXY_METHOD_HELLO		0
 #define PW_CORE_PROXY_METHOD_SYNC		1
-#define PW_CORE_PROXY_METHOD_GET_REGISTRY	2
-#define PW_CORE_PROXY_METHOD_CREATE_OBJECT	3
-#define PW_CORE_PROXY_METHOD_DESTROY		4
-#define PW_CORE_PROXY_METHOD_NUM		5
+#define PW_CORE_PROXY_METHOD_DONE		2
+#define PW_CORE_PROXY_METHOD_ERROR		3
+#define PW_CORE_PROXY_METHOD_GET_REGISTRY	4
+#define PW_CORE_PROXY_METHOD_CREATE_OBJECT	5
+#define PW_CORE_PROXY_METHOD_DESTROY		6
+#define PW_CORE_PROXY_METHOD_NUM		7
 
 #define PW_LINK_OUTPUT_NODE_ID	"link.output_node.id"
 #define PW_LINK_OUTPUT_PORT_ID	"link.output_port.id"
@@ -96,17 +98,44 @@ struct pw_core_proxy_methods {
 	 * Start a conversation with the server. This will send
 	 * the core info..
 	 */
-	void (*hello) (void *object, uint32_t version);
+	int (*hello) (void *object, uint32_t version);
 	/**
 	 * Do server roundtrip
 	 *
-	 * Ask the server to emit the 'done' event with \a id.
+	 * Ask the server to emit the 'done' event with \a seq.
+	 *
 	 * Since methods are handled in-order and events are delivered
 	 * in-order, this can be used as a barrier to ensure all previous
 	 * methods and the resulting events have been handled.
-	 * \param seq the sequence number passed to the done event
+	 *
+	 * \param seq the seq number passed to the done event
 	 */
-	void (*sync) (void *object, uint32_t seq);
+	int (*sync) (void *object, uint32_t id, uint32_t seq);
+	/**
+	 * Reply to a server sync event.
+	 *
+	 * Reply to the server sync event with the same seq.
+	 *
+	 * \param seq the seq number received in the sync event
+	 */
+	int (*done) (void *object, uint32_t id, uint32_t seq);
+	/**
+	 * Fatal error event
+         *
+         * The error method is sent out when a fatal (non-recoverable)
+         * error has occurred. The id argument is the proxy object where
+         * the error occurred, most often in response to an event on that
+         * object. The message is a brief description of the error,
+         * for (debugging) convenience.
+	 *
+	 * This method is usually also emited on the resource object with
+	 * \a id.
+	 *
+         * \param id object where the error occurred
+         * \param res error code
+         * \param message error description
+	 */
+	int (*error) (void *object, uint32_t id, int res, const char *message);
 	/**
 	 * Get the registry object
 	 *
@@ -115,7 +144,7 @@ struct pw_core_proxy_methods {
 	 * \param version the client proxy id
 	 * \param id the client proxy id
 	 */
-	void (*get_registry) (void *object, uint32_t version, uint32_t new_id);
+	int (*get_registry) (void *object, uint32_t version, uint32_t new_id);
 	/**
 	 * Create a new object on the PipeWire server from a factory.
 	 *
@@ -125,7 +154,7 @@ struct pw_core_proxy_methods {
 	 * \param props extra properties
 	 * \param new_id the client proxy id
 	 */
-	void (*create_object) (void *object,
+	int (*create_object) (void *object,
 			       const char *factory_name,
 			       uint32_t type,
 			       uint32_t version,
@@ -138,19 +167,51 @@ struct pw_core_proxy_methods {
 	 *
 	 * \param id the client proxy id to destroy
 	 */
-	void (*destroy) (void *object, uint32_t id);
+	int (*destroy) (void *object, uint32_t id);
 };
 
-static inline void
+static inline int
 pw_core_proxy_hello(struct pw_core_proxy *core, uint32_t version)
 {
-	pw_proxy_do((struct pw_proxy*)core, struct pw_core_proxy_methods, hello, version);
+	return pw_proxy_do((struct pw_proxy*)core, struct pw_core_proxy_methods, hello, version);
 }
 
-static inline void
-pw_core_proxy_sync(struct pw_core_proxy *core, uint32_t seq)
+static inline int
+pw_core_proxy_sync(struct pw_core_proxy *core, uint32_t id, uint32_t seq)
 {
-	pw_proxy_do((struct pw_proxy*)core, struct pw_core_proxy_methods, sync, seq);
+	return pw_proxy_do((struct pw_proxy*)core, struct pw_core_proxy_methods, sync, id, seq);
+}
+
+static inline int
+pw_core_proxy_done(struct pw_core_proxy *core, uint32_t id, uint32_t seq)
+{
+	return pw_proxy_do((struct pw_proxy*)core, struct pw_core_proxy_methods, done, id, seq);
+}
+
+static inline int
+pw_core_proxy_error(struct pw_core_proxy *core, uint32_t id, int res, const char *message)
+{
+	return pw_proxy_do((struct pw_proxy*)core, struct pw_core_proxy_methods, error, id, res, message);
+}
+
+static inline int
+pw_core_proxy_errorv(struct pw_core_proxy *core, uint32_t id, int res, const char *message, va_list args)
+{
+	char buffer[1024];
+	vsnprintf(buffer, sizeof(buffer), message, args);
+	buffer[1023] = '\0';
+	return pw_core_proxy_error(core, id, res, buffer);
+}
+
+static inline int
+pw_core_proxy_errorf(struct pw_core_proxy *core, uint32_t id, int res, const char *message, ...)
+{
+        va_list args;
+	int r;
+	va_start(args, message);
+	r = pw_core_proxy_errorv(core, id, res, message, args);
+	va_end(args);
+	return r;
 }
 
 static inline struct pw_registry_proxy *
@@ -175,17 +236,18 @@ pw_core_proxy_create_object(struct pw_core_proxy *core,
 	return p;
 }
 
-static inline void
+static inline int
 pw_core_proxy_destroy(struct pw_core_proxy *core, struct pw_proxy *proxy)
 {
-	pw_proxy_do((struct pw_proxy*)core, struct pw_core_proxy_methods, destroy, pw_proxy_get_id(proxy));
+	return pw_proxy_do((struct pw_proxy*)core, struct pw_core_proxy_methods, destroy, pw_proxy_get_id(proxy));
 }
 
-#define PW_CORE_PROXY_EVENT_DONE         0
-#define PW_CORE_PROXY_EVENT_ERROR        1
-#define PW_CORE_PROXY_EVENT_REMOVE_ID    2
-#define PW_CORE_PROXY_EVENT_INFO         3
-#define PW_CORE_PROXY_EVENT_NUM          4
+#define PW_CORE_PROXY_EVENT_INFO	0
+#define PW_CORE_PROXY_EVENT_DONE	1
+#define PW_CORE_PROXY_EVENT_SYNC	2
+#define PW_CORE_PROXY_EVENT_ERROR	3
+#define PW_CORE_PROXY_EVENT_REMOVE_ID	4
+#define PW_CORE_PROXY_EVENT_NUM		5
 
 /** \struct pw_core_proxy_events
  *  \brief Core events
@@ -194,14 +256,33 @@ pw_core_proxy_destroy(struct pw_core_proxy *core, struct pw_proxy *proxy)
 struct pw_core_proxy_events {
 #define PW_VERSION_CORE_PROXY_EVENTS	0
 	uint32_t version;
+
+	/**
+	 * Notify new core info
+	 *
+	 * This event is emited when first bound to the core or when the
+	 * hello method is called.
+	 *
+	 * \param info new core info
+	 */
+	int (*info) (void *object, const struct pw_core_info *info);
 	/**
 	 * Emit a done event
 	 *
 	 * The done event is emited as a result of a sync method with the
-	 * same sequence number.
-	 * \param seq the sequence number passed to the sync method call
+	 * same seq number.
+	 *
+	 * \param seq the seq number passed to the sync method call
 	 */
-	void (*done) (void *object, uint32_t seq);
+	int (*done) (void *object, uint32_t id, uint32_t seq);
+
+	/** Emit a sync event
+	 *
+	 * The client should reply with a done reply with the same seq
+	 * number.
+	 */
+	int (*sync) (void *object, uint32_t id, uint32_t seq);
+
 	/**
 	 * Fatal error event
          *
@@ -218,7 +299,7 @@ struct pw_core_proxy_events {
          * \param res error code
          * \param message error description
 	 */
-	void (*error) (void *object, uint32_t id, int res, const char *message);
+	int (*error) (void *object, uint32_t id, int res, const char *message);
 	/**
 	 * Remove an object ID
          *
@@ -230,13 +311,7 @@ struct pw_core_proxy_events {
 	 *
          * \param id deleted object ID
 	 */
-	void (*remove_id) (void *object, uint32_t id);
-	/**
-	 * Notify new core info
-	 *
-	 * \param info new core info
-	 */
-	void (*info) (void *object, const struct pw_core_info *info);
+	int (*remove_id) (void *object, uint32_t id);
 };
 
 static inline void
@@ -249,27 +324,29 @@ pw_core_proxy_add_listener(struct pw_core_proxy *core,
 }
 
 
+#define pw_core_resource_info(r,...)         pw_resource_notify(r,struct pw_core_proxy_events,info,__VA_ARGS__)
 #define pw_core_resource_done(r,...)         pw_resource_notify(r,struct pw_core_proxy_events,done,__VA_ARGS__)
+#define pw_core_resource_sync(r,...)         pw_resource_notify(r,struct pw_core_proxy_events,sync,__VA_ARGS__)
 #define pw_core_resource_error(r,...)        pw_resource_notify(r,struct pw_core_proxy_events,error,__VA_ARGS__)
 #define pw_core_resource_remove_id(r,...)    pw_resource_notify(r,struct pw_core_proxy_events,remove_id,__VA_ARGS__)
-#define pw_core_resource_info(r,...)         pw_resource_notify(r,struct pw_core_proxy_events,info,__VA_ARGS__)
 
-static inline void
+static inline int
 pw_core_resource_errorv(struct pw_resource *resource, uint32_t id, int res, const char *message, va_list args)
 {
 	char buffer[1024];
 	vsnprintf(buffer, sizeof(buffer), message, args);
 	buffer[1023] = '\0';
-	pw_core_resource_error(resource, id, res, buffer);
+	return pw_core_resource_error(resource, id, res, buffer);
 }
 
-static inline void
+static inline int
 pw_core_resource_errorf(struct pw_resource *resource, uint32_t id, int res, const char *message, ...)
 {
         va_list args;
 	va_start(args, message);
-	pw_core_resource_errorv(resource, id, res, message, args);
+	res = pw_core_resource_errorv(resource, id, res, message, args);
 	va_end(args);
+	return res;
 }
 
 #define PW_VERSION_REGISTRY			0
@@ -325,7 +402,7 @@ struct pw_registry_proxy_methods {
 	 * \param version the interface version to use
 	 * \param new_id the client proxy to use
 	 */
-	void (*bind) (void *object, uint32_t id, uint32_t type, uint32_t version, uint32_t new_id);
+	int (*bind) (void *object, uint32_t id, uint32_t type, uint32_t version, uint32_t new_id);
 
 	/**
 	 * Attempt to destroy a global object
@@ -334,7 +411,7 @@ struct pw_registry_proxy_methods {
 	 *
 	 * \param id the global id to destroy
 	 */
-	void (*destroy) (void *object, uint32_t id);
+	int (*destroy) (void *object, uint32_t id);
 };
 
 /** Registry */
@@ -349,11 +426,11 @@ pw_registry_proxy_bind(struct pw_registry_proxy *registry,
 	return p;
 }
 
-static inline void
+static inline int
 pw_registry_proxy_destroy(struct pw_registry_proxy *registry, uint32_t id)
 {
 	struct pw_proxy *reg = (struct pw_proxy*)registry;
-	pw_proxy_do(reg, struct pw_registry_proxy_methods, destroy, id);
+	return pw_proxy_do(reg, struct pw_registry_proxy_methods, destroy, id);
 }
 
 #define PW_REGISTRY_PROXY_EVENT_GLOBAL             0
@@ -377,9 +454,9 @@ struct pw_registry_proxy_events {
 	 * \param version the version of the interface
 	 * \param props extra properties of the global
 	 */
-	void (*global) (void *object, uint32_t id, uint32_t parent_id,
-			uint32_t permissions, uint32_t type, uint32_t version,
-			const struct spa_dict *props);
+	int (*global) (void *object, uint32_t id, uint32_t parent_id,
+		       uint32_t permissions, uint32_t type, uint32_t version,
+		       const struct spa_dict *props);
 	/**
 	 * Notify of a global object removal
 	 *
@@ -389,7 +466,7 @@ struct pw_registry_proxy_events {
 	 *
 	 * \param id the id of the global that was removed
 	 */
-	void (*global_remove) (void *object, uint32_t id);
+	int (*global_remove) (void *object, uint32_t id);
 };
 
 static inline void
@@ -427,7 +504,7 @@ struct pw_module_proxy_events {
 	 *
 	 * \param info info about the module
 	 */
-	void (*info) (void *object, const struct pw_module_info *info);
+	int (*info) (void *object, const struct pw_module_info *info);
 };
 
 static inline void
@@ -463,8 +540,8 @@ struct pw_device_proxy_methods {
 	 * \param num the maximum number of params to retrieve
 	 * \param filter a param filter or NULL
 	 */
-	void (*enum_params) (void *object, uint32_t id, uint32_t start, uint32_t num,
-			     const struct spa_pod *filter);
+	int (*enum_params) (void *object, uint32_t id, uint32_t start, uint32_t num,
+			    const struct spa_pod *filter);
 	/**
 	 * Set a parameter on the device
 	 *
@@ -472,23 +549,23 @@ struct pw_device_proxy_methods {
 	 * \param flags extra parameter flags
 	 * \param param the parameter to set
 	 */
-	void (*set_param) (void *object, uint32_t id, uint32_t flags,
-			   const struct spa_pod *param);
+	int (*set_param) (void *object, uint32_t id, uint32_t flags,
+			  const struct spa_pod *param);
 };
 
-static inline void
+static inline int
 pw_device_proxy_enum_params(struct pw_device_proxy *device, uint32_t id, uint32_t index,
 		uint32_t num, const struct spa_pod *filter)
 {
-	pw_proxy_do((struct pw_proxy*)device, struct pw_device_proxy_methods, enum_params,
+	return pw_proxy_do((struct pw_proxy*)device, struct pw_device_proxy_methods, enum_params,
 			id, index, num, filter);
 }
 
-static inline void
+static inline int
 pw_device_proxy_set_param(struct pw_device_proxy *device, uint32_t id, uint32_t flags,
 		const struct spa_pod *param)
 {
-	pw_proxy_do((struct pw_proxy*)device, struct pw_device_proxy_methods, set_param,
+	return pw_proxy_do((struct pw_proxy*)device, struct pw_device_proxy_methods, set_param,
 			id, flags, param);
 }
 
@@ -505,7 +582,7 @@ struct pw_device_proxy_events {
 	 *
 	 * \param info info about the device
 	 */
-	void (*info) (void *object, const struct pw_device_info *info);
+	int (*info) (void *object, const struct pw_device_info *info);
 	/**
 	 * Notify a device param
 	 *
@@ -516,9 +593,9 @@ struct pw_device_proxy_events {
 	 * \param next the param index of the next param
 	 * \param param the parameter
 	 */
-	void (*param) (void *object,
-		       uint32_t id, uint32_t index, uint32_t next,
-		       const struct spa_pod *param);
+	int (*param) (void *object,
+		      uint32_t id, uint32_t index, uint32_t next,
+		      const struct spa_pod *param);
 };
 
 static inline void
@@ -555,7 +632,7 @@ struct pw_node_proxy_methods {
 	 * \param num the maximum number of params to retrieve
 	 * \param filter a param filter or NULL
 	 */
-	void (*enum_params) (void *object, uint32_t id, uint32_t start, uint32_t num,
+	int (*enum_params) (void *object, uint32_t id, uint32_t start, uint32_t num,
 			const struct spa_pod *filter);
 
 	/**
@@ -565,7 +642,7 @@ struct pw_node_proxy_methods {
 	 * \param flags extra parameter flags
 	 * \param param the parameter to set
 	 */
-	void (*set_param) (void *object, uint32_t id, uint32_t flags,
+	int (*set_param) (void *object, uint32_t id, uint32_t flags,
 			const struct spa_pod *param);
 
 	/**
@@ -573,30 +650,30 @@ struct pw_node_proxy_methods {
 	 *
 	 * \param command the command to send
 	 */
-	void (*send_command) (void *object, const struct spa_command *command);
+	int (*send_command) (void *object, const struct spa_command *command);
 };
 
 /** Node */
-static inline void
+static inline int
 pw_node_proxy_enum_params(struct pw_node_proxy *node, uint32_t id, uint32_t index,
 		uint32_t num, const struct spa_pod *filter)
 {
-	pw_proxy_do((struct pw_proxy*)node, struct pw_node_proxy_methods, enum_params,
+	return pw_proxy_do((struct pw_proxy*)node, struct pw_node_proxy_methods, enum_params,
 			id, index, num, filter);
 }
 
-static inline void
+static inline int
 pw_node_proxy_set_param(struct pw_node_proxy *node, uint32_t id, uint32_t flags,
 		const struct spa_pod *param)
 {
-	pw_proxy_do((struct pw_proxy*)node, struct pw_node_proxy_methods, set_param,
+	return pw_proxy_do((struct pw_proxy*)node, struct pw_node_proxy_methods, set_param,
 			id, flags, param);
 }
 
-static inline void
+static inline int
 pw_node_proxy_send_command(struct pw_node_proxy *node, const struct spa_command *command)
 {
-	pw_proxy_do((struct pw_proxy*)node, struct pw_node_proxy_methods, send_command,
+	return pw_proxy_do((struct pw_proxy*)node, struct pw_node_proxy_methods, send_command,
 			command);
 }
 
@@ -613,7 +690,7 @@ struct pw_node_proxy_events {
 	 *
 	 * \param info info about the node
 	 */
-	void (*info) (void *object, const struct pw_node_info *info);
+	int (*info) (void *object, const struct pw_node_info *info);
 	/**
 	 * Notify a node param
 	 *
@@ -624,9 +701,9 @@ struct pw_node_proxy_events {
 	 * \param next the param index of the next param
 	 * \param param the parameter
 	 */
-	void (*param) (void *object,
-		       uint32_t id, uint32_t index, uint32_t next,
-		       const struct spa_pod *param);
+	int (*param) (void *object,
+		      uint32_t id, uint32_t index, uint32_t next,
+		      const struct spa_pod *param);
 };
 
 static inline void
@@ -662,16 +739,16 @@ struct pw_port_proxy_methods {
 	 * \param num the maximum number of params to retrieve
 	 * \param filter a param filter or NULL
 	 */
-	void (*enum_params) (void *object, uint32_t id, uint32_t start, uint32_t num,
+	int (*enum_params) (void *object, uint32_t id, uint32_t start, uint32_t num,
 			const struct spa_pod *filter);
 };
 
 /** Port params */
-static inline void
+static inline int
 pw_port_proxy_enum_params(struct pw_port_proxy *port, uint32_t id, uint32_t index,
 		uint32_t num, const struct spa_pod *filter)
 {
-	pw_proxy_do((struct pw_proxy*)port, struct pw_port_proxy_methods, enum_params,
+	return pw_proxy_do((struct pw_proxy*)port, struct pw_port_proxy_methods, enum_params,
 			id, index, num, filter);
 }
 
@@ -688,7 +765,7 @@ struct pw_port_proxy_events {
 	 *
 	 * \param info info about the port
 	 */
-	void (*info) (void *object, const struct pw_port_info *info);
+	int (*info) (void *object, const struct pw_port_info *info);
 	/**
 	 * Notify a port param
 	 *
@@ -699,7 +776,7 @@ struct pw_port_proxy_events {
 	 * \param next the param index of the next param
 	 * \param param the parameter
 	 */
-	void (*param) (void *object,
+	int (*param) (void *object,
 		       uint32_t id, uint32_t index, uint32_t next,
 		       const struct spa_pod *param);
 };
@@ -738,7 +815,7 @@ struct pw_factory_proxy_events {
 	 *
 	 * \param info info about the factory
 	 */
-	void (*info) (void *object, const struct pw_factory_info *info);
+	int (*info) (void *object, const struct pw_factory_info *info);
 };
 
 /** Factory */
@@ -773,13 +850,13 @@ struct pw_client_proxy_methods {
 	 * \param res an errno style error code
 	 * \param message an error string
 	 */
-	void (*error) (void *object, uint32_t id, int res, const char *message);
+	int (*error) (void *object, uint32_t id, int res, const char *message);
 	/**
 	 * Update client properties
 	 *
 	 * \param props new properties
 	 */
-	void (*update_properties) (void *object, const struct spa_dict *props);
+	int (*update_properties) (void *object, const struct spa_dict *props);
 
 	/**
 	 * Get client permissions
@@ -789,7 +866,7 @@ struct pw_client_proxy_methods {
 	 * \param index the first index to query, 0 for first
 	 * \param num the maximum number of items to get
 	 */
-	void (*get_permissions) (void *object, uint32_t index, uint32_t num);
+	int (*get_permissions) (void *object, uint32_t index, uint32_t num);
 	/**
 	 * Manage the permissions of the global objects for this
 	 * client
@@ -803,34 +880,34 @@ struct pw_client_proxy_methods {
 	 * \param n_permissions number of permissions
 	 * \param permissions array of permissions
 	 */
-	void (*update_permissions) (void *object, uint32_t n_permissions,
+	int (*update_permissions) (void *object, uint32_t n_permissions,
 			const struct pw_permission *permissions);
 };
 
 /** Client permissions */
-static inline void
+static inline int
 pw_client_proxy_error(struct pw_client_proxy *client, uint32_t id, int res, const char *message)
 {
-	pw_proxy_do((struct pw_proxy*)client, struct pw_client_proxy_methods, error, id, res, message);
+	return pw_proxy_do((struct pw_proxy*)client, struct pw_client_proxy_methods, error, id, res, message);
 }
 
-static inline void
+static inline int
 pw_client_proxy_update_properties(struct pw_client_proxy *client, const struct spa_dict *props)
 {
-	pw_proxy_do((struct pw_proxy*)client, struct pw_client_proxy_methods, update_properties, props);
+	return pw_proxy_do((struct pw_proxy*)client, struct pw_client_proxy_methods, update_properties, props);
 }
 
-static inline void
+static inline int
 pw_client_proxy_get_permissions(struct pw_client_proxy *client, uint32_t index, uint32_t num)
 {
-	pw_proxy_do((struct pw_proxy*)client, struct pw_client_proxy_methods, get_permissions, index, num);
+	return pw_proxy_do((struct pw_proxy*)client, struct pw_client_proxy_methods, get_permissions, index, num);
 }
 
-static inline void
+static inline int
 pw_client_proxy_update_permissions(struct pw_client_proxy *client, uint32_t n_permissions,
                         const struct pw_permission *permissions)
 {
-	pw_proxy_do((struct pw_proxy*)client, struct pw_client_proxy_methods, update_permissions,
+	return pw_proxy_do((struct pw_proxy*)client, struct pw_client_proxy_methods, update_permissions,
 			n_permissions, permissions);
 }
 
@@ -847,7 +924,7 @@ struct pw_client_proxy_events {
 	 *
 	 * \param info info about the client
 	 */
-	void (*info) (void *object, const struct pw_client_info *info);
+	int (*info) (void *object, const struct pw_client_info *info);
 	/**
 	 * Notify a client permission
 	 *
@@ -858,7 +935,7 @@ struct pw_client_proxy_events {
 	 * \param n_permissions the number of permissions
 	 * \param permissions the permissions
 	 */
-	void (*permissions) (void *object,
+	int (*permissions) (void *object,
 			     uint32_t index,
 			     uint32_t n_permissions,
 			     const struct pw_permission *permissions);
@@ -899,7 +976,7 @@ struct pw_link_proxy_events {
 	 *
 	 * \param info info about the link
 	 */
-	void (*info) (void *object, const struct pw_link_info *info);
+	int (*info) (void *object, const struct pw_link_info *info);
 };
 
 /** Link */

src/pipewire/link.c

@@ -298,9 +298,11 @@ static int do_negotiate(struct pw_link *this, uint32_t in_state, uint32_t out_st
 			asprintf(&error, "error set output format: %d (%s)", res, spa_strerror(res));
 			goto error;
 		}
-		if (SPA_RESULT_IS_ASYNC(res))
+		if (SPA_RESULT_IS_ASYNC(res)) {
+			spa_node_sync(output->node->node, res);
 			pw_work_queue_add(impl->work, output->node, res, complete_ready,
 					  &this->rt.out_mix);
+		}
 	}
 	if (in_mix_state == PW_PORT_STATE_CONFIGURE) {
 		pw_log_debug("link %p: doing set format on input mix", this);
@@ -312,6 +314,7 @@ static int do_negotiate(struct pw_link *this, uint32_t in_state, uint32_t out_st
 			goto error;
 		}
 		if (SPA_RESULT_IS_ASYNC(res2)) {
+			spa_node_sync(input->node->node, res2);
 			pw_work_queue_add(impl->work, input->node, res2, complete_ready,
 					  &this->rt.in_mix);
 			if (res == 0)
@@ -676,9 +679,11 @@ static int do_allocation(struct pw_link *this, uint32_t in_state, uint32_t out_s
 				asprintf(&error, "error alloc output buffers: %d", res);
 				goto error;
 			}
-			if (SPA_RESULT_IS_ASYNC(res))
+			if (SPA_RESULT_IS_ASYNC(res)) {
+				spa_node_sync(output->node->node, res);
 				pw_work_queue_add(impl->work, output->node, res, complete_paused,
 					  &this->rt.out_mix);
+			}
 
 			out_flags &= ~SPA_PORT_FLAG_CAN_USE_BUFFERS;
 			move_allocation(&allocation, &output->allocation);
@@ -694,9 +699,11 @@ static int do_allocation(struct pw_link *this, uint32_t in_state, uint32_t out_s
 				asprintf(&error, "error alloc input buffers: %d", res);
 				goto error;
 			}
-			if (SPA_RESULT_IS_ASYNC(res))
+			if (SPA_RESULT_IS_ASYNC(res)) {
+				spa_node_sync(input->node->node, res);
 				pw_work_queue_add(impl->work, input->node, res, complete_paused,
 					  &this->rt.in_mix);
+			}
 
 			in_flags &= ~SPA_PORT_FLAG_CAN_USE_BUFFERS;
 			pw_log_debug("link %p: allocated %d buffers %p from input port", this,
@@ -715,9 +722,11 @@ static int do_allocation(struct pw_link *this, uint32_t in_state, uint32_t out_s
 					spa_strerror(res));
 			goto error;
 		}
-		if (SPA_RESULT_IS_ASYNC(res))
+		if (SPA_RESULT_IS_ASYNC(res)) {
+			spa_node_sync(output->node->node, res);
 			pw_work_queue_add(impl->work, output->node, res, complete_paused,
 					  &this->rt.out_mix);
+		}
 
 		move_allocation(&allocation, &output->allocation);
 
@@ -733,9 +742,11 @@ static int do_allocation(struct pw_link *this, uint32_t in_state, uint32_t out_s
 					spa_strerror(res));
 			goto error;
 		}
-		if (SPA_RESULT_IS_ASYNC(res))
+		if (SPA_RESULT_IS_ASYNC(res)) {
+			spa_node_sync(input->node->node, res);
 			pw_work_queue_add(impl->work, input->node, res, complete_paused,
 					  &this->rt.in_mix);
+		}
 
 	} else {
 		asprintf(&error, "no common buffer alloc found");

src/pipewire/node.c

@@ -60,6 +60,7 @@ struct impl {
 	struct pw_node_activation node_activation;
 
 	uint32_t next_position;
+	int last_error;
 };
 
 struct resource_data {
@@ -249,7 +250,7 @@ static int reply_param(void *data, uint32_t id, uint32_t index, uint32_t next, s
 	return 0;
 }
 
-static void node_enum_params(void *object, uint32_t id, uint32_t index, uint32_t num,
+static int node_enum_params(void *object, uint32_t id, uint32_t index, uint32_t num,
 		const struct spa_pod *filter)
 {
 	struct pw_resource *resource = object;
@@ -264,9 +265,10 @@ static void node_enum_params(void *object, uint32_t id, uint32_t index, uint32_t
 		pw_core_resource_error(resource->client->core_resource,
 				resource->id, res, spa_strerror(res));
 	}
+	return 0;
 }
 
-static void node_set_param(void *object, uint32_t id, uint32_t flags,
+static int node_set_param(void *object, uint32_t id, uint32_t flags,
 		const struct spa_pod *param)
 {
 	struct pw_resource *resource = object;
@@ -280,9 +282,10 @@ static void node_set_param(void *object, uint32_t id, uint32_t flags,
 		pw_core_resource_error(resource->client->core_resource,
 				resource->id, res, spa_strerror(res));
 	}
+	return 0;
 }
 
-static void node_send_command(void *object, const struct spa_command *command)
+static int node_send_command(void *object, const struct spa_command *command)
 {
 	struct pw_resource *resource = object;
 	struct resource_data *data = pw_resource_get_user_data(resource);
@@ -296,6 +299,7 @@ static void node_send_command(void *object, const struct spa_command *command)
 		spa_node_send_command(node->node, command);
 		break;
 	}
+	return 0;
 }
 
 static const struct pw_node_proxy_methods node_methods = {
@@ -777,16 +781,17 @@ int pw_node_update_properties(struct pw_node *node, const struct spa_dict *dict)
 	return changed;
 }
 
-static void node_info(void *data, const struct spa_node_info *info)
+static int node_info(void *data, const struct spa_node_info *info)
 {
 	struct pw_node *node = data;
 	node->info.max_input_ports = info->max_input_ports;
 	node->info.max_output_ports = info->max_output_ports;
 	if (info->change_mask & SPA_NODE_CHANGE_MASK_PROPS)
 		pw_node_update_properties(node, info->props);
+	return 0;
 }
 
-static void node_port_info(void *data, enum spa_direction direction, uint32_t port_id,
+static int node_port_info(void *data, enum spa_direction direction, uint32_t port_id,
 		const struct spa_port_info *info)
 {
 	struct pw_node *node = data;
@@ -826,27 +831,42 @@ static void node_port_info(void *data, enum spa_direction direction, uint32_t po
 			}
 		}
 	}
+	return 0;
 }
 
-static void node_done(void *data, int seq, int res)
+static int node_error(void *data, int res, const char *message)
 {
 	struct pw_node *node = data;
 	struct impl *impl = SPA_CONTAINER_OF(node, struct impl, this);
 
-	pw_log_debug("node %p: async complete event %d %d %s", node, seq, res, spa_strerror(res));
-	pw_work_queue_complete(impl->work, node, seq, res);
-	pw_node_events_async_complete(node, seq, res);
+	pw_log_debug("node %p: error event %d: %s", node, res, message);
+	impl->last_error = res;
+	node_update_state(node, PW_NODE_STATE_ERROR, strdup(message));
+	return 0;
 }
 
-static void node_event(void *data, struct spa_event *event)
+static int node_done(void *data, uint32_t seq)
+{
+	struct pw_node *node = data;
+	struct impl *impl = SPA_CONTAINER_OF(node, struct impl, this);
+
+	pw_log_debug("node %p: done event %u", node, seq);
+	pw_work_queue_complete(impl->work, node, seq, impl->last_error);
+	pw_node_events_async_complete(node, seq, impl->last_error);
+	impl->last_error = 0;
+	return 0;
+}
+
+static int node_event(void *data, struct spa_event *event)
 {
 	struct pw_node *node = data;
 
 	pw_log_trace("node %p: event %d", node, SPA_EVENT_TYPE(event));
 	pw_node_events_event(node, event);
+	return 0;
 }
 
-static void node_ready(void *data, int status)
+static int node_ready(void *data, int status)
 {
 	struct pw_node *node = data;
 	struct pw_node *driver = node->driver_node;
@@ -855,16 +875,17 @@ static void node_ready(void *data, int status)
 			node->driver, node->exported, driver);
 
 	if (driver->rt.root.graph == NULL)
-		return;
+		return -EINVAL;
 
 	if (status == SPA_STATUS_HAVE_BUFFER)
 		spa_graph_node_process(&driver->rt.root);
 
 	spa_graph_run(driver->rt.driver);
 	spa_graph_link_trigger(&driver->rt.driver_link);
+	return 0;
 }
 
-static void node_reuse_buffer(void *data, uint32_t port_id, uint32_t buffer_id)
+static int node_reuse_buffer(void *data, uint32_t port_id, uint32_t buffer_id)
 {
 	struct pw_node *node = data;
         struct spa_graph_port *p, *pp;
@@ -877,13 +898,15 @@ static void node_reuse_buffer(void *data, uint32_t port_id, uint32_t buffer_id)
 			spa_graph_node_reuse_buffer(pp->node, pp->port_id, buffer_id);
 		break;
 	}
+	return 0;
 }
 
 static const struct spa_node_callbacks node_callbacks = {
 	SPA_VERSION_NODE_CALLBACKS,
+	.done = node_done,
+	.error = node_error,
 	.info = node_info,
 	.port_info = node_port_info,
-	.done = node_done,
 	.event = node_event,
 	.ready = node_ready,
 	.reuse_buffer = node_reuse_buffer,
@@ -1209,6 +1232,9 @@ int pw_node_set_state(struct pw_node *node, enum pw_node_state state)
 	if (SPA_RESULT_IS_ERROR(res))
 		return res;
 
+	if (SPA_RESULT_IS_ASYNC(res))
+		spa_node_sync(node->node, res);
+
 	pw_work_queue_add(impl->work,
 			  node, res, on_state_complete, SPA_INT_TO_PTR(state));
 

src/pipewire/port.c

@@ -467,7 +467,7 @@ static int reply_param(void *data, uint32_t id, uint32_t index, uint32_t next, s
 	return 0;
 }
 
-static void port_enum_params(void *object, uint32_t id, uint32_t index, uint32_t num,
+static int port_enum_params(void *object, uint32_t id, uint32_t index, uint32_t num,
 		const struct spa_pod *filter)
 {
 	struct pw_resource *resource = object;
@@ -479,6 +479,7 @@ static void port_enum_params(void *object, uint32_t id, uint32_t index, uint32_t
 			reply_param, resource)) < 0)
 		pw_core_resource_error(resource->client->core_resource,
 				resource->id, res, spa_strerror(res));
+	return res;
 }
 
 static const struct pw_port_proxy_methods port_methods = {

src/pipewire/private.h

@@ -515,6 +515,8 @@ struct pw_link {
 #define pw_resource_events_emit(o,m,v,...) spa_hook_list_call(&o->listener_list, struct pw_resource_events, m, v, ##__VA_ARGS__)
 
 #define pw_resource_events_destroy(o)	pw_resource_events_emit(o, destroy, 0)
+#define pw_resource_events_done(o,s)	pw_resource_events_emit(o, done, 0, s)
+#define pw_resource_events_error(o,e,m)	pw_resource_events_emit(o, error, 0, e, m)
 
 struct pw_resource {
 	struct pw_core *core;		/**< the core object */
@@ -539,6 +541,7 @@ struct pw_resource {
 
 #define pw_proxy_events_emit(o,m,v,...) spa_hook_list_call(&o->listener_list, struct pw_proxy_events, m, v, ##__VA_ARGS__)
 #define pw_proxy_events_destroy(p)	pw_proxy_events_emit(p, destroy, 0)
+#define pw_proxy_events_done(p,s)	pw_proxy_events_emit(p, done, 0, s)
 #define pw_proxy_events_error(p,r,m)	pw_proxy_events_emit(p, error, 0, r, m)
 
 struct pw_proxy {

src/pipewire/proxy.c

@@ -28,6 +28,7 @@
 #include <pipewire/remote.h>
 #include <pipewire/private.h>
 #include <pipewire/type.h>
+#include <pipewire/interfaces.h>
 
 #include <spa/debug/types.h>
 
@@ -145,6 +146,27 @@ void pw_proxy_destroy(struct pw_proxy *proxy)
 	free(impl);
 }
 
+SPA_EXPORT
+int pw_proxy_sync(struct pw_proxy *proxy, uint32_t seq)
+{
+	int res = -EIO;
+	if (proxy->remote->core_proxy != NULL)
+		res = pw_core_proxy_sync(proxy->remote->core_proxy, proxy->id, seq);
+	return res;
+}
+
+SPA_EXPORT
+int pw_proxy_error(struct pw_proxy *proxy, int result, const char *error, ...)
+{
+	va_list ap;
+	int res = -EIO;
+	va_start(ap, error);
+	if (proxy->remote->core_proxy != NULL)
+		res = pw_core_proxy_errorv(proxy->remote->core_proxy, proxy->id, result, error, ap);
+	va_end(ap);
+	return res;
+}
+
 SPA_EXPORT
 struct spa_hook_list *pw_proxy_get_proxy_listeners(struct pw_proxy *proxy)
 {

src/pipewire/proxy.h

@@ -111,6 +111,9 @@ struct pw_proxy_events {
 	/** The proxy is destroyed */
         void (*destroy) (void *data);
 
+	/** a reply to a sync method completed */
+        void (*done) (void *data, uint32_t seq);
+
 	/** an error occured on the proxy */
         void (*error) (void *data, int res, const char *message);
 };
@@ -147,6 +150,13 @@ uint32_t pw_proxy_get_id(struct pw_proxy *proxy);
 /** Get the protocol used for the proxy */
 struct pw_protocol *pw_proxy_get_protocol(struct pw_proxy *proxy);
 
+/** Generate an sync method for a proxy. This will generate a done event
+ * with the same \a seq. */
+int pw_proxy_sync(struct pw_proxy *proxy, uint32_t seq);
+
+/** Generate an error for a proxy */
+int pw_proxy_error(struct pw_proxy *proxy, int result, const char *error, ...);
+
 /** Get the listener of proxy */
 struct spa_hook_list *pw_proxy_get_proxy_listeners(struct pw_proxy *proxy);
 

src/pipewire/remote.c

@@ -98,8 +98,27 @@ pw_remote_update_state(struct pw_remote *remote, enum pw_remote_state state, con
 	return 0;
 }
 
+static int core_event_sync(void *data, uint32_t id, uint32_t seq)
+{
+	struct pw_remote *this = data;
+	pw_log_debug("remote %p: object %u sync %u", this, id, seq);
+	return pw_core_proxy_done(this->core_proxy, id, seq);
+}
 
-static void core_event_error(void *data, uint32_t id, int res, const char *message)
+static int core_event_done(void *data, uint32_t id, uint32_t seq)
+{
+	struct pw_remote *this = data;
+	struct pw_proxy *proxy;
+
+	pw_log_debug("remote %p: object %u done %u", this, id, seq);
+
+	proxy = pw_map_lookup(&this->objects, id);
+	if (proxy)
+		pw_proxy_events_done(proxy, seq);
+	return 0;
+}
+
+static int core_event_error(void *data, uint32_t id, int res, const char *message)
 {
 	struct pw_remote *this = data;
 	struct pw_proxy *proxy;
@@ -110,9 +129,10 @@ static void core_event_error(void *data, uint32_t id, int res, const char *messa
 	proxy = pw_map_lookup(&this->objects, id);
 	if (proxy)
 		pw_proxy_events_error(proxy, res, message);
+	return 0;
 }
 
-static void core_event_remove_id(void *data, uint32_t id)
+static int core_event_remove_id(void *data, uint32_t id)
 {
 	struct pw_remote *this = data;
 	struct pw_proxy *proxy;
@@ -123,11 +143,14 @@ static void core_event_remove_id(void *data, uint32_t id)
 		pw_proxy_destroy(proxy);
 
 	pw_map_remove(&this->objects, id);
+	return 0;
 }
 
 static const struct pw_core_proxy_events core_proxy_events = {
 	PW_VERSION_CORE_PROXY_EVENTS,
 	.error = core_event_error,
+	.sync = core_event_sync,
+	.done = core_event_done,
 	.remove_id = core_event_remove_id,
 };
 

src/pipewire/resource.c

@@ -170,13 +170,24 @@ const struct pw_protocol_marshal *pw_resource_get_marshal(struct pw_resource *re
 }
 
 SPA_EXPORT
-void pw_resource_error(struct pw_resource *resource, int result, const char *error, ...)
+int pw_resource_sync(struct pw_resource *resource, uint32_t seq)
+{
+	int res = -EIO;
+	if (resource->client->core_resource != NULL)
+		res = pw_core_resource_sync(resource->client->core_resource, resource->id, seq);
+	return res;
+}
+
+SPA_EXPORT
+int pw_resource_error(struct pw_resource *resource, int result, const char *error, ...)
 {
 	va_list ap;
+	int res = -EIO;
 	va_start(ap, error);
-	if (resource->client->core_resource == NULL)
-		pw_core_resource_errorv(resource->client->core_resource, resource->id, result, error, ap);
+	if (resource->client->core_resource != NULL)
+		res = pw_core_resource_errorv(resource->client->core_resource, resource->id, result, error, ap);
 	va_end(ap);
+	return res;
 }
 
 SPA_EXPORT

src/pipewire/resource.h

@@ -67,6 +67,12 @@ struct pw_resource_events {
 
 	/** The resource is destroyed */
 	void (*destroy) (void *data);
+
+	/** a reply to a sync event completed */
+        void (*done) (void *data, uint32_t seq);
+
+	/** an error occured on the resource */
+        void (*error) (void *data, int res, const char *message);
 };
 
 /** Make a new resource for client */
@@ -116,8 +122,12 @@ void pw_resource_add_override(struct pw_resource *resource,
 			      const void *implementation,
 			      void *data);
 
+/** Generate an sync method for a resource. This will generate a done event
+ * with the same \a seq. */
+int pw_resource_sync(struct pw_resource *resource, uint32_t seq);
+
 /** Generate an error for a resource */
-void pw_resource_error(struct pw_resource *resource, int result, const char *error, ...);
+int pw_resource_error(struct pw_resource *resource, int result, const char *error, ...);
 
 /** Get the implementation list of a resource */
 struct spa_hook_list *pw_resource_get_implementation(struct pw_resource *resource);

src/pipewire/stream.c

@@ -452,6 +452,9 @@ static int port_set_format(struct spa_node *node,
 	if (count == 0)
 		pw_stream_finish_format(stream, 0, NULL, 0);
 
+	if (stream->state == PW_STREAM_STATE_ERROR)
+		return -EIO;
+
 	stream_set_state(stream,
 			p ?
 			    PW_STREAM_STATE_READY :
@@ -772,9 +775,16 @@ static void proxy_destroy(void *_data)
 	stream_set_state(stream, PW_STREAM_STATE_UNCONNECTED, NULL);
 }
 
+static void proxy_error(void *_data, int res, const char *message)
+{
+	struct pw_stream *stream = _data;
+	stream_set_state(stream, PW_STREAM_STATE_ERROR, message);
+}
+
 static const struct pw_proxy_events proxy_events = {
 	PW_VERSION_PROXY_EVENTS,
 	.destroy = proxy_destroy,
+	.error = proxy_error,
 };
 
 static int handle_connect(struct pw_stream *stream)
@@ -1174,6 +1184,12 @@ void pw_stream_finish_format(struct pw_stream *stream,
 
 	pw_log_debug("stream %p: finish format %d %d", stream, res, impl->pending_seq);
 
+	if (res < 0) {
+		pw_proxy_error(stream->proxy, res, "format failed");
+		stream_set_state(stream, PW_STREAM_STATE_ERROR, "format error");
+		return;
+	}
+
 	clear_params(stream, PARAM_TYPE_OTHER);
 	for (i = 0; i < n_params; i++)
 		add_param(stream, PARAM_TYPE_OTHER, params[i]);

src/tests/test-interfaces.c

@@ -37,28 +37,33 @@ static void test_core_abi(void)
 	struct pw_core_proxy_events e;
 	struct {
 		uint32_t version;
-	        void (*hello) (void *object, uint32_t version);
-	        void (*sync) (void *object, uint32_t seq);
-	        void (*get_registry) (void *object, uint32_t version, uint32_t new_id);
-	        void (*create_object) (void *object,
+	        int (*hello) (void *object, uint32_t version);
+	        int (*sync) (void *object, uint32_t id, uint32_t seq);
+	        int (*done) (void *object, uint32_t id, uint32_t seq);
+	        int (*error) (void *object, uint32_t id, int res, const char *error);
+	        int (*get_registry) (void *object, uint32_t version, uint32_t new_id);
+	        int (*create_object) (void *object,
 				       const char *factory_name,
 				       uint32_t type,
 				       uint32_t version,
 				       const struct spa_dict *props,
 				       uint32_t new_id);
-		void (*destroy) (void *object, uint32_t id);
+		int (*destroy) (void *object, uint32_t id);
 	} methods = { PW_VERSION_CORE_PROXY_METHODS, };
 	struct {
 		uint32_t version;
-	        void (*done) (void *object, uint32_t seq);
-	        void (*error) (void *object, uint32_t id, int res, const char *error);
-	        void (*remove_id) (void *object, uint32_t id);
-		void (*info) (void *object, const struct pw_core_info *info);
+		int (*info) (void *object, const struct pw_core_info *info);
+	        int (*done) (void *object, uint32_t id, uint32_t seq);
+	        int (*sync) (void *object, uint32_t id, uint32_t seq);
+	        int (*error) (void *object, uint32_t id, int res, const char *error);
+	        int (*remove_id) (void *object, uint32_t id);
 	} events = { PW_VERSION_CORE_PROXY_EVENTS, };
 
 	TEST_FUNC(m, methods, version);
 	TEST_FUNC(m, methods, hello);
 	TEST_FUNC(m, methods, sync);
+	TEST_FUNC(m, methods, done);
+	TEST_FUNC(e, methods, error);
 	TEST_FUNC(m, methods, get_registry);
 	TEST_FUNC(m, methods, create_object);
 	TEST_FUNC(m, methods, destroy);
@@ -66,10 +71,11 @@ static void test_core_abi(void)
 	spa_assert(sizeof(m) == sizeof(methods));
 
 	TEST_FUNC(e, events, version);
+	TEST_FUNC(e, events, info);
 	TEST_FUNC(e, events, done);
+	TEST_FUNC(e, events, sync);
 	TEST_FUNC(e, events, error);
 	TEST_FUNC(e, events, remove_id);
-	TEST_FUNC(e, events, info);
 	spa_assert(PW_VERSION_CORE_PROXY_EVENTS == 0);
 	spa_assert(sizeof(e) == sizeof(events));
 }
@@ -80,15 +86,15 @@ static void test_registry_abi(void)
 	struct pw_registry_proxy_events e;
 	struct {
 		uint32_t version;
-		void (*bind) (void *object, uint32_t id, uint32_t type, uint32_t version, uint32_t new_id);
-		void (*destroy) (void *object, uint32_t id);
+		int (*bind) (void *object, uint32_t id, uint32_t type, uint32_t version, uint32_t new_id);
+		int (*destroy) (void *object, uint32_t id);
 	} methods = { PW_VERSION_REGISTRY_PROXY_METHODS, };
 	struct {
 		uint32_t version;
-		void (*global) (void *object, uint32_t id, uint32_t parent_id,
+		int (*global) (void *object, uint32_t id, uint32_t parent_id,
 			uint32_t permissions, uint32_t type, uint32_t version,
 			const struct spa_dict *props);
-		void (*global_remove) (void *object, uint32_t id);
+		int (*global_remove) (void *object, uint32_t id);
 	} events = { PW_VERSION_REGISTRY_PROXY_EVENTS, };
 
 	TEST_FUNC(m, methods, version);
@@ -113,7 +119,7 @@ static void test_module_abi(void)
 	} methods = { PW_VERSION_MODULE_PROXY_METHODS, };
 	struct {
 		uint32_t version;
-		void (*info) (void *object, const struct pw_module_info *info);
+		int (*info) (void *object, const struct pw_module_info *info);
 	} events = { PW_VERSION_MODULE_PROXY_EVENTS, };
 
 	TEST_FUNC(m, methods, version);
@@ -132,15 +138,15 @@ static void test_device_abi(void)
 	struct pw_device_proxy_events e;
 	struct {
 		uint32_t version;
-		void (*enum_params) (void *object, uint32_t id, uint32_t start, uint32_t num,
+		int (*enum_params) (void *object, uint32_t id, uint32_t start, uint32_t num,
 			const struct spa_pod *filter);
-		void (*set_param) (void *object, uint32_t id, uint32_t flags,
+		int (*set_param) (void *object, uint32_t id, uint32_t flags,
 			const struct spa_pod *param);
 	} methods = { PW_VERSION_DEVICE_PROXY_METHODS, };
 	struct {
 		uint32_t version;
-		void (*info) (void *object, const struct pw_device_info *info);
-		void (*param) (void *object,
+		int (*info) (void *object, const struct pw_device_info *info);
+		int (*param) (void *object,
 			uint32_t id, uint32_t index, uint32_t next,
 			const struct spa_pod *param);
 	} events = { PW_VERSION_DEVICE_PROXY_EVENTS, };
@@ -164,16 +170,16 @@ static void test_node_abi(void)
 	struct pw_node_proxy_events e;
 	struct {
 		uint32_t version;
-		void (*enum_params) (void *object, uint32_t id, uint32_t start, uint32_t num,
+		int (*enum_params) (void *object, uint32_t id, uint32_t start, uint32_t num,
                         const struct spa_pod *filter);
-		void (*set_param) (void *object, uint32_t id, uint32_t flags,
+		int (*set_param) (void *object, uint32_t id, uint32_t flags,
 			const struct spa_pod *param);
-		void (*send_command) (void *object, const struct spa_command *command);
+		int (*send_command) (void *object, const struct spa_command *command);
 	} methods = { PW_VERSION_NODE_PROXY_METHODS, };
 	struct {
 		uint32_t version;
-		void (*info) (void *object, const struct pw_node_info *info);
-		void (*param) (void *object,
+		int (*info) (void *object, const struct pw_node_info *info);
+		int (*param) (void *object,
 			uint32_t id, uint32_t index, uint32_t next,
 			const struct spa_pod *param);
 	} events = { PW_VERSION_NODE_PROXY_EVENTS, };
@@ -198,13 +204,13 @@ static void test_port_abi(void)
 	struct pw_port_proxy_events e;
 	struct {
 		uint32_t version;
-		void (*enum_params) (void *object, uint32_t id, uint32_t start, uint32_t num,
+		int (*enum_params) (void *object, uint32_t id, uint32_t start, uint32_t num,
                         const struct spa_pod *filter);
 	} methods = { PW_VERSION_PORT_PROXY_METHODS, };
 	struct {
 		uint32_t version;
-		void (*info) (void *object, const struct pw_port_info *info);
-		void (*param) (void *object,
+		int (*info) (void *object, const struct pw_port_info *info);
+		int (*param) (void *object,
 			uint32_t id, uint32_t index, uint32_t next,
 			const struct spa_pod *param);
 	} events = { PW_VERSION_PORT_PROXY_EVENTS, };
@@ -230,7 +236,7 @@ static void test_factory_abi(void)
 	} methods = { PW_VERSION_FACTORY_PROXY_METHODS, };
 	struct {
 		uint32_t version;
-		void (*info) (void *object, const struct pw_factory_info *info);
+		int (*info) (void *object, const struct pw_factory_info *info);
 	} events = { PW_VERSION_FACTORY_PROXY_EVENTS, };
 
 	TEST_FUNC(m, methods, version);
@@ -249,16 +255,16 @@ static void test_client_abi(void)
 	struct pw_client_proxy_events e;
 	struct {
 		uint32_t version;
-		void (*error) (void *object, uint32_t id, int res, const char *error);
-		void (*update_properties) (void *object, const struct spa_dict *props);
-		void (*get_permissions) (void *object, uint32_t index, uint32_t num);
-		void (*update_permissions) (void *object, uint32_t n_permissions,
+		int (*error) (void *object, uint32_t id, int res, const char *error);
+		int (*update_properties) (void *object, const struct spa_dict *props);
+		int (*get_permissions) (void *object, uint32_t index, uint32_t num);
+		int (*update_permissions) (void *object, uint32_t n_permissions,
 			const struct pw_permission *permissions);
 	} methods = { PW_VERSION_CLIENT_PROXY_METHODS, };
 	struct {
 		uint32_t version;
-		void (*info) (void *object, const struct pw_client_info *info);
-		void (*permissions) (void *object, uint32_t index,
+		int (*info) (void *object, const struct pw_client_info *info);
+		int (*permissions) (void *object, uint32_t index,
 			uint32_t n_permissions, const struct pw_permission *permissions);
 	} events = { PW_VERSION_CLIENT_PROXY_EVENTS, };
 
@@ -285,7 +291,7 @@ static void test_link_abi(void)
 	} methods = { PW_VERSION_LINK_PROXY_METHODS, };
 	struct {
 		uint32_t version;
-		void (*info) (void *object, const struct pw_link_info *info);
+		int (*info) (void *object, const struct pw_link_info *info);
 	} events = { PW_VERSION_LINK_PROXY_EVENTS, };
 
 	TEST_FUNC(m, methods, version);

src/tools/pipewire-cli.c

@@ -242,12 +242,13 @@ static bool do_load_module(struct data *data, const char *cmd, char *args, char
 	return true;
 }
 
-static void on_core_info(void *_data, const struct pw_core_info *info)
+static int on_core_info(void *_data, const struct pw_core_info *info)
 {
 	struct remote_data *rd = _data;
 	free(rd->name);
 	rd->name = strdup(info->name);
 	fprintf(stdout, "remote %d is named '%s'\n", rd->id, rd->name);
+	return 0;
 }
 
 static void show_prompt(struct remote_data *rd)
@@ -256,7 +257,7 @@ static void show_prompt(struct remote_data *rd)
 	fflush(stdout);
 }
 
-static void on_core_done(void *_data, uint32_t seq)
+static int on_core_done(void *_data, uint32_t id, uint32_t seq)
 {
 	struct remote_data *rd = _data;
 
@@ -267,6 +268,7 @@ static void on_core_done(void *_data, uint32_t seq)
 	default:
 		break;
 	}
+	return 0;
 }
 
 static int print_global(void *obj, void *data)
@@ -285,9 +287,9 @@ static int print_global(void *obj, void *data)
 	return 0;
 }
 
-static void registry_event_global(void *data, uint32_t id, uint32_t parent_id,
-				  uint32_t permissions, uint32_t type, uint32_t version,
-				  const struct spa_dict *props)
+static int registry_event_global(void *data, uint32_t id, uint32_t parent_id,
+		uint32_t permissions, uint32_t type, uint32_t version,
+		const struct spa_dict *props)
 {
 	struct remote_data *rd = data;
 	struct global *global;
@@ -309,6 +311,7 @@ static void registry_event_global(void *data, uint32_t id, uint32_t parent_id,
 	while (id > size)
 		pw_map_insert_at(&rd->globals, size++, NULL);
 	pw_map_insert_at(&rd->globals, id, global);
+	return 0;
 }
 
 static int destroy_global(void *obj, void *data)
@@ -325,7 +328,7 @@ static int destroy_global(void *obj, void *data)
 	return 0;
 }
 
-static void registry_event_global_remove(void *data, uint32_t id)
+static int registry_event_global_remove(void *data, uint32_t id)
 {
 	struct remote_data *rd = data;
 	struct global *global;
@@ -333,12 +336,13 @@ static void registry_event_global_remove(void *data, uint32_t id)
 	global = pw_map_lookup(&rd->globals, id);
 	if (global == NULL) {
 		fprintf(stdout, "remote %d removed unknown global %d\n", rd->id, id);
-		return;
+		return -EINVAL;
 	}
 
 	fprintf(stdout, "remote %d removed global: ", rd->id);
 	print_global(global, NULL);
 	destroy_global(global, rd);
+	return 0;
 }
 
 static const struct pw_registry_proxy_events registry_events = {
@@ -392,7 +396,7 @@ static void on_state_changed(void *_data, enum pw_remote_state old,
 		pw_registry_proxy_add_listener(rd->registry_proxy,
 					       &rd->registry_listener,
 					       &registry_events, rd);
-		pw_core_proxy_sync(rd->core_proxy, 1);
+		pw_core_proxy_sync(rd->core_proxy, 0, 1);
 		break;
 
 	default:
@@ -627,7 +631,7 @@ static void info_device(struct proxy_data *pd)
 	info->change_mask = 0;
 }
 
-static void core_event_info(void *object, const struct pw_core_info *info)
+static int core_event_info(void *object, const struct pw_core_info *info)
 {
 	struct proxy_data *pd = object;
 	struct remote_data *rd = pd->rd;
@@ -640,6 +644,7 @@ static void core_event_info(void *object, const struct pw_core_info *info)
 		info_core(pd);
 		pd->global->info_pending = false;
 	}
+	return 0;
 }
 
 static const struct pw_core_proxy_events core_events = {
@@ -648,7 +653,7 @@ static const struct pw_core_proxy_events core_events = {
 };
 
 
-static void module_event_info(void *object, const struct pw_module_info *info)
+static int module_event_info(void *object, const struct pw_module_info *info)
 {
 	struct proxy_data *pd = object;
 	struct remote_data *rd = pd->rd;
@@ -661,6 +666,7 @@ static void module_event_info(void *object, const struct pw_module_info *info)
 		info_module(pd);
 		pd->global->info_pending = false;
 	}
+	return 0;
 }
 
 static const struct pw_module_proxy_events module_events = {
@@ -668,7 +674,7 @@ static const struct pw_module_proxy_events module_events = {
 	.info = module_event_info
 };
 
-static void node_event_info(void *object, const struct pw_node_info *info)
+static int node_event_info(void *object, const struct pw_node_info *info)
 {
 	struct proxy_data *pd = object;
 	struct remote_data *rd = pd->rd;
@@ -681,9 +687,10 @@ static void node_event_info(void *object, const struct pw_node_info *info)
 		info_node(pd);
 		pd->global->info_pending = false;
 	}
+	return 0;
 }
 
-static void node_event_param(void *object, uint32_t id, uint32_t index, uint32_t next,
+static int node_event_param(void *object, uint32_t id, uint32_t index, uint32_t next,
 		const struct spa_pod *param)
 {
         struct proxy_data *data = object;
@@ -696,6 +703,7 @@ static void node_event_param(void *object, uint32_t id, uint32_t index, uint32_t
 		spa_debug_format(2, NULL, param);
 	else
 		spa_debug_pod(2, NULL, param);
+	return 0;
 }
 
 static const struct pw_node_proxy_events node_events = {
@@ -705,7 +713,7 @@ static const struct pw_node_proxy_events node_events = {
 };
 
 
-static void port_event_info(void *object, const struct pw_port_info *info)
+static int port_event_info(void *object, const struct pw_port_info *info)
 {
 	struct proxy_data *pd = object;
 	struct remote_data *rd = pd->rd;
@@ -718,9 +726,10 @@ static void port_event_info(void *object, const struct pw_port_info *info)
 		info_port(pd);
 		pd->global->info_pending = false;
 	}
+	return 0;
 }
 
-static void port_event_param(void *object, uint32_t id, uint32_t index, uint32_t next,
+static int port_event_param(void *object, uint32_t id, uint32_t index, uint32_t next,
 		const struct spa_pod *param)
 {
         struct proxy_data *data = object;
@@ -733,6 +742,7 @@ static void port_event_param(void *object, uint32_t id, uint32_t index, uint32_t
 		spa_debug_format(2, NULL, param);
 	else
 		spa_debug_pod(2, NULL, param);
+	return 0;
 }
 
 static const struct pw_port_proxy_events port_events = {
@@ -741,7 +751,7 @@ static const struct pw_port_proxy_events port_events = {
 	.param = port_event_param
 };
 
-static void factory_event_info(void *object, const struct pw_factory_info *info)
+static int factory_event_info(void *object, const struct pw_factory_info *info)
 {
 	struct proxy_data *pd = object;
 	struct remote_data *rd = pd->rd;
@@ -754,6 +764,7 @@ static void factory_event_info(void *object, const struct pw_factory_info *info)
 		info_factory(pd);
 		pd->global->info_pending = false;
 	}
+	return 0;
 }
 
 static const struct pw_factory_proxy_events factory_events = {
@@ -761,7 +772,7 @@ static const struct pw_factory_proxy_events factory_events = {
 	.info = factory_event_info
 };
 
-static void client_event_info(void *object, const struct pw_client_info *info)
+static int client_event_info(void *object, const struct pw_client_info *info)
 {
 	struct proxy_data *pd = object;
 	struct remote_data *rd = pd->rd;
@@ -774,9 +785,10 @@ static void client_event_info(void *object, const struct pw_client_info *info)
 		info_client(pd);
 		pd->global->info_pending = false;
 	}
+	return 0;
 }
 
-static void client_event_permissions(void *object, uint32_t index,
+static int client_event_permissions(void *object, uint32_t index,
 		uint32_t n_permissions, const struct pw_permission *permissions)
 {
         struct proxy_data *data = object;
@@ -793,6 +805,7 @@ static void client_event_permissions(void *object, uint32_t index,
 			fprintf(stdout, "  %u:", permissions[i].id);
 		fprintf(stdout, " %08x\n", permissions[i].permissions);
 	}
+	return 0;
 }
 
 static const struct pw_client_proxy_events client_events = {
@@ -801,7 +814,7 @@ static const struct pw_client_proxy_events client_events = {
 	.permissions = client_event_permissions
 };
 
-static void link_event_info(void *object, const struct pw_link_info *info)
+static int link_event_info(void *object, const struct pw_link_info *info)
 {
 	struct proxy_data *pd = object;
 	struct remote_data *rd = pd->rd;
@@ -814,6 +827,7 @@ static void link_event_info(void *object, const struct pw_link_info *info)
 		info_link(pd);
 		pd->global->info_pending = false;
 	}
+	return 0;
 }
 
 static const struct pw_link_proxy_events link_events = {
@@ -822,7 +836,7 @@ static const struct pw_link_proxy_events link_events = {
 };
 
 
-static void device_event_info(void *object, const struct pw_device_info *info)
+static int device_event_info(void *object, const struct pw_device_info *info)
 {
 	struct proxy_data *pd = object;
 	struct remote_data *rd = pd->rd;
@@ -835,6 +849,7 @@ static void device_event_info(void *object, const struct pw_device_info *info)
 		info_device(pd);
 		pd->global->info_pending = false;
 	}
+	return 0;
 }
 
 static const struct pw_device_proxy_events device_events = {
@@ -1375,7 +1390,7 @@ static void do_input(void *data, int fd, enum spa_io mask)
 		if (d->current == NULL)
 			pw_main_loop_quit(d->loop);
 		else if (d->current->core_proxy)
-			pw_core_proxy_sync(d->current->core_proxy, 1);
+			pw_core_proxy_sync(d->current->core_proxy, 0, 1);
 	}
 }
 

src/tools/pipewire-monitor.c

@@ -82,7 +82,7 @@ static void add_pending(struct proxy_data *pd)
 
 	spa_list_append(&d->pending_list, &pd->pending_link);
 	pd->pending_seq = ++d->seq;
-	pw_core_proxy_sync(d->core_proxy, pd->pending_seq);
+	pw_core_proxy_sync(d->core_proxy, 0, pd->pending_seq);
 }
 
 static void remove_pending(struct proxy_data *pd)
@@ -93,7 +93,7 @@ static void remove_pending(struct proxy_data *pd)
 	}
 }
 
-static void on_core_done(void *data, uint32_t seq)
+static int on_core_done(void *data, uint32_t id, uint32_t seq)
 {
 	struct data *d = data;
 	struct proxy_data *pd, *t;
@@ -104,6 +104,7 @@ static void on_core_done(void *data, uint32_t seq)
 			pd->print_func(pd);
 		}
 	}
+	return 0;
 }
 
 static void clear_params(struct proxy_data *data)
@@ -118,12 +119,15 @@ static void clear_params(struct proxy_data *data)
 	data->params = NULL;
 }
 
-static void add_param(struct proxy_data *data, const struct spa_pod *param)
+static int add_param(struct proxy_data *data, const struct spa_pod *param)
 {
         uint32_t idx = data->n_params++;
 
         data->params = realloc(data->params, sizeof(struct spa_pod *) * data->n_params);
+	if (data->params == NULL)
+		return -ENOMEM;
         data->params[idx] = pw_spa_pod_copy(param);
+	return 0;
 }
 
 static void print_properties(const struct spa_dict *props, char mark)
@@ -146,7 +150,7 @@ static void print_properties(const struct spa_dict *props, char mark)
 
 #define MARK_CHANGE(f) ((print_mark && ((info)->change_mask & (1 << (f)))) ? '*' : ' ')
 
-static void on_core_info(void *data, const struct pw_core_info *info)
+static int on_core_info(void *data, const struct pw_core_info *info)
 {
 	bool print_all = true, print_mark = false;
 
@@ -159,9 +163,10 @@ static void on_core_info(void *data, const struct pw_core_info *info)
 		printf("%c\tname: \"%s\"\n", MARK_CHANGE(3), info->name);
 		print_properties(info->props, MARK_CHANGE(4));
 	}
+	return 0;
 }
 
-static void module_event_info(void *object, const struct pw_module_info *info)
+static int module_event_info(void *object, const struct pw_module_info *info)
 {
         struct proxy_data *data = object;
 	bool print_all, print_mark;
@@ -191,6 +196,7 @@ static void module_event_info(void *object, const struct pw_module_info *info)
 		printf("%c\targs: \"%s\"\n", MARK_CHANGE(2), info->args);
 		print_properties(info->props, MARK_CHANGE(3));
 	}
+	return 0;
 }
 
 static const struct pw_module_proxy_events module_events = {
@@ -247,7 +253,7 @@ static void print_node(struct proxy_data *data)
 	}
 }
 
-static void node_event_info(void *object, const struct pw_node_info *info)
+static int node_event_info(void *object, const struct pw_node_info *info)
 {
         struct proxy_data *data = object;
 	bool is_new = data->info == NULL;
@@ -261,13 +267,14 @@ static void node_event_info(void *object, const struct pw_node_info *info)
 	}
 	if (data->pending_seq == SPA_ID_INVALID)
 		data->print_func(data);
+	return 0;
 }
 
-static void node_event_param(void *object, uint32_t id, uint32_t index, uint32_t next,
+static int node_event_param(void *object, uint32_t id, uint32_t index, uint32_t next,
 		const struct spa_pod *param)
 {
         struct proxy_data *data = object;
-	add_param(data, param);
+	return add_param(data, param);
 }
 
 static const struct pw_node_proxy_events node_events = {
@@ -313,7 +320,7 @@ static void print_port(struct proxy_data *data)
 	}
 }
 
-static void port_event_info(void *object, const struct pw_port_info *info)
+static int port_event_info(void *object, const struct pw_port_info *info)
 {
 
         struct proxy_data *data = object;
@@ -328,13 +335,14 @@ static void port_event_info(void *object, const struct pw_port_info *info)
 	}
 	if (data->pending_seq == SPA_ID_INVALID)
 		data->print_func(data);
+	return 0;
 }
 
-static void port_event_param(void *object, uint32_t id, uint32_t index, uint32_t next,
+static int port_event_param(void *object, uint32_t id, uint32_t index, uint32_t next,
 		const struct spa_pod *param)
 {
         struct proxy_data *data = object;
-	add_param(data, param);
+	return add_param(data, param);
 }
 
 static const struct pw_port_proxy_events port_events = {
@@ -343,7 +351,7 @@ static const struct pw_port_proxy_events port_events = {
         .param = port_event_param
 };
 
-static void factory_event_info(void *object, const struct pw_factory_info *info)
+static int factory_event_info(void *object, const struct pw_factory_info *info)
 {
         struct proxy_data *data = object;
 	bool print_all, print_mark;
@@ -372,6 +380,7 @@ static void factory_event_info(void *object, const struct pw_factory_info *info)
 	if (print_all) {
 		print_properties(info->props, MARK_CHANGE(0));
 	}
+	return 0;
 }
 
 static const struct pw_factory_proxy_events factory_events = {
@@ -379,7 +388,7 @@ static const struct pw_factory_proxy_events factory_events = {
         .info = factory_event_info
 };
 
-static void client_event_info(void *object, const struct pw_client_info *info)
+static int client_event_info(void *object, const struct pw_client_info *info)
 {
         struct proxy_data *data = object;
 	bool print_all, print_mark;
@@ -406,6 +415,7 @@ static void client_event_info(void *object, const struct pw_client_info *info)
 	if (print_all) {
 		print_properties(info->props, MARK_CHANGE(0));
 	}
+	return 0;
 }
 
 static const struct pw_client_proxy_events client_events = {
@@ -413,7 +423,7 @@ static const struct pw_client_proxy_events client_events = {
         .info = client_event_info
 };
 
-static void link_event_info(void *object, const struct pw_link_info *info)
+static int link_event_info(void *object, const struct pw_link_info *info)
 {
         struct proxy_data *data = object;
 	bool print_all, print_mark;
@@ -454,6 +464,7 @@ static void link_event_info(void *object, const struct pw_link_info *info)
 			printf("\t\tnone\n");
 		print_properties(info->props, MARK_CHANGE(4));
 	}
+	return 0;
 }
 
 static const struct pw_link_proxy_events link_events = {
@@ -461,9 +472,7 @@ static const struct pw_link_proxy_events link_events = {
 	.info = link_event_info
 };
 
-
-
-static void device_event_info(void *object, const struct pw_device_info *info)
+static int device_event_info(void *object, const struct pw_device_info *info)
 {
         struct proxy_data *data = object;
 	bool print_all, print_mark;
@@ -490,6 +499,7 @@ static void device_event_info(void *object, const struct pw_device_info *info)
 	if (print_all) {
 		print_properties(info->props, MARK_CHANGE(0));
 	}
+	return 0;
 }
 
 static const struct pw_device_proxy_events device_events = {
@@ -518,7 +528,7 @@ static const struct pw_proxy_events proxy_events = {
 	.destroy = destroy_proxy,
 };
 
-static void registry_event_global(void *data, uint32_t id, uint32_t parent_id,
+static int registry_event_global(void *data, uint32_t id, uint32_t parent_id,
 				  uint32_t permissions, uint32_t type, uint32_t version,
 				  const struct spa_dict *props)
 {
@@ -577,7 +587,7 @@ static void registry_event_global(void *data, uint32_t id, uint32_t parent_id,
 						  permissions & PW_PERM_X ? 'x' : '-');
 		printf("\ttype: %s (version %d)\n", spa_debug_type_find_name(pw_type_info(), type), version);
 		print_properties(props, ' ');
-		return;
+		return 0;
 	}
 
         proxy = pw_registry_proxy_bind(d->registry_proxy, id, type,
@@ -600,18 +610,18 @@ static void registry_event_global(void *data, uint32_t id, uint32_t parent_id,
 	pd->print_func = print_func;
         pw_proxy_add_proxy_listener(proxy, &pd->proxy_proxy_listener, events, pd);
         pw_proxy_add_listener(proxy, &pd->proxy_listener, &proxy_events, pd);
-
-        return;
+        return 0;
 
       no_mem:
         printf("failed to create proxy");
-        return;
+        return -ENOMEM;
 }
 
-static void registry_event_global_remove(void *object, uint32_t id)
+static int registry_event_global_remove(void *object, uint32_t id)
 {
 	printf("removed:\n");
 	printf("\tid: %u\n", id);
+	return 0;
 }
 
 static const struct pw_registry_proxy_events registry_events = {