pipewire/src/pipewire/impl-node.c

/* PipeWire
 *
 * Copyright © 2018 Wim Taymans
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>

#include <spa/support/system.h>
#include <spa/pod/parser.h>
#include <spa/pod/filter.h>
#include <spa/node/utils.h>
#include <spa/debug/types.h>
#include <spa/utils/string.h>

#include "pipewire/impl-node.h"
#include "pipewire/private.h"

#define NAME "node"

#define DEFAULT_SYNC_TIMEOUT  ((uint64_t)(5 * SPA_NSEC_PER_SEC))

/** \cond */
struct impl {
	struct pw_impl_node this;

	enum pw_node_state pending;
	uint32_t pending_id;

	struct pw_work_queue *work;

	int last_error;

	struct spa_list param_list;
	struct spa_list pending_list;

	unsigned int pause_on_idle:1;
	unsigned int cache_params:1;
};

#define pw_node_resource(r,m,v,...)	pw_resource_call(r,struct pw_node_events,m,v,__VA_ARGS__)
#define pw_node_resource_info(r,...)	pw_node_resource(r,info,0,__VA_ARGS__)
#define pw_node_resource_param(r,...)	pw_node_resource(r,param,0,__VA_ARGS__)

struct resource_data {
	struct pw_impl_node *node;

	struct pw_resource *resource;
	struct spa_hook resource_listener;
	struct spa_hook object_listener;

	uint32_t subscribe_ids[MAX_PARAMS];
	uint32_t n_subscribe_ids;

	/* for async replies */
	int seq;
	int end;
	struct spa_hook listener;
};

/** \endcond */

static void node_deactivate(struct pw_impl_node *this)
{
	struct pw_impl_port *port;
	struct pw_impl_link *link;

	pw_log_debug(NAME" %p: deactivate", this);
	spa_list_for_each(port, &this->input_ports, link) {
		spa_list_for_each(link, &port->links, input_link)
			pw_impl_link_deactivate(link);
	}
	spa_list_for_each(port, &this->output_ports, link) {
		spa_list_for_each(link, &port->links, output_link)
			pw_impl_link_deactivate(link);
	}
}

static void add_node(struct pw_impl_node *this, struct pw_impl_node *driver)
{
	struct pw_node_activation_state *dstate, *nstate;
	struct pw_node_target *t;

	if (this->exported)
		return;

	pw_log_trace(NAME" %p: add to driver %p %p %p", this, driver,
			driver->rt.activation, this->rt.activation);

	/* signal the driver */
	this->rt.driver_target.activation = driver->rt.activation;
	this->rt.driver_target.node = driver;
	this->rt.driver_target.data = driver;
	spa_list_append(&this->rt.target_list, &this->rt.driver_target.link);

	spa_list_append(&driver->rt.target_list, &this->rt.target.link);
	nstate = &this->rt.activation->state[0];
	if (!this->rt.target.active) {
		nstate->required++;
		this->rt.target.active = true;
	}

	spa_list_for_each(t, &this->rt.target_list, link) {
		dstate = &t->activation->state[0];
		if (!t->active) {
			dstate->required++;
			t->active = true;
		}
		pw_log_trace(NAME" %p: driver state:%p pending:%d/%d, node state:%p pending:%d/%d",
				this, dstate, dstate->pending, dstate->required,
				nstate, nstate->pending, nstate->required);
	}
}

static void remove_node(struct pw_impl_node *this)
{
	struct pw_node_activation_state *dstate, *nstate;
	struct pw_node_target *t;

	if (this->exported)
		return;

	pw_log_trace(NAME" %p: remove from driver %p %p %p",
			this, this->rt.driver_target.data,
			this->rt.driver_target.activation, this->rt.activation);

	spa_list_remove(&this->rt.target.link);

	nstate = &this->rt.activation->state[0];
	if (this->rt.target.active) {
		nstate->required--;
		this->rt.target.active = false;
	}

	spa_list_for_each(t, &this->rt.target_list, link) {
		dstate = &t->activation->state[0];
		if (t->active) {
			dstate->required--;
			t->active = false;
		}
		pw_log_trace(NAME" %p: driver state:%p pending:%d/%d, node state:%p pending:%d/%d",
				this, dstate, dstate->pending, dstate->required,
				nstate, nstate->pending, nstate->required);
	}
	spa_list_remove(&this->rt.driver_target.link);

	this->rt.driver_target.node = NULL;
}

static int
do_node_remove(struct spa_loop *loop,
	       bool async, uint32_t seq, const void *data, size_t size, void *user_data)
{
	struct pw_impl_node *this = user_data;
	if (this->source.loop != NULL) {
		spa_loop_remove_source(loop, &this->source);
		remove_node(this);
	}
	return 0;
}

static int pause_node(struct pw_impl_node *this)
{
	struct impl *impl = SPA_CONTAINER_OF(this, struct impl, this);
	int res = 0;

	pw_log_debug(NAME" %p: pause node state:%s pause-on-idle:%d", this,
			pw_node_state_as_string(this->info.state), impl->pause_on_idle);

	if (impl->pending <= PW_NODE_STATE_IDLE)
		return 0;

	node_deactivate(this);

	pw_loop_invoke(this->data_loop, do_node_remove, 1, NULL, 0, true, this);

	res = spa_node_send_command(this->node,
				    &SPA_NODE_COMMAND_INIT(SPA_NODE_COMMAND_Pause));
	if (res < 0)
		pw_log_debug(NAME" %p: pause node error %s", this, spa_strerror(res));

	return res;
}

static int start_node(struct pw_impl_node *this)
{
	struct impl *impl = SPA_CONTAINER_OF(this, struct impl, this);
	int res = 0;

	if (impl->pending >= PW_NODE_STATE_RUNNING)
		return 0;

	pw_log_debug(NAME" %p: start node", this);

	if (!(this->driving && this->driver))
		res = spa_node_send_command(this->node,
			&SPA_NODE_COMMAND_INIT(SPA_NODE_COMMAND_Start));

	if (res < 0)
		pw_log_error("(%s-%u) start node error %d: %s", this->name, this->info.id,
				res, spa_strerror(res));

	return res;
}

static void emit_info_changed(struct pw_impl_node *node, bool flags_changed)
{
	if (node->info.change_mask == 0 && !flags_changed)
		return;

	pw_impl_node_emit_info_changed(node, &node->info);

	if (node->global && node->info.change_mask != 0) {
		struct pw_resource *resource;
		spa_list_for_each(resource, &node->global->resource_list, link)
			pw_node_resource_info(resource, &node->info);
	}

	node->info.change_mask = 0;
}

static int resource_is_subscribed(struct pw_resource *resource, uint32_t id)
{
	struct resource_data *data = pw_resource_get_user_data(resource);
	uint32_t i;

	for (i = 0; i < data->n_subscribe_ids; i++) {
		if (data->subscribe_ids[i] == id)
			return 1;
	}
	return 0;
}

static int notify_param(void *data, int seq, uint32_t id,
		uint32_t index, uint32_t next, struct spa_pod *param)
{
	struct pw_impl_node *node = data;
	struct pw_resource *resource;

	spa_list_for_each(resource, &node->global->resource_list, link) {
		if (!resource_is_subscribed(resource, id))
			continue;

		pw_log_debug(NAME" %p: resource %p notify param %d", node, resource, id);
		pw_node_resource_param(resource, seq, id, index, next, param);
	}
	return 0;
}

static void emit_params(struct pw_impl_node *node, uint32_t *changed_ids, uint32_t n_changed_ids)
{
	uint32_t i;
	int res;

	if (node->global == NULL)
		return;

	pw_log_debug(NAME" %p: emit %d params", node, n_changed_ids);

	for (i = 0; i < n_changed_ids; i++) {
		struct pw_resource *resource;
		int subscribed = 0;

		/* first check if anyone is subscribed */
		spa_list_for_each(resource, &node->global->resource_list, link) {
			if ((subscribed = resource_is_subscribed(resource, changed_ids[i])))
				break;
		}
		if (!subscribed)
			continue;

		if ((res = pw_impl_node_for_each_param(node, 1, changed_ids[i], 0, UINT32_MAX,
					NULL, notify_param, node)) < 0) {
			pw_log_error(NAME" %p: error %d (%s)", node, res, spa_strerror(res));
		}
	}
}

static int
do_node_add(struct spa_loop *loop,
	    bool async, uint32_t seq, const void *data, size_t size, void *user_data)
{
	struct pw_impl_node *this = user_data;
	struct pw_impl_node *driver = this->driver_node;

	if (this->source.loop == NULL) {
		spa_loop_add_source(loop, &this->source);
		add_node(this, driver);
	}
	return 0;
}

static void node_update_state(struct pw_impl_node *node, enum pw_node_state state, int res, char *error)
{
	struct impl *impl = SPA_CONTAINER_OF(node, struct impl, this);
	enum pw_node_state old = node->info.state;

	switch (state) {
	case PW_NODE_STATE_RUNNING:
		if (node->driving && node->driver) {
			res = spa_node_send_command(node->node,
				&SPA_NODE_COMMAND_INIT(SPA_NODE_COMMAND_Start));
			if (res < 0) {
				state = PW_NODE_STATE_ERROR;
				error = spa_aprintf("Start error: %s", spa_strerror(res));
			}
		}
		if (res >= 0)
			pw_loop_invoke(node->data_loop, do_node_add, 1, NULL, 0, true, node);
		break;
	default:
		break;
	}

	free((char*)node->info.error);
	node->info.error = error;
	node->info.state = state;
	impl->pending = state;

	pw_log_debug(NAME" %p: (%s) %s -> %s (%s)", node, node->name,
		     pw_node_state_as_string(old), pw_node_state_as_string(state), error);

	if (old == state)
		return;

	if (state == PW_NODE_STATE_ERROR) {
		pw_log_error("(%s-%u) %s -> error (%s)", node->name, node->info.id,
		     pw_node_state_as_string(old), error);
	} else {
		pw_log_info("(%s-%u) %s -> %s", node->name, node->info.id,
		     pw_node_state_as_string(old), pw_node_state_as_string(state));
	}
	pw_impl_node_emit_state_changed(node, old, state, error);

	node->info.change_mask |= PW_NODE_CHANGE_MASK_STATE;
	emit_info_changed(node, false);

	if (state == PW_NODE_STATE_ERROR && node->global) {
		struct pw_resource *resource;
		spa_list_for_each(resource, &node->global->resource_list, link)
			pw_resource_error(resource, res, error);
	}
}

static int suspend_node(struct pw_impl_node *this)
{
	int res = 0;
	struct pw_impl_port *p;

	pw_log_debug(NAME" %p: suspend node state:%s", this,
			pw_node_state_as_string(this->info.state));

	if (this->info.state > 0 && this->info.state <= PW_NODE_STATE_SUSPENDED)
		return 0;

	pause_node(this);

	spa_list_for_each(p, &this->input_ports, link) {
		if ((res = pw_impl_port_set_param(p, SPA_PARAM_Format, 0, NULL)) < 0)
			pw_log_warn(NAME" %p: error unset format input: %s",
					this, spa_strerror(res));
		/* force CONFIGURE in case of async */
		p->state = PW_IMPL_PORT_STATE_CONFIGURE;
	}

	spa_list_for_each(p, &this->output_ports, link) {
		if ((res = pw_impl_port_set_param(p, SPA_PARAM_Format, 0, NULL)) < 0)
			pw_log_warn(NAME" %p: error unset format output: %s",
					this, spa_strerror(res));
		/* force CONFIGURE in case of async */
		p->state = PW_IMPL_PORT_STATE_CONFIGURE;
	}

	res = spa_node_send_command(this->node,
				    &SPA_NODE_COMMAND_INIT(SPA_NODE_COMMAND_Suspend));
	if (res == -ENOTSUP)
		res = spa_node_send_command(this->node,
				    &SPA_NODE_COMMAND_INIT(SPA_NODE_COMMAND_Pause));
	if (res < 0 && res != -EIO)
		pw_log_warn(NAME" %p: suspend node error %s", this, spa_strerror(res));

	node_update_state(this, PW_NODE_STATE_SUSPENDED, 0, NULL);

	return res;
}

static void
clear_info(struct pw_impl_node *this)
{
	free(this->name);
	free((char*)this->info.error);
}

static int reply_param(void *data, int seq, uint32_t id,
		uint32_t index, uint32_t next, struct spa_pod *param)
{
	struct resource_data *d = data;
	pw_log_debug(NAME" %p: resource %p reply param %d", d->node, d->resource, seq);
	pw_node_resource_param(d->resource, seq, id, index, next, param);
	return 0;
}

static int node_enum_params(void *object, int seq, uint32_t id,
		uint32_t index, uint32_t num, const struct spa_pod *filter)
{
	struct resource_data *data = object;
	struct pw_resource *resource = data->resource;
	struct pw_impl_node *node = data->node;
	int res;

	pw_log_debug(NAME" %p: resource %p enum params seq:%d id:%d (%s) index:%u num:%u",
			node, resource, seq, id,
			spa_debug_type_find_name(spa_type_param, id), index, num);

	if ((res = pw_impl_node_for_each_param(node, seq, id, index, num,
				filter, reply_param, data)) < 0) {
		pw_resource_errorf(resource, res,
				"enum params id:%d (%s) failed", id,
				spa_debug_type_find_name(spa_type_param, id));
	}
	return 0;
}

static int node_subscribe_params(void *object, uint32_t *ids, uint32_t n_ids)
{
	struct resource_data *data = object;
	struct pw_resource *resource = data->resource;
	uint32_t i;

	n_ids = SPA_MIN(n_ids, SPA_N_ELEMENTS(data->subscribe_ids));
	data->n_subscribe_ids = n_ids;

	for (i = 0; i < n_ids; i++) {
		data->subscribe_ids[i] = ids[i];
		pw_log_debug(NAME" %p: resource %p subscribe param id:%d (%s)",
				data->node, resource, ids[i],
				spa_debug_type_find_name(spa_type_param, ids[i]));
		node_enum_params(data, 1, ids[i], 0, UINT32_MAX, NULL);
	}
	return 0;
}

static void remove_busy_resource(struct resource_data *d)
{
	if (d->end != -1) {
		spa_hook_remove(&d->listener);
		d->end = -1;
		pw_impl_client_set_busy(d->resource->client, false);
	}
}

static void result_node_sync(void *data, int seq, int res, uint32_t type, const void *result)
{
	struct resource_data *d = data;

	pw_log_debug(NAME" %p: sync result %d %d (%d/%d)", d->node, res, seq, d->seq, d->end);
	if (seq == d->end)
		remove_busy_resource(d);
}

static int node_set_param(void *object, uint32_t id, uint32_t flags,
		const struct spa_pod *param)
{
	struct resource_data *data = object;
	struct pw_resource *resource = data->resource;
	struct pw_impl_node *node = data->node;
	struct pw_impl_client *client = resource->client;
	int res;
	static const struct spa_node_events node_events = {
		SPA_VERSION_NODE_EVENTS,
		.result = result_node_sync,
	};

	pw_log_debug(NAME" %p: resource %p set param id:%d (%s) %08x", node, resource,
			id, spa_debug_type_find_name(spa_type_param, id), flags);

	res = spa_node_set_param(node->node, id, flags, param);

	if (res < 0) {
		pw_resource_errorf(resource, res,
				"set param id:%d (%s) flags:%08x failed", id,
				spa_debug_type_find_name(spa_type_param, id), flags);

	} else if (SPA_RESULT_IS_ASYNC(res)) {
		pw_impl_client_set_busy(client, true);
		if (data->end == -1)
			spa_node_add_listener(node->node, &data->listener,
				&node_events, data);
		data->seq = res;
		data->end = spa_node_sync(node->node, res);
	}
	return 0;
}

static int node_send_command(void *object, const struct spa_command *command)
{
	struct resource_data *data = object;
	struct pw_impl_node *node = data->node;

	switch (SPA_NODE_COMMAND_ID(command)) {
	case SPA_NODE_COMMAND_Suspend:
		suspend_node(node);
		break;
	default:
		spa_node_send_command(node->node, command);
		break;
	}
	return 0;
}

static const struct pw_node_methods node_methods = {
	PW_VERSION_NODE_METHODS,
	.subscribe_params = node_subscribe_params,
	.enum_params = node_enum_params,
	.set_param = node_set_param,
	.send_command = node_send_command
};

static void resource_destroy(void *data)
{
	struct resource_data *d = data;
	remove_busy_resource(d);
	spa_hook_remove(&d->resource_listener);
	spa_hook_remove(&d->object_listener);
}

static void resource_pong(void *data, int seq)
{
	struct resource_data *d = data;
	struct pw_resource *resource = d->resource;
	pw_log_debug(NAME" %p: resource %p: got pong %d", d->node,
			resource, seq);
}

static const struct pw_resource_events resource_events = {
	PW_VERSION_RESOURCE_EVENTS,
	.destroy = resource_destroy,
	.pong = resource_pong,
};

static int
global_bind(void *_data, struct pw_impl_client *client, uint32_t permissions,
	    uint32_t version, uint32_t id)
{
	struct pw_impl_node *this = _data;
	struct pw_global *global = this->global;
	struct pw_resource *resource;
	struct resource_data *data;

	resource = pw_resource_new(client, id, permissions, global->type, version, sizeof(*data));
	if (resource == NULL)
		goto error_resource;

	data = pw_resource_get_user_data(resource);
	data->node = this;
	data->resource = resource;
	data->end = -1;

	pw_resource_add_listener(resource,
			&data->resource_listener,
			&resource_events, data);
	pw_resource_add_object_listener(resource,
			&data->object_listener,
			&node_methods, data);

	pw_log_debug(NAME" %p: bound to %d", this, resource->id);
	pw_global_add_resource(global, resource);

	this->info.change_mask = PW_NODE_CHANGE_MASK_ALL;
	pw_node_resource_info(resource, &this->info);
	this->info.change_mask = 0;

	return 0;

error_resource:
	pw_log_error(NAME" %p: can't create node resource: %m", this);
	return -errno;
}

static void global_destroy(void *data)
{
	struct pw_impl_node *this = data;
	spa_hook_remove(&this->global_listener);
	this->global = NULL;
	pw_impl_node_destroy(this);
}

static const struct pw_global_events global_events = {
	PW_VERSION_GLOBAL_EVENTS,
	.destroy = global_destroy,
};

static inline void insert_driver(struct pw_context *context, struct pw_impl_node *node)
{
	struct pw_impl_node *n, *t;

	spa_list_for_each_safe(n, t, &context->driver_list, driver_link) {
		if (n->priority_driver < node->priority_driver)
			break;
	}
	spa_list_append(&n->driver_link, &node->driver_link);
}

static void update_io(struct pw_impl_node *node)
{
	pw_log_debug(NAME" %p: id:%d", node, node->info.id);

	if (spa_node_set_io(node->node,
			    SPA_IO_Position,
			    &node->rt.activation->position,
			    sizeof(struct spa_io_position)) >= 0) {
		pw_log_debug(NAME" %p: set position %p", node, &node->rt.activation->position);
		node->rt.position = &node->rt.activation->position;
	} else if (node->driver) {
		pw_log_warn(NAME" %p: can't set position on driver", node);
	}
	if (spa_node_set_io(node->node,
			    SPA_IO_Clock,
			    &node->rt.activation->position.clock,
			    sizeof(struct spa_io_clock)) >= 0) {
		pw_log_debug(NAME" %p: set clock %p", node, &node->rt.activation->position.clock);
		node->rt.clock = &node->rt.activation->position.clock;
	}
}

SPA_EXPORT
int pw_impl_node_register(struct pw_impl_node *this,
		     struct pw_properties *properties)
{
	static const char * const keys[] = {
		PW_KEY_OBJECT_PATH,
		PW_KEY_MODULE_ID,
		PW_KEY_FACTORY_ID,
		PW_KEY_CLIENT_ID,
		PW_KEY_DEVICE_ID,
		PW_KEY_PRIORITY_SESSION,
		PW_KEY_PRIORITY_DRIVER,
		PW_KEY_APP_NAME,
		PW_KEY_NODE_DESCRIPTION,
		PW_KEY_NODE_NAME,
		PW_KEY_NODE_NICK,
		PW_KEY_NODE_SESSION,
		PW_KEY_MEDIA_CLASS,
		PW_KEY_MEDIA_TYPE,
		PW_KEY_MEDIA_CATEGORY,
		PW_KEY_MEDIA_ROLE,
		NULL
	};

	struct pw_context *context = this->context;
	struct pw_impl_port *port;

	pw_log_debug(NAME" %p: register", this);

	if (this->registered)
		goto error_existed;

	this->global = pw_global_new(context,
				     PW_TYPE_INTERFACE_Node,
				     PW_VERSION_NODE,
				     properties,
				     global_bind,
				     this);
	if (this->global == NULL)
		return -errno;

	spa_list_append(&context->node_list, &this->link);
	if (this->driver)
		insert_driver(context, this);
	this->registered = true;

	this->rt.activation->position.clock.id = this->global->id;

	this->info.id = this->global->id;
	pw_properties_setf(this->properties, PW_KEY_OBJECT_ID, "%d", this->info.id);
	this->info.props = &this->properties->dict;

	pw_global_update_keys(this->global, &this->properties->dict, keys);

	pw_impl_node_initialized(this);

	pw_global_add_listener(this->global, &this->global_listener, &global_events, this);
	pw_global_register(this->global);

	if (this->node)
		update_io(this);

	spa_list_for_each(port, &this->input_ports, link)
		pw_impl_port_register(port, NULL);
	spa_list_for_each(port, &this->output_ports, link)
		pw_impl_port_register(port, NULL);

	if (this->active)
		pw_context_recalc_graph(context, "register active node");

	return 0;

error_existed:
	pw_properties_free(properties);
	return -EEXIST;
}

SPA_EXPORT
int pw_impl_node_initialized(struct pw_impl_node *this)
{
	pw_log_debug(NAME" %p initialized", this);
	pw_impl_node_emit_initialized(this);
	node_update_state(this, PW_NODE_STATE_SUSPENDED, 0, NULL);
	return 0;
}

static int
do_move_nodes(struct spa_loop *loop,
		bool async, uint32_t seq, const void *data, size_t size, void *user_data)
{
	struct impl *impl = user_data;
	struct pw_impl_node *driver = *(struct pw_impl_node **)data;
	struct pw_impl_node *node = &impl->this;
	int res;

	pw_log_trace(NAME" %p: driver:%p->%p", node, node->driver_node, driver);

	if ((res = spa_node_set_io(node->node,
		    SPA_IO_Position,
		    &driver->rt.activation->position,
		    sizeof(struct spa_io_position))) < 0) {
		pw_log_debug(NAME" %p: set position: %s", node, spa_strerror(res));
	}

	pw_log_trace(NAME" %p: set position %p", node, &driver->rt.activation->position);
	node->rt.position = &driver->rt.activation->position;

	if (node->source.loop != NULL) {
		remove_node(node);
		add_node(node, driver);
	}
	return 0;
}

static void remove_segment_owner(struct pw_impl_node *driver, uint32_t node_id)
{
	struct pw_node_activation *a = driver->rt.activation;
	ATOMIC_CAS(a->segment_owner[0], node_id, 0);
	ATOMIC_CAS(a->segment_owner[1], node_id, 0);
}

SPA_EXPORT
int pw_impl_node_set_driver(struct pw_impl_node *node, struct pw_impl_node *driver)
{
	struct impl *impl = SPA_CONTAINER_OF(node, struct impl, this);
	struct pw_impl_node *old = node->driver_node;

	if (driver == NULL)
		driver = node;

	spa_list_remove(&node->follower_link);
	spa_list_append(&driver->follower_list, &node->follower_link);

	if (old == driver)
		return 0;

	remove_segment_owner(old, node->info.id);

	node->driving = node->driver && driver == node;
	pw_log_debug(NAME" %p: driver %p driving:%u", node,
		driver, node->driving);
	pw_log_info("(%s-%u) -> change driver (%s-%d -> %s-%d)",
			node->name, node->info.id,
			old->name, old->info.id, driver->name, driver->info.id);

	node->driver_node = driver;

	pw_loop_invoke(node->data_loop,
		       do_move_nodes, SPA_ID_INVALID, &driver, sizeof(struct pw_impl_node *),
		       true, impl);

	pw_impl_node_emit_driver_changed(node, old, driver);

	return 0;
}

static void check_properties(struct pw_impl_node *node)
{
	struct impl *impl = SPA_CONTAINER_OF(node, struct impl, this);
	struct pw_context *context = node->context;
	const char *str, *recalc_reason = NULL;
	struct spa_fraction frac;
	bool driver;

	if ((str = pw_properties_get(node->properties, PW_KEY_PRIORITY_DRIVER))) {
		node->priority_driver = pw_properties_parse_int(str);
		pw_log_debug(NAME" %p: priority driver %d", node, node->priority_driver);
	}

	if ((str = pw_properties_get(node->properties, PW_KEY_NODE_NAME)) &&
	    (node->name == NULL || !spa_streq(node->name, str))) {
		free(node->name);
		node->name = strdup(str);
		pw_log_debug(NAME" %p: name '%s'", node, node->name);
	}

	str = pw_properties_get(node->properties, PW_KEY_NODE_PAUSE_ON_IDLE);
	impl->pause_on_idle = str ? pw_properties_parse_bool(str) : true;

	str = pw_properties_get(node->properties, PW_KEY_NODE_CACHE_PARAMS);
	impl->cache_params = str ? pw_properties_parse_bool(str) : true;

	str = pw_properties_get(node->properties, PW_KEY_NODE_DRIVER);
	driver = str ? pw_properties_parse_bool(str) : false;

	if (node->driver != driver) {
		pw_log_debug(NAME" %p: driver %d -> %d", node, node->driver, driver);
		node->driver = driver;
		if (node->registered) {
			if (driver)
				insert_driver(context, node);
			else
				spa_list_remove(&node->driver_link);
		}
		recalc_reason = "driver changed";
	}

	/* group defines what nodes are scheduled together */
	if ((str = pw_properties_get(node->properties, PW_KEY_NODE_GROUP)) == NULL)
		str = "";

	if (!spa_streq(str, node->group)) {
		pw_log_info(NAME" %p: group '%s'->'%s'", node, node->group, str);
		snprintf(node->group, sizeof(node->group), "%s", str);
		node->freewheel = spa_streq(node->group, "pipewire.freewheel");
		recalc_reason = "group changed";
	}

	str = pw_properties_get(node->properties, PW_KEY_NODE_WANT_DRIVER);
	node->want_driver = str ? pw_properties_parse_bool(str) : false;

	str = pw_properties_get(node->properties, PW_KEY_NODE_ALWAYS_PROCESS);
	node->always_process = str ? pw_properties_parse_bool(str) : false;

	if (node->always_process)
		node->want_driver = true;

	if ((str = pw_properties_get(node->properties, PW_KEY_NODE_LATENCY))) {
                if (sscanf(str, "%u/%u", &frac.num, &frac.denom) == 2 && frac.denom != 0) {
			if (node->latency.num != frac.num || node->latency.denom != frac.denom) {
				pw_log_info("(%s-%u) latency:%u/%u -> %u/%u", node->name,
						node->info.id, node->latency.num,
						node->latency.denom, frac.num, frac.denom);
				node->latency = frac;
				recalc_reason = "quantum changed";
			}
		}
	}
	if ((str = pw_properties_get(node->properties, PW_KEY_NODE_MAX_LATENCY))) {
                if (sscanf(str, "%u/%u", &frac.num, &frac.denom) == 2 && frac.denom != 0) {
			if (node->max_latency.num != frac.num || node->max_latency.denom != frac.denom) {
				pw_log_info("(%s-%u) max-latency:%u/%u -> %u/%u", node->name,
						node->info.id, node->max_latency.num,
						node->max_latency.denom, frac.num, frac.denom);
				node->max_latency = frac;
				recalc_reason = "max quantum changed";
			}
		}
	}
	str = pw_properties_get(node->properties, PW_KEY_NODE_LOCK_QUANTUM);
	node->lock_quantum = str ? pw_properties_parse_bool(str) : false;

	if ((str = pw_properties_get(node->properties, PW_KEY_NODE_RATE))) {
                if (sscanf(str, "%u/%u", &frac.num, &frac.denom) == 2 && frac.denom != 0) {
			if (node->rate.num != frac.num || node->rate.denom != frac.denom) {
				pw_log_info("(%s-%u) rate:%u/%u -> %u/%u", node->name,
						node->info.id, node->rate.num,
						node->rate.denom, frac.num, frac.denom);
				node->rate = frac;
				recalc_reason = "node rate changed";
			}
		}
	}
	str = pw_properties_get(node->properties, PW_KEY_NODE_LOCK_RATE);
	node->lock_rate = str ? pw_properties_parse_bool(str) : false;

	pw_log_debug(NAME" %p: driver:%d recalc:%s active:%d", node, node->driver,
			recalc_reason, node->active);

	if (recalc_reason != NULL && node->active)
		pw_context_recalc_graph(context, recalc_reason);
}

static const char *str_status(uint32_t status)
{
	switch (status) {
	case PW_NODE_ACTIVATION_NOT_TRIGGERED:
		return "not-triggered";
	case PW_NODE_ACTIVATION_TRIGGERED:
		return "triggered";
	case PW_NODE_ACTIVATION_AWAKE:
		return "awake";
	case PW_NODE_ACTIVATION_FINISHED:
		return "finished";
	}
	return "unknown";
}

static void dump_states(struct pw_impl_node *driver)
{
	struct pw_node_target *t;
	struct pw_node_activation *na = driver->rt.activation;
	struct spa_io_clock *cl = &na->position.clock;

	spa_list_for_each(t, &driver->rt.target_list, link) {
		struct pw_node_activation *a = t->activation;
		struct pw_node_activation_state *state = &a->state[0];
		if (t->node == NULL)
			continue;
		if (a->status == PW_NODE_ACTIVATION_TRIGGERED ||
		    a->status == PW_NODE_ACTIVATION_AWAKE) {
			pw_log_info("(%s-%u) client too slow! rate:%u/%u pos:%"PRIu64" status:%s",
				t->node->name, t->node->info.id,
				(uint32_t)(cl->rate.num * cl->duration), cl->rate.denom,
				cl->position, str_status(a->status));
		}
		pw_log_debug("(%s-%u) state:%p pending:%d/%d s:%"PRIu64" a:%"PRIu64" f:%"PRIu64
				" waiting:%"PRIu64" process:%"PRIu64" status:%s sync:%d",
				t->node->name, t->node->info.id, state,
				state->pending, state->required,
				a->signal_time,
				a->awake_time,
				a->finish_time,
				a->awake_time - a->signal_time,
				a->finish_time - a->awake_time,
				str_status(a->status), a->pending_sync);
	}
}

static inline int resume_node(struct pw_impl_node *this, int status)
{
	struct pw_node_target *t;
	struct timespec ts;
	struct pw_node_activation *activation = this->rt.activation;
	struct spa_system *data_system = this->context->data_system;
	uint64_t nsec;

	spa_system_clock_gettime(data_system, CLOCK_MONOTONIC, &ts);
	nsec = SPA_TIMESPEC_TO_NSEC(&ts);
	activation->status = PW_NODE_ACTIVATION_FINISHED;
	activation->finish_time = nsec;

	pw_log_trace_fp(NAME" %p: trigger peers %"PRIu64, this, nsec);

	spa_list_for_each(t, &this->rt.target_list, link) {
		struct pw_node_activation *a = t->activation;
		struct pw_node_activation_state *state = &a->state[0];

		pw_log_trace_fp(NAME" %p: state:%p pending:%d/%d", t->node, state,
                                state->pending, state->required);

		if (pw_node_activation_state_dec(state, 1)) {
			a->status = PW_NODE_ACTIVATION_TRIGGERED;
			a->signal_time = nsec;
			t->signal(t->data);
		}
	}
	return 0;
}

static inline void calculate_stats(struct pw_impl_node *this,  struct pw_node_activation *a)
{
	if (SPA_LIKELY(a->signal_time > a->prev_signal_time)) {
		uint64_t process_time = a->finish_time - a->signal_time;
		uint64_t period_time = a->signal_time - a->prev_signal_time;
		float load = (float) process_time / (float) period_time;
		a->cpu_load[0] = (a->cpu_load[0] + load) / 2.0f;
		a->cpu_load[1] = (a->cpu_load[1] * 7.0f + load) / 8.0f;
		a->cpu_load[2] = (a->cpu_load[2] * 31.0f + load) / 32.0f;
	}
}

static inline int process_node(void *data)
{
	struct pw_impl_node *this = data;
	struct timespec ts;
        struct pw_impl_port *p;
	struct pw_node_activation *a = this->rt.activation;
	struct spa_system *data_system = this->context->data_system;
	int status;

	spa_system_clock_gettime(data_system, CLOCK_MONOTONIC, &ts);
	a->status = PW_NODE_ACTIVATION_AWAKE;
	a->awake_time = SPA_TIMESPEC_TO_NSEC(&ts);

	pw_log_trace_fp(NAME" %p: process %"PRIu64, this, a->awake_time);

	/* not implemented yet, just clear the flags */
	a->pending_sync = false;
	a->pending_new_pos = false;

	spa_list_for_each(p, &this->rt.input_mix, rt.node_link)
		spa_node_process(p->mix);

	status = spa_node_process(this->node);
	a->state[0].status = status;

	if (status & SPA_STATUS_HAVE_DATA) {
		spa_list_for_each(p, &this->rt.output_mix, rt.node_link)
			spa_node_process(p->mix);
	}

	if (SPA_UNLIKELY(this == this->driver_node && !this->exported)) {
		spa_system_clock_gettime(data_system, CLOCK_MONOTONIC, &ts);
		a->status = PW_NODE_ACTIVATION_FINISHED;
		a->signal_time = a->finish_time;
		a->finish_time = SPA_TIMESPEC_TO_NSEC(&ts);

		/* calculate CPU time */
		calculate_stats(this, a);

		pw_log_trace_fp(NAME" %p: graph completed wait:%"PRIu64" run:%"PRIu64
				" busy:%"PRIu64" period:%"PRIu64" cpu:%f:%f:%f", this,
				a->awake_time - a->signal_time,
				a->finish_time - a->awake_time,
				a->finish_time - a->signal_time,
				a->signal_time - a->prev_signal_time,
				a->cpu_load[0], a->cpu_load[1], a->cpu_load[2]);

		pw_context_driver_emit_complete(this->context, this);

	} else if (status == SPA_STATUS_OK) {
		pw_log_trace_fp(NAME" %p: async continue", this);
	} else {
		resume_node(this, status);
	}
	if (status & SPA_STATUS_DRAINED) {
		pw_context_driver_emit_drained(this->context, this);
	}
	return 0;
}

static void node_on_fd_events(struct spa_source *source)
{
	struct pw_impl_node *this = source->data;
	struct spa_system *data_system = this->context->data_system;

	if (SPA_UNLIKELY(source->rmask & (SPA_IO_ERR | SPA_IO_HUP))) {
		pw_log_warn(NAME" %p: got socket error %08x", this, source->rmask);
		return;
	}

	if (SPA_LIKELY(source->rmask & SPA_IO_IN)) {
		uint64_t cmd;

		if (SPA_UNLIKELY(spa_system_eventfd_read(data_system, this->source.fd, &cmd) < 0))
			pw_log_warn(NAME" %p: read failed %m", this);
		else if (SPA_UNLIKELY(cmd > 1))
			pw_log_info("(%s-%u) client missed %"PRIu64" wakeups",
				this->name, this->info.id, cmd - 1);

		pw_log_trace_fp(NAME" %p: got process", this);
		this->rt.target.signal(this->rt.target.data);
	}
}

static void reset_segment(struct spa_io_segment *seg)
{
	spa_zero(*seg);
	seg->rate = 1.0;
}

static void reset_position(struct pw_impl_node *this, struct spa_io_position *pos)
{
	uint32_t i;
	struct settings *s = &this->context->settings;
	uint32_t quantum = s->clock_force_quantum == 0 ? s->clock_quantum : s->clock_force_quantum;
	uint32_t rate = s->clock_force_rate == 0 ? s->clock_rate : s->clock_force_rate;

	pos->clock.rate = SPA_FRACTION(1, rate);
	pos->clock.duration = quantum;
	pos->video.flags = SPA_IO_VIDEO_SIZE_VALID;
	pos->video.size = s->video_size;
	pos->video.stride = pos->video.size.width * 16;
	pos->video.framerate = s->video_rate;
	pos->offset = INT64_MIN;

	pos->n_segments = 1;
	for (i = 0; i < SPA_IO_POSITION_MAX_SEGMENTS; i++)
		reset_segment(&pos->segments[i]);
}

SPA_EXPORT
struct pw_impl_node *pw_context_create_node(struct pw_context *context,
			    struct pw_properties *properties,
			    size_t user_data_size)
{
	struct impl *impl;
	struct pw_impl_node *this;
	size_t size;
	struct spa_system *data_system = context->data_system;
	int res;

	impl = calloc(1, sizeof(struct impl) + user_data_size);
	if (impl == NULL) {
		res = -errno;
		goto error_exit;
	}

	spa_list_init(&impl->param_list);
	spa_list_init(&impl->pending_list);

	this = &impl->this;
	this->context = context;
	this->name = strdup("node");

	if (user_data_size > 0)
                this->user_data = SPA_PTROFF(impl, sizeof(struct impl), void);

	if (properties == NULL)
		properties = pw_properties_new(NULL, NULL);
	if (properties == NULL) {
		res = -errno;
		goto error_clean;
	}

	this->properties = properties;

	if ((res = spa_system_eventfd_create(data_system, SPA_FD_CLOEXEC | SPA_FD_NONBLOCK)) < 0)
		goto error_clean;

	pw_log_debug(NAME" %p: new fd:%d", this, res);

	this->source.fd = res;
	this->source.func = node_on_fd_events;
	this->source.data = this;
	this->source.mask = SPA_IO_IN | SPA_IO_ERR | SPA_IO_HUP;
	this->source.rmask = 0;

	size = sizeof(struct pw_node_activation);

	this->activation = pw_mempool_alloc(this->context->pool,
			PW_MEMBLOCK_FLAG_READWRITE |
			PW_MEMBLOCK_FLAG_SEAL |
			PW_MEMBLOCK_FLAG_MAP,
			SPA_DATA_MemFd, size);
	if (this->activation == NULL) {
		res = -errno;
                goto error_clean;
	}

	impl->work = pw_work_queue_new(this->context->main_loop);
	if (impl->work == NULL) {
		res = -errno;
		goto error_clean;
	}
	impl->pending_id = SPA_ID_INVALID;

	this->data_loop = context->data_loop;

	spa_list_init(&this->follower_list);

	spa_hook_list_init(&this->listener_list);

	this->info.state = PW_NODE_STATE_CREATING;
	this->info.props = &this->properties->dict;
	this->info.params = this->params;

	spa_list_init(&this->input_ports);
	pw_map_init(&this->input_port_map, 64, 64);
	spa_list_init(&this->output_ports);
	pw_map_init(&this->output_port_map, 64, 64);

	spa_list_init(&this->rt.input_mix);
	spa_list_init(&this->rt.output_mix);
	spa_list_init(&this->rt.target_list);

	this->rt.activation = this->activation->map->ptr;
	this->rt.target.activation = this->rt.activation;
	this->rt.target.node = this;
	this->rt.target.signal = process_node;
	this->rt.target.data = this;
	this->rt.driver_target.signal = process_node;

	reset_position(this, &this->rt.activation->position);
	this->rt.activation->sync_timeout = DEFAULT_SYNC_TIMEOUT;
	this->rt.activation->sync_left = 0;

	this->rt.rate_limit.interval = 2 * SPA_NSEC_PER_SEC;
	this->rt.rate_limit.burst = 1;

	check_properties(this);

	this->driver_node = this;
	spa_list_append(&this->follower_list, &this->follower_link);
	this->driving = true;

	return this;

error_clean:
	if (this->activation)
		pw_memblock_unref(this->activation);
	if (this->source.fd != -1)
		spa_system_close(this->context->data_system, this->source.fd);
	free(impl);
error_exit:
	pw_properties_free(properties);
	errno = -res;
	return NULL;
}

SPA_EXPORT
const struct pw_node_info *pw_impl_node_get_info(struct pw_impl_node *node)
{
	return &node->info;
}

SPA_EXPORT
void * pw_impl_node_get_user_data(struct pw_impl_node *node)
{
	return node->user_data;
}

SPA_EXPORT
struct pw_context * pw_impl_node_get_context(struct pw_impl_node *node)
{
	return node->context;
}

SPA_EXPORT
struct pw_global *pw_impl_node_get_global(struct pw_impl_node *node)
{
	return node->global;
}

SPA_EXPORT
const struct pw_properties *pw_impl_node_get_properties(struct pw_impl_node *node)
{
	return node->properties;
}

static int update_properties(struct pw_impl_node *node, const struct spa_dict *dict, bool filter)
{
	static const char * const ignored[] = {
		PW_KEY_OBJECT_ID,
		PW_KEY_MODULE_ID,
		PW_KEY_FACTORY_ID,
		PW_KEY_CLIENT_ID,
		PW_KEY_DEVICE_ID,
		NULL
	};

	int changed;

	changed = pw_properties_update_ignore(node->properties, dict, filter ? ignored : NULL);
	node->info.props = &node->properties->dict;

	pw_log_debug(NAME" %p: updated %d properties", node, changed);

	if (changed) {
		check_properties(node);
		node->info.change_mask |= PW_NODE_CHANGE_MASK_PROPS;
	}
	return changed;
}

SPA_EXPORT
int pw_impl_node_update_properties(struct pw_impl_node *node, const struct spa_dict *dict)
{
	int changed = update_properties(node, dict, false);
	emit_info_changed(node, false);
	return changed;
}

static void node_info(void *data, const struct spa_node_info *info)
{
	struct pw_impl_node *node = data;
	uint32_t changed_ids[MAX_PARAMS], n_changed_ids = 0;
	bool flags_changed = false;

	node->info.max_input_ports = info->max_input_ports;
	node->info.max_output_ports = info->max_output_ports;

	pw_log_debug(NAME" %p: flags:%08"PRIx64" change_mask:%08"PRIx64" max_in:%u max_out:%u",
			node, info->flags, info->change_mask, info->max_input_ports,
			info->max_output_ports);

	if (info->change_mask & SPA_NODE_CHANGE_MASK_FLAGS) {
		if (node->spa_flags != info->flags) {
			flags_changed = node->spa_flags != 0;
			pw_log_debug(NAME" %p: flags %"PRIu64"->%"PRIu64, node, node->spa_flags, info->flags);
			node->spa_flags = info->flags;
		}
	}
	if (info->change_mask & SPA_NODE_CHANGE_MASK_PROPS) {
		update_properties(node, info->props, true);
	}
	if (info->change_mask & SPA_NODE_CHANGE_MASK_PARAMS) {
		uint32_t i;

		node->info.change_mask |= PW_NODE_CHANGE_MASK_PARAMS;
		node->info.n_params = SPA_MIN(info->n_params, SPA_N_ELEMENTS(node->params));

		for (i = 0; i < node->info.n_params; i++) {
			uint32_t id = info->params[i].id;

			pw_log_debug(NAME" %p: param %d id:%d (%s) %08x:%08x", node, i,
					id, spa_debug_type_find_name(spa_type_param, id),
					node->info.params[i].flags, info->params[i].flags);

			node->info.params[i].id = info->params[i].id;
			if (node->info.params[i].flags == info->params[i].flags)
				continue;

			pw_log_debug(NAME" %p: update param %d", node, id);
			node->info.params[i] = info->params[i];
			node->info.params[i].user = 0;

			if (info->params[i].flags & SPA_PARAM_INFO_READ)
				changed_ids[n_changed_ids++] = id;
		}
	}
	emit_info_changed(node, flags_changed);

	if (n_changed_ids > 0)
		emit_params(node, changed_ids, n_changed_ids);

	if (flags_changed)
		pw_context_recalc_graph(node->context, "node flags changed");
}

static void node_port_info(void *data, enum spa_direction direction, uint32_t port_id,
		const struct spa_port_info *info)
{
	struct pw_impl_node *node = data;
	struct pw_impl_port *port = pw_impl_node_find_port(node, direction, port_id);

	if (info == NULL) {
		if (port) {
			pw_log_debug(NAME" %p: %s port %d removed", node,
					pw_direction_as_string(direction), port_id);
			pw_impl_port_destroy(port);
		} else {
			pw_log_warn(NAME" %p: %s port %d unknown", node,
					pw_direction_as_string(direction), port_id);
		}
	} else if (port) {
		pw_log_debug(NAME" %p: %s port %d changed", node,
				pw_direction_as_string(direction), port_id);
		pw_impl_port_update_info(port, info);
	} else {
		int res;

		pw_log_debug(NAME" %p: %s port %d added", node,
				pw_direction_as_string(direction), port_id);

		if ((port = pw_context_create_port(node->context, direction, port_id, info,
					node->port_user_data_size))) {
			if ((res = pw_impl_port_add(port, node)) < 0) {
				pw_log_error(NAME" %p: can't add port %p: %d, %s",
						node, port, res, spa_strerror(res));
				pw_impl_port_destroy(port);
			}
		}
	}
}

static void node_result(void *data, int seq, int res, uint32_t type, const void *result)
{
	struct pw_impl_node *node = data;
	struct impl *impl = SPA_CONTAINER_OF(node, struct impl, this);

	pw_log_trace(NAME" %p: result seq:%d res:%d type:%u", node, seq, res, type);
	if (res < 0)
		impl->last_error = res;

	if (SPA_RESULT_IS_ASYNC(seq))
	        pw_work_queue_complete(impl->work, &impl->this, SPA_RESULT_ASYNC_SEQ(seq), res);

	pw_impl_node_emit_result(node, seq, res, type, result);
}

static void node_event(void *data, const struct spa_event *event)
{
	struct pw_impl_node *node = data;
	struct impl *impl = SPA_CONTAINER_OF(node, struct impl, this);

	pw_log_trace(NAME" %p: event %d", node, SPA_EVENT_TYPE(event));

	switch (SPA_NODE_EVENT_ID(event)) {
	case SPA_NODE_EVENT_Error:
		impl->last_error = -EFAULT;
		node_update_state(node, PW_NODE_STATE_ERROR,
				-EFAULT, strdup("Received error event"));
		break;
	default:
		pw_log_debug("unhandled event");
		break;
	}
	pw_impl_node_emit_event(node, event);
}

static const struct spa_node_events node_events = {
	SPA_VERSION_NODE_EVENTS,
	.info = node_info,
	.port_info = node_port_info,
	.result = node_result,
	.event = node_event,
};

#define SYNC_CHECK	0
#define SYNC_START	1
#define SYNC_STOP	2

static int check_updates(struct pw_impl_node *node, uint32_t *reposition_owner)
{
	int res = SYNC_CHECK;
	struct pw_node_activation *a = node->rt.activation;
	uint32_t command;

	if (SPA_UNLIKELY(a->position.offset == INT64_MIN))
		a->position.offset = a->position.clock.position;

	command = ATOMIC_XCHG(a->command, PW_NODE_ACTIVATION_COMMAND_NONE);
	*reposition_owner = ATOMIC_XCHG(a->reposition_owner, 0);

	if (SPA_UNLIKELY(command != PW_NODE_ACTIVATION_COMMAND_NONE)) {
		pw_log_debug(NAME" %p: update command:%u", node, command);
		switch (command) {
		case PW_NODE_ACTIVATION_COMMAND_STOP:
			a->position.state = SPA_IO_POSITION_STATE_STOPPED;
			res = SYNC_STOP;
			break;
		case PW_NODE_ACTIVATION_COMMAND_START:
			a->position.state = SPA_IO_POSITION_STATE_STARTING;
			a->sync_left = a->sync_timeout /
				((a->position.clock.duration * SPA_NSEC_PER_SEC) /
				 a->position.clock.rate.denom);
			res = SYNC_START;
			break;
		}
	}
	return res;
}

static void do_reposition(struct pw_impl_node *driver, struct pw_impl_node *node)
{
	struct pw_node_activation *a = driver->rt.activation;
	struct spa_io_segment *dst, *src;

	src = &node->rt.activation->reposition;
	dst = &a->position.segments[0];

	pw_log_trace(NAME" %p: update position:%"PRIu64, node, src->position);

	dst->version = src->version;
	dst->flags = src->flags;
	dst->start = src->start;
	dst->duration = src->duration;
	dst->rate = src->rate;
	dst->position = src->position;
	if (src->bar.flags & SPA_IO_SEGMENT_BAR_FLAG_VALID)
		dst->bar = src->bar;
	if (src->video.flags & SPA_IO_SEGMENT_VIDEO_FLAG_VALID)
		dst->video = src->video;

	if (dst->start == 0)
		dst->start = a->position.clock.position - a->position.offset;

	switch (a->position.state) {
	case SPA_IO_POSITION_STATE_RUNNING:
		a->position.state = SPA_IO_POSITION_STATE_STARTING;
		a->sync_left = a->sync_timeout /
			((a->position.clock.duration * SPA_NSEC_PER_SEC) /
			 a->position.clock.rate.denom);
		break;
	}
}

static void update_position(struct pw_impl_node *node, int all_ready)
{
	struct pw_node_activation *a = node->rt.activation;

	if (a->position.state == SPA_IO_POSITION_STATE_STARTING) {
		if (!all_ready && --a->sync_left == 0) {
			pw_log_warn("(%s-%u) sync timeout, going to RUNNING",
					node->name, node->info.id);
			pw_context_driver_emit_timeout(node->context, node);
			dump_states(node);
			all_ready = true;
		}
		if (all_ready)
			a->position.state = SPA_IO_POSITION_STATE_RUNNING;
	}
	if (a->position.state != SPA_IO_POSITION_STATE_RUNNING)
		a->position.offset += a->position.clock.duration;
}

static int node_ready(void *data, int status)
{
	struct pw_impl_node *node = data, *reposition_node = NULL;
	struct pw_impl_node *driver = node->driver_node;
	struct pw_node_target *t;
	struct pw_impl_port *p;

	pw_log_trace_fp(NAME" %p: ready driver:%d exported:%d %p status:%d", node,
			node->driver, node->exported, driver, status);

	if (SPA_UNLIKELY(node == driver)) {
		struct pw_node_activation *a = node->rt.activation;
		struct pw_node_activation_state *state = &a->state[0];
		int sync_type, all_ready, update_sync, target_sync;
		uint32_t owner[2], reposition_owner;
		uint64_t min_timeout = UINT64_MAX;

		if (SPA_UNLIKELY(state->pending > 0)) {
			pw_context_driver_emit_incomplete(node->context, node);
			if (ratelimit_test(&node->rt.rate_limit, a->signal_time)) {
				pw_log_debug("(%s-%u) graph not finished: state:%p quantum:%"PRIu64
						" pending %d/%d", node->name, node->info.id,
						state, a->position.clock.duration,
						state->pending, state->required);
				dump_states(node);
			}
			node->rt.target.signal(node->rt.target.data);
		}

		sync_type = check_updates(node, &reposition_owner);
		owner[0] = ATOMIC_LOAD(a->segment_owner[0]);
		owner[1] = ATOMIC_LOAD(a->segment_owner[1]);
		all_ready = sync_type == SYNC_CHECK;
		update_sync = !all_ready;
		target_sync = sync_type == SYNC_START ? true : false;

		spa_list_for_each(t, &driver->rt.target_list, link) {
			struct pw_node_activation *ta = t->activation;

			ta->status = PW_NODE_ACTIVATION_NOT_TRIGGERED;
			pw_node_activation_state_reset(&ta->state[0]);

			if (SPA_LIKELY(t->node)) {
				uint32_t id = t->node->info.id;

				/* this is the node with reposition info */
				if (SPA_UNLIKELY(id == reposition_owner))
					reposition_node = t->node;

				/* update extra segment info if it is the owner */
				if (SPA_UNLIKELY(id == owner[0]))
					a->position.segments[0].bar = ta->segment.bar;
				if (SPA_UNLIKELY(id == owner[1]))
					a->position.segments[0].video = ta->segment.video;

				min_timeout = SPA_MIN(min_timeout, ta->sync_timeout);
			}

			if (SPA_UNLIKELY(update_sync)) {
				ta->pending_sync = target_sync;
				ta->pending_new_pos = target_sync;
			} else {
				all_ready &= ta->pending_sync == false;
			}
		}
		a->prev_signal_time = a->signal_time;
		a->sync_timeout = SPA_MIN(min_timeout, DEFAULT_SYNC_TIMEOUT);

		if (SPA_UNLIKELY(reposition_node))
			do_reposition(node, reposition_node);

		update_position(node, all_ready);

		pw_context_driver_emit_start(node->context, node);
	}
	if (SPA_UNLIKELY(node->driver && !node->driving))
		return 0;

	if (status & SPA_STATUS_HAVE_DATA) {
		spa_list_for_each(p, &node->rt.output_mix, rt.node_link)
			spa_node_process(p->mix);
	}
	return resume_node(node, status);
}

static int node_reuse_buffer(void *data, uint32_t port_id, uint32_t buffer_id)
{
	struct pw_impl_node *node = data;
	struct pw_impl_port *p;

	spa_list_for_each(p, &node->rt.input_mix, rt.node_link) {
		if (p->port_id != port_id)
			continue;
		spa_node_port_reuse_buffer(p->mix, 0, buffer_id);
		break;
	}
	return 0;
}

static void update_xrun_stats(struct pw_node_activation *a, uint64_t trigger, uint64_t delay)
{
	a->xrun_count++;
	a->xrun_time = trigger;
	a->xrun_delay = delay;
	a->max_delay = SPA_MAX(a->max_delay, delay);
}

static int node_xrun(void *data, uint64_t trigger, uint64_t delay, struct spa_pod *info)
{
	struct pw_impl_node *this = data;
	struct pw_node_activation *a = this->rt.activation;
	struct pw_node_activation *da = this->rt.driver_target.activation;

	update_xrun_stats(a, trigger, delay);
	if (da && da != a)
		update_xrun_stats(da, trigger, delay);

	if (ratelimit_test(&this->rt.rate_limit, a->signal_time)) {
		struct spa_fraction rate;
		if (da) {
			struct spa_io_clock *cl = &da->position.clock;
			rate.num = cl->rate.num * cl->duration;
			rate.denom = cl->rate.denom;
		} else {
			rate = SPA_FRACTION(0,0);
		}
		pw_log_info("(%s-%d) XRun! rate:%u/%u count:%u time:%"PRIu64
				" delay:%"PRIu64" max:%"PRIu64,
				this->name, this->info.id,
				rate.num, rate.denom, a->xrun_count,
				trigger, delay, a->max_delay);
	}

	pw_context_driver_emit_xrun(this->context, this);

	return 0;
}

static const struct spa_node_callbacks node_callbacks = {
	SPA_VERSION_NODE_CALLBACKS,
	.ready = node_ready,
	.reuse_buffer = node_reuse_buffer,
	.xrun = node_xrun,
};

SPA_EXPORT
int pw_impl_node_set_implementation(struct pw_impl_node *node,
			struct spa_node *spa_node)
{
	int res;

	pw_log_debug(NAME" %p: implementation %p", node, spa_node);

	if (node->node) {
		pw_log_error(NAME" %p: implementation existed %p", node, node->node);
		return -EEXIST;
	}

	node->node = spa_node;
	spa_node_set_callbacks(node->node, &node_callbacks, node);
	res = spa_node_add_listener(node->node, &node->listener, &node_events, node);

	if (node->registered)
		update_io(node);

	return res;
}

SPA_EXPORT
struct spa_node *pw_impl_node_get_implementation(struct pw_impl_node *node)
{
	return node->node;
}

SPA_EXPORT
void pw_impl_node_add_listener(struct pw_impl_node *node,
			   struct spa_hook *listener,
			   const struct pw_impl_node_events *events,
			   void *data)
{
	spa_hook_list_append(&node->listener_list, listener, events, data);
}

/** Destroy a node
 * \param node a node to destroy
 *
 * Remove \a node. This will stop the transfer on the node and
 * free the resources allocated by \a node.
 */
SPA_EXPORT
void pw_impl_node_destroy(struct pw_impl_node *node)
{
	struct impl *impl = SPA_CONTAINER_OF(node, struct impl, this);
	struct pw_impl_port *port;
	struct pw_impl_node *follower;
	bool active;

	active = node->active;
	node->active = false;

	pw_log_debug(NAME" %p: destroy", impl);
	pw_log_info("(%s-%u) destroy", node->name, node->info.id);

	suspend_node(node);

	pw_impl_node_emit_destroy(node);

	pw_log_debug(NAME" %p: driver node %p", impl, node->driver_node);

	/* remove ourself as a follower from the driver node */
	spa_list_remove(&node->follower_link);
	remove_segment_owner(node->driver_node, node->info.id);

	spa_list_consume(follower, &node->follower_list, follower_link) {
		pw_log_debug(NAME" %p: reassign follower %p", impl, follower);
		pw_impl_node_set_driver(follower, NULL);
	}

	if (node->registered) {
		spa_list_remove(&node->link);
		if (node->driver)
			spa_list_remove(&node->driver_link);
	}

	if (node->node) {
		spa_hook_remove(&node->listener);
		spa_node_set_callbacks(node->node, NULL, NULL);
	}

	pw_log_debug(NAME" %p: destroy ports", node);
	spa_list_consume(port, &node->input_ports, link)
		pw_impl_port_destroy(port);
	spa_list_consume(port, &node->output_ports, link)
		pw_impl_port_destroy(port);

	if (node->global) {
		spa_hook_remove(&node->global_listener);
		pw_global_destroy(node->global);
	}

	if (active)
		pw_context_recalc_graph(node->context, "active node destroy");

	pw_log_debug(NAME" %p: free", node);
	pw_impl_node_emit_free(node);

	spa_hook_list_clean(&node->listener_list);

	pw_memblock_unref(node->activation);

	pw_work_queue_destroy(impl->work);

	pw_param_clear(&impl->param_list, SPA_ID_INVALID);
	pw_param_clear(&impl->pending_list, SPA_ID_INVALID);

	pw_map_clear(&node->input_port_map);
	pw_map_clear(&node->output_port_map);

	pw_properties_free(node->properties);

	clear_info(node);

	spa_system_close(node->context->data_system, node->source.fd);
	free(impl);
}

SPA_EXPORT
int pw_impl_node_for_each_port(struct pw_impl_node *node,
			  enum pw_direction direction,
			  int (*callback) (void *data, struct pw_impl_port *port),
			  void *data)
{
	struct spa_list *ports;
	struct pw_impl_port *p, *t;
	int res;

	if (direction == PW_DIRECTION_INPUT)
		ports = &node->input_ports;
	else
		ports = &node->output_ports;

	spa_list_for_each_safe(p, t, ports, link)
		if ((res = callback(data, p)) != 0)
			return res;
	return 0;
}

struct result_node_params_data {
	struct impl *impl;
	void *data;
	int (*callback) (void *data, int seq,
			uint32_t id, uint32_t index, uint32_t next,
			struct spa_pod *param);
	int seq;
	uint32_t count;
	unsigned int cache:1;
};

static void result_node_params(void *data, int seq, int res, uint32_t type, const void *result)
{
	struct result_node_params_data *d = data;
	struct impl *impl = d->impl;
	switch (type) {
	case SPA_RESULT_TYPE_NODE_PARAMS:
	{
		const struct spa_result_node_params *r = result;
		if (d->seq == seq) {
			d->callback(d->data, seq, r->id, r->index, r->next, r->param);
			if (d->cache) {
				if (d->count++ == 0)
					pw_param_add(&impl->pending_list, r->id, NULL);
				pw_param_add(&impl->pending_list, r->id, r->param);
			}
		}
		break;
	}
	default:
		break;
	}
}

SPA_EXPORT
int pw_impl_node_for_each_param(struct pw_impl_node *node,
			   int seq, uint32_t param_id,
			   uint32_t index, uint32_t max,
			   const struct spa_pod *filter,
			   int (*callback) (void *data, int seq,
					    uint32_t id, uint32_t index, uint32_t next,
					    struct spa_pod *param),
			   void *data)
{
	int res;
	struct impl *impl = SPA_CONTAINER_OF(node, struct impl, this);
	struct result_node_params_data user_data = { impl, data, callback, seq, 0, false };
	struct spa_hook listener;
	struct spa_param_info *pi;
	static const struct spa_node_events node_events = {
		SPA_VERSION_NODE_EVENTS,
		.result = result_node_params,
	};

	pi = pw_param_info_find(node->info.params, node->info.n_params, param_id);
	if (pi == NULL)
		return -ENOENT;

	if (max == 0)
		max = UINT32_MAX;

	pw_log_debug(NAME" %p: params id:%d (%s) index:%u max:%u cached:%d", node, param_id,
			spa_debug_type_find_name(spa_type_param, param_id),
			index, max, pi->user);

	if (pi->user == 1) {
		struct pw_param *p;
		uint8_t buffer[1024];
		struct spa_pod_builder b = { 0 };
	        struct spa_result_node_params result;
		uint32_t count = 0;

		result.id = param_id;
		result.next = 0;

		spa_list_for_each(p, &impl->param_list, link) {
			result.index = result.next++;
			if (p->id != param_id)
				continue;

			if (result.index < index)
				continue;

			spa_pod_builder_init(&b, buffer, sizeof(buffer));
			if (spa_pod_filter(&b, &result.param, p->param, filter) != 0)
				continue;

			pw_log_debug(NAME " %p: %d param %u", node, seq, result.index);
			result_node_params(&user_data, seq, 0, SPA_RESULT_TYPE_NODE_PARAMS, &result);

			if (++count == max)
				break;
		}
		res = 0;
	} else {
		user_data.cache = impl->cache_params &&
			(filter == NULL && index == 0 && max == UINT32_MAX);

		spa_zero(listener);
		spa_node_add_listener(node->node, &listener, &node_events, &user_data);
		res = spa_node_enum_params(node->node, seq,
						param_id, index, max,
						filter);
		spa_hook_remove(&listener);

		if (user_data.cache) {
			pw_param_update(&impl->param_list, &impl->pending_list);
			pi->user = 1;
		}
	}
	return res;
}

SPA_EXPORT
int pw_impl_node_set_param(struct pw_impl_node *node,
		uint32_t id, uint32_t flags, const struct spa_pod *param)
{
	pw_log_debug(NAME" %p: set_param id:%d (%s) flags:%08x param:%p", node, id,
			spa_debug_type_find_name(spa_type_param, id), flags, param);
	return spa_node_set_param(node->node, id, flags, param);
}

SPA_EXPORT
struct pw_impl_port *
pw_impl_node_find_port(struct pw_impl_node *node, enum pw_direction direction, uint32_t port_id)
{
	struct pw_impl_port *port, *p;
	struct pw_map *portmap;
	struct spa_list *ports;

	if (direction == PW_DIRECTION_INPUT) {
		portmap = &node->input_port_map;
		ports = &node->input_ports;
	} else {
		portmap = &node->output_port_map;
		ports = &node->output_ports;
	}

	if (port_id != PW_ID_ANY)
		port = pw_map_lookup(portmap, port_id);
	else {
		port = NULL;
		/* try to find an unlinked port */
		spa_list_for_each(p, ports, link) {
			if (spa_list_is_empty(&p->links)) {
				port = p;
				break;
			}
			/* We can use this port if it can multiplex */
			if (SPA_FLAG_IS_SET(p->mix_flags, PW_IMPL_PORT_MIX_FLAG_MULTI))
				port = p;
		}
	}
	pw_log_debug(NAME" %p: return %s port %d: %p", node,
			pw_direction_as_string(direction), port_id, port);
	return port;
}

SPA_EXPORT
uint32_t pw_impl_node_get_free_port_id(struct pw_impl_node *node, enum pw_direction direction)
{
	uint32_t n_ports, max_ports;
	struct pw_map *portmap;
	uint32_t port_id;
	bool dynamic;
	int res;

	if (direction == PW_DIRECTION_INPUT) {
		max_ports = node->info.max_input_ports;
		n_ports = node->info.n_input_ports;
		portmap = &node->input_port_map;
		dynamic = SPA_FLAG_IS_SET(node->spa_flags, SPA_NODE_FLAG_IN_DYNAMIC_PORTS);
	} else {
		max_ports = node->info.max_output_ports;
		n_ports = node->info.n_output_ports;
		portmap = &node->output_port_map;
		dynamic = SPA_FLAG_IS_SET(node->spa_flags, SPA_NODE_FLAG_OUT_DYNAMIC_PORTS);
	}
	pw_log_debug(NAME" %p: direction %s n_ports:%u max_ports:%u",
			node, pw_direction_as_string(direction), n_ports, max_ports);

	if (!dynamic || n_ports >= max_ports) {
		res = -ENOSPC;
		goto error;
	}

	port_id = pw_map_insert_new(portmap, NULL);
	if (port_id == SPA_ID_INVALID) {
		res = -errno;
		goto error;
	}

	pw_log_debug(NAME" %p: free port %d", node, port_id);

	return port_id;

error:
	pw_log_warn(NAME" %p: no more port available: %s", node, spa_strerror(res));
	errno = -res;
	return SPA_ID_INVALID;
}

static void on_state_complete(void *obj, void *data, int res, uint32_t seq)
{
	struct pw_impl_node *node = obj;
	struct impl *impl = SPA_CONTAINER_OF(node, struct impl, this);
	enum pw_node_state state = SPA_PTR_TO_INT(data);
	char *error = NULL;

	impl->pending_id = SPA_ID_INVALID;

	pw_log_debug(NAME" %p: state complete res:%d seq:%d", node, res, seq);
	if (impl->last_error < 0) {
		res = impl->last_error;
		impl->last_error = 0;
	}
	if (SPA_RESULT_IS_ERROR(res)) {
		if (node->info.state == PW_NODE_STATE_SUSPENDED) {
			state = PW_NODE_STATE_SUSPENDED;
			res = 0;
		} else {
			error = spa_aprintf("error changing node state: %s", spa_strerror(res));
			state = PW_NODE_STATE_ERROR;
		}
	}
	node_update_state(node, state, res, error);
}

static void node_activate(struct pw_impl_node *this)
{
	struct pw_impl_port *port;

	pw_log_debug(NAME" %p: activate", this);
	spa_list_for_each(port, &this->input_ports, link) {
		struct pw_impl_link *link;
		spa_list_for_each(link, &port->links, input_link)
			pw_impl_link_activate(link);
	}
	spa_list_for_each(port, &this->output_ports, link) {
		struct pw_impl_link *link;
		spa_list_for_each(link, &port->links, output_link)
			pw_impl_link_activate(link);
	}
}

/** Set the node state
 * \param node a \ref pw_impl_node
 * \param state a \ref pw_node_state
 * \return 0 on success < 0 on error
 *
 * Set the state of \a node to \a state.
 */
SPA_EXPORT
int pw_impl_node_set_state(struct pw_impl_node *node, enum pw_node_state state)
{
	int res = 0;
	struct impl *impl = SPA_CONTAINER_OF(node, struct impl, this);
	enum pw_node_state old = impl->pending;

	pw_log_debug(NAME" %p: set state (%s) %s -> %s, active %d", node,
			pw_node_state_as_string(node->info.state),
			pw_node_state_as_string(old),
			pw_node_state_as_string(state),
			node->active);

	if (old != state)
		pw_impl_node_emit_state_request(node, state);

	switch (state) {
	case PW_NODE_STATE_CREATING:
		return -EIO;

	case PW_NODE_STATE_SUSPENDED:
		res = suspend_node(node);
		break;

	case PW_NODE_STATE_IDLE:
		if (impl->pause_on_idle)
			res = pause_node(node);
		break;

	case PW_NODE_STATE_RUNNING:
		if (node->active) {
			node_activate(node);
			res = start_node(node);
		}
		break;

	case PW_NODE_STATE_ERROR:
		break;
	}
	if (SPA_RESULT_IS_ERROR(res))
		return res;

	if (SPA_RESULT_IS_ASYNC(res)) {
		res = spa_node_sync(node->node, res);
	}

	if (old != state) {
		if (impl->pending_id != SPA_ID_INVALID) {
			pw_work_queue_cancel(impl->work, node, impl->pending_id);
			node->info.state = impl->pending;
		}
		impl->pending = state;
		impl->pending_id = pw_work_queue_add(impl->work,
				node, res, on_state_complete, SPA_INT_TO_PTR(state));
	}
	return res;
}

SPA_EXPORT
int pw_impl_node_set_active(struct pw_impl_node *node, bool active)
{
	bool old = node->active;

	if (old != active) {
		pw_log_debug(NAME" %p: %s", node, active ? "activate" : "deactivate");

		node->active = active;
		pw_impl_node_emit_active_changed(node, active);

		if (node->registered)
			pw_context_recalc_graph(node->context,
					active ? "node activate" : "node deactivate");
	}
	return 0;
}

SPA_EXPORT
bool pw_impl_node_is_active(struct pw_impl_node *node)
{
	return node->active;
}