[babeltrace.git] / lib / graph / graph.c

/*
 * graph.c
 *
 * Babeltrace Plugin Component Graph
 *
 * Copyright 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 * Copyright 2017 Philippe Proulx <pproulx@efficios.com>
 *
 * 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 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.
 */

#define BT_LOG_TAG "GRAPH"
#include <babeltrace/lib-logging-internal.h>

#include <babeltrace/graph/component-internal.h>
#include <babeltrace/graph/graph-internal.h>
#include <babeltrace/graph/connection-internal.h>
#include <babeltrace/graph/component-sink-internal.h>
#include <babeltrace/graph/component-source.h>
#include <babeltrace/graph/component-filter.h>
#include <babeltrace/graph/port.h>
#include <babeltrace/graph/notification-internal.h>
#include <babeltrace/graph/notification-event-internal.h>
#include <babeltrace/graph/notification-packet-internal.h>
#include <babeltrace/compiler-internal.h>
#include <babeltrace/types.h>
#include <babeltrace/values.h>
#include <babeltrace/values-internal.h>
#include <babeltrace/assert-internal.h>
#include <babeltrace/assert-pre-internal.h>
#include <unistd.h>
#include <glib.h>

struct bt_graph_listener {
        void *func;
        bt_graph_listener_removed removed;
        void *data;
};

static
int init_listeners_array(GArray **listeners)
{
        int ret = 0;

        BT_ASSERT(listeners);
        *listeners = g_array_new(FALSE, TRUE, sizeof(struct bt_graph_listener));
        if (!*listeners) {
                BT_LOGE_STR("Failed to allocate one GArray.");
                ret = -1;
                goto end;
        }

end:
        return ret;
}

static
void call_remove_listeners(GArray *listeners)
{
        size_t i;

        for (i = 0; i < listeners->len; i++) {
                struct bt_graph_listener listener =
                        g_array_index(listeners, struct bt_graph_listener, i);

                if (listener.removed) {
                        listener.removed(listener.data);
                }
        }
}

static
void bt_graph_destroy(struct bt_object *obj)
{
        struct bt_graph *graph = container_of(obj,
                        struct bt_graph, base);

        /*
         * The graph's reference count is 0 if we're here. Increment
         * it to avoid a double-destroy (possibly infinitely recursive)
         * in this situation:
         *
         * 1. We put and destroy a connection.
         * 2. This connection's destructor finalizes its active
         *    notification iterators.
         * 3. A notification iterator's finalization function gets a
         *    new reference on its component (reference count goes from
         *    0 to 1).
         * 4. Since this component's reference count goes to 1, it takes
         *    a reference on its parent (this graph). This graph's
         *    reference count goes from 0 to 1.
         * 5. The notification iterator's finalization function puts its
         *    component reference (reference count goes from 1 to 0).
         * 6. Since this component's reference count goes from 1 to 0,
         *    it puts its parent (this graph). This graph's reference
         *    count goes from 1 to 0.
         * 7. Since this graph's reference count goes from 1 to 0,
         *    its destructor is called (this function).
         *
         * With the incrementation below, the graph's reference count at
         * step 4 goes from 1 to 2, and from 2 to 1 at step 6. This
         * ensures that this function is not called two times.
         */
        BT_LOGD("Destroying graph: addr=%p", graph);
        obj->ref_count++;

        /*
         * Cancel the graph to disallow some operations, like creating
         * notification iterators and adding ports to components.
         */
        (void) bt_graph_cancel(graph);

        /* Call all remove listeners */
        call_remove_listeners(graph->listeners.port_added);
        call_remove_listeners(graph->listeners.port_removed);
        call_remove_listeners(graph->listeners.ports_connected);
        call_remove_listeners(graph->listeners.ports_disconnected);

        if (graph->notifications) {
                g_ptr_array_free(graph->notifications, TRUE);
        }

        if (graph->connections) {
                BT_LOGD_STR("Destroying connections.");
                g_ptr_array_free(graph->connections, TRUE);
        }

        if (graph->components) {
                BT_LOGD_STR("Destroying components.");
                g_ptr_array_free(graph->components, TRUE);
        }

        if (graph->sinks_to_consume) {
                g_queue_free(graph->sinks_to_consume);
        }

        if (graph->listeners.port_added) {
                g_array_free(graph->listeners.port_added, TRUE);
        }

        if (graph->listeners.port_removed) {
                g_array_free(graph->listeners.port_removed, TRUE);
        }

        if (graph->listeners.ports_connected) {
                g_array_free(graph->listeners.ports_connected, TRUE);
        }

        if (graph->listeners.ports_disconnected) {
                g_array_free(graph->listeners.ports_disconnected, TRUE);
        }

        bt_object_pool_finalize(&graph->event_notif_pool);
        bt_object_pool_finalize(&graph->packet_begin_notif_pool);
        bt_object_pool_finalize(&graph->packet_end_notif_pool);
        g_free(graph);
}

static
void destroy_notification_event(struct bt_notification *notif,
                struct bt_graph *graph)
{
        bt_notification_event_destroy(notif);
}

static
void destroy_notification_packet_begin(struct bt_notification *notif,
                struct bt_graph *graph)
{
        bt_notification_packet_begin_destroy(notif);
}

static
void destroy_notification_packet_end(struct bt_notification *notif,
                struct bt_graph *graph)
{
        bt_notification_packet_end_destroy(notif);
}

static
void notify_notification_graph_is_destroyed(struct bt_notification *notif)
{
        bt_notification_unlink_graph(notif);
}

struct bt_graph *bt_graph_create(void)
{
        struct bt_graph *graph;
        int ret;

        BT_LOGD_STR("Creating graph object.");
        graph = g_new0(struct bt_graph, 1);
        if (!graph) {
                BT_LOGE_STR("Failed to allocate one graph.");
                goto end;
        }

        bt_object_init_shared(&graph->base, bt_graph_destroy);
        graph->connections = g_ptr_array_new_with_free_func(
                (GDestroyNotify) bt_object_try_spec_release);
        if (!graph->connections) {
                BT_LOGE_STR("Failed to allocate one GPtrArray.");
                goto error;
        }
        graph->components = g_ptr_array_new_with_free_func(
                (GDestroyNotify) bt_object_try_spec_release);
        if (!graph->components) {
                BT_LOGE_STR("Failed to allocate one GPtrArray.");
                goto error;
        }
        graph->sinks_to_consume = g_queue_new();
        if (!graph->sinks_to_consume) {
                BT_LOGE_STR("Failed to allocate one GQueue.");
                goto error;
        }

        bt_graph_set_can_consume(graph, BT_TRUE);
        ret = init_listeners_array(&graph->listeners.port_added);
        if (ret) {
                BT_LOGE_STR("Cannot create the \"port added\" listener array.");
                goto error;
        }

        ret = init_listeners_array(&graph->listeners.port_removed);
        if (ret) {
                BT_LOGE_STR("Cannot create the \"port removed\" listener array.");
                goto error;
        }

        ret = init_listeners_array(&graph->listeners.ports_connected);
        if (ret) {
                BT_LOGE_STR("Cannot create the \"port connected\" listener array.");
                goto error;
        }

        ret = init_listeners_array(&graph->listeners.ports_disconnected);
        if (ret) {
                BT_LOGE_STR("Cannot create the \"port disconneted\" listener array.");
                goto error;
        }

        ret = bt_object_pool_initialize(&graph->event_notif_pool,
                (bt_object_pool_new_object_func) bt_notification_event_new,
                (bt_object_pool_destroy_object_func) destroy_notification_event,
                graph);
        if (ret) {
                BT_LOGE("Failed to initialize event notification pool: ret=%d",
                        ret);
                goto error;
        }

        ret = bt_object_pool_initialize(&graph->packet_begin_notif_pool,
                (bt_object_pool_new_object_func) bt_notification_packet_begin_new,
                (bt_object_pool_destroy_object_func) destroy_notification_packet_begin,
                graph);
        if (ret) {
                BT_LOGE("Failed to initialize packet beginning notification pool: ret=%d",
                        ret);
                goto error;
        }

        ret = bt_object_pool_initialize(&graph->packet_end_notif_pool,
                (bt_object_pool_new_object_func) bt_notification_packet_end_new,
                (bt_object_pool_destroy_object_func) destroy_notification_packet_end,
                graph);
        if (ret) {
                BT_LOGE("Failed to initialize packet end notification pool: ret=%d",
                        ret);
                goto error;
        }

        graph->notifications = g_ptr_array_new_with_free_func(
                (GDestroyNotify) notify_notification_graph_is_destroyed);
        BT_LOGD("Created graph object: addr=%p", graph);

end:
        return graph;
error:
        BT_PUT(graph);
        goto end;
}

enum bt_graph_status bt_graph_connect_ports(struct bt_graph *graph,
                struct bt_port *upstream_port, struct bt_port *downstream_port,
                struct bt_connection **user_connection)
{
        enum bt_graph_status status = BT_GRAPH_STATUS_OK;
        struct bt_connection *connection = NULL;
        struct bt_graph *upstream_graph = NULL;
        struct bt_graph *downstream_graph = NULL;
        struct bt_component *upstream_component = NULL;
        struct bt_component *downstream_component = NULL;
        enum bt_component_status component_status;
        bt_bool init_can_consume;

        if (!graph) {
                BT_LOGW_STR("Invalid parameter: graph is NULL.");
                status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }
        init_can_consume = graph->can_consume;

        if (!upstream_port) {
                BT_LOGW_STR("Invalid parameter: upstream port is NULL.");
                status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }

        if (!downstream_port) {
                BT_LOGW_STR("Invalid parameter: downstream port is NULL.");
                status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }

        BT_LOGD("Connecting component ports within graph: "
                "graph-addr=%p, "
                "upstream-port-addr=%p, upstream-port-name=\"%s\", "
                "downstream-port-addr=%p, downstream-port-name=\"%s\"",
                graph, upstream_port, bt_port_get_name(upstream_port),
                downstream_port, bt_port_get_name(downstream_port));

        if (graph->canceled) {
                BT_LOGW_STR("Invalid parameter: graph is canceled.");
                status = BT_GRAPH_STATUS_CANCELED;
                goto end;
        }

        bt_graph_set_can_consume(graph, BT_FALSE);

        /* Ensure appropriate types for upstream and downstream ports. */
        if (bt_port_get_type(upstream_port) != BT_PORT_TYPE_OUTPUT) {
                BT_LOGW_STR("Invalid parameter: upstream port is not an output port.");
                status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }
        if (bt_port_get_type(downstream_port) != BT_PORT_TYPE_INPUT) {
                BT_LOGW_STR("Invalid parameter: downstream port is not an input port.");
                status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }

        /* Ensure that both ports are currently unconnected. */
        if (bt_port_is_connected(upstream_port)) {
                BT_LOGW_STR("Invalid parameter: upstream port is already connected.");
                status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }

        if (bt_port_is_connected(downstream_port)) {
                BT_LOGW_STR("Invalid parameter: downstream port is already connected.");
                status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }

        /*
         * Ensure that both ports are still attached to their creating
         * component.
         */
        upstream_component = bt_port_get_component(upstream_port);
        if (!upstream_component) {
                BT_LOGW_STR("Invalid parameter: upstream port is loose (does not belong to a component)");
                status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }

        downstream_component = bt_port_get_component(downstream_port);
        if (!downstream_component) {
                BT_LOGW_STR("Invalid parameter: downstream port is loose (does not belong to a component)");
                status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }

        BT_LOGD("Connecting component ports: "
                "upstream-comp-addr=%p, upstream-comp-name=\"%s\", "
                "downstream-comp-addr=%p, downstream-comp-name=\"%s\"",
                upstream_component, bt_component_get_name(upstream_component),
                downstream_component, bt_component_get_name(downstream_component));

        /*
         * At this point the ports are not connected yet. Both
         * components need to accept an eventual connection to their
         * port by the other port before we continue.
         */
        BT_LOGD_STR("Asking upstream component to accept the connection.");
        component_status = bt_component_accept_port_connection(
                upstream_component, upstream_port, downstream_port);
        if (component_status != BT_COMPONENT_STATUS_OK) {
                if (component_status == BT_COMPONENT_STATUS_REFUSE_PORT_CONNECTION) {
                        BT_LOGD_STR("Upstream component refused the connection.");
                } else {
                        BT_LOGW("Cannot ask upstream component to accept the connection: "
                                "status=%s", bt_component_status_string(component_status));
                }

                status = bt_graph_status_from_component_status(
                        component_status);
                goto end;
        }

        BT_LOGD_STR("Asking downstream component to accept the connection.");
        component_status = bt_component_accept_port_connection(
                downstream_component, downstream_port, upstream_port);
        if (component_status != BT_COMPONENT_STATUS_OK) {
                if (component_status == BT_COMPONENT_STATUS_REFUSE_PORT_CONNECTION) {
                        BT_LOGD_STR("Downstream component refused the connection.");
                } else {
                        BT_LOGW("Cannot ask downstream component to accept the connection: "
                                "status=%s", bt_component_status_string(component_status));
                }

                status = bt_graph_status_from_component_status(
                        component_status);
                goto end;
        }

        BT_LOGD_STR("Creating connection.");
        connection = bt_connection_create(graph, upstream_port,
                        downstream_port);
        if (!connection) {
                BT_LOGW("Cannot create connection object.");
                status = BT_GRAPH_STATUS_NOMEM;
                goto end;
        }

        BT_LOGD("Connection object created: conn-addr=%p", connection);

        /*
         * Ownership of upstream_component/downstream_component and of
         * the connection object is transferred to the graph.
         */
        g_ptr_array_add(graph->connections, connection);

        /*
         * Notify both components that their port is connected.
         */
        BT_LOGD_STR("Notifying upstream component that its port is connected.");
        bt_component_port_connected(upstream_component, upstream_port,
                downstream_port);
        BT_LOGD_STR("Notifying downstream component that its port is connected.");
        bt_component_port_connected(downstream_component, downstream_port,
                upstream_port);

        /*
         * Notify the graph's creator that both ports are connected.
         */
        BT_LOGD_STR("Notifying graph's user that new component ports are connected.");
        bt_graph_notify_ports_connected(graph, upstream_port, downstream_port);
        BT_LOGD("Connected component ports within graph: "
                "graph-addr=%p, "
                "upstream-comp-addr=%p, upstream-comp-name=\"%s\", "
                "downstream-comp-addr=%p, downstream-comp-name=\"%s\", "
                "upstream-port-addr=%p, upstream-port-name=\"%s\", "
                "downstream-port-addr=%p, downstream-port-name=\"%s\"",
                graph,
                upstream_component, bt_component_get_name(upstream_component),
                downstream_component, bt_component_get_name(downstream_component),
                upstream_port, bt_port_get_name(upstream_port),
                downstream_port, bt_port_get_name(downstream_port));

        if (user_connection) {
                /* Move reference to user */
                *user_connection = connection;
                connection = NULL;
        }

end:
        bt_put(upstream_graph);
        bt_put(downstream_graph);
        bt_put(upstream_component);
        bt_put(downstream_component);
        bt_put(connection);
        if (graph) {
                (void) init_can_consume;
                bt_graph_set_can_consume(graph, init_can_consume);
        }
        return status;
}

static inline
enum bt_graph_status consume_graph_sink(struct bt_component *sink)
{
        enum bt_component_status comp_status;

        BT_ASSERT(sink);
        comp_status = bt_component_sink_consume(sink);
        BT_LOGV("Consumed from sink: addr=%p, name=\"%s\", status=%s",
                sink, bt_component_get_name(sink),
                bt_component_status_string(comp_status));
        BT_ASSERT_PRE(comp_status == BT_COMPONENT_STATUS_OK ||
                comp_status == BT_COMPONENT_STATUS_END ||
                comp_status == BT_COMPONENT_STATUS_AGAIN ||
                comp_status == BT_COMPONENT_STATUS_ERROR ||
                comp_status == BT_COMPONENT_STATUS_NOMEM,
                "Invalid component status returned by consuming function: "
                "status=%s", bt_component_status_string(comp_status));
        return (enum bt_graph_status) comp_status;
}

/*
 * `node` is removed from the queue of sinks to consume when passed to
 * this function. This function adds it back to the queue if there's
 * still something to consume afterwards.
 */
static inline
enum bt_graph_status consume_sink_node(struct bt_graph *graph,
                GList *node)
{
        enum bt_graph_status status;
        struct bt_component *sink;

        sink = node->data;
        status = consume_graph_sink(sink);
        if (unlikely(status != BT_GRAPH_STATUS_END)) {
                g_queue_push_tail_link(graph->sinks_to_consume, node);
                goto end;
        }

        /* End reached, the node is not added back to the queue and free'd. */
        g_queue_delete_link(graph->sinks_to_consume, node);

        /* Don't forward an END status if there are sinks left to consume. */
        if (!g_queue_is_empty(graph->sinks_to_consume)) {
                status = BT_GRAPH_STATUS_OK;
                goto end;
        }

end:
        BT_LOGV("Consumed sink node: status=%s", bt_graph_status_string(status));
        return status;
}

BT_HIDDEN
enum bt_graph_status bt_graph_consume_sink_no_check(struct bt_graph *graph,
                struct bt_component *sink)
{
        enum bt_graph_status status;
        GList *sink_node;
        int index;

        BT_LOGV("Making specific sink consume: addr=%p, "
                "comp-addr=%p, comp-name=\"%s\"",
                graph, sink, bt_component_get_name(sink));

        BT_ASSERT(bt_component_borrow_graph(sink) == graph);

        if (g_queue_is_empty(graph->sinks_to_consume)) {
                BT_LOGV_STR("Graph's sink queue is empty: end of graph.");
                status = BT_GRAPH_STATUS_END;
                goto end;
        }

        index = g_queue_index(graph->sinks_to_consume, sink);
        if (index < 0) {
                BT_LOGV_STR("Sink is not marked as consumable: sink is ended.");
                status = BT_GRAPH_STATUS_END;
                goto end;
        }

        sink_node = g_queue_pop_nth_link(graph->sinks_to_consume, index);
        BT_ASSERT(sink_node);
        status = consume_sink_node(graph, sink_node);

end:
        return status;
}

static inline
enum bt_graph_status bt_graph_consume_no_check(struct bt_graph *graph)
{
        enum bt_graph_status status = BT_GRAPH_STATUS_OK;
        struct bt_component *sink;
        GList *current_node;

        BT_LOGV("Making next sink consume: addr=%p", graph);
        BT_ASSERT_PRE(graph->has_sink,
                "Graph has no sink component: %!+g", graph);

        if (unlikely(g_queue_is_empty(graph->sinks_to_consume))) {
                BT_LOGV_STR("Graph's sink queue is empty: end of graph.");
                status = BT_GRAPH_STATUS_END;
                goto end;
        }

        current_node = g_queue_pop_head_link(graph->sinks_to_consume);
        sink = current_node->data;
        BT_LOGV("Chose next sink to consume: comp-addr=%p, comp-name=\"%s\"",
                sink, bt_component_get_name(sink));
        status = consume_sink_node(graph, current_node);

end:
        return status;
}

enum bt_graph_status bt_graph_consume(struct bt_graph *graph)
{
        enum bt_graph_status status;

        BT_ASSERT_PRE_NON_NULL(graph, "Graph");
        BT_ASSERT_PRE(!graph->canceled, "Graph is canceled: %!+g", graph);
        BT_ASSERT_PRE(graph->can_consume,
                "Cannot consume graph in its current state: %!+g", graph);
        bt_graph_set_can_consume(graph, BT_FALSE);
        status = bt_graph_consume_no_check(graph);
        bt_graph_set_can_consume(graph, BT_TRUE);
        return status;
}

enum bt_graph_status bt_graph_run(struct bt_graph *graph)
{
        enum bt_graph_status status = BT_GRAPH_STATUS_OK;

        if (!graph) {
                BT_LOGW_STR("Invalid parameter: graph is NULL.");
                status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }

        if (graph->canceled) {
                BT_LOGW("Invalid parameter: graph is canceled: "
                        "graph-addr=%p", graph);
                status = BT_GRAPH_STATUS_CANCELED;
                goto end;
        }

        BT_ASSERT_PRE(graph->can_consume,
                "Cannot consume graph in its current state: %!+g", graph);
        bt_graph_set_can_consume(graph, BT_FALSE);
        BT_LOGV("Running graph: addr=%p", graph);

        do {
                /*
                 * Check if the graph is canceled at each iteration. If
                 * the graph was canceled by another thread or by a
                 * signal, this is not a warning nor an error, it was
                 * intentional: log with a DEBUG level only.
                 */
                if (unlikely(graph->canceled)) {
                        BT_LOGD("Stopping the graph: graph is canceled: "
                                "graph-addr=%p", graph);
                        status = BT_GRAPH_STATUS_CANCELED;
                        goto end;
                }

                status = bt_graph_consume_no_check(graph);
                if (unlikely(status == BT_GRAPH_STATUS_AGAIN)) {
                        /*
                         * If AGAIN is received and there are multiple
                         * sinks, go ahead and consume from the next
                         * sink.
                         *
                         * However, in the case where a single sink is
                         * left, the caller can decide to busy-wait and
                         * call bt_graph_run() continuously until the
                         * source is ready or it can decide to sleep for
                         * an arbitrary amount of time.
                         */
                        if (graph->sinks_to_consume->length > 1) {
                                status = BT_GRAPH_STATUS_OK;
                        }
                } else if (status == BT_GRAPH_STATUS_NO_SINK) {
                        goto end;
                }
        } while (status == BT_GRAPH_STATUS_OK);

        if (g_queue_is_empty(graph->sinks_to_consume)) {
                status = BT_GRAPH_STATUS_END;
        }

end:
        BT_LOGV("Graph ran: status=%s", bt_graph_status_string(status));
        if (graph) {
                bt_graph_set_can_consume(graph, BT_TRUE);
        }
        return status;
}

static
int add_listener(GArray *listeners, void *func, void *removed, void *data)
{
        struct bt_graph_listener listener = {
                .func = func,
                .removed = removed,
                .data = data,
        };

        g_array_append_val(listeners, listener);
        return listeners->len - 1;
}

int bt_graph_add_port_added_listener(
                struct bt_graph *graph,
                bt_graph_port_added_listener listener,
                bt_graph_listener_removed listener_removed, void *data)
{
        int ret;

        if (!graph) {
                BT_LOGW_STR("Invalid parameter: graph is NULL.");
                ret = -1;
                goto end;
        }

        if (graph->in_remove_listener) {
                BT_LOGW("Cannot call this function during the execution of a remove listener: "
                        "addr=%p", graph);
                ret = -1;
                goto end;
        }

        if (!listener) {
                BT_LOGW_STR("Invalid parameter: listener is NULL.");
                ret = -1;
                goto end;
        }

        ret = add_listener(graph->listeners.port_added, listener,
                listener_removed, data);
        BT_LOGV("Added \"port added\" listener to graph: "
                "graph-addr=%p, listener-addr=%p, pos=%d",
                graph, listener, ret);

end:
        return ret;
}

int bt_graph_add_port_removed_listener(
                struct bt_graph *graph,
                bt_graph_port_removed_listener listener,
                bt_graph_listener_removed listener_removed, void *data)
{
        int ret;

        if (!graph) {
                BT_LOGW_STR("Invalid parameter: graph is NULL.");
                ret = -1;
                goto end;
        }

        if (graph->in_remove_listener) {
                BT_LOGW("Cannot call this function during the execution of a remove listener: "
                        "addr=%p", graph);
                ret = -1;
                goto end;
        }

        if (!listener) {
                BT_LOGW_STR("Invalid parameter: listener is NULL.");
                ret = -1;
                goto end;
        }

        ret = add_listener(graph->listeners.port_removed, listener,
                listener_removed, data);
        BT_LOGV("Added \"port removed\" listener to graph: "
                "graph-addr=%p, listener-addr=%p, pos=%d",
                graph, listener, ret);

end:
        return ret;
}

int bt_graph_add_ports_connected_listener(
                struct bt_graph *graph,
                bt_graph_ports_connected_listener listener,
                bt_graph_listener_removed listener_removed, void *data)
{
        int ret;

        if (!graph) {
                BT_LOGW_STR("Invalid parameter: graph is NULL.");
                ret = -1;
                goto end;
        }

        if (graph->in_remove_listener) {
                BT_LOGW("Cannot call this function during the execution of a remove listener: "
                        "addr=%p", graph);
                ret = -1;
                goto end;
        }

        if (!listener) {
                BT_LOGW_STR("Invalid parameter: listener is NULL.");
                ret = -1;
                goto end;
        }

        ret = add_listener(graph->listeners.ports_connected, listener,
                listener_removed, data);
        BT_LOGV("Added \"port connected\" listener to graph: "
                "graph-addr=%p, listener-addr=%p, pos=%d",
                graph, listener, ret);

end:
        return ret;
}

int bt_graph_add_ports_disconnected_listener(
                struct bt_graph *graph,
                bt_graph_ports_disconnected_listener listener,
                bt_graph_listener_removed listener_removed, void *data)
{
        int ret;

        if (!graph) {
                BT_LOGW_STR("Invalid parameter: graph is NULL.");
                ret = -1;
                goto end;
        }

        if (graph->in_remove_listener) {
                BT_LOGW("Cannot call this function during the execution of a remove listener: "
                        "addr=%p", graph);
                ret = -1;
                goto end;
        }

        if (!listener) {
                BT_LOGW_STR("Invalid parameter: listener is NULL.");
                ret = -1;
                goto end;
        }

        ret = add_listener(graph->listeners.ports_disconnected, listener,
                listener_removed, data);
        BT_LOGV("Added \"port disconnected\" listener to graph: "
                "graph-addr=%p, listener-addr=%p, pos=%d",
                graph, listener, ret);

end:
        return ret;
}

BT_HIDDEN
void bt_graph_notify_port_added(struct bt_graph *graph, struct bt_port *port)
{
        size_t i;

        BT_LOGV("Notifying graph listeners that a port was added: "
                "graph-addr=%p, port-addr=%p, port-name=\"%s\"",
                graph, port, bt_port_get_name(port));

        for (i = 0; i < graph->listeners.port_added->len; i++) {
                struct bt_graph_listener listener =
                        g_array_index(graph->listeners.port_added,
                                struct bt_graph_listener, i);
                bt_graph_port_added_listener func = listener.func;

                BT_ASSERT(func);
                func(port, listener.data);
        }
}

BT_HIDDEN
void bt_graph_notify_port_removed(struct bt_graph *graph,
                struct bt_component *comp, struct bt_port *port)
{
        size_t i;

        BT_LOGV("Notifying graph listeners that a port was removed: "
                "graph-addr=%p, port-addr=%p, port-name=\"%s\"",
                graph, port, bt_port_get_name(port));

        for (i = 0; i < graph->listeners.port_removed->len; i++) {
                struct bt_graph_listener listener =
                        g_array_index(graph->listeners.port_removed,
                                struct bt_graph_listener, i);
                bt_graph_port_removed_listener func = listener.func;

                BT_ASSERT(func);
                func(comp, port, listener.data);
        }
}

BT_HIDDEN
void bt_graph_notify_ports_connected(struct bt_graph *graph,
                struct bt_port *upstream_port, struct bt_port *downstream_port)
{
        size_t i;

        BT_LOGV("Notifying graph listeners that two ports were connected: "
                "graph-addr=%p, "
                "upstream-port-addr=%p, upstream-port-name=\"%s\", "
                "downstream-port-addr=%p, downstream-port-name=\"%s\"",
                graph, upstream_port, bt_port_get_name(upstream_port),
                downstream_port, bt_port_get_name(downstream_port));

        for (i = 0; i < graph->listeners.ports_connected->len; i++) {
                struct bt_graph_listener listener =
                        g_array_index(graph->listeners.ports_connected,
                                struct bt_graph_listener, i);
                bt_graph_ports_connected_listener func = listener.func;

                BT_ASSERT(func);
                func(upstream_port, downstream_port, listener.data);
        }
}

BT_HIDDEN
void bt_graph_notify_ports_disconnected(struct bt_graph *graph,
                struct bt_component *upstream_comp,
                struct bt_component *downstream_comp,
                struct bt_port *upstream_port, struct bt_port *downstream_port)
{
        size_t i;

        BT_LOGV("Notifying graph listeners that two ports were disconnected: "
                "graph-addr=%p, "
                "upstream-port-addr=%p, upstream-port-name=\"%s\", "
                "downstream-port-addr=%p, downstream-port-name=\"%s\"",
                graph, upstream_port, bt_port_get_name(upstream_port),
                downstream_port, bt_port_get_name(downstream_port));

        for (i = 0; i < graph->listeners.ports_disconnected->len; i++) {
                struct bt_graph_listener listener =
                        g_array_index(graph->listeners.ports_disconnected,
                                struct bt_graph_listener, i);
                bt_graph_ports_disconnected_listener func = listener.func;

                BT_ASSERT(func);
                func(upstream_comp, downstream_comp, upstream_port,
                        downstream_port, listener.data);
        }
}

enum bt_graph_status bt_graph_cancel(struct bt_graph *graph)
{
        enum bt_graph_status ret = BT_GRAPH_STATUS_OK;

        if (!graph) {
                BT_LOGW_STR("Invalid parameter: graph is NULL.");
                ret = BT_GRAPH_STATUS_INVALID;
                goto end;
        }

        graph->canceled = BT_TRUE;
        BT_LOGV("Canceled graph: addr=%p", graph);

end:
        return ret;
}

bt_bool bt_graph_is_canceled(struct bt_graph *graph)
{
        bt_bool canceled = BT_FALSE;

        if (!graph) {
                BT_LOGW_STR("Invalid parameter: graph is NULL.");
                goto end;
        }

        canceled = graph->canceled;

end:
        return canceled;
}

BT_HIDDEN
void bt_graph_remove_connection(struct bt_graph *graph,
                struct bt_connection *connection)
{
        BT_ASSERT(graph);
        BT_ASSERT(connection);
        BT_LOGV("Removing graph's connection: graph-addr=%p, conn-addr=%p",
                graph, connection);
        g_ptr_array_remove(graph->connections, connection);
}

enum bt_graph_status bt_graph_add_component_with_init_method_data(
                struct bt_graph *graph,
                struct bt_component_class *component_class,
                const char *name, struct bt_value *params,
                void *init_method_data,
                struct bt_component **user_component)
{
        enum bt_graph_status graph_status = BT_GRAPH_STATUS_OK;
        enum bt_component_status comp_status;
        struct bt_component *component = NULL;
        enum bt_component_class_type type;
        size_t i;
        bt_bool init_can_consume;

        bt_get(params);

        if (!graph) {
                BT_LOGW_STR("Invalid parameter: graph is NULL.");
                graph_status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }
        init_can_consume = graph->can_consume;

        if (!component_class) {
                BT_LOGW_STR("Invalid parameter: component class is NULL.");
                graph_status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }

        graph->can_consume = BT_FALSE;
        type = bt_component_class_get_type(component_class);
        BT_LOGD("Adding component to graph: "
                "graph-addr=%p, comp-cls-addr=%p, "
                "comp-cls-type=%s, name=\"%s\", params-addr=%p, "
                "init-method-data-addr=%p",
                graph, component_class, bt_component_class_type_string(type),
                name, params, init_method_data);

        if (!name) {
                BT_LOGW_STR("Invalid parameter: name is NULL.");
                graph_status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }

        if (graph->canceled) {
                BT_LOGW_STR("Invalid parameter: graph is canceled.");
                graph_status = BT_GRAPH_STATUS_CANCELED;
                goto end;
        }

        if (type != BT_COMPONENT_CLASS_TYPE_SOURCE &&
                        type != BT_COMPONENT_CLASS_TYPE_FILTER &&
                        type != BT_COMPONENT_CLASS_TYPE_SINK) {
                BT_LOGW("Invalid parameter: unknown component class type: "
                        "type=%d", type);
                graph_status = BT_GRAPH_STATUS_INVALID;
                goto end;
        }

        for (i = 0; i < graph->components->len; i++) {
                void *other_comp = graph->components->pdata[i];

                if (strcmp(name, bt_component_get_name(other_comp)) == 0) {
                        BT_LOGW("Invalid parameter: another component with the same name already exists in the graph: "
                                "other-comp-addr=%p, name=\"%s\"",
                                other_comp, name);
                        graph_status = BT_GRAPH_STATUS_INVALID;
                        goto end;
                }
        }

        /*
         * Parameters must be a map value, but we create a convenient
         * empty one if it's NULL.
         */
        if (params) {
                if (!bt_value_is_map(params)) {
                        BT_LOGW("Invalid parameter: initialization parameters must be a map value: "
                                "type=%s",
                                bt_value_type_string(bt_value_get_type(params)));
                        graph_status = BT_GRAPH_STATUS_INVALID;
                        goto end;
                }
        } else {
                params = bt_value_map_create();
                if (!params) {
                        BT_LOGE_STR("Cannot create map value object.");
                        graph_status = BT_GRAPH_STATUS_NOMEM;
                        goto end;
                }
        }

        comp_status = bt_component_create(component_class, name, &component);
        if (comp_status != BT_COMPONENT_STATUS_OK) {
                BT_LOGE("Cannot create empty component object: status=%s",
                        bt_component_status_string(comp_status));
                graph_status = bt_graph_status_from_component_status(
                        comp_status);
                goto end;
        }

        /*
         * The user's initialization method needs to see that this
         * component is part of the graph. If the user method fails, we
         * immediately remove the component from the graph's components.
         */
        g_ptr_array_add(graph->components, component);
        bt_component_set_graph(component, graph);

        if (component_class->methods.init) {
                BT_LOGD_STR("Calling user's initialization method.");
                comp_status = component_class->methods.init(
                        bt_private_component_from_component(component), params,
                        init_method_data);
                BT_LOGD("User method returned: status=%s",
                        bt_component_status_string(comp_status));
                if (comp_status != BT_COMPONENT_STATUS_OK) {
                        BT_LOGW_STR("Initialization method failed.");
                        graph_status = bt_graph_status_from_component_status(
                                comp_status);
                        bt_component_set_graph(component, NULL);
                        g_ptr_array_remove_fast(graph->components, component);
                        goto end;
                }
        }

        /*
         * Mark the component as initialized so that its finalization
         * method is called when it is destroyed.
         */
        component->initialized = true;

        /*
         * If it's a sink component, it needs to be part of the graph's
         * sink queue to be consumed by bt_graph_consume().
         */
        if (bt_component_is_sink(component)) {
                graph->has_sink = BT_TRUE;
                g_queue_push_tail(graph->sinks_to_consume, component);
        }

        /*
         * Freeze the component class now that it's instantiated at
         * least once.
         */
        BT_LOGD_STR("Freezing component class.");
        bt_component_class_freeze(component->class);
        BT_LOGD("Added component to graph: "
                "graph-addr=%p, comp-cls-addr=%p, "
                "comp-cls-type=%s, name=\"%s\", params-addr=%p, "
                "init-method-data-addr=%p, comp-addr=%p",
                graph, component_class, bt_component_class_type_string(type),
                name, params, init_method_data, component);

        if (user_component) {
                /* Move reference to user */
                *user_component = component;
                component = NULL;
        }

end:
        bt_put(component);
        bt_put(params);
        if (graph) {
                graph->can_consume = init_can_consume;
        }
        return graph_status;
}

enum bt_graph_status bt_graph_add_component(
                struct bt_graph *graph,
                struct bt_component_class *component_class,
                const char *name, struct bt_value *params,
                struct bt_component **component)
{
        return bt_graph_add_component_with_init_method_data(graph,
                component_class, name, params, NULL, component);
}

BT_HIDDEN
int bt_graph_remove_unconnected_component(struct bt_graph *graph,
                struct bt_component *component)
{
        bt_bool init_can_consume;
        int64_t count;
        uint64_t i;
        int ret = 0;

        BT_ASSERT(graph);
        BT_ASSERT(component);
        BT_ASSERT(component->base.ref_count == 0);
        BT_ASSERT(bt_component_borrow_graph(component) == graph);

        init_can_consume = graph->can_consume;
        count = bt_component_get_input_port_count(component);

        for (i = 0; i < count; i++) {
                struct bt_port *port =
                        bt_component_get_input_port_by_index(component, i);

                BT_ASSERT(port);
                bt_put(port);

                if (bt_port_is_connected(port)) {
                        BT_LOGW("Cannot remove component from graph: "
                                "an input port is connected: "
                                "graph-addr=%p, comp-addr=%p, "
                                "comp-name=\"%s\", connected-port-addr=%p, "
                                "connected-port-name=\"%s\"",
                                graph, component,
                                bt_component_get_name(component),
                                port, bt_port_get_name(port));
                        goto error;
                }
        }

        count = bt_component_get_output_port_count(component);

        for (i = 0; i < count; i++) {
                struct bt_port *port =
                        bt_component_get_output_port_by_index(component, i);

                BT_ASSERT(port);
                bt_put(port);

                if (bt_port_is_connected(port)) {
                        BT_LOGW("Cannot remove component from graph: "
                                "an output port is connected: "
                                "graph-addr=%p, comp-addr=%p, "
                                "comp-name=\"%s\", connected-port-addr=%p, "
                                "connected-port-name=\"%s\"",
                                graph, component,
                                bt_component_get_name(component),
                                port, bt_port_get_name(port));
                        goto error;
                }
        }

        graph->can_consume = BT_FALSE;

        /* Possibly remove from sinks to consume */
        (void) g_queue_remove(graph->sinks_to_consume, component);

        if (graph->sinks_to_consume->length == 0) {
                graph->has_sink = BT_FALSE;
        }

        /*
         * This calls bt_object_try_spec_release() on the component, and
         * since its reference count is 0, its destructor is called. Its
         * destructor calls the user's finalization method (if set).
         */
        g_ptr_array_remove(graph->components, component);
        goto end;

error:
        ret = -1;

end:
        graph->can_consume = init_can_consume;
        return ret;
}

BT_HIDDEN
void bt_graph_add_notification(struct bt_graph *graph,
                struct bt_notification *notif)
{
        BT_ASSERT(graph);
        BT_ASSERT(notif);

        /*
         * It's okay not to take a reference because, when a
         * notification's reference count drops to 0, either:
         *
         * * It is recycled back to one of this graph's pool.
         * * It is destroyed because it doesn't have any link to any
         *   graph, which means the original graph is already destroyed.
         */
        g_ptr_array_add(graph->notifications, notif);
}