lib/graph/graph.c

   1 /*
   2  * graph.c
   3  *
   4  * Babeltrace Plugin Component Graph
   5  *
   6  * Copyright 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   7  * Copyright 2017 Philippe Proulx <pproulx@efficios.com>
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a copy
  10  * of this software and associated documentation files (the "Software"), to deal
  11  * in the Software without restriction, including without limitation the rights
  12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13  * copies of the Software, and to permit persons to whom the Software is
  14  * furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included in
  17  * all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  22  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  25  * SOFTWARE.
  26  */
  27
  28 #define BT_LOG_TAG "GRAPH"
  29 #include <babeltrace/lib-logging-internal.h>
  30
  31 #include <babeltrace/graph/component-internal.h>
  32 #include <babeltrace/graph/graph-internal.h>
  33 #include <babeltrace/graph/connection-internal.h>
  34 #include <babeltrace/graph/component-sink-internal.h>
  35 #include <babeltrace/graph/component-source.h>
  36 #include <babeltrace/graph/component-filter.h>
  37 #include <babeltrace/graph/port.h>
  38 #include <babeltrace/graph/notification-internal.h>
  39 #include <babeltrace/graph/notification-event-internal.h>
  40 #include <babeltrace/graph/notification-packet-internal.h>
  41 #include <babeltrace/compiler-internal.h>
  42 #include <babeltrace/types.h>
  43 #include <babeltrace/values.h>
  44 #include <babeltrace/values-internal.h>
  45 #include <babeltrace/assert-internal.h>
  46 #include <babeltrace/assert-pre-internal.h>
  47 #include <unistd.h>
  48 #include <glib.h>
  49
  50 struct bt_graph_listener {
  51         void *func;
  52         bt_graph_listener_removed removed;
  53         void *data;
  54 };
  55
  56 static
  57 int init_listeners_array(GArray **listeners)
  58 {
  59         int ret = 0;
  60
  61         BT_ASSERT(listeners);
  62         *listeners = g_array_new(FALSE, TRUE, sizeof(struct bt_graph_listener));
  63         if (!*listeners) {
  64                 BT_LOGE_STR("Failed to allocate one GArray.");
  65                 ret = -1;
  66                 goto end;
  67         }
  68
  69 end:
  70         return ret;
  71 }
  72
  73 static
  74 void call_remove_listeners(GArray *listeners)
  75 {
  76         size_t i;
  77
  78         for (i = 0; i < listeners->len; i++) {
  79                 struct bt_graph_listener listener =
  80                         g_array_index(listeners, struct bt_graph_listener, i);
  81
  82                 if (listener.removed) {
  83                         listener.removed(listener.data);
  84                 }
  85         }
  86 }
  87
  88 static
  89 void bt_graph_destroy(struct bt_object *obj)
  90 {
  91         struct bt_graph *graph = container_of(obj,
  92                         struct bt_graph, base);
  93
  94         /*
  95          * The graph's reference count is 0 if we're here. Increment
  96          * it to avoid a double-destroy (possibly infinitely recursive)
  97          * in this situation:
  98          *
  99          * 1. We put and destroy a connection.
 100          * 2. This connection's destructor finalizes its active
 101          *    notification iterators.
 102          * 3. A notification iterator's finalization function gets a
 103          *    new reference on its component (reference count goes from
 104          *    0 to 1).
 105          * 4. Since this component's reference count goes to 1, it takes
 106          *    a reference on its parent (this graph). This graph's
 107          *    reference count goes from 0 to 1.
 108          * 5. The notification iterator's finalization function puts its
 109          *    component reference (reference count goes from 1 to 0).
 110          * 6. Since this component's reference count goes from 1 to 0,
 111          *    it puts its parent (this graph). This graph's reference
 112          *    count goes from 1 to 0.
 113          * 7. Since this graph's reference count goes from 1 to 0,
 114          *    its destructor is called (this function).
 115          *
 116          * With the incrementation below, the graph's reference count at
 117          * step 4 goes from 1 to 2, and from 2 to 1 at step 6. This
 118          * ensures that this function is not called two times.
 119          */
 120         BT_LOGD("Destroying graph: addr=%p", graph);
 121         obj->ref_count++;
 122
 123         /*
 124          * Cancel the graph to disallow some operations, like creating
 125          * notification iterators and adding ports to components.
 126          */
 127         (void) bt_graph_cancel(graph);
 128
 129         /* Call all remove listeners */
 130         call_remove_listeners(graph->listeners.port_added);
 131         call_remove_listeners(graph->listeners.port_removed);
 132         call_remove_listeners(graph->listeners.ports_connected);
 133         call_remove_listeners(graph->listeners.ports_disconnected);
 134
 135         if (graph->notifications) {
 136                 g_ptr_array_free(graph->notifications, TRUE);
 137         }
 138
 139         if (graph->connections) {
 140                 BT_LOGD_STR("Destroying connections.");
 141                 g_ptr_array_free(graph->connections, TRUE);
 142         }
 143
 144         if (graph->components) {
 145                 BT_LOGD_STR("Destroying components.");
 146                 g_ptr_array_free(graph->components, TRUE);
 147         }
 148
 149         if (graph->sinks_to_consume) {
 150                 g_queue_free(graph->sinks_to_consume);
 151         }
 152
 153         if (graph->listeners.port_added) {
 154                 g_array_free(graph->listeners.port_added, TRUE);
 155         }
 156
 157         if (graph->listeners.port_removed) {
 158                 g_array_free(graph->listeners.port_removed, TRUE);
 159         }
 160
 161         if (graph->listeners.ports_connected) {
 162                 g_array_free(graph->listeners.ports_connected, TRUE);
 163         }
 164
 165         if (graph->listeners.ports_disconnected) {
 166                 g_array_free(graph->listeners.ports_disconnected, TRUE);
 167         }
 168
 169         bt_object_pool_finalize(&graph->event_notif_pool);
 170         bt_object_pool_finalize(&graph->packet_begin_notif_pool);
 171         bt_object_pool_finalize(&graph->packet_end_notif_pool);
 172         g_free(graph);
 173 }
 174
 175 static
 176 void destroy_notification_event(struct bt_notification *notif,
 177                 struct bt_graph *graph)
 178 {
 179         bt_notification_event_destroy(notif);
 180 }
 181
 182 static
 183 void destroy_notification_packet_begin(struct bt_notification *notif,
 184                 struct bt_graph *graph)
 185 {
 186         bt_notification_packet_begin_destroy(notif);
 187 }
 188
 189 static
 190 void destroy_notification_packet_end(struct bt_notification *notif,
 191                 struct bt_graph *graph)
 192 {
 193         bt_notification_packet_end_destroy(notif);
 194 }
 195
 196 static
 197 void notify_notification_graph_is_destroyed(struct bt_notification *notif)
 198 {
 199         bt_notification_unlink_graph(notif);
 200 }
 201
 202 struct bt_graph *bt_graph_create(void)
 203 {
 204         struct bt_graph *graph;
 205         int ret;
 206
 207         BT_LOGD_STR("Creating graph object.");
 208         graph = g_new0(struct bt_graph, 1);
 209         if (!graph) {
 210                 BT_LOGE_STR("Failed to allocate one graph.");
 211                 goto end;
 212         }
 213
 214         bt_object_init_shared(&graph->base, bt_graph_destroy);
 215         graph->connections = g_ptr_array_new_with_free_func(
 216                 (GDestroyNotify) bt_object_try_spec_release);
 217         if (!graph->connections) {
 218                 BT_LOGE_STR("Failed to allocate one GPtrArray.");
 219                 goto error;
 220         }
 221         graph->components = g_ptr_array_new_with_free_func(
 222                 (GDestroyNotify) bt_object_try_spec_release);
 223         if (!graph->components) {
 224                 BT_LOGE_STR("Failed to allocate one GPtrArray.");
 225                 goto error;
 226         }
 227         graph->sinks_to_consume = g_queue_new();
 228         if (!graph->sinks_to_consume) {
 229                 BT_LOGE_STR("Failed to allocate one GQueue.");
 230                 goto error;
 231         }
 232
 233         bt_graph_set_can_consume(graph, BT_TRUE);
 234         ret = init_listeners_array(&graph->listeners.port_added);
 235         if (ret) {
 236                 BT_LOGE_STR("Cannot create the \"port added\" listener array.");
 237                 goto error;
 238         }
 239
 240         ret = init_listeners_array(&graph->listeners.port_removed);
 241         if (ret) {
 242                 BT_LOGE_STR("Cannot create the \"port removed\" listener array.");
 243                 goto error;
 244         }
 245
 246         ret = init_listeners_array(&graph->listeners.ports_connected);
 247         if (ret) {
 248                 BT_LOGE_STR("Cannot create the \"port connected\" listener array.");
 249                 goto error;
 250         }
 251
 252         ret = init_listeners_array(&graph->listeners.ports_disconnected);
 253         if (ret) {
 254                 BT_LOGE_STR("Cannot create the \"port disconneted\" listener array.");
 255                 goto error;
 256         }
 257
 258         ret = bt_object_pool_initialize(&graph->event_notif_pool,
 259                 (bt_object_pool_new_object_func) bt_notification_event_new,
 260                 (bt_object_pool_destroy_object_func) destroy_notification_event,
 261                 graph);
 262         if (ret) {
 263                 BT_LOGE("Failed to initialize event notification pool: ret=%d",
 264                         ret);
 265                 goto error;
 266         }
 267
 268         ret = bt_object_pool_initialize(&graph->packet_begin_notif_pool,
 269                 (bt_object_pool_new_object_func) bt_notification_packet_begin_new,
 270                 (bt_object_pool_destroy_object_func) destroy_notification_packet_begin,
 271                 graph);
 272         if (ret) {
 273                 BT_LOGE("Failed to initialize packet beginning notification pool: ret=%d",
 274                         ret);
 275                 goto error;
 276         }
 277
 278         ret = bt_object_pool_initialize(&graph->packet_end_notif_pool,
 279                 (bt_object_pool_new_object_func) bt_notification_packet_end_new,
 280                 (bt_object_pool_destroy_object_func) destroy_notification_packet_end,
 281                 graph);
 282         if (ret) {
 283                 BT_LOGE("Failed to initialize packet end notification pool: ret=%d",
 284                         ret);
 285                 goto error;
 286         }
 287
 288         graph->notifications = g_ptr_array_new_with_free_func(
 289                 (GDestroyNotify) notify_notification_graph_is_destroyed);
 290         BT_LOGD("Created graph object: addr=%p", graph);
 291
 292 end:
 293         return graph;
 294 error:
 295         BT_OBJECT_PUT_REF_AND_RESET(graph);
 296         goto end;
 297 }
 298
 299 enum bt_graph_status bt_graph_connect_ports(struct bt_graph *graph,
 300                 struct bt_port *upstream_port, struct bt_port *downstream_port,
 301                 struct bt_connection **user_connection)
 302 {
 303         enum bt_graph_status status = BT_GRAPH_STATUS_OK;
 304         struct bt_connection *connection = NULL;
 305         struct bt_graph *upstream_graph = NULL;
 306         struct bt_graph *downstream_graph = NULL;
 307         struct bt_component *upstream_component = NULL;
 308         struct bt_component *downstream_component = NULL;
 309         enum bt_component_status component_status;
 310         bt_bool init_can_consume;
 311
 312         if (!graph) {
 313                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 314                 status = BT_GRAPH_STATUS_INVALID;
 315                 goto end;
 316         }
 317         init_can_consume = graph->can_consume;
 318
 319         if (!upstream_port) {
 320                 BT_LOGW_STR("Invalid parameter: upstream port is NULL.");
 321                 status = BT_GRAPH_STATUS_INVALID;
 322                 goto end;
 323         }
 324
 325         if (!downstream_port) {
 326                 BT_LOGW_STR("Invalid parameter: downstream port is NULL.");
 327                 status = BT_GRAPH_STATUS_INVALID;
 328                 goto end;
 329         }
 330
 331         BT_LOGD("Connecting component ports within graph: "
 332                 "graph-addr=%p, "
 333                 "upstream-port-addr=%p, upstream-port-name=\"%s\", "
 334                 "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 335                 graph, upstream_port, bt_port_get_name(upstream_port),
 336                 downstream_port, bt_port_get_name(downstream_port));
 337
 338         if (graph->canceled) {
 339                 BT_LOGW_STR("Invalid parameter: graph is canceled.");
 340                 status = BT_GRAPH_STATUS_CANCELED;
 341                 goto end;
 342         }
 343
 344         bt_graph_set_can_consume(graph, BT_FALSE);
 345
 346         /* Ensure appropriate types for upstream and downstream ports. */
 347         if (bt_port_get_type(upstream_port) != BT_PORT_TYPE_OUTPUT) {
 348                 BT_LOGW_STR("Invalid parameter: upstream port is not an output port.");
 349                 status = BT_GRAPH_STATUS_INVALID;
 350                 goto end;
 351         }
 352         if (bt_port_get_type(downstream_port) != BT_PORT_TYPE_INPUT) {
 353                 BT_LOGW_STR("Invalid parameter: downstream port is not an input port.");
 354                 status = BT_GRAPH_STATUS_INVALID;
 355                 goto end;
 356         }
 357
 358         /* Ensure that both ports are currently unconnected. */
 359         if (bt_port_is_connected(upstream_port)) {
 360                 BT_LOGW_STR("Invalid parameter: upstream port is already connected.");
 361                 status = BT_GRAPH_STATUS_INVALID;
 362                 goto end;
 363         }
 364
 365         if (bt_port_is_connected(downstream_port)) {
 366                 BT_LOGW_STR("Invalid parameter: downstream port is already connected.");
 367                 status = BT_GRAPH_STATUS_INVALID;
 368                 goto end;
 369         }
 370
 371         /*
 372          * Ensure that both ports are still attached to their creating
 373          * component.
 374          */
 375         upstream_component = bt_port_get_component(upstream_port);
 376         if (!upstream_component) {
 377                 BT_LOGW_STR("Invalid parameter: upstream port is loose (does not belong to a component)");
 378                 status = BT_GRAPH_STATUS_INVALID;
 379                 goto end;
 380         }
 381
 382         downstream_component = bt_port_get_component(downstream_port);
 383         if (!downstream_component) {
 384                 BT_LOGW_STR("Invalid parameter: downstream port is loose (does not belong to a component)");
 385                 status = BT_GRAPH_STATUS_INVALID;
 386                 goto end;
 387         }
 388
 389         BT_LOGD("Connecting component ports: "
 390                 "upstream-comp-addr=%p, upstream-comp-name=\"%s\", "
 391                 "downstream-comp-addr=%p, downstream-comp-name=\"%s\"",
 392                 upstream_component, bt_component_get_name(upstream_component),
 393                 downstream_component, bt_component_get_name(downstream_component));
 394
 395         /*
 396          * At this point the ports are not connected yet. Both
 397          * components need to accept an eventual connection to their
 398          * port by the other port before we continue.
 399          */
 400         BT_LOGD_STR("Asking upstream component to accept the connection.");
 401         component_status = bt_component_accept_port_connection(
 402                 upstream_component, upstream_port, downstream_port);
 403         if (component_status != BT_COMPONENT_STATUS_OK) {
 404                 if (component_status == BT_COMPONENT_STATUS_REFUSE_PORT_CONNECTION) {
 405                         BT_LOGD_STR("Upstream component refused the connection.");
 406                 } else {
 407                         BT_LOGW("Cannot ask upstream component to accept the connection: "
 408                                 "status=%s", bt_component_status_string(component_status));
 409                 }
 410
 411                 status = bt_graph_status_from_component_status(
 412                         component_status);
 413                 goto end;
 414         }
 415
 416         BT_LOGD_STR("Asking downstream component to accept the connection.");
 417         component_status = bt_component_accept_port_connection(
 418                 downstream_component, downstream_port, upstream_port);
 419         if (component_status != BT_COMPONENT_STATUS_OK) {
 420                 if (component_status == BT_COMPONENT_STATUS_REFUSE_PORT_CONNECTION) {
 421                         BT_LOGD_STR("Downstream component refused the connection.");
 422                 } else {
 423                         BT_LOGW("Cannot ask downstream component to accept the connection: "
 424                                 "status=%s", bt_component_status_string(component_status));
 425                 }
 426
 427                 status = bt_graph_status_from_component_status(
 428                         component_status);
 429                 goto end;
 430         }
 431
 432         BT_LOGD_STR("Creating connection.");
 433         connection = bt_connection_create(graph, upstream_port,
 434                         downstream_port);
 435         if (!connection) {
 436                 BT_LOGW("Cannot create connection object.");
 437                 status = BT_GRAPH_STATUS_NOMEM;
 438                 goto end;
 439         }
 440
 441         BT_LOGD("Connection object created: conn-addr=%p", connection);
 442
 443         /*
 444          * Ownership of upstream_component/downstream_component and of
 445          * the connection object is transferred to the graph.
 446          */
 447         g_ptr_array_add(graph->connections, connection);
 448
 449         /*
 450          * Notify both components that their port is connected.
 451          */
 452         BT_LOGD_STR("Notifying upstream component that its port is connected.");
 453         component_status = bt_component_port_connected(upstream_component,
 454                 upstream_port, downstream_port);
 455         if (component_status != BT_COMPONENT_STATUS_OK) {
 456                 BT_LOGW("Error while notifying upstream component that its port is connected: "
 457                         "status=%s, graph-addr=%p, "
 458                         "upstream-comp-addr=%p, upstream-comp-name=\"%s\", "
 459                         "downstream-comp-addr=%p, downstream-comp-name=\"%s\", "
 460                         "upstream-port-addr=%p, upstream-port-name=\"%s\", "
 461                         "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 462                         bt_component_status_string(component_status), graph,
 463                         upstream_component, bt_component_get_name(upstream_component),
 464                         downstream_component, bt_component_get_name(downstream_component),
 465                         upstream_port, bt_port_get_name(upstream_port),
 466                         downstream_port, bt_port_get_name(downstream_port));
 467                 bt_connection_end(connection, true);
 468                 status = bt_graph_status_from_component_status(
 469                         component_status);
 470                 goto end;
 471         }
 472
 473         connection->notified_upstream_port_connected = true;
 474         BT_LOGD_STR("Notifying downstream component that its port is connected.");
 475         component_status = bt_component_port_connected(downstream_component,
 476                 downstream_port, upstream_port);
 477         if (component_status != BT_COMPONENT_STATUS_OK) {
 478                 BT_LOGW("Error while notifying downstream component that its port is connected: "
 479                         "status=%s, graph-addr=%p, "
 480                         "upstream-comp-addr=%p, upstream-comp-name=\"%s\", "
 481                         "downstream-comp-addr=%p, downstream-comp-name=\"%s\", "
 482                         "upstream-port-addr=%p, upstream-port-name=\"%s\", "
 483                         "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 484                         bt_component_status_string(component_status), graph,
 485                         upstream_component, bt_component_get_name(upstream_component),
 486                         downstream_component, bt_component_get_name(downstream_component),
 487                         upstream_port, bt_port_get_name(upstream_port),
 488                         downstream_port, bt_port_get_name(downstream_port));
 489                 bt_connection_end(connection, true);
 490                 status = bt_graph_status_from_component_status(
 491                         component_status);
 492                 goto end;
 493         }
 494
 495         connection->notified_downstream_port_connected = true;
 496
 497         /*
 498          * Notify the graph's creator that both ports are connected.
 499          */
 500         BT_LOGD_STR("Notifying graph's user that new component ports are connected.");
 501         bt_graph_notify_ports_connected(graph, upstream_port, downstream_port);
 502         connection->notified_graph_ports_connected = true;
 503         BT_LOGD("Connected component ports within graph: "
 504                 "graph-addr=%p, "
 505                 "upstream-comp-addr=%p, upstream-comp-name=\"%s\", "
 506                 "downstream-comp-addr=%p, downstream-comp-name=\"%s\", "
 507                 "upstream-port-addr=%p, upstream-port-name=\"%s\", "
 508                 "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 509                 graph,
 510                 upstream_component, bt_component_get_name(upstream_component),
 511                 downstream_component, bt_component_get_name(downstream_component),
 512                 upstream_port, bt_port_get_name(upstream_port),
 513                 downstream_port, bt_port_get_name(downstream_port));
 514
 515         if (user_connection) {
 516                 /* Move reference to user */
 517                 *user_connection = connection;
 518                 connection = NULL;
 519         }
 520
 521 end:
 522         bt_object_put_ref(upstream_graph);
 523         bt_object_put_ref(downstream_graph);
 524         bt_object_put_ref(upstream_component);
 525         bt_object_put_ref(downstream_component);
 526         bt_object_put_ref(connection);
 527         if (graph) {
 528                 (void) init_can_consume;
 529                 bt_graph_set_can_consume(graph, init_can_consume);
 530         }
 531         return status;
 532 }
 533
 534 static inline
 535 enum bt_graph_status consume_graph_sink(struct bt_component *sink)
 536 {
 537         enum bt_component_status comp_status;
 538
 539         BT_ASSERT(sink);
 540         comp_status = bt_component_sink_consume(sink);
 541         BT_LOGV("Consumed from sink: addr=%p, name=\"%s\", status=%s",
 542                 sink, bt_component_get_name(sink),
 543                 bt_component_status_string(comp_status));
 544         BT_ASSERT_PRE(comp_status == BT_COMPONENT_STATUS_OK ||
 545                 comp_status == BT_COMPONENT_STATUS_END ||
 546                 comp_status == BT_COMPONENT_STATUS_AGAIN ||
 547                 comp_status == BT_COMPONENT_STATUS_ERROR ||
 548                 comp_status == BT_COMPONENT_STATUS_NOMEM,
 549                 "Invalid component status returned by consuming function: "
 550                 "status=%s", bt_component_status_string(comp_status));
 551         return (enum bt_graph_status) comp_status;
 552 }
 553
 554 /*
 555  * `node` is removed from the queue of sinks to consume when passed to
 556  * this function. This function adds it back to the queue if there's
 557  * still something to consume afterwards.
 558  */
 559 static inline
 560 enum bt_graph_status consume_sink_node(struct bt_graph *graph,
 561                 GList *node)
 562 {
 563         enum bt_graph_status status;
 564         struct bt_component *sink;
 565
 566         sink = node->data;
 567         status = consume_graph_sink(sink);
 568         if (unlikely(status != BT_GRAPH_STATUS_END)) {
 569                 g_queue_push_tail_link(graph->sinks_to_consume, node);
 570                 goto end;
 571         }
 572
 573         /* End reached, the node is not added back to the queue and free'd. */
 574         g_queue_delete_link(graph->sinks_to_consume, node);
 575
 576         /* Don't forward an END status if there are sinks left to consume. */
 577         if (!g_queue_is_empty(graph->sinks_to_consume)) {
 578                 status = BT_GRAPH_STATUS_OK;
 579                 goto end;
 580         }
 581
 582 end:
 583         BT_LOGV("Consumed sink node: status=%s", bt_graph_status_string(status));
 584         return status;
 585 }
 586
 587 BT_HIDDEN
 588 enum bt_graph_status bt_graph_consume_sink_no_check(struct bt_graph *graph,
 589                 struct bt_component *sink)
 590 {
 591         enum bt_graph_status status;
 592         GList *sink_node;
 593         int index;
 594
 595         BT_LOGV("Making specific sink consume: addr=%p, "
 596                 "comp-addr=%p, comp-name=\"%s\"",
 597                 graph, sink, bt_component_get_name(sink));
 598
 599         BT_ASSERT(bt_component_borrow_graph(sink) == graph);
 600
 601         if (g_queue_is_empty(graph->sinks_to_consume)) {
 602                 BT_LOGV_STR("Graph's sink queue is empty: end of graph.");
 603                 status = BT_GRAPH_STATUS_END;
 604                 goto end;
 605         }
 606
 607         index = g_queue_index(graph->sinks_to_consume, sink);
 608         if (index < 0) {
 609                 BT_LOGV_STR("Sink is not marked as consumable: sink is ended.");
 610                 status = BT_GRAPH_STATUS_END;
 611                 goto end;
 612         }
 613
 614         sink_node = g_queue_pop_nth_link(graph->sinks_to_consume, index);
 615         BT_ASSERT(sink_node);
 616         status = consume_sink_node(graph, sink_node);
 617
 618 end:
 619         return status;
 620 }
 621
 622 static inline
 623 enum bt_graph_status bt_graph_consume_no_check(struct bt_graph *graph)
 624 {
 625         enum bt_graph_status status = BT_GRAPH_STATUS_OK;
 626         struct bt_component *sink;
 627         GList *current_node;
 628
 629         BT_LOGV("Making next sink consume: addr=%p", graph);
 630         BT_ASSERT_PRE(graph->has_sink,
 631                 "Graph has no sink component: %!+g", graph);
 632
 633         if (unlikely(g_queue_is_empty(graph->sinks_to_consume))) {
 634                 BT_LOGV_STR("Graph's sink queue is empty: end of graph.");
 635                 status = BT_GRAPH_STATUS_END;
 636                 goto end;
 637         }
 638
 639         current_node = g_queue_pop_head_link(graph->sinks_to_consume);
 640         sink = current_node->data;
 641         BT_LOGV("Chose next sink to consume: comp-addr=%p, comp-name=\"%s\"",
 642                 sink, bt_component_get_name(sink));
 643         status = consume_sink_node(graph, current_node);
 644
 645 end:
 646         return status;
 647 }
 648
 649 enum bt_graph_status bt_graph_consume(struct bt_graph *graph)
 650 {
 651         enum bt_graph_status status;
 652
 653         BT_ASSERT_PRE_NON_NULL(graph, "Graph");
 654         BT_ASSERT_PRE(!graph->canceled, "Graph is canceled: %!+g", graph);
 655         BT_ASSERT_PRE(graph->can_consume,
 656                 "Cannot consume graph in its current state: %!+g", graph);
 657         bt_graph_set_can_consume(graph, BT_FALSE);
 658         status = bt_graph_consume_no_check(graph);
 659         bt_graph_set_can_consume(graph, BT_TRUE);
 660         return status;
 661 }
 662
 663 enum bt_graph_status bt_graph_run(struct bt_graph *graph)
 664 {
 665         enum bt_graph_status status = BT_GRAPH_STATUS_OK;
 666
 667         if (!graph) {
 668                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 669                 status = BT_GRAPH_STATUS_INVALID;
 670                 goto end;
 671         }
 672
 673         if (graph->canceled) {
 674                 BT_LOGW("Invalid parameter: graph is canceled: "
 675                         "graph-addr=%p", graph);
 676                 status = BT_GRAPH_STATUS_CANCELED;
 677                 goto end;
 678         }
 679
 680         BT_ASSERT_PRE(graph->can_consume,
 681                 "Cannot consume graph in its current state: %!+g", graph);
 682         bt_graph_set_can_consume(graph, BT_FALSE);
 683         BT_LOGV("Running graph: addr=%p", graph);
 684
 685         do {
 686                 /*
 687                  * Check if the graph is canceled at each iteration. If
 688                  * the graph was canceled by another thread or by a
 689                  * signal, this is not a warning nor an error, it was
 690                  * intentional: log with a DEBUG level only.
 691                  */
 692                 if (unlikely(graph->canceled)) {
 693                         BT_LOGD("Stopping the graph: graph is canceled: "
 694                                 "graph-addr=%p", graph);
 695                         status = BT_GRAPH_STATUS_CANCELED;
 696                         goto end;
 697                 }
 698
 699                 status = bt_graph_consume_no_check(graph);
 700                 if (unlikely(status == BT_GRAPH_STATUS_AGAIN)) {
 701                         /*
 702                          * If AGAIN is received and there are multiple
 703                          * sinks, go ahead and consume from the next
 704                          * sink.
 705                          *
 706                          * However, in the case where a single sink is
 707                          * left, the caller can decide to busy-wait and
 708                          * call bt_graph_run() continuously until the
 709                          * source is ready or it can decide to sleep for
 710                          * an arbitrary amount of time.
 711                          */
 712                         if (graph->sinks_to_consume->length > 1) {
 713                                 status = BT_GRAPH_STATUS_OK;
 714                         }
 715                 } else if (status == BT_GRAPH_STATUS_NO_SINK) {
 716                         goto end;
 717                 }
 718         } while (status == BT_GRAPH_STATUS_OK);
 719
 720         if (g_queue_is_empty(graph->sinks_to_consume)) {
 721                 status = BT_GRAPH_STATUS_END;
 722         }
 723
 724 end:
 725         BT_LOGV("Graph ran: status=%s", bt_graph_status_string(status));
 726         if (graph) {
 727                 bt_graph_set_can_consume(graph, BT_TRUE);
 728         }
 729         return status;
 730 }
 731
 732 static
 733 int add_listener(GArray *listeners, void *func, void *removed, void *data)
 734 {
 735         struct bt_graph_listener listener = {
 736                 .func = func,
 737                 .removed = removed,
 738                 .data = data,
 739         };
 740
 741         g_array_append_val(listeners, listener);
 742         return listeners->len - 1;
 743 }
 744
 745 int bt_graph_add_port_added_listener(
 746                 struct bt_graph *graph,
 747                 bt_graph_port_added_listener listener,
 748                 bt_graph_listener_removed listener_removed, void *data)
 749 {
 750         int ret;
 751
 752         if (!graph) {
 753                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 754                 ret = -1;
 755                 goto end;
 756         }
 757
 758         if (graph->in_remove_listener) {
 759                 BT_LOGW("Cannot call this function during the execution of a remove listener: "
 760                         "addr=%p", graph);
 761                 ret = -1;
 762                 goto end;
 763         }
 764
 765         if (!listener) {
 766                 BT_LOGW_STR("Invalid parameter: listener is NULL.");
 767                 ret = -1;
 768                 goto end;
 769         }
 770
 771         ret = add_listener(graph->listeners.port_added, listener,
 772                 listener_removed, data);
 773         BT_LOGV("Added \"port added\" listener to graph: "
 774                 "graph-addr=%p, listener-addr=%p, pos=%d",
 775                 graph, listener, ret);
 776
 777 end:
 778         return ret;
 779 }
 780
 781 int bt_graph_add_port_removed_listener(
 782                 struct bt_graph *graph,
 783                 bt_graph_port_removed_listener listener,
 784                 bt_graph_listener_removed listener_removed, void *data)
 785 {
 786         int ret;
 787
 788         if (!graph) {
 789                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 790                 ret = -1;
 791                 goto end;
 792         }
 793
 794         if (graph->in_remove_listener) {
 795                 BT_LOGW("Cannot call this function during the execution of a remove listener: "
 796                         "addr=%p", graph);
 797                 ret = -1;
 798                 goto end;
 799         }
 800
 801         if (!listener) {
 802                 BT_LOGW_STR("Invalid parameter: listener is NULL.");
 803                 ret = -1;
 804                 goto end;
 805         }
 806
 807         ret = add_listener(graph->listeners.port_removed, listener,
 808                 listener_removed, data);
 809         BT_LOGV("Added \"port removed\" listener to graph: "
 810                 "graph-addr=%p, listener-addr=%p, pos=%d",
 811                 graph, listener, ret);
 812
 813 end:
 814         return ret;
 815 }
 816
 817 int bt_graph_add_ports_connected_listener(
 818                 struct bt_graph *graph,
 819                 bt_graph_ports_connected_listener listener,
 820                 bt_graph_listener_removed listener_removed, void *data)
 821 {
 822         int ret;
 823
 824         if (!graph) {
 825                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 826                 ret = -1;
 827                 goto end;
 828         }
 829
 830         if (graph->in_remove_listener) {
 831                 BT_LOGW("Cannot call this function during the execution of a remove listener: "
 832                         "addr=%p", graph);
 833                 ret = -1;
 834                 goto end;
 835         }
 836
 837         if (!listener) {
 838                 BT_LOGW_STR("Invalid parameter: listener is NULL.");
 839                 ret = -1;
 840                 goto end;
 841         }
 842
 843         ret = add_listener(graph->listeners.ports_connected, listener,
 844                 listener_removed, data);
 845         BT_LOGV("Added \"port connected\" listener to graph: "
 846                 "graph-addr=%p, listener-addr=%p, pos=%d",
 847                 graph, listener, ret);
 848
 849 end:
 850         return ret;
 851 }
 852
 853 int bt_graph_add_ports_disconnected_listener(
 854                 struct bt_graph *graph,
 855                 bt_graph_ports_disconnected_listener listener,
 856                 bt_graph_listener_removed listener_removed, void *data)
 857 {
 858         int ret;
 859
 860         if (!graph) {
 861                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 862                 ret = -1;
 863                 goto end;
 864         }
 865
 866         if (graph->in_remove_listener) {
 867                 BT_LOGW("Cannot call this function during the execution of a remove listener: "
 868                         "addr=%p", graph);
 869                 ret = -1;
 870                 goto end;
 871         }
 872
 873         if (!listener) {
 874                 BT_LOGW_STR("Invalid parameter: listener is NULL.");
 875                 ret = -1;
 876                 goto end;
 877         }
 878
 879         ret = add_listener(graph->listeners.ports_disconnected, listener,
 880                 listener_removed, data);
 881         BT_LOGV("Added \"port disconnected\" listener to graph: "
 882                 "graph-addr=%p, listener-addr=%p, pos=%d",
 883                 graph, listener, ret);
 884
 885 end:
 886         return ret;
 887 }
 888
 889 BT_HIDDEN
 890 void bt_graph_notify_port_added(struct bt_graph *graph, struct bt_port *port)
 891 {
 892         size_t i;
 893
 894         BT_LOGV("Notifying graph listeners that a port was added: "
 895                 "graph-addr=%p, port-addr=%p, port-name=\"%s\"",
 896                 graph, port, bt_port_get_name(port));
 897
 898         for (i = 0; i < graph->listeners.port_added->len; i++) {
 899                 struct bt_graph_listener listener =
 900                         g_array_index(graph->listeners.port_added,
 901                                 struct bt_graph_listener, i);
 902                 bt_graph_port_added_listener func = listener.func;
 903
 904                 BT_ASSERT(func);
 905                 func(port, listener.data);
 906         }
 907 }
 908
 909 BT_HIDDEN
 910 void bt_graph_notify_port_removed(struct bt_graph *graph,
 911                 struct bt_component *comp, struct bt_port *port)
 912 {
 913         size_t i;
 914
 915         BT_LOGV("Notifying graph listeners that a port was removed: "
 916                 "graph-addr=%p, port-addr=%p, port-name=\"%s\"",
 917                 graph, port, bt_port_get_name(port));
 918
 919         for (i = 0; i < graph->listeners.port_removed->len; i++) {
 920                 struct bt_graph_listener listener =
 921                         g_array_index(graph->listeners.port_removed,
 922                                 struct bt_graph_listener, i);
 923                 bt_graph_port_removed_listener func = listener.func;
 924
 925                 BT_ASSERT(func);
 926                 func(comp, port, listener.data);
 927         }
 928 }
 929
 930 BT_HIDDEN
 931 void bt_graph_notify_ports_connected(struct bt_graph *graph,
 932                 struct bt_port *upstream_port, struct bt_port *downstream_port)
 933 {
 934         size_t i;
 935
 936         BT_LOGV("Notifying graph listeners that two ports were connected: "
 937                 "graph-addr=%p, "
 938                 "upstream-port-addr=%p, upstream-port-name=\"%s\", "
 939                 "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 940                 graph, upstream_port, bt_port_get_name(upstream_port),
 941                 downstream_port, bt_port_get_name(downstream_port));
 942
 943         for (i = 0; i < graph->listeners.ports_connected->len; i++) {
 944                 struct bt_graph_listener listener =
 945                         g_array_index(graph->listeners.ports_connected,
 946                                 struct bt_graph_listener, i);
 947                 bt_graph_ports_connected_listener func = listener.func;
 948
 949                 BT_ASSERT(func);
 950                 func(upstream_port, downstream_port, listener.data);
 951         }
 952 }
 953
 954 BT_HIDDEN
 955 void bt_graph_notify_ports_disconnected(struct bt_graph *graph,
 956                 struct bt_component *upstream_comp,
 957                 struct bt_component *downstream_comp,
 958                 struct bt_port *upstream_port, struct bt_port *downstream_port)
 959 {
 960         size_t i;
 961
 962         BT_LOGV("Notifying graph listeners that two ports were disconnected: "
 963                 "graph-addr=%p, "
 964                 "upstream-port-addr=%p, upstream-port-name=\"%s\", "
 965                 "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 966                 graph, upstream_port, bt_port_get_name(upstream_port),
 967                 downstream_port, bt_port_get_name(downstream_port));
 968
 969         for (i = 0; i < graph->listeners.ports_disconnected->len; i++) {
 970                 struct bt_graph_listener listener =
 971                         g_array_index(graph->listeners.ports_disconnected,
 972                                 struct bt_graph_listener, i);
 973                 bt_graph_ports_disconnected_listener func = listener.func;
 974
 975                 BT_ASSERT(func);
 976                 func(upstream_comp, downstream_comp, upstream_port,
 977                         downstream_port, listener.data);
 978         }
 979 }
 980
 981 enum bt_graph_status bt_graph_cancel(struct bt_graph *graph)
 982 {
 983         enum bt_graph_status ret = BT_GRAPH_STATUS_OK;
 984
 985         if (!graph) {
 986                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 987                 ret = BT_GRAPH_STATUS_INVALID;
 988                 goto end;
 989         }
 990
 991         graph->canceled = BT_TRUE;
 992         BT_LOGV("Canceled graph: addr=%p", graph);
 993
 994 end:
 995         return ret;
 996 }
 997
 998 bt_bool bt_graph_is_canceled(struct bt_graph *graph)
 999 {
1000         bt_bool canceled = BT_FALSE;
1001
1002         if (!graph) {
1003                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
1004                 goto end;
1005         }
1006
1007         canceled = graph->canceled;
1008
1009 end:
1010         return canceled;
1011 }
1012
1013 BT_HIDDEN
1014 void bt_graph_remove_connection(struct bt_graph *graph,
1015                 struct bt_connection *connection)
1016 {
1017         BT_ASSERT(graph);
1018         BT_ASSERT(connection);
1019         BT_LOGV("Removing graph's connection: graph-addr=%p, conn-addr=%p",
1020                 graph, connection);
1021         g_ptr_array_remove(graph->connections, connection);
1022 }
1023
1024 enum bt_graph_status bt_graph_add_component_with_init_method_data(
1025                 struct bt_graph *graph,
1026                 struct bt_component_class *component_class,
1027                 const char *name, struct bt_value *params,
1028                 void *init_method_data,
1029                 struct bt_component **user_component)
1030 {
1031         enum bt_graph_status graph_status = BT_GRAPH_STATUS_OK;
1032         enum bt_component_status comp_status;
1033         struct bt_component *component = NULL;
1034         enum bt_component_class_type type;
1035         size_t i;
1036         bt_bool init_can_consume;
1037
1038         bt_object_get_ref(params);
1039
1040         if (!graph) {
1041                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
1042                 graph_status = BT_GRAPH_STATUS_INVALID;
1043                 goto end;
1044         }
1045         init_can_consume = graph->can_consume;
1046
1047         if (!component_class) {
1048                 BT_LOGW_STR("Invalid parameter: component class is NULL.");
1049                 graph_status = BT_GRAPH_STATUS_INVALID;
1050                 goto end;
1051         }
1052
1053         graph->can_consume = BT_FALSE;
1054         type = bt_component_class_get_type(component_class);
1055         BT_LOGD("Adding component to graph: "
1056                 "graph-addr=%p, comp-cls-addr=%p, "
1057                 "comp-cls-type=%s, name=\"%s\", params-addr=%p, "
1058                 "init-method-data-addr=%p",
1059                 graph, component_class, bt_component_class_type_string(type),
1060                 name, params, init_method_data);
1061
1062         if (!name) {
1063                 BT_LOGW_STR("Invalid parameter: name is NULL.");
1064                 graph_status = BT_GRAPH_STATUS_INVALID;
1065                 goto end;
1066         }
1067
1068         if (graph->canceled) {
1069                 BT_LOGW_STR("Invalid parameter: graph is canceled.");
1070                 graph_status = BT_GRAPH_STATUS_CANCELED;
1071                 goto end;
1072         }
1073
1074         if (type != BT_COMPONENT_CLASS_TYPE_SOURCE &&
1075                         type != BT_COMPONENT_CLASS_TYPE_FILTER &&
1076                         type != BT_COMPONENT_CLASS_TYPE_SINK) {
1077                 BT_LOGW("Invalid parameter: unknown component class type: "
1078                         "type=%d", type);
1079                 graph_status = BT_GRAPH_STATUS_INVALID;
1080                 goto end;
1081         }
1082
1083         for (i = 0; i < graph->components->len; i++) {
1084                 void *other_comp = graph->components->pdata[i];
1085
1086                 if (strcmp(name, bt_component_get_name(other_comp)) == 0) {
1087                         BT_LOGW("Invalid parameter: another component with the same name already exists in the graph: "
1088                                 "other-comp-addr=%p, name=\"%s\"",
1089                                 other_comp, name);
1090                         graph_status = BT_GRAPH_STATUS_INVALID;
1091                         goto end;
1092                 }
1093         }
1094
1095         /*
1096          * Parameters must be a map value, but we create a convenient
1097          * empty one if it's NULL.
1098          */
1099         if (params) {
1100                 if (!bt_value_is_map(params)) {
1101                         BT_LOGW("Invalid parameter: initialization parameters must be a map value: "
1102                                 "type=%s",
1103                                 bt_value_type_string(bt_value_get_type(params)));
1104                         graph_status = BT_GRAPH_STATUS_INVALID;
1105                         goto end;
1106                 }
1107         } else {
1108                 params = bt_value_map_create();
1109                 if (!params) {
1110                         BT_LOGE_STR("Cannot create map value object.");
1111                         graph_status = BT_GRAPH_STATUS_NOMEM;
1112                         goto end;
1113                 }
1114         }
1115
1116         comp_status = bt_component_create(component_class, name, &component);
1117         if (comp_status != BT_COMPONENT_STATUS_OK) {
1118                 BT_LOGE("Cannot create empty component object: status=%s",
1119                         bt_component_status_string(comp_status));
1120                 graph_status = bt_graph_status_from_component_status(
1121                         comp_status);
1122                 goto end;
1123         }
1124
1125         /*
1126          * The user's initialization method needs to see that this
1127          * component is part of the graph. If the user method fails, we
1128          * immediately remove the component from the graph's components.
1129          */
1130         g_ptr_array_add(graph->components, component);
1131         bt_component_set_graph(component, graph);
1132
1133         if (component_class->methods.init) {
1134                 BT_LOGD_STR("Calling user's initialization method.");
1135                 comp_status = component_class->methods.init(
1136                         bt_private_component_from_component(component), params,
1137                         init_method_data);
1138                 BT_LOGD("User method returned: status=%s",
1139                         bt_component_status_string(comp_status));
1140                 if (comp_status != BT_COMPONENT_STATUS_OK) {
1141                         BT_LOGW_STR("Initialization method failed.");
1142                         graph_status = bt_graph_status_from_component_status(
1143                                 comp_status);
1144                         bt_component_set_graph(component, NULL);
1145                         g_ptr_array_remove_fast(graph->components, component);
1146                         goto end;
1147                 }
1148         }
1149
1150         /*
1151          * Mark the component as initialized so that its finalization
1152          * method is called when it is destroyed.
1153          */
1154         component->initialized = true;
1155
1156         /*
1157          * If it's a sink component, it needs to be part of the graph's
1158          * sink queue to be consumed by bt_graph_consume().
1159          */
1160         if (bt_component_is_sink(component)) {
1161                 graph->has_sink = BT_TRUE;
1162                 g_queue_push_tail(graph->sinks_to_consume, component);
1163         }
1164
1165         /*
1166          * Freeze the component class now that it's instantiated at
1167          * least once.
1168          */
1169         BT_LOGD_STR("Freezing component class.");
1170         bt_component_class_freeze(component->class);
1171         BT_LOGD("Added component to graph: "
1172                 "graph-addr=%p, comp-cls-addr=%p, "
1173                 "comp-cls-type=%s, name=\"%s\", params-addr=%p, "
1174                 "init-method-data-addr=%p, comp-addr=%p",
1175                 graph, component_class, bt_component_class_type_string(type),
1176                 name, params, init_method_data, component);
1177
1178         if (user_component) {
1179                 /* Move reference to user */
1180                 *user_component = component;
1181                 component = NULL;
1182         }
1183
1184 end:
1185         bt_object_put_ref(component);
1186         bt_object_put_ref(params);
1187         if (graph) {
1188                 graph->can_consume = init_can_consume;
1189         }
1190         return graph_status;
1191 }
1192
1193 enum bt_graph_status bt_graph_add_component(
1194                 struct bt_graph *graph,
1195                 struct bt_component_class *component_class,
1196                 const char *name, struct bt_value *params,
1197                 struct bt_component **component)
1198 {
1199         return bt_graph_add_component_with_init_method_data(graph,
1200                 component_class, name, params, NULL, component);
1201 }
1202
1203 BT_HIDDEN
1204 int bt_graph_remove_unconnected_component(struct bt_graph *graph,
1205                 struct bt_component *component)
1206 {
1207         bt_bool init_can_consume;
1208         int64_t count;
1209         uint64_t i;
1210         int ret = 0;
1211
1212         BT_ASSERT(graph);
1213         BT_ASSERT(component);
1214         BT_ASSERT(component->base.ref_count == 0);
1215         BT_ASSERT(bt_component_borrow_graph(component) == graph);
1216
1217         init_can_consume = graph->can_consume;
1218         count = bt_component_get_input_port_count(component);
1219
1220         for (i = 0; i < count; i++) {
1221                 struct bt_port *port =
1222                         bt_component_get_input_port_by_index(component, i);
1223
1224                 BT_ASSERT(port);
1225                 bt_object_put_ref(port);
1226
1227                 if (bt_port_is_connected(port)) {
1228                         BT_LOGW("Cannot remove component from graph: "
1229                                 "an input port is connected: "
1230                                 "graph-addr=%p, comp-addr=%p, "
1231                                 "comp-name=\"%s\", connected-port-addr=%p, "
1232                                 "connected-port-name=\"%s\"",
1233                                 graph, component,
1234                                 bt_component_get_name(component),
1235                                 port, bt_port_get_name(port));
1236                         goto error;
1237                 }
1238         }
1239
1240         count = bt_component_get_output_port_count(component);
1241
1242         for (i = 0; i < count; i++) {
1243                 struct bt_port *port =
1244                         bt_component_get_output_port_by_index(component, i);
1245
1246                 BT_ASSERT(port);
1247                 bt_object_put_ref(port);
1248
1249                 if (bt_port_is_connected(port)) {
1250                         BT_LOGW("Cannot remove component from graph: "
1251                                 "an output port is connected: "
1252                                 "graph-addr=%p, comp-addr=%p, "
1253                                 "comp-name=\"%s\", connected-port-addr=%p, "
1254                                 "connected-port-name=\"%s\"",
1255                                 graph, component,
1256                                 bt_component_get_name(component),
1257                                 port, bt_port_get_name(port));
1258                         goto error;
1259                 }
1260         }
1261
1262         graph->can_consume = BT_FALSE;
1263
1264         /* Possibly remove from sinks to consume */
1265         (void) g_queue_remove(graph->sinks_to_consume, component);
1266
1267         if (graph->sinks_to_consume->length == 0) {
1268                 graph->has_sink = BT_FALSE;
1269         }
1270
1271         /*
1272          * This calls bt_object_try_spec_release() on the component, and
1273          * since its reference count is 0, its destructor is called. Its
1274          * destructor calls the user's finalization method (if set).
1275          */
1276         g_ptr_array_remove(graph->components, component);
1277         goto end;
1278
1279 error:
1280         ret = -1;
1281
1282 end:
1283         graph->can_consume = init_can_consume;
1284         return ret;
1285 }
1286
1287 BT_HIDDEN
1288 void bt_graph_add_notification(struct bt_graph *graph,
1289                 struct bt_notification *notif)
1290 {
1291         BT_ASSERT(graph);
1292         BT_ASSERT(notif);
1293
1294         /*
1295          * It's okay not to take a reference because, when a
1296          * notification's reference count drops to 0, either:
1297          *
1298          * * It is recycled back to one of this graph's pool.
1299          * * It is destroyed because it doesn't have any link to any
1300          *   graph, which means the original graph is already destroyed.
1301          */
1302         g_ptr_array_add(graph->notifications, notif);
1303 }