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/common-internal.h>
  43 #include <babeltrace/types.h>
  44 #include <babeltrace/values.h>
  45 #include <babeltrace/private-values.h>
  46 #include <babeltrace/values-internal.h>
  47 #include <babeltrace/assert-internal.h>
  48 #include <babeltrace/assert-pre-internal.h>
  49 #include <unistd.h>
  50 #include <glib.h>
  51
  52 struct bt_graph_listener {
  53         void *func;
  54         bt_graph_listener_removed removed;
  55         void *data;
  56 };
  57
  58 static
  59 int init_listeners_array(GArray **listeners)
  60 {
  61         int ret = 0;
  62
  63         BT_ASSERT(listeners);
  64         *listeners = g_array_new(FALSE, TRUE, sizeof(struct bt_graph_listener));
  65         if (!*listeners) {
  66                 BT_LOGE_STR("Failed to allocate one GArray.");
  67                 ret = -1;
  68                 goto end;
  69         }
  70
  71 end:
  72         return ret;
  73 }
  74
  75 static
  76 void call_remove_listeners(GArray *listeners)
  77 {
  78         size_t i;
  79
  80         for (i = 0; i < listeners->len; i++) {
  81                 struct bt_graph_listener listener =
  82                         g_array_index(listeners, struct bt_graph_listener, i);
  83
  84                 if (listener.removed) {
  85                         listener.removed(listener.data);
  86                 }
  87         }
  88 }
  89
  90 static
  91 void bt_graph_destroy(struct bt_object *obj)
  92 {
  93         struct bt_graph *graph = container_of(obj,
  94                         struct bt_graph, base);
  95
  96         /*
  97          * The graph's reference count is 0 if we're here. Increment
  98          * it to avoid a double-destroy (possibly infinitely recursive)
  99          * in this situation:
 100          *
 101          * 1. We put and destroy a connection.
 102          * 2. This connection's destructor finalizes its active
 103          *    notification iterators.
 104          * 3. A notification iterator's finalization function gets a
 105          *    new reference on its component (reference count goes from
 106          *    0 to 1).
 107          * 4. Since this component's reference count goes to 1, it takes
 108          *    a reference on its parent (this graph). This graph's
 109          *    reference count goes from 0 to 1.
 110          * 5. The notification iterator's finalization function puts its
 111          *    component reference (reference count goes from 1 to 0).
 112          * 6. Since this component's reference count goes from 1 to 0,
 113          *    it puts its parent (this graph). This graph's reference
 114          *    count goes from 1 to 0.
 115          * 7. Since this graph's reference count goes from 1 to 0,
 116          *    its destructor is called (this function).
 117          *
 118          * With the incrementation below, the graph's reference count at
 119          * step 4 goes from 1 to 2, and from 2 to 1 at step 6. This
 120          * ensures that this function is not called two times.
 121          */
 122         BT_LOGD("Destroying graph: addr=%p", graph);
 123         obj->ref_count++;
 124
 125         /*
 126          * Cancel the graph to disallow some operations, like creating
 127          * notification iterators and adding ports to components.
 128          */
 129         (void) bt_graph_cancel(graph);
 130
 131         /* Call all remove listeners */
 132         call_remove_listeners(graph->listeners.port_added);
 133         call_remove_listeners(graph->listeners.port_removed);
 134         call_remove_listeners(graph->listeners.ports_connected);
 135         call_remove_listeners(graph->listeners.ports_disconnected);
 136
 137         if (graph->notifications) {
 138                 g_ptr_array_free(graph->notifications, TRUE);
 139         }
 140
 141         if (graph->connections) {
 142                 BT_LOGD_STR("Destroying connections.");
 143                 g_ptr_array_free(graph->connections, TRUE);
 144         }
 145
 146         if (graph->components) {
 147                 BT_LOGD_STR("Destroying components.");
 148                 g_ptr_array_free(graph->components, TRUE);
 149         }
 150
 151         if (graph->sinks_to_consume) {
 152                 g_queue_free(graph->sinks_to_consume);
 153         }
 154
 155         if (graph->listeners.port_added) {
 156                 g_array_free(graph->listeners.port_added, TRUE);
 157         }
 158
 159         if (graph->listeners.port_removed) {
 160                 g_array_free(graph->listeners.port_removed, TRUE);
 161         }
 162
 163         if (graph->listeners.ports_connected) {
 164                 g_array_free(graph->listeners.ports_connected, TRUE);
 165         }
 166
 167         if (graph->listeners.ports_disconnected) {
 168                 g_array_free(graph->listeners.ports_disconnected, TRUE);
 169         }
 170
 171         bt_object_pool_finalize(&graph->event_notif_pool);
 172         bt_object_pool_finalize(&graph->packet_begin_notif_pool);
 173         bt_object_pool_finalize(&graph->packet_end_notif_pool);
 174         g_free(graph);
 175 }
 176
 177 static
 178 void destroy_notification_event(struct bt_notification *notif,
 179                 struct bt_graph *graph)
 180 {
 181         bt_notification_event_destroy(notif);
 182 }
 183
 184 static
 185 void destroy_notification_packet_begin(struct bt_notification *notif,
 186                 struct bt_graph *graph)
 187 {
 188         bt_notification_packet_begin_destroy(notif);
 189 }
 190
 191 static
 192 void destroy_notification_packet_end(struct bt_notification *notif,
 193                 struct bt_graph *graph)
 194 {
 195         bt_notification_packet_end_destroy(notif);
 196 }
 197
 198 static
 199 void notify_notification_graph_is_destroyed(struct bt_notification *notif)
 200 {
 201         bt_notification_unlink_graph(notif);
 202 }
 203
 204 struct bt_graph *bt_graph_create(void)
 205 {
 206         struct bt_graph *graph;
 207         int ret;
 208
 209         BT_LOGD_STR("Creating graph object.");
 210         graph = g_new0(struct bt_graph, 1);
 211         if (!graph) {
 212                 BT_LOGE_STR("Failed to allocate one graph.");
 213                 goto end;
 214         }
 215
 216         bt_object_init_shared(&graph->base, bt_graph_destroy);
 217         graph->connections = g_ptr_array_new_with_free_func(
 218                 (GDestroyNotify) bt_object_try_spec_release);
 219         if (!graph->connections) {
 220                 BT_LOGE_STR("Failed to allocate one GPtrArray.");
 221                 goto error;
 222         }
 223         graph->components = g_ptr_array_new_with_free_func(
 224                 (GDestroyNotify) bt_object_try_spec_release);
 225         if (!graph->components) {
 226                 BT_LOGE_STR("Failed to allocate one GPtrArray.");
 227                 goto error;
 228         }
 229         graph->sinks_to_consume = g_queue_new();
 230         if (!graph->sinks_to_consume) {
 231                 BT_LOGE_STR("Failed to allocate one GQueue.");
 232                 goto error;
 233         }
 234
 235         bt_graph_set_can_consume(graph, BT_TRUE);
 236         ret = init_listeners_array(&graph->listeners.port_added);
 237         if (ret) {
 238                 BT_LOGE_STR("Cannot create the \"port added\" listener array.");
 239                 goto error;
 240         }
 241
 242         ret = init_listeners_array(&graph->listeners.port_removed);
 243         if (ret) {
 244                 BT_LOGE_STR("Cannot create the \"port removed\" listener array.");
 245                 goto error;
 246         }
 247
 248         ret = init_listeners_array(&graph->listeners.ports_connected);
 249         if (ret) {
 250                 BT_LOGE_STR("Cannot create the \"port connected\" listener array.");
 251                 goto error;
 252         }
 253
 254         ret = init_listeners_array(&graph->listeners.ports_disconnected);
 255         if (ret) {
 256                 BT_LOGE_STR("Cannot create the \"port disconneted\" listener array.");
 257                 goto error;
 258         }
 259
 260         ret = bt_object_pool_initialize(&graph->event_notif_pool,
 261                 (bt_object_pool_new_object_func) bt_notification_event_new,
 262                 (bt_object_pool_destroy_object_func) destroy_notification_event,
 263                 graph);
 264         if (ret) {
 265                 BT_LOGE("Failed to initialize event notification pool: ret=%d",
 266                         ret);
 267                 goto error;
 268         }
 269
 270         ret = bt_object_pool_initialize(&graph->packet_begin_notif_pool,
 271                 (bt_object_pool_new_object_func) bt_notification_packet_begin_new,
 272                 (bt_object_pool_destroy_object_func) destroy_notification_packet_begin,
 273                 graph);
 274         if (ret) {
 275                 BT_LOGE("Failed to initialize packet beginning notification pool: ret=%d",
 276                         ret);
 277                 goto error;
 278         }
 279
 280         ret = bt_object_pool_initialize(&graph->packet_end_notif_pool,
 281                 (bt_object_pool_new_object_func) bt_notification_packet_end_new,
 282                 (bt_object_pool_destroy_object_func) destroy_notification_packet_end,
 283                 graph);
 284         if (ret) {
 285                 BT_LOGE("Failed to initialize packet end notification pool: ret=%d",
 286                         ret);
 287                 goto error;
 288         }
 289
 290         graph->notifications = g_ptr_array_new_with_free_func(
 291                 (GDestroyNotify) notify_notification_graph_is_destroyed);
 292         BT_LOGD("Created graph object: addr=%p", graph);
 293
 294 end:
 295         return graph;
 296 error:
 297         BT_OBJECT_PUT_REF_AND_RESET(graph);
 298         goto end;
 299 }
 300
 301 enum bt_graph_status bt_graph_connect_ports(struct bt_graph *graph,
 302                 struct bt_port *upstream_port, struct bt_port *downstream_port,
 303                 struct bt_connection **user_connection)
 304 {
 305         enum bt_graph_status status = BT_GRAPH_STATUS_OK;
 306         struct bt_connection *connection = NULL;
 307         struct bt_graph *upstream_graph = NULL;
 308         struct bt_graph *downstream_graph = NULL;
 309         struct bt_component *upstream_component = NULL;
 310         struct bt_component *downstream_component = NULL;
 311         enum bt_component_status component_status;
 312         bt_bool init_can_consume;
 313
 314         if (!graph) {
 315                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 316                 status = BT_GRAPH_STATUS_INVALID;
 317                 goto end;
 318         }
 319         init_can_consume = graph->can_consume;
 320
 321         if (!upstream_port) {
 322                 BT_LOGW_STR("Invalid parameter: upstream port is NULL.");
 323                 status = BT_GRAPH_STATUS_INVALID;
 324                 goto end;
 325         }
 326
 327         if (!downstream_port) {
 328                 BT_LOGW_STR("Invalid parameter: downstream port is NULL.");
 329                 status = BT_GRAPH_STATUS_INVALID;
 330                 goto end;
 331         }
 332
 333         BT_LOGD("Connecting component ports within graph: "
 334                 "graph-addr=%p, "
 335                 "upstream-port-addr=%p, upstream-port-name=\"%s\", "
 336                 "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 337                 graph, upstream_port, bt_port_get_name(upstream_port),
 338                 downstream_port, bt_port_get_name(downstream_port));
 339
 340         if (graph->canceled) {
 341                 BT_LOGW_STR("Invalid parameter: graph is canceled.");
 342                 status = BT_GRAPH_STATUS_CANCELED;
 343                 goto end;
 344         }
 345
 346         bt_graph_set_can_consume(graph, BT_FALSE);
 347
 348         /* Ensure appropriate types for upstream and downstream ports. */
 349         if (bt_port_get_type(upstream_port) != BT_PORT_TYPE_OUTPUT) {
 350                 BT_LOGW_STR("Invalid parameter: upstream port is not an output port.");
 351                 status = BT_GRAPH_STATUS_INVALID;
 352                 goto end;
 353         }
 354         if (bt_port_get_type(downstream_port) != BT_PORT_TYPE_INPUT) {
 355                 BT_LOGW_STR("Invalid parameter: downstream port is not an input port.");
 356                 status = BT_GRAPH_STATUS_INVALID;
 357                 goto end;
 358         }
 359
 360         /* Ensure that both ports are currently unconnected. */
 361         if (bt_port_is_connected(upstream_port)) {
 362                 BT_LOGW_STR("Invalid parameter: upstream port is already connected.");
 363                 status = BT_GRAPH_STATUS_INVALID;
 364                 goto end;
 365         }
 366
 367         if (bt_port_is_connected(downstream_port)) {
 368                 BT_LOGW_STR("Invalid parameter: downstream port is already connected.");
 369                 status = BT_GRAPH_STATUS_INVALID;
 370                 goto end;
 371         }
 372
 373         /*
 374          * Ensure that both ports are still attached to their creating
 375          * component.
 376          */
 377         upstream_component = bt_port_get_component(upstream_port);
 378         if (!upstream_component) {
 379                 BT_LOGW_STR("Invalid parameter: upstream port is loose (does not belong to a component)");
 380                 status = BT_GRAPH_STATUS_INVALID;
 381                 goto end;
 382         }
 383
 384         downstream_component = bt_port_get_component(downstream_port);
 385         if (!downstream_component) {
 386                 BT_LOGW_STR("Invalid parameter: downstream port is loose (does not belong to a component)");
 387                 status = BT_GRAPH_STATUS_INVALID;
 388                 goto end;
 389         }
 390
 391         BT_LOGD("Connecting component ports: "
 392                 "upstream-comp-addr=%p, upstream-comp-name=\"%s\", "
 393                 "downstream-comp-addr=%p, downstream-comp-name=\"%s\"",
 394                 upstream_component, bt_component_get_name(upstream_component),
 395                 downstream_component, bt_component_get_name(downstream_component));
 396
 397         /*
 398          * At this point the ports are not connected yet. Both
 399          * components need to accept an eventual connection to their
 400          * port by the other port before we continue.
 401          */
 402         BT_LOGD_STR("Asking upstream component to accept the connection.");
 403         component_status = bt_component_accept_port_connection(
 404                 upstream_component, upstream_port, downstream_port);
 405         if (component_status != BT_COMPONENT_STATUS_OK) {
 406                 if (component_status == BT_COMPONENT_STATUS_REFUSE_PORT_CONNECTION) {
 407                         BT_LOGD_STR("Upstream component refused the connection.");
 408                 } else {
 409                         BT_LOGW("Cannot ask upstream component to accept the connection: "
 410                                 "status=%s", bt_component_status_string(component_status));
 411                 }
 412
 413                 status = bt_graph_status_from_component_status(
 414                         component_status);
 415                 goto end;
 416         }
 417
 418         BT_LOGD_STR("Asking downstream component to accept the connection.");
 419         component_status = bt_component_accept_port_connection(
 420                 downstream_component, downstream_port, upstream_port);
 421         if (component_status != BT_COMPONENT_STATUS_OK) {
 422                 if (component_status == BT_COMPONENT_STATUS_REFUSE_PORT_CONNECTION) {
 423                         BT_LOGD_STR("Downstream component refused the connection.");
 424                 } else {
 425                         BT_LOGW("Cannot ask downstream component to accept the connection: "
 426                                 "status=%s", bt_component_status_string(component_status));
 427                 }
 428
 429                 status = bt_graph_status_from_component_status(
 430                         component_status);
 431                 goto end;
 432         }
 433
 434         BT_LOGD_STR("Creating connection.");
 435         connection = bt_connection_create(graph, upstream_port,
 436                         downstream_port);
 437         if (!connection) {
 438                 BT_LOGW("Cannot create connection object.");
 439                 status = BT_GRAPH_STATUS_NOMEM;
 440                 goto end;
 441         }
 442
 443         BT_LOGD("Connection object created: conn-addr=%p", connection);
 444
 445         /*
 446          * Ownership of upstream_component/downstream_component and of
 447          * the connection object is transferred to the graph.
 448          */
 449         g_ptr_array_add(graph->connections, connection);
 450
 451         /*
 452          * Notify both components that their port is connected.
 453          */
 454         BT_LOGD_STR("Notifying upstream component that its port is connected.");
 455         component_status = bt_component_port_connected(upstream_component,
 456                 upstream_port, downstream_port);
 457         if (component_status != BT_COMPONENT_STATUS_OK) {
 458                 BT_LOGW("Error while notifying upstream component that its port is connected: "
 459                         "status=%s, graph-addr=%p, "
 460                         "upstream-comp-addr=%p, upstream-comp-name=\"%s\", "
 461                         "downstream-comp-addr=%p, downstream-comp-name=\"%s\", "
 462                         "upstream-port-addr=%p, upstream-port-name=\"%s\", "
 463                         "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 464                         bt_component_status_string(component_status), graph,
 465                         upstream_component, bt_component_get_name(upstream_component),
 466                         downstream_component, bt_component_get_name(downstream_component),
 467                         upstream_port, bt_port_get_name(upstream_port),
 468                         downstream_port, bt_port_get_name(downstream_port));
 469                 bt_connection_end(connection, true);
 470                 status = bt_graph_status_from_component_status(
 471                         component_status);
 472                 goto end;
 473         }
 474
 475         connection->notified_upstream_port_connected = true;
 476         BT_LOGD_STR("Notifying downstream component that its port is connected.");
 477         component_status = bt_component_port_connected(downstream_component,
 478                 downstream_port, upstream_port);
 479         if (component_status != BT_COMPONENT_STATUS_OK) {
 480                 BT_LOGW("Error while notifying downstream component that its port is connected: "
 481                         "status=%s, graph-addr=%p, "
 482                         "upstream-comp-addr=%p, upstream-comp-name=\"%s\", "
 483                         "downstream-comp-addr=%p, downstream-comp-name=\"%s\", "
 484                         "upstream-port-addr=%p, upstream-port-name=\"%s\", "
 485                         "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 486                         bt_component_status_string(component_status), graph,
 487                         upstream_component, bt_component_get_name(upstream_component),
 488                         downstream_component, bt_component_get_name(downstream_component),
 489                         upstream_port, bt_port_get_name(upstream_port),
 490                         downstream_port, bt_port_get_name(downstream_port));
 491                 bt_connection_end(connection, true);
 492                 status = bt_graph_status_from_component_status(
 493                         component_status);
 494                 goto end;
 495         }
 496
 497         connection->notified_downstream_port_connected = true;
 498
 499         /*
 500          * Notify the graph's creator that both ports are connected.
 501          */
 502         BT_LOGD_STR("Notifying graph's user that new component ports are connected.");
 503         bt_graph_notify_ports_connected(graph, upstream_port, downstream_port);
 504         connection->notified_graph_ports_connected = true;
 505         BT_LOGD("Connected component ports within graph: "
 506                 "graph-addr=%p, "
 507                 "upstream-comp-addr=%p, upstream-comp-name=\"%s\", "
 508                 "downstream-comp-addr=%p, downstream-comp-name=\"%s\", "
 509                 "upstream-port-addr=%p, upstream-port-name=\"%s\", "
 510                 "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 511                 graph,
 512                 upstream_component, bt_component_get_name(upstream_component),
 513                 downstream_component, bt_component_get_name(downstream_component),
 514                 upstream_port, bt_port_get_name(upstream_port),
 515                 downstream_port, bt_port_get_name(downstream_port));
 516
 517         if (user_connection) {
 518                 /* Move reference to user */
 519                 *user_connection = connection;
 520                 connection = NULL;
 521         }
 522
 523 end:
 524         bt_object_put_ref(upstream_graph);
 525         bt_object_put_ref(downstream_graph);
 526         bt_object_put_ref(upstream_component);
 527         bt_object_put_ref(downstream_component);
 528         bt_object_put_ref(connection);
 529         if (graph) {
 530                 (void) init_can_consume;
 531                 bt_graph_set_can_consume(graph, init_can_consume);
 532         }
 533         return status;
 534 }
 535
 536 static inline
 537 enum bt_graph_status consume_graph_sink(struct bt_component *sink)
 538 {
 539         enum bt_component_status comp_status;
 540
 541         BT_ASSERT(sink);
 542         comp_status = bt_component_sink_consume(sink);
 543         BT_LOGV("Consumed from sink: addr=%p, name=\"%s\", status=%s",
 544                 sink, bt_component_get_name(sink),
 545                 bt_component_status_string(comp_status));
 546         BT_ASSERT_PRE(comp_status == BT_COMPONENT_STATUS_OK ||
 547                 comp_status == BT_COMPONENT_STATUS_END ||
 548                 comp_status == BT_COMPONENT_STATUS_AGAIN ||
 549                 comp_status == BT_COMPONENT_STATUS_ERROR ||
 550                 comp_status == BT_COMPONENT_STATUS_NOMEM,
 551                 "Invalid component status returned by consuming function: "
 552                 "status=%s", bt_component_status_string(comp_status));
 553         return (enum bt_graph_status) comp_status;
 554 }
 555
 556 /*
 557  * `node` is removed from the queue of sinks to consume when passed to
 558  * this function. This function adds it back to the queue if there's
 559  * still something to consume afterwards.
 560  */
 561 static inline
 562 enum bt_graph_status consume_sink_node(struct bt_graph *graph,
 563                 GList *node)
 564 {
 565         enum bt_graph_status status;
 566         struct bt_component *sink;
 567
 568         sink = node->data;
 569         status = consume_graph_sink(sink);
 570         if (unlikely(status != BT_GRAPH_STATUS_END)) {
 571                 g_queue_push_tail_link(graph->sinks_to_consume, node);
 572                 goto end;
 573         }
 574
 575         /* End reached, the node is not added back to the queue and free'd. */
 576         g_queue_delete_link(graph->sinks_to_consume, node);
 577
 578         /* Don't forward an END status if there are sinks left to consume. */
 579         if (!g_queue_is_empty(graph->sinks_to_consume)) {
 580                 status = BT_GRAPH_STATUS_OK;
 581                 goto end;
 582         }
 583
 584 end:
 585         BT_LOGV("Consumed sink node: status=%s", bt_graph_status_string(status));
 586         return status;
 587 }
 588
 589 BT_HIDDEN
 590 enum bt_graph_status bt_graph_consume_sink_no_check(struct bt_graph *graph,
 591                 struct bt_component *sink)
 592 {
 593         enum bt_graph_status status;
 594         GList *sink_node;
 595         int index;
 596
 597         BT_LOGV("Making specific sink consume: addr=%p, "
 598                 "comp-addr=%p, comp-name=\"%s\"",
 599                 graph, sink, bt_component_get_name(sink));
 600
 601         BT_ASSERT(bt_component_borrow_graph(sink) == graph);
 602
 603         if (g_queue_is_empty(graph->sinks_to_consume)) {
 604                 BT_LOGV_STR("Graph's sink queue is empty: end of graph.");
 605                 status = BT_GRAPH_STATUS_END;
 606                 goto end;
 607         }
 608
 609         index = g_queue_index(graph->sinks_to_consume, sink);
 610         if (index < 0) {
 611                 BT_LOGV_STR("Sink is not marked as consumable: sink is ended.");
 612                 status = BT_GRAPH_STATUS_END;
 613                 goto end;
 614         }
 615
 616         sink_node = g_queue_pop_nth_link(graph->sinks_to_consume, index);
 617         BT_ASSERT(sink_node);
 618         status = consume_sink_node(graph, sink_node);
 619
 620 end:
 621         return status;
 622 }
 623
 624 static inline
 625 enum bt_graph_status bt_graph_consume_no_check(struct bt_graph *graph)
 626 {
 627         enum bt_graph_status status = BT_GRAPH_STATUS_OK;
 628         struct bt_component *sink;
 629         GList *current_node;
 630
 631         BT_LOGV("Making next sink consume: addr=%p", graph);
 632         BT_ASSERT_PRE(graph->has_sink,
 633                 "Graph has no sink component: %!+g", graph);
 634
 635         if (unlikely(g_queue_is_empty(graph->sinks_to_consume))) {
 636                 BT_LOGV_STR("Graph's sink queue is empty: end of graph.");
 637                 status = BT_GRAPH_STATUS_END;
 638                 goto end;
 639         }
 640
 641         current_node = g_queue_pop_head_link(graph->sinks_to_consume);
 642         sink = current_node->data;
 643         BT_LOGV("Chose next sink to consume: comp-addr=%p, comp-name=\"%s\"",
 644                 sink, bt_component_get_name(sink));
 645         status = consume_sink_node(graph, current_node);
 646
 647 end:
 648         return status;
 649 }
 650
 651 enum bt_graph_status bt_graph_consume(struct bt_graph *graph)
 652 {
 653         enum bt_graph_status status;
 654
 655         BT_ASSERT_PRE_NON_NULL(graph, "Graph");
 656         BT_ASSERT_PRE(!graph->canceled, "Graph is canceled: %!+g", graph);
 657         BT_ASSERT_PRE(graph->can_consume,
 658                 "Cannot consume graph in its current state: %!+g", graph);
 659         bt_graph_set_can_consume(graph, BT_FALSE);
 660         status = bt_graph_consume_no_check(graph);
 661         bt_graph_set_can_consume(graph, BT_TRUE);
 662         return status;
 663 }
 664
 665 enum bt_graph_status bt_graph_run(struct bt_graph *graph)
 666 {
 667         enum bt_graph_status status = BT_GRAPH_STATUS_OK;
 668
 669         if (!graph) {
 670                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 671                 status = BT_GRAPH_STATUS_INVALID;
 672                 goto end;
 673         }
 674
 675         if (graph->canceled) {
 676                 BT_LOGW("Invalid parameter: graph is canceled: "
 677                         "graph-addr=%p", graph);
 678                 status = BT_GRAPH_STATUS_CANCELED;
 679                 goto end;
 680         }
 681
 682         BT_ASSERT_PRE(graph->can_consume,
 683                 "Cannot consume graph in its current state: %!+g", graph);
 684         bt_graph_set_can_consume(graph, BT_FALSE);
 685         BT_LOGV("Running graph: addr=%p", graph);
 686
 687         do {
 688                 /*
 689                  * Check if the graph is canceled at each iteration. If
 690                  * the graph was canceled by another thread or by a
 691                  * signal, this is not a warning nor an error, it was
 692                  * intentional: log with a DEBUG level only.
 693                  */
 694                 if (unlikely(graph->canceled)) {
 695                         BT_LOGD("Stopping the graph: graph is canceled: "
 696                                 "graph-addr=%p", graph);
 697                         status = BT_GRAPH_STATUS_CANCELED;
 698                         goto end;
 699                 }
 700
 701                 status = bt_graph_consume_no_check(graph);
 702                 if (unlikely(status == BT_GRAPH_STATUS_AGAIN)) {
 703                         /*
 704                          * If AGAIN is received and there are multiple
 705                          * sinks, go ahead and consume from the next
 706                          * sink.
 707                          *
 708                          * However, in the case where a single sink is
 709                          * left, the caller can decide to busy-wait and
 710                          * call bt_graph_run() continuously until the
 711                          * source is ready or it can decide to sleep for
 712                          * an arbitrary amount of time.
 713                          */
 714                         if (graph->sinks_to_consume->length > 1) {
 715                                 status = BT_GRAPH_STATUS_OK;
 716                         }
 717                 } else if (status == BT_GRAPH_STATUS_NO_SINK) {
 718                         goto end;
 719                 }
 720         } while (status == BT_GRAPH_STATUS_OK);
 721
 722         if (g_queue_is_empty(graph->sinks_to_consume)) {
 723                 status = BT_GRAPH_STATUS_END;
 724         }
 725
 726 end:
 727         BT_LOGV("Graph ran: status=%s", bt_graph_status_string(status));
 728         if (graph) {
 729                 bt_graph_set_can_consume(graph, BT_TRUE);
 730         }
 731         return status;
 732 }
 733
 734 static
 735 int add_listener(GArray *listeners, void *func, void *removed, void *data)
 736 {
 737         struct bt_graph_listener listener = {
 738                 .func = func,
 739                 .removed = removed,
 740                 .data = data,
 741         };
 742
 743         g_array_append_val(listeners, listener);
 744         return listeners->len - 1;
 745 }
 746
 747 int bt_graph_add_port_added_listener(
 748                 struct bt_graph *graph,
 749                 bt_graph_port_added_listener listener,
 750                 bt_graph_listener_removed listener_removed, void *data)
 751 {
 752         int ret;
 753
 754         if (!graph) {
 755                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 756                 ret = -1;
 757                 goto end;
 758         }
 759
 760         if (graph->in_remove_listener) {
 761                 BT_LOGW("Cannot call this function during the execution of a remove listener: "
 762                         "addr=%p", graph);
 763                 ret = -1;
 764                 goto end;
 765         }
 766
 767         if (!listener) {
 768                 BT_LOGW_STR("Invalid parameter: listener is NULL.");
 769                 ret = -1;
 770                 goto end;
 771         }
 772
 773         ret = add_listener(graph->listeners.port_added, listener,
 774                 listener_removed, data);
 775         BT_LOGV("Added \"port added\" listener to graph: "
 776                 "graph-addr=%p, listener-addr=%p, pos=%d",
 777                 graph, listener, ret);
 778
 779 end:
 780         return ret;
 781 }
 782
 783 int bt_graph_add_port_removed_listener(
 784                 struct bt_graph *graph,
 785                 bt_graph_port_removed_listener listener,
 786                 bt_graph_listener_removed listener_removed, void *data)
 787 {
 788         int ret;
 789
 790         if (!graph) {
 791                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 792                 ret = -1;
 793                 goto end;
 794         }
 795
 796         if (graph->in_remove_listener) {
 797                 BT_LOGW("Cannot call this function during the execution of a remove listener: "
 798                         "addr=%p", graph);
 799                 ret = -1;
 800                 goto end;
 801         }
 802
 803         if (!listener) {
 804                 BT_LOGW_STR("Invalid parameter: listener is NULL.");
 805                 ret = -1;
 806                 goto end;
 807         }
 808
 809         ret = add_listener(graph->listeners.port_removed, listener,
 810                 listener_removed, data);
 811         BT_LOGV("Added \"port removed\" listener to graph: "
 812                 "graph-addr=%p, listener-addr=%p, pos=%d",
 813                 graph, listener, ret);
 814
 815 end:
 816         return ret;
 817 }
 818
 819 int bt_graph_add_ports_connected_listener(
 820                 struct bt_graph *graph,
 821                 bt_graph_ports_connected_listener listener,
 822                 bt_graph_listener_removed listener_removed, void *data)
 823 {
 824         int ret;
 825
 826         if (!graph) {
 827                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 828                 ret = -1;
 829                 goto end;
 830         }
 831
 832         if (graph->in_remove_listener) {
 833                 BT_LOGW("Cannot call this function during the execution of a remove listener: "
 834                         "addr=%p", graph);
 835                 ret = -1;
 836                 goto end;
 837         }
 838
 839         if (!listener) {
 840                 BT_LOGW_STR("Invalid parameter: listener is NULL.");
 841                 ret = -1;
 842                 goto end;
 843         }
 844
 845         ret = add_listener(graph->listeners.ports_connected, listener,
 846                 listener_removed, data);
 847         BT_LOGV("Added \"port connected\" listener to graph: "
 848                 "graph-addr=%p, listener-addr=%p, pos=%d",
 849                 graph, listener, ret);
 850
 851 end:
 852         return ret;
 853 }
 854
 855 int bt_graph_add_ports_disconnected_listener(
 856                 struct bt_graph *graph,
 857                 bt_graph_ports_disconnected_listener listener,
 858                 bt_graph_listener_removed listener_removed, void *data)
 859 {
 860         int ret;
 861
 862         if (!graph) {
 863                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 864                 ret = -1;
 865                 goto end;
 866         }
 867
 868         if (graph->in_remove_listener) {
 869                 BT_LOGW("Cannot call this function during the execution of a remove listener: "
 870                         "addr=%p", graph);
 871                 ret = -1;
 872                 goto end;
 873         }
 874
 875         if (!listener) {
 876                 BT_LOGW_STR("Invalid parameter: listener is NULL.");
 877                 ret = -1;
 878                 goto end;
 879         }
 880
 881         ret = add_listener(graph->listeners.ports_disconnected, listener,
 882                 listener_removed, data);
 883         BT_LOGV("Added \"port disconnected\" listener to graph: "
 884                 "graph-addr=%p, listener-addr=%p, pos=%d",
 885                 graph, listener, ret);
 886
 887 end:
 888         return ret;
 889 }
 890
 891 BT_HIDDEN
 892 void bt_graph_notify_port_added(struct bt_graph *graph, struct bt_port *port)
 893 {
 894         size_t i;
 895
 896         BT_LOGV("Notifying graph listeners that a port was added: "
 897                 "graph-addr=%p, port-addr=%p, port-name=\"%s\"",
 898                 graph, port, bt_port_get_name(port));
 899
 900         for (i = 0; i < graph->listeners.port_added->len; i++) {
 901                 struct bt_graph_listener listener =
 902                         g_array_index(graph->listeners.port_added,
 903                                 struct bt_graph_listener, i);
 904                 bt_graph_port_added_listener func = listener.func;
 905
 906                 BT_ASSERT(func);
 907                 func(port, listener.data);
 908         }
 909 }
 910
 911 BT_HIDDEN
 912 void bt_graph_notify_port_removed(struct bt_graph *graph,
 913                 struct bt_component *comp, struct bt_port *port)
 914 {
 915         size_t i;
 916
 917         BT_LOGV("Notifying graph listeners that a port was removed: "
 918                 "graph-addr=%p, port-addr=%p, port-name=\"%s\"",
 919                 graph, port, bt_port_get_name(port));
 920
 921         for (i = 0; i < graph->listeners.port_removed->len; i++) {
 922                 struct bt_graph_listener listener =
 923                         g_array_index(graph->listeners.port_removed,
 924                                 struct bt_graph_listener, i);
 925                 bt_graph_port_removed_listener func = listener.func;
 926
 927                 BT_ASSERT(func);
 928                 func(comp, port, listener.data);
 929         }
 930 }
 931
 932 BT_HIDDEN
 933 void bt_graph_notify_ports_connected(struct bt_graph *graph,
 934                 struct bt_port *upstream_port, struct bt_port *downstream_port)
 935 {
 936         size_t i;
 937
 938         BT_LOGV("Notifying graph listeners that two ports were connected: "
 939                 "graph-addr=%p, "
 940                 "upstream-port-addr=%p, upstream-port-name=\"%s\", "
 941                 "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 942                 graph, upstream_port, bt_port_get_name(upstream_port),
 943                 downstream_port, bt_port_get_name(downstream_port));
 944
 945         for (i = 0; i < graph->listeners.ports_connected->len; i++) {
 946                 struct bt_graph_listener listener =
 947                         g_array_index(graph->listeners.ports_connected,
 948                                 struct bt_graph_listener, i);
 949                 bt_graph_ports_connected_listener func = listener.func;
 950
 951                 BT_ASSERT(func);
 952                 func(upstream_port, downstream_port, listener.data);
 953         }
 954 }
 955
 956 BT_HIDDEN
 957 void bt_graph_notify_ports_disconnected(struct bt_graph *graph,
 958                 struct bt_component *upstream_comp,
 959                 struct bt_component *downstream_comp,
 960                 struct bt_port *upstream_port, struct bt_port *downstream_port)
 961 {
 962         size_t i;
 963
 964         BT_LOGV("Notifying graph listeners that two ports were disconnected: "
 965                 "graph-addr=%p, "
 966                 "upstream-port-addr=%p, upstream-port-name=\"%s\", "
 967                 "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 968                 graph, upstream_port, bt_port_get_name(upstream_port),
 969                 downstream_port, bt_port_get_name(downstream_port));
 970
 971         for (i = 0; i < graph->listeners.ports_disconnected->len; i++) {
 972                 struct bt_graph_listener listener =
 973                         g_array_index(graph->listeners.ports_disconnected,
 974                                 struct bt_graph_listener, i);
 975                 bt_graph_ports_disconnected_listener func = listener.func;
 976
 977                 BT_ASSERT(func);
 978                 func(upstream_comp, downstream_comp, upstream_port,
 979                         downstream_port, listener.data);
 980         }
 981 }
 982
 983 enum bt_graph_status bt_graph_cancel(struct bt_graph *graph)
 984 {
 985         enum bt_graph_status ret = BT_GRAPH_STATUS_OK;
 986
 987         if (!graph) {
 988                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
 989                 ret = BT_GRAPH_STATUS_INVALID;
 990                 goto end;
 991         }
 992
 993         graph->canceled = BT_TRUE;
 994         BT_LOGV("Canceled graph: addr=%p", graph);
 995
 996 end:
 997         return ret;
 998 }
 999
1000 bt_bool bt_graph_is_canceled(struct bt_graph *graph)
1001 {
1002         bt_bool canceled = BT_FALSE;
1003
1004         if (!graph) {
1005                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
1006                 goto end;
1007         }
1008
1009         canceled = graph->canceled;
1010
1011 end:
1012         return canceled;
1013 }
1014
1015 BT_HIDDEN
1016 void bt_graph_remove_connection(struct bt_graph *graph,
1017                 struct bt_connection *connection)
1018 {
1019         BT_ASSERT(graph);
1020         BT_ASSERT(connection);
1021         BT_LOGV("Removing graph's connection: graph-addr=%p, conn-addr=%p",
1022                 graph, connection);
1023         g_ptr_array_remove(graph->connections, connection);
1024 }
1025
1026 enum bt_graph_status bt_graph_add_component_with_init_method_data(
1027                 struct bt_graph *graph,
1028                 struct bt_component_class *component_class,
1029                 const char *name, struct bt_value *params,
1030                 void *init_method_data,
1031                 struct bt_component **user_component)
1032 {
1033         enum bt_graph_status graph_status = BT_GRAPH_STATUS_OK;
1034         enum bt_component_status comp_status;
1035         struct bt_component *component = NULL;
1036         enum bt_component_class_type type;
1037         size_t i;
1038         bt_bool init_can_consume;
1039
1040         bt_object_get_ref(params);
1041
1042         if (!graph) {
1043                 BT_LOGW_STR("Invalid parameter: graph is NULL.");
1044                 graph_status = BT_GRAPH_STATUS_INVALID;
1045                 goto end;
1046         }
1047         init_can_consume = graph->can_consume;
1048
1049         if (!component_class) {
1050                 BT_LOGW_STR("Invalid parameter: component class is NULL.");
1051                 graph_status = BT_GRAPH_STATUS_INVALID;
1052                 goto end;
1053         }
1054
1055         graph->can_consume = BT_FALSE;
1056         type = bt_component_class_get_type(component_class);
1057         BT_LOGD("Adding component to graph: "
1058                 "graph-addr=%p, comp-cls-addr=%p, "
1059                 "comp-cls-type=%s, name=\"%s\", params-addr=%p, "
1060                 "init-method-data-addr=%p",
1061                 graph, component_class, bt_component_class_type_string(type),
1062                 name, params, init_method_data);
1063
1064         if (!name) {
1065                 BT_LOGW_STR("Invalid parameter: name is NULL.");
1066                 graph_status = BT_GRAPH_STATUS_INVALID;
1067                 goto end;
1068         }
1069
1070         if (graph->canceled) {
1071                 BT_LOGW_STR("Invalid parameter: graph is canceled.");
1072                 graph_status = BT_GRAPH_STATUS_CANCELED;
1073                 goto end;
1074         }
1075
1076         if (type != BT_COMPONENT_CLASS_TYPE_SOURCE &&
1077                         type != BT_COMPONENT_CLASS_TYPE_FILTER &&
1078                         type != BT_COMPONENT_CLASS_TYPE_SINK) {
1079                 BT_LOGW("Invalid parameter: unknown component class type: "
1080                         "type=%d", type);
1081                 graph_status = BT_GRAPH_STATUS_INVALID;
1082                 goto end;
1083         }
1084
1085         for (i = 0; i < graph->components->len; i++) {
1086                 void *other_comp = graph->components->pdata[i];
1087
1088                 if (strcmp(name, bt_component_get_name(other_comp)) == 0) {
1089                         BT_LOGW("Invalid parameter: another component with the same name already exists in the graph: "
1090                                 "other-comp-addr=%p, name=\"%s\"",
1091                                 other_comp, name);
1092                         graph_status = BT_GRAPH_STATUS_INVALID;
1093                         goto end;
1094                 }
1095         }
1096
1097         /*
1098          * Parameters must be a map value, but we create a convenient
1099          * empty one if it's NULL.
1100          */
1101         if (params) {
1102                 if (!bt_value_is_map(params)) {
1103                         BT_LOGW("Invalid parameter: initialization parameters must be a map value: "
1104                                 "type=%s",
1105                                 bt_common_value_type_string(
1106                                         bt_value_get_type(params)));
1107                         graph_status = BT_GRAPH_STATUS_INVALID;
1108                         goto end;
1109                 }
1110         } else {
1111                 params = bt_value_borrow_from_private(
1112                         bt_private_value_map_create());
1113                 if (!params) {
1114                         BT_LOGE_STR("Cannot create map value object.");
1115                         graph_status = BT_GRAPH_STATUS_NOMEM;
1116                         goto end;
1117                 }
1118         }
1119
1120         comp_status = bt_component_create(component_class, name, &component);
1121         if (comp_status != BT_COMPONENT_STATUS_OK) {
1122                 BT_LOGE("Cannot create empty component object: status=%s",
1123                         bt_component_status_string(comp_status));
1124                 graph_status = bt_graph_status_from_component_status(
1125                         comp_status);
1126                 goto end;
1127         }
1128
1129         /*
1130          * The user's initialization method needs to see that this
1131          * component is part of the graph. If the user method fails, we
1132          * immediately remove the component from the graph's components.
1133          */
1134         g_ptr_array_add(graph->components, component);
1135         bt_component_set_graph(component, graph);
1136
1137         if (component_class->methods.init) {
1138                 BT_LOGD_STR("Calling user's initialization method.");
1139                 comp_status = component_class->methods.init(
1140                         bt_private_component_from_component(component), params,
1141                         init_method_data);
1142                 BT_LOGD("User method returned: status=%s",
1143                         bt_component_status_string(comp_status));
1144                 if (comp_status != BT_COMPONENT_STATUS_OK) {
1145                         BT_LOGW_STR("Initialization method failed.");
1146                         graph_status = bt_graph_status_from_component_status(
1147                                 comp_status);
1148                         bt_component_set_graph(component, NULL);
1149                         g_ptr_array_remove_fast(graph->components, component);
1150                         goto end;
1151                 }
1152         }
1153
1154         /*
1155          * Mark the component as initialized so that its finalization
1156          * method is called when it is destroyed.
1157          */
1158         component->initialized = true;
1159
1160         /*
1161          * If it's a sink component, it needs to be part of the graph's
1162          * sink queue to be consumed by bt_graph_consume().
1163          */
1164         if (bt_component_is_sink(component)) {
1165                 graph->has_sink = BT_TRUE;
1166                 g_queue_push_tail(graph->sinks_to_consume, component);
1167         }
1168
1169         /*
1170          * Freeze the component class now that it's instantiated at
1171          * least once.
1172          */
1173         BT_LOGD_STR("Freezing component class.");
1174         bt_component_class_freeze(component->class);
1175         BT_LOGD("Added component to graph: "
1176                 "graph-addr=%p, comp-cls-addr=%p, "
1177                 "comp-cls-type=%s, name=\"%s\", params-addr=%p, "
1178                 "init-method-data-addr=%p, comp-addr=%p",
1179                 graph, component_class, bt_component_class_type_string(type),
1180                 name, params, init_method_data, component);
1181
1182         if (user_component) {
1183                 /* Move reference to user */
1184                 *user_component = component;
1185                 component = NULL;
1186         }
1187
1188 end:
1189         bt_object_put_ref(component);
1190         bt_object_put_ref(params);
1191         if (graph) {
1192                 graph->can_consume = init_can_consume;
1193         }
1194         return graph_status;
1195 }
1196
1197 enum bt_graph_status bt_graph_add_component(
1198                 struct bt_graph *graph,
1199                 struct bt_component_class *component_class,
1200                 const char *name, struct bt_value *params,
1201                 struct bt_component **component)
1202 {
1203         return bt_graph_add_component_with_init_method_data(graph,
1204                 component_class, name, params, NULL, component);
1205 }
1206
1207 BT_HIDDEN
1208 int bt_graph_remove_unconnected_component(struct bt_graph *graph,
1209                 struct bt_component *component)
1210 {
1211         bt_bool init_can_consume;
1212         int64_t count;
1213         uint64_t i;
1214         int ret = 0;
1215
1216         BT_ASSERT(graph);
1217         BT_ASSERT(component);
1218         BT_ASSERT(component->base.ref_count == 0);
1219         BT_ASSERT(bt_component_borrow_graph(component) == graph);
1220
1221         init_can_consume = graph->can_consume;
1222         count = bt_component_get_input_port_count(component);
1223
1224         for (i = 0; i < count; i++) {
1225                 struct bt_port *port =
1226                         bt_component_get_input_port_by_index(component, i);
1227
1228                 BT_ASSERT(port);
1229                 bt_object_put_ref(port);
1230
1231                 if (bt_port_is_connected(port)) {
1232                         BT_LOGW("Cannot remove component from graph: "
1233                                 "an input port is connected: "
1234                                 "graph-addr=%p, comp-addr=%p, "
1235                                 "comp-name=\"%s\", connected-port-addr=%p, "
1236                                 "connected-port-name=\"%s\"",
1237                                 graph, component,
1238                                 bt_component_get_name(component),
1239                                 port, bt_port_get_name(port));
1240                         goto error;
1241                 }
1242         }
1243
1244         count = bt_component_get_output_port_count(component);
1245
1246         for (i = 0; i < count; i++) {
1247                 struct bt_port *port =
1248                         bt_component_get_output_port_by_index(component, i);
1249
1250                 BT_ASSERT(port);
1251                 bt_object_put_ref(port);
1252
1253                 if (bt_port_is_connected(port)) {
1254                         BT_LOGW("Cannot remove component from graph: "
1255                                 "an output port is connected: "
1256                                 "graph-addr=%p, comp-addr=%p, "
1257                                 "comp-name=\"%s\", connected-port-addr=%p, "
1258                                 "connected-port-name=\"%s\"",
1259                                 graph, component,
1260                                 bt_component_get_name(component),
1261                                 port, bt_port_get_name(port));
1262                         goto error;
1263                 }
1264         }
1265
1266         graph->can_consume = BT_FALSE;
1267
1268         /* Possibly remove from sinks to consume */
1269         (void) g_queue_remove(graph->sinks_to_consume, component);
1270
1271         if (graph->sinks_to_consume->length == 0) {
1272                 graph->has_sink = BT_FALSE;
1273         }
1274
1275         /*
1276          * This calls bt_object_try_spec_release() on the component, and
1277          * since its reference count is 0, its destructor is called. Its
1278          * destructor calls the user's finalization method (if set).
1279          */
1280         g_ptr_array_remove(graph->components, component);
1281         goto end;
1282
1283 error:
1284         ret = -1;
1285
1286 end:
1287         graph->can_consume = init_can_consume;
1288         return ret;
1289 }
1290
1291 BT_HIDDEN
1292 void bt_graph_add_notification(struct bt_graph *graph,
1293                 struct bt_notification *notif)
1294 {
1295         BT_ASSERT(graph);
1296         BT_ASSERT(notif);
1297
1298         /*
1299          * It's okay not to take a reference because, when a
1300          * notification's reference count drops to 0, either:
1301          *
1302          * * It is recycled back to one of this graph's pool.
1303          * * It is destroyed because it doesn't have any link to any
1304          *   graph, which means the original graph is already destroyed.
1305          */
1306         g_ptr_array_add(graph->notifications, notif);
1307 }