lib/component/graph.c

   1 /*
   2  * graph.c
   3  *
   4  * Babeltrace Plugin Component Graph
   5  *
   6  * Copyright 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   7  *
   8  * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a copy
  11  * of this software and associated documentation files (the "Software"), to deal
  12  * in the Software without restriction, including without limitation the rights
  13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14  * copies of the Software, and to permit persons to whom the Software is
  15  * furnished to do so, subject to the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be included in
  18  * all copies or substantial portions of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  23  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  26  * SOFTWARE.
  27  */
  28
  29 #include <babeltrace/component/component-internal.h>
  30 #include <babeltrace/component/graph-internal.h>
  31 #include <babeltrace/component/connection-internal.h>
  32 #include <babeltrace/component/component-sink-internal.h>
  33 #include <babeltrace/component/component-source.h>
  34 #include <babeltrace/component/component-filter.h>
  35 #include <babeltrace/component/port.h>
  36 #include <babeltrace/compiler.h>
  37 #include <unistd.h>
  38
  39 static
  40 void bt_graph_destroy(struct bt_object *obj)
  41 {
  42         struct bt_graph *graph = container_of(obj,
  43                         struct bt_graph, base);
  44
  45         if (graph->components) {
  46                 g_ptr_array_free(graph->components, TRUE);
  47         }
  48         if (graph->connections) {
  49                 g_ptr_array_free(graph->connections, TRUE);
  50         }
  51         if (graph->sinks_to_consume) {
  52                 g_queue_free(graph->sinks_to_consume);
  53         }
  54         g_free(graph);
  55 }
  56
  57 struct bt_graph *bt_graph_create(void)
  58 {
  59         struct bt_graph *graph;
  60
  61         graph = g_new0(struct bt_graph, 1);
  62         if (!graph) {
  63                 goto end;
  64         }
  65
  66         bt_object_init(graph, bt_graph_destroy);
  67
  68         graph->connections = g_ptr_array_new_with_free_func(bt_object_release);
  69         if (!graph->connections) {
  70                 goto error;
  71         }
  72         graph->components = g_ptr_array_new_with_free_func(bt_object_release);
  73         if (!graph->components) {
  74                 goto error;
  75         }
  76         graph->sinks_to_consume = g_queue_new();
  77         if (!graph->sinks_to_consume) {
  78                 goto error;
  79         }
  80 end:
  81         return graph;
  82 error:
  83         BT_PUT(graph);
  84         goto end;
  85 }
  86
  87 struct bt_connection *bt_graph_connect(struct bt_graph *graph,
  88                 struct bt_port *upstream_port,
  89                 struct bt_port *downstream_port)
  90 {
  91         struct bt_connection *connection = NULL;
  92         struct bt_graph *upstream_graph = NULL;
  93         struct bt_graph *downstream_graph = NULL;
  94         struct bt_component *upstream_component = NULL;
  95         struct bt_component *downstream_component = NULL;
  96         enum bt_component_status component_status;
  97         bool upstream_was_already_in_graph;
  98         bool downstream_was_already_in_graph;
  99
 100         if (!graph || !upstream_port || !downstream_port) {
 101                 goto end;
 102         }
 103
 104         if (bt_port_get_type(upstream_port) != BT_PORT_TYPE_OUTPUT) {
 105                 goto end;
 106         }
 107         if (bt_port_get_type(downstream_port) != BT_PORT_TYPE_INPUT) {
 108                 goto end;
 109         }
 110
 111         /* Ensure the components are not already part of another graph. */
 112         upstream_component = bt_port_get_component(upstream_port);
 113         assert(upstream_component);
 114         upstream_graph = bt_component_get_graph(upstream_component);
 115         if (upstream_graph && (graph != upstream_graph)) {
 116                 fprintf(stderr, "Upstream component is already part of another graph\n");
 117                 goto error;
 118         }
 119         upstream_was_already_in_graph = (graph == upstream_graph);
 120
 121         downstream_component = bt_port_get_component(downstream_port);
 122         assert(downstream_component);
 123         downstream_graph = bt_component_get_graph(downstream_component);
 124         if (downstream_graph && (graph != downstream_graph)) {
 125                 fprintf(stderr, "Downstream component is already part of another graph\n");
 126                 goto error;
 127         }
 128         downstream_was_already_in_graph = (graph == downstream_graph);
 129
 130         connection = bt_connection_create(graph, upstream_port,
 131                         downstream_port);
 132         if (!connection) {
 133                 goto error;
 134         }
 135
 136         /*
 137          * Ownership of up/downstream_component and of the connection object is
 138          * transferred to the graph.
 139          */
 140         g_ptr_array_add(graph->connections, connection);
 141
 142         if (!upstream_was_already_in_graph) {
 143                 g_ptr_array_add(graph->components, upstream_component);
 144                 bt_component_set_graph(upstream_component, graph);
 145         }
 146         if (!downstream_was_already_in_graph) {
 147                 g_ptr_array_add(graph->components, downstream_component);
 148                 bt_component_set_graph(downstream_component, graph);
 149                 if (bt_component_get_class_type(downstream_component) ==
 150                                 BT_COMPONENT_CLASS_TYPE_SINK) {
 151                         g_queue_push_tail(graph->sinks_to_consume,
 152                                         downstream_component);
 153                 }
 154         }
 155
 156         /*
 157          * The graph is now the parent of these components which garantees their
 158          * existence for the duration of the graph's lifetime.
 159          */
 160
 161         /*
 162          * The components and connection are added to the graph before invoking
 163          * the new_connection method in order to make them visible to the
 164          * components during the method's invocation.
 165          */
 166         component_status = bt_component_new_connection(upstream_component,
 167                         upstream_port, connection);
 168         if (component_status != BT_COMPONENT_STATUS_OK) {
 169                 goto error;
 170         }
 171         component_status = bt_component_new_connection(downstream_component,
 172                         downstream_port, connection);
 173         if (component_status != BT_COMPONENT_STATUS_OK) {
 174                 goto error;
 175         }
 176 end:
 177         bt_put(upstream_graph);
 178         bt_put(downstream_graph);
 179         return connection;
 180 error:
 181         if (components_added) {
 182                 if (bt_component_get_class_type(downstream_component) ==
 183                                 BT_COMPONENT_CLASS_TYPE_SINK) {
 184                         g_queue_pop_tail(graph->sinks_to_consume);
 185                 }
 186                 g_ptr_array_set_size(graph->connections,
 187                                 graph->connections->len - 1);
 188                 g_ptr_array_set_size(graph->components,
 189                                 graph->components->len - 2);
 190         }
 191         goto end;
 192 }
 193
 194 static
 195 enum bt_component_status get_component_port_counts(
 196                 struct bt_component *component, uint64_t *input_count,
 197                 uint64_t *output_count)
 198 {
 199         enum bt_component_status ret;
 200
 201         switch (bt_component_get_class_type(component)) {
 202         case BT_COMPONENT_CLASS_TYPE_SOURCE:
 203                 ret = bt_component_source_get_output_port_count(component,
 204                                 output_count);
 205                 if (ret != BT_COMPONENT_STATUS_OK) {
 206                         goto end;
 207                 }
 208                 break;
 209         case BT_COMPONENT_CLASS_TYPE_FILTER:
 210                 ret = bt_component_filter_get_output_port_count(component,
 211                                 output_count);
 212                 if (ret != BT_COMPONENT_STATUS_OK) {
 213                         goto end;
 214                 }
 215                 ret = bt_component_filter_get_input_port_count(component,
 216                                 input_count);
 217                 if (ret != BT_COMPONENT_STATUS_OK) {
 218                         goto end;
 219                 }
 220                 break;
 221         case BT_COMPONENT_CLASS_TYPE_SINK:
 222                 ret = bt_component_sink_get_input_port_count(component,
 223                                 input_count);
 224                 if (ret != BT_COMPONENT_STATUS_OK) {
 225                         goto end;
 226                 }
 227                 break;
 228         default:
 229                 assert(false);
 230                 break;
 231         }
 232         ret = BT_COMPONENT_STATUS_OK;
 233 end:
 234         return ret;
 235 }
 236
 237 static
 238 struct bt_port *get_input_port(struct bt_component *component, int index)
 239 {
 240         struct bt_port *port = NULL;
 241
 242         switch (bt_component_get_class_type(component)) {
 243         case BT_COMPONENT_CLASS_TYPE_FILTER:
 244                 port = bt_component_filter_get_input_port_at_index(component,
 245                                 index);
 246                 break;
 247         case BT_COMPONENT_CLASS_TYPE_SINK:
 248                 port = bt_component_sink_get_input_port_at_index(component,
 249                                 index);
 250                 break;
 251         default:
 252                 assert(false);
 253         }
 254         return port;
 255 }
 256
 257 static
 258 struct bt_port *get_output_port(struct bt_component *component, int index)
 259 {
 260         struct bt_port *port = NULL;
 261
 262         switch (bt_component_get_class_type(component)) {
 263         case BT_COMPONENT_CLASS_TYPE_SOURCE:
 264                 port = bt_component_source_get_output_port_at_index(component,
 265                                 index);
 266                 break;
 267         case BT_COMPONENT_CLASS_TYPE_FILTER:
 268                 port = bt_component_filter_get_output_port_at_index(component,
 269                                 index);
 270                 break;
 271         default:
 272                 assert(false);
 273         }
 274         return port;
 275 }
 276
 277 enum bt_graph_status bt_graph_add_component_as_sibling(struct bt_graph *graph,
 278                 struct bt_component *origin,
 279                 struct bt_component *new_component)
 280 {
 281         uint64_t origin_input_port_count = 0;
 282         uint64_t origin_output_port_count = 0;
 283         uint64_t new_input_port_count = 0;
 284         uint64_t new_output_port_count = 0;
 285         enum bt_graph_status status = BT_GRAPH_STATUS_OK;
 286         struct bt_graph *origin_graph = NULL;
 287         struct bt_graph *new_graph = NULL;
 288         struct bt_port *origin_port = NULL;
 289         struct bt_port *new_port = NULL;
 290         struct bt_port *upstream_port = NULL;
 291         struct bt_port *downstream_port = NULL;
 292         struct bt_connection *origin_connection = NULL;
 293         struct bt_connection *new_connection = NULL;
 294         int port_index;
 295
 296         if (!graph || !origin || !new_component) {
 297                 status = BT_GRAPH_STATUS_INVALID;
 298                 goto end;
 299         }
 300
 301         if (bt_component_get_class_type(origin) !=
 302                         bt_component_get_class_type(new_component)) {
 303                 status = BT_GRAPH_STATUS_INVALID;
 304                 goto end;
 305         }
 306
 307         origin_graph = bt_component_get_graph(origin);
 308         if (!origin_graph || (origin_graph != graph)) {
 309                 status = BT_GRAPH_STATUS_INVALID;
 310                 goto end;
 311         }
 312
 313         new_graph = bt_component_get_graph(new_component);
 314         if (new_graph) {
 315                 status = BT_GRAPH_STATUS_ALREADY_IN_A_GRAPH;
 316                 goto end;
 317         }
 318
 319         if (get_component_port_counts(origin, &origin_input_port_count,
 320                         &origin_output_port_count) != BT_COMPONENT_STATUS_OK) {
 321                 status = BT_GRAPH_STATUS_INVALID;
 322                 goto end;
 323         }
 324         if (get_component_port_counts(new_component, &new_input_port_count,
 325                         &new_output_port_count) != BT_COMPONENT_STATUS_OK) {
 326                 status = BT_GRAPH_STATUS_INVALID;
 327                 goto end;
 328         }
 329
 330         if (origin_input_port_count != new_input_port_count ||
 331                         origin_output_port_count != new_output_port_count) {
 332                 status = BT_GRAPH_STATUS_INVALID;
 333                 goto end;
 334         }
 335
 336         /* Replicate input connections. */
 337         for (port_index = 0; port_index< origin_input_port_count; port_index++) {
 338                 uint64_t connection_count, connection_index;
 339
 340                 origin_port = get_input_port(origin, port_index);
 341                 if (!origin_port) {
 342                         status = BT_GRAPH_STATUS_ERROR;
 343                         goto error_disconnect;
 344                 }
 345                 new_port = get_input_port(new_component, port_index);
 346                 if (!new_port) {
 347                         status = BT_GRAPH_STATUS_ERROR;
 348                         goto error_disconnect;
 349                 }
 350
 351                 if (bt_port_get_connection_count(origin_port, &connection_count) !=
 352                                 BT_PORT_STATUS_OK) {
 353                         status = BT_GRAPH_STATUS_ERROR;
 354                         goto error_disconnect;
 355                 }
 356
 357                 for (connection_index = 0; connection_index < connection_count;
 358                                 connection_index++) {
 359                         origin_connection = bt_port_get_connection(origin_port,
 360                                         connection_index);
 361                         if (!origin_connection) {
 362                                 goto error_disconnect;
 363                         }
 364
 365                         upstream_port = bt_connection_get_output_port(
 366                                         origin_connection);
 367                         if (!upstream_port) {
 368                                 goto error_disconnect;
 369                         }
 370
 371                         new_connection = bt_graph_connect(graph, upstream_port,
 372                                         new_port);
 373                         if (!new_connection) {
 374                                 goto error_disconnect;
 375                         }
 376
 377                         BT_PUT(upstream_port);
 378                         BT_PUT(origin_connection);
 379                         BT_PUT(new_connection);
 380                 }
 381                 BT_PUT(origin_port);
 382                 BT_PUT(new_port);
 383         }
 384
 385         /* Replicate output connections. */
 386         for (port_index = 0; port_index< origin_output_port_count; port_index++) {
 387                 uint64_t connection_count, connection_index;
 388
 389                 origin_port = get_output_port(origin, port_index);
 390                 if (!origin_port) {
 391                         status = BT_GRAPH_STATUS_ERROR;
 392                         goto error_disconnect;
 393                 }
 394                 new_port = get_output_port(new_component, port_index);
 395                 if (!new_port) {
 396                         status = BT_GRAPH_STATUS_ERROR;
 397                         goto error_disconnect;
 398                 }
 399
 400                 if (bt_port_get_connection_count(origin_port, &connection_count) !=
 401                                 BT_PORT_STATUS_OK) {
 402                         status = BT_GRAPH_STATUS_ERROR;
 403                         goto error_disconnect;
 404                 }
 405
 406                 for (connection_index = 0; connection_index < connection_count;
 407                                 connection_index++) {
 408                         origin_connection = bt_port_get_connection(origin_port,
 409                                         connection_index);
 410                         if (!origin_connection) {
 411                                 goto error_disconnect;
 412                         }
 413
 414                         downstream_port = bt_connection_get_input_port(
 415                                         origin_connection);
 416                         if (!downstream_port) {
 417                                 goto error_disconnect;
 418                         }
 419
 420                         new_connection = bt_graph_connect(graph, new_port,
 421                                         downstream_port);
 422                         if (!new_connection) {
 423                                 goto error_disconnect;
 424                         }
 425
 426                         BT_PUT(downstream_port);
 427                         BT_PUT(origin_connection);
 428                         BT_PUT(new_connection);
 429                 }
 430                 BT_PUT(origin_port);
 431                 BT_PUT(new_port);
 432         }
 433 end:
 434         bt_put(origin_graph);
 435         bt_put(new_graph);
 436         bt_put(origin_port);
 437         bt_put(new_port);
 438         bt_put(upstream_port);
 439         bt_put(downstream_port);
 440         bt_put(origin_connection);
 441         bt_put(new_connection);
 442         return status;
 443 error_disconnect:
 444         /* Destroy all connections of the new component. */
 445         /* FIXME. */
 446         goto end;
 447 }
 448
 449 enum bt_component_status bt_graph_consume(struct bt_graph *graph)
 450 {
 451         struct bt_component *sink;
 452         enum bt_component_status status;
 453         GList *current_node;
 454
 455         if (!graph) {
 456                 status = BT_COMPONENT_STATUS_INVALID;
 457                 goto end;
 458         }
 459
 460         if (g_queue_is_empty(graph->sinks_to_consume)) {
 461                 status = BT_COMPONENT_STATUS_END;
 462                 goto end;
 463         }
 464
 465         current_node = g_queue_pop_head_link(graph->sinks_to_consume);
 466         sink = current_node->data;
 467         status = bt_component_sink_consume(sink);
 468         if (status != BT_COMPONENT_STATUS_END) {
 469                 g_queue_push_tail_link(graph->sinks_to_consume, current_node);
 470                 goto end;
 471         }
 472
 473         /* End reached, the node is not added back to the queue and free'd. */
 474         g_queue_delete_link(graph->sinks_to_consume, current_node);
 475
 476         /* Don't forward an END status if there are sinks left to consume. */
 477         if (!g_queue_is_empty(graph->sinks_to_consume)) {
 478                 status = BT_GRAPH_STATUS_OK;
 479                 goto end;
 480         }
 481 end:
 482         return status;
 483 }
 484
 485 enum bt_graph_status bt_graph_run(struct bt_graph *graph,
 486                 enum bt_component_status *_component_status)
 487 {
 488         enum bt_component_status component_status;
 489         enum bt_graph_status graph_status = BT_GRAPH_STATUS_OK;
 490
 491         if (!graph) {
 492                 graph_status = BT_GRAPH_STATUS_INVALID;
 493                 goto error;
 494         }
 495
 496         do {
 497                 component_status = bt_graph_consume(graph);
 498                 if (component_status == BT_COMPONENT_STATUS_AGAIN) {
 499                         /*
 500                          * If AGAIN is received and there are multiple sinks,
 501                          * go ahead and consume from the next sink.
 502                          *
 503                          * However, in the case where a single sink is left,
 504                          * the caller can decide to busy-wait and call
 505                          * bt_graph_run continuously until the source is ready
 506                          * or it can decide to sleep for an arbitrary amount of
 507                          * time.
 508                          */
 509                         if (graph->sinks_to_consume->length > 1) {
 510                                 component_status = BT_COMPONENT_STATUS_OK;
 511                         }
 512                 }
 513         } while (component_status == BT_COMPONENT_STATUS_OK);
 514
 515         if (_component_status) {
 516                 *_component_status = component_status;
 517         }
 518
 519         if (g_queue_is_empty(graph->sinks_to_consume)) {
 520                 graph_status = BT_GRAPH_STATUS_END;
 521         } else if (component_status == BT_COMPONENT_STATUS_AGAIN) {
 522                 graph_status = BT_GRAPH_STATUS_AGAIN;
 523         } else {
 524                 graph_status = BT_GRAPH_STATUS_ERROR;
 525         }
 526 error:
 527         return graph_status;
 528 }