plugins/utils/muxer/muxer.c

   1 /*
   2  * Copyright 2017 Philippe Proulx <pproulx@efficios.com>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to deal
   6  * in the Software without restriction, including without limitation the rights
   7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  * copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  20  * SOFTWARE.
  21  */
  22
  23 #include <babeltrace/babeltrace-internal.h>
  24 #include <babeltrace/compat/uuid-internal.h>
  25 #include <babeltrace/ctf-ir/clock-class.h>
  26 #include <babeltrace/ctf-ir/event.h>
  27 #include <babeltrace/graph/clock-class-priority-map.h>
  28 #include <babeltrace/graph/component-filter.h>
  29 #include <babeltrace/graph/component.h>
  30 #include <babeltrace/graph/notification-event.h>
  31 #include <babeltrace/graph/notification-inactivity.h>
  32 #include <babeltrace/graph/notification-iterator.h>
  33 #include <babeltrace/graph/notification.h>
  34 #include <babeltrace/graph/port.h>
  35 #include <babeltrace/graph/private-component-filter.h>
  36 #include <babeltrace/graph/private-component.h>
  37 #include <babeltrace/graph/private-component.h>
  38 #include <babeltrace/graph/private-connection.h>
  39 #include <babeltrace/graph/private-notification-iterator.h>
  40 #include <babeltrace/graph/private-port.h>
  41 #include <babeltrace/graph/connection.h>
  42 #include <plugins-common.h>
  43 #include <glib.h>
  44 #include <stdbool.h>
  45 #include <assert.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48
  49 #define ASSUME_ABSOLUTE_CLOCK_CLASSES_PARAM_NAME        "assume-absolute-clock-classes"
  50
  51 struct muxer_comp {
  52         /* Array of struct bt_private_notification_iterator * (weak refs) */
  53         GPtrArray *muxer_notif_iters;
  54
  55         /* Weak ref */
  56         struct bt_private_component *priv_comp;
  57         unsigned int next_port_num;
  58         size_t available_input_ports;
  59         bool error;
  60         bool initializing_muxer_notif_iter;
  61         bool assume_absolute_clock_classes;
  62 };
  63
  64 struct muxer_upstream_notif_iter {
  65         /* Owned by this, NULL if ended */
  66         struct bt_notification_iterator *notif_iter;
  67
  68         /*
  69          * This flag is true if the upstream notification iterator's
  70          * current notification must be considered for the multiplexing
  71          * operations. If the upstream iterator returns
  72          * BT_NOTIFICATION_ITERATOR_STATUS_AGAIN, then this object
  73          * is considered invalid, because its current notification is
  74          * still the previous one, but we already took it into account.
  75          *
  76          * The value of this flag is not important if notif_iter above
  77          * is NULL (which means the upstream iterator is finished).
  78          */
  79         bool is_valid;
  80 };
  81
  82 enum muxer_notif_iter_clock_class_expectation {
  83         MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_ANY = 0,
  84         MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_ABSOLUTE,
  85         MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_SPEC_UUID,
  86         MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_NO_UUID,
  87 };
  88
  89 struct muxer_notif_iter {
  90         /*
  91          * Array of struct muxer_upstream_notif_iter * (owned by this).
  92          *
  93          * NOTE: This array is searched in linearly to find the youngest
  94          * current notification. Keep this until benchmarks confirm that
  95          * another data structure is faster than this for our typical
  96          * use cases.
  97          */
  98         GPtrArray *muxer_upstream_notif_iters;
  99
 100         /*
 101          * List of "recently" connected input ports (weak) to
 102          * handle by this muxer notification iterator.
 103          * muxer_port_connected() adds entries to this list, and the
 104          * entries are removed when a notification iterator is created
 105          * on the port's connection and put into
 106          * muxer_upstream_notif_iters above by
 107          * muxer_notif_iter_handle_newly_connected_ports().
 108          */
 109         GList *newly_connected_priv_ports;
 110
 111         /* Next thing to return by the "next" method */
 112         struct bt_notification_iterator_next_return next_next_return;
 113
 114         /* Last time returned in a notification */
 115         int64_t last_returned_ts_ns;
 116
 117         /* Clock class expectation state */
 118         enum muxer_notif_iter_clock_class_expectation clock_class_expectation;
 119
 120         /*
 121          * Expected clock class UUID, only valid when
 122          * clock_class_expectation is
 123          * MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_SPEC_UUID.
 124          */
 125         unsigned char expected_clock_class_uuid[BABELTRACE_UUID_LEN];
 126 };
 127
 128 static
 129 void destroy_muxer_upstream_notif_iter(
 130                 struct muxer_upstream_notif_iter *muxer_upstream_notif_iter)
 131 {
 132         if (!muxer_upstream_notif_iter) {
 133                 return;
 134         }
 135
 136         bt_put(muxer_upstream_notif_iter->notif_iter);
 137         g_free(muxer_upstream_notif_iter);
 138 }
 139
 140 static
 141 struct muxer_upstream_notif_iter *muxer_notif_iter_add_upstream_notif_iter(
 142                 struct muxer_notif_iter *muxer_notif_iter,
 143                 struct bt_notification_iterator *notif_iter,
 144                 struct bt_private_port *priv_port)
 145 {
 146         struct muxer_upstream_notif_iter *muxer_upstream_notif_iter =
 147                 g_new0(struct muxer_upstream_notif_iter, 1);
 148
 149         if (!muxer_upstream_notif_iter) {
 150                 goto end;
 151         }
 152
 153         muxer_upstream_notif_iter->notif_iter = bt_get(notif_iter);
 154         muxer_upstream_notif_iter->is_valid = false;
 155         g_ptr_array_add(muxer_notif_iter->muxer_upstream_notif_iters,
 156                 muxer_upstream_notif_iter);
 157
 158 end:
 159         return muxer_upstream_notif_iter;
 160 }
 161
 162 static
 163 enum bt_component_status ensure_available_input_port(
 164                 struct bt_private_component *priv_comp)
 165 {
 166         struct muxer_comp *muxer_comp =
 167                 bt_private_component_get_user_data(priv_comp);
 168         enum bt_component_status status = BT_COMPONENT_STATUS_OK;
 169         GString *port_name = NULL;
 170
 171         assert(muxer_comp);
 172
 173         if (muxer_comp->available_input_ports >= 1) {
 174                 goto end;
 175         }
 176
 177         port_name = g_string_new("in");
 178         if (!port_name) {
 179                 status = BT_COMPONENT_STATUS_NOMEM;
 180                 goto end;
 181         }
 182
 183         g_string_append_printf(port_name, "%u", muxer_comp->next_port_num);
 184         status = bt_private_component_filter_add_input_private_port(
 185                 priv_comp, port_name->str, NULL, NULL);
 186         if (status != BT_COMPONENT_STATUS_OK) {
 187                 goto end;
 188         }
 189
 190         muxer_comp->available_input_ports++;
 191         muxer_comp->next_port_num++;
 192
 193 end:
 194         if (port_name) {
 195                 g_string_free(port_name, TRUE);
 196         }
 197
 198         return status;
 199 }
 200
 201 static
 202 enum bt_component_status create_output_port(
 203                 struct bt_private_component *priv_comp)
 204 {
 205         return bt_private_component_filter_add_output_private_port(
 206                 priv_comp, "out", NULL, NULL);
 207 }
 208
 209 static
 210 void destroy_muxer_comp(struct muxer_comp *muxer_comp)
 211 {
 212         if (!muxer_comp) {
 213                 return;
 214         }
 215
 216         if (muxer_comp->muxer_notif_iters) {
 217                 g_ptr_array_free(muxer_comp->muxer_notif_iters, TRUE);
 218         }
 219
 220         g_free(muxer_comp);
 221 }
 222
 223 static
 224 struct bt_value *get_default_params(void)
 225 {
 226         struct bt_value *params;
 227         int ret;
 228
 229         params = bt_value_map_create();
 230         if (!params) {
 231                 goto error;
 232         }
 233
 234         ret = bt_value_map_insert_bool(params,
 235                 ASSUME_ABSOLUTE_CLOCK_CLASSES_PARAM_NAME, false);
 236         if (ret) {
 237                 goto error;
 238         }
 239
 240         goto end;
 241
 242 error:
 243         BT_PUT(params);
 244
 245 end:
 246         return params;
 247 }
 248
 249 static
 250 int configure_muxer_comp(struct muxer_comp *muxer_comp, struct bt_value *params)
 251 {
 252         struct bt_value *default_params = NULL;
 253         struct bt_value *real_params = NULL;
 254         struct bt_value *assume_absolute_clock_classes = NULL;
 255         int ret = 0;
 256         bt_bool bool_val;
 257
 258         default_params = get_default_params();
 259         if (!default_params) {
 260                 goto error;
 261         }
 262
 263         real_params = bt_value_map_extend(default_params, params);
 264         if (!real_params) {
 265                 goto error;
 266         }
 267
 268         assume_absolute_clock_classes = bt_value_map_get(real_params,
 269                 ASSUME_ABSOLUTE_CLOCK_CLASSES_PARAM_NAME);
 270         if (!bt_value_is_bool(assume_absolute_clock_classes)) {
 271                 goto error;
 272         }
 273
 274         if (bt_value_bool_get(assume_absolute_clock_classes, &bool_val)) {
 275                 goto error;
 276         }
 277
 278         muxer_comp->assume_absolute_clock_classes = (bool) bool_val;
 279
 280         goto end;
 281
 282 error:
 283         ret = -1;
 284
 285 end:
 286         bt_put(default_params);
 287         bt_put(real_params);
 288         bt_put(assume_absolute_clock_classes);
 289         return ret;
 290 }
 291
 292 BT_HIDDEN
 293 enum bt_component_status muxer_init(
 294                 struct bt_private_component *priv_comp,
 295                 struct bt_value *params, void *init_data)
 296 {
 297         int ret;
 298         enum bt_component_status status = BT_COMPONENT_STATUS_OK;
 299         struct muxer_comp *muxer_comp = g_new0(struct muxer_comp, 1);
 300
 301         if (!muxer_comp) {
 302                 goto error;
 303         }
 304
 305         ret = configure_muxer_comp(muxer_comp, params);
 306         if (ret) {
 307                 goto error;
 308         }
 309
 310         muxer_comp->muxer_notif_iters = g_ptr_array_new();
 311         if (!muxer_comp->muxer_notif_iters) {
 312                 goto error;
 313         }
 314
 315         muxer_comp->priv_comp = priv_comp;
 316         ret = bt_private_component_set_user_data(priv_comp, muxer_comp);
 317         assert(ret == 0);
 318         status = ensure_available_input_port(priv_comp);
 319         if (status != BT_COMPONENT_STATUS_OK) {
 320                 goto error;
 321         }
 322
 323         ret = create_output_port(priv_comp);
 324         if (ret) {
 325                 goto error;
 326         }
 327
 328         goto end;
 329
 330 error:
 331         destroy_muxer_comp(muxer_comp);
 332         ret = bt_private_component_set_user_data(priv_comp, NULL);
 333         assert(ret == 0);
 334
 335         if (status == BT_COMPONENT_STATUS_OK) {
 336                 status = BT_COMPONENT_STATUS_ERROR;
 337         }
 338
 339 end:
 340         return status;
 341 }
 342
 343 BT_HIDDEN
 344 void muxer_finalize(struct bt_private_component *priv_comp)
 345 {
 346         struct muxer_comp *muxer_comp =
 347                 bt_private_component_get_user_data(priv_comp);
 348
 349         destroy_muxer_comp(muxer_comp);
 350 }
 351
 352 static
 353 struct bt_notification_iterator *create_notif_iter_on_input_port(
 354                 struct bt_private_port *priv_port, int *ret)
 355 {
 356         struct bt_port *port = bt_port_from_private_port(priv_port);
 357         struct bt_notification_iterator *notif_iter = NULL;
 358         struct bt_private_connection *priv_conn = NULL;
 359         enum bt_connection_status conn_status;
 360
 361         assert(ret);
 362         *ret = 0;
 363         assert(port);
 364
 365         assert(bt_port_is_connected(port));
 366         priv_conn = bt_private_port_get_private_connection(priv_port);
 367         if (!priv_conn) {
 368                 *ret = -1;
 369                 goto end;
 370         }
 371
 372         // TODO: Advance the iterator to >= the time of the latest
 373         //       returned notification by the muxer notification
 374         //       iterator which creates it.
 375         conn_status = bt_private_connection_create_notification_iterator(
 376                 priv_conn, NULL, &notif_iter);
 377         if (conn_status != BT_CONNECTION_STATUS_OK) {
 378                 *ret = -1;
 379                 goto end;
 380         }
 381
 382 end:
 383         bt_put(port);
 384         bt_put(priv_conn);
 385         return notif_iter;
 386 }
 387
 388 static
 389 enum bt_notification_iterator_status muxer_upstream_notif_iter_next(
 390                 struct muxer_upstream_notif_iter *muxer_upstream_notif_iter)
 391 {
 392         enum bt_notification_iterator_status status;
 393
 394         status = bt_notification_iterator_next(
 395                 muxer_upstream_notif_iter->notif_iter);
 396
 397         switch (status) {
 398         case BT_NOTIFICATION_ITERATOR_STATUS_OK:
 399                 /*
 400                  * Notification iterator's current notification is valid:
 401                  * it must be considered for muxing operations.
 402                  */
 403                 muxer_upstream_notif_iter->is_valid = true;
 404                 break;
 405         case BT_NOTIFICATION_ITERATOR_STATUS_AGAIN:
 406                 /*
 407                  * Notification iterator's current notification is not
 408                  * valid anymore. Return
 409                  * BT_NOTIFICATION_ITERATOR_STATUS_AGAIN
 410                  * immediately.
 411                  */
 412                 muxer_upstream_notif_iter->is_valid = false;
 413                 break;
 414         case BT_NOTIFICATION_ITERATOR_STATUS_END:       /* Fall-through. */
 415         case BT_NOTIFICATION_ITERATOR_STATUS_CANCELED:
 416                 /*
 417                  * Notification iterator reached the end: release it. It
 418                  * won't be considered again to find the youngest
 419                  * notification.
 420                  */
 421                 BT_PUT(muxer_upstream_notif_iter->notif_iter);
 422                 muxer_upstream_notif_iter->is_valid = false;
 423                 status = BT_NOTIFICATION_ITERATOR_STATUS_OK;
 424                 break;
 425         default:
 426                 /* Error or unsupported status code */
 427                 status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
 428                 break;
 429         }
 430
 431         return status;
 432 }
 433
 434 static
 435 int muxer_notif_iter_handle_newly_connected_ports(
 436                 struct muxer_notif_iter *muxer_notif_iter)
 437 {
 438         int ret = 0;
 439
 440         /*
 441          * Here we create one upstream notification iterator for each
 442          * newly connected port. We do not perform an initial "next" on
 443          * those new upstream notification iterators: they are
 444          * invalidated, to be validated later. The list of newly
 445          * connected ports to handle here is updated by
 446          * muxer_port_connected().
 447          */
 448         while (true) {
 449                 GList *node = muxer_notif_iter->newly_connected_priv_ports;
 450                 struct bt_private_port *priv_port;
 451                 struct bt_port *port;
 452                 struct bt_notification_iterator *upstream_notif_iter = NULL;
 453                 struct muxer_upstream_notif_iter *muxer_upstream_notif_iter;
 454
 455                 if (!node) {
 456                         break;
 457                 }
 458
 459                 priv_port = node->data;
 460                 port = bt_port_from_private_port(priv_port);
 461                 assert(port);
 462
 463                 if (!bt_port_is_connected(port)) {
 464                         /*
 465                          * Looks like this port is not connected
 466                          * anymore: we can't create an upstream
 467                          * notification iterator on its (non-existing)
 468                          * connection in this case.
 469                          */
 470                         goto remove_node;
 471                 }
 472
 473                 BT_PUT(port);
 474                 upstream_notif_iter = create_notif_iter_on_input_port(priv_port,
 475                         &ret);
 476                 if (ret) {
 477                         assert(!upstream_notif_iter);
 478                         goto error;
 479                 }
 480
 481                 muxer_upstream_notif_iter =
 482                         muxer_notif_iter_add_upstream_notif_iter(
 483                                 muxer_notif_iter, upstream_notif_iter,
 484                                 priv_port);
 485                 BT_PUT(upstream_notif_iter);
 486                 if (!muxer_upstream_notif_iter) {
 487                         goto error;
 488                 }
 489
 490 remove_node:
 491                 bt_put(upstream_notif_iter);
 492                 bt_put(port);
 493                 muxer_notif_iter->newly_connected_priv_ports =
 494                         g_list_delete_link(
 495                                 muxer_notif_iter->newly_connected_priv_ports,
 496                                 node);
 497         }
 498
 499         goto end;
 500
 501 error:
 502         if (ret >= 0) {
 503                 ret = -1;
 504         }
 505
 506 end:
 507         return ret;
 508 }
 509
 510 static
 511 int get_notif_ts_ns(struct muxer_comp *muxer_comp,
 512                 struct muxer_notif_iter *muxer_notif_iter,
 513                 struct bt_notification *notif, int64_t last_returned_ts_ns,
 514                 int64_t *ts_ns)
 515 {
 516         struct bt_clock_class_priority_map *cc_prio_map = NULL;
 517         struct bt_ctf_clock_class *clock_class = NULL;
 518         struct bt_ctf_clock_value *clock_value = NULL;
 519         struct bt_ctf_event *event = NULL;
 520         int ret = 0;
 521         const unsigned char *cc_uuid;
 522
 523         assert(notif);
 524         assert(ts_ns);
 525
 526         switch (bt_notification_get_type(notif)) {
 527         case BT_NOTIFICATION_TYPE_EVENT:
 528                 cc_prio_map =
 529                         bt_notification_event_get_clock_class_priority_map(
 530                                 notif);
 531                 break;
 532
 533         case BT_NOTIFICATION_TYPE_INACTIVITY:
 534                 cc_prio_map =
 535                         bt_notification_inactivity_get_clock_class_priority_map(
 536                                 notif);
 537                 break;
 538         default:
 539                 /* All the other notifications have a higher priority */
 540                 *ts_ns = last_returned_ts_ns;
 541                 goto end;
 542         }
 543
 544         if (!cc_prio_map) {
 545                 goto error;
 546         }
 547
 548         /*
 549          * If the clock class priority map is empty, then we consider
 550          * that this notification has no time. In this case it's always
 551          * the youngest.
 552          */
 553         if (bt_clock_class_priority_map_get_clock_class_count(cc_prio_map) == 0) {
 554                 *ts_ns = last_returned_ts_ns;
 555                 goto end;
 556         }
 557
 558         clock_class =
 559                 bt_clock_class_priority_map_get_highest_priority_clock_class(
 560                         cc_prio_map);
 561         if (!clock_class) {
 562                 goto error;
 563         }
 564
 565         cc_uuid = bt_ctf_clock_class_get_uuid(clock_class);
 566
 567         if (muxer_notif_iter->clock_class_expectation ==
 568                         MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_ANY) {
 569                 /*
 570                  * This is the first clock class that this muxer
 571                  * notification iterator encounters. Its properties
 572                  * determine what to expect for the whole lifetime of
 573                  * the iterator without a true
 574                  * `assume-absolute-clock-classes` parameter.
 575                  */
 576                 if (bt_ctf_clock_class_is_absolute(clock_class)) {
 577                         /* Expect absolute clock classes */
 578                         muxer_notif_iter->clock_class_expectation =
 579                                 MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_ABSOLUTE;
 580                 } else {
 581                         if (cc_uuid) {
 582                                 /*
 583                                  * Expect non-absolute clock classes
 584                                  * with a specific UUID.
 585                                  */
 586                                 muxer_notif_iter->clock_class_expectation =
 587                                         MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_SPEC_UUID;
 588                                 memcpy(muxer_notif_iter->expected_clock_class_uuid,
 589                                         cc_uuid, BABELTRACE_UUID_LEN);
 590                         } else {
 591                                 /*
 592                                  * Expect non-absolute clock classes
 593                                  * with no UUID.
 594                                  */
 595                                 muxer_notif_iter->clock_class_expectation =
 596                                         MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_NO_UUID;
 597                         }
 598                 }
 599         }
 600
 601         if (!muxer_comp->assume_absolute_clock_classes) {
 602                 switch (muxer_notif_iter->clock_class_expectation) {
 603                 case MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_ABSOLUTE:
 604                         if (!bt_ctf_clock_class_is_absolute(clock_class)) {
 605                                 goto error;
 606                         }
 607                         break;
 608                 case MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_NO_UUID:
 609                         if (bt_ctf_clock_class_is_absolute(clock_class)) {
 610                                 goto error;
 611                         }
 612
 613                         if (cc_uuid) {
 614                                 goto error;
 615                         }
 616                         break;
 617                 case MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_SPEC_UUID:
 618                         if (bt_ctf_clock_class_is_absolute(clock_class)) {
 619                                 goto error;
 620                         }
 621
 622                         if (!cc_uuid) {
 623                                 goto error;
 624                         }
 625
 626                         if (memcmp(muxer_notif_iter->expected_clock_class_uuid,
 627                                         cc_uuid, BABELTRACE_UUID_LEN) != 0) {
 628                                 goto error;
 629                         }
 630                         break;
 631                 default:
 632                         /* Unexpected */
 633                         abort();
 634                 }
 635         }
 636
 637         switch (bt_notification_get_type(notif)) {
 638         case BT_NOTIFICATION_TYPE_EVENT:
 639                 event = bt_notification_event_get_event(notif);
 640                 assert(event);
 641                 clock_value = bt_ctf_event_get_clock_value(event,
 642                         clock_class);
 643                 break;
 644         case BT_NOTIFICATION_TYPE_INACTIVITY:
 645                 clock_value = bt_notification_inactivity_get_clock_value(
 646                         notif, clock_class);
 647                 break;
 648         default:
 649                 abort();
 650         }
 651
 652         if (!clock_value) {
 653                 goto error;
 654         }
 655
 656         ret = bt_ctf_clock_value_get_value_ns_from_epoch(clock_value, ts_ns);
 657         if (ret) {
 658                 goto error;
 659         }
 660
 661         goto end;
 662
 663 error:
 664         ret = -1;
 665
 666 end:
 667         bt_put(cc_prio_map);
 668         bt_put(event);
 669         bt_put(clock_class);
 670         bt_put(clock_value);
 671         return ret;
 672 }
 673
 674 /*
 675  * This function finds the youngest available notification amongst the
 676  * non-ended upstream notification iterators and returns the upstream
 677  * notification iterator which has it, or
 678  * BT_NOTIFICATION_ITERATOR_STATUS_END if there's no available
 679  * notification.
 680  *
 681  * This function does NOT:
 682  *
 683  * * Update any upstream notification iterator.
 684  * * Check for newly connected ports.
 685  * * Check the upstream notification iterators to retry.
 686  *
 687  * On sucess, this function sets *muxer_upstream_notif_iter to the
 688  * upstream notification iterator of which the current notification is
 689  * the youngest, and sets *ts_ns to its time.
 690  */
 691 static
 692 enum bt_notification_iterator_status
 693 muxer_notif_iter_youngest_upstream_notif_iter(
 694                 struct muxer_comp *muxer_comp,
 695                 struct muxer_notif_iter *muxer_notif_iter,
 696                 struct muxer_upstream_notif_iter **muxer_upstream_notif_iter,
 697                 int64_t *ts_ns)
 698 {
 699         size_t i;
 700         int ret;
 701         int64_t youngest_ts_ns = INT64_MAX;
 702         enum bt_notification_iterator_status status =
 703                 BT_NOTIFICATION_ITERATOR_STATUS_OK;
 704
 705         assert(muxer_comp);
 706         assert(muxer_notif_iter);
 707         assert(muxer_upstream_notif_iter);
 708         *muxer_upstream_notif_iter = NULL;
 709
 710         for (i = 0; i < muxer_notif_iter->muxer_upstream_notif_iters->len; i++) {
 711                 struct bt_notification *notif;
 712                 struct muxer_upstream_notif_iter *cur_muxer_upstream_notif_iter =
 713                         g_ptr_array_index(muxer_notif_iter->muxer_upstream_notif_iters, i);
 714                 int64_t notif_ts_ns;
 715
 716                 if (!cur_muxer_upstream_notif_iter->notif_iter) {
 717                         /* This upstream notification iterator is ended */
 718                         continue;
 719                 }
 720
 721                 assert(cur_muxer_upstream_notif_iter->is_valid);
 722                 notif = bt_notification_iterator_get_notification(
 723                         cur_muxer_upstream_notif_iter->notif_iter);
 724                 assert(notif);
 725                 ret = get_notif_ts_ns(muxer_comp, muxer_notif_iter, notif,
 726                         muxer_notif_iter->last_returned_ts_ns, &notif_ts_ns);
 727                 bt_put(notif);
 728                 if (ret) {
 729                         *muxer_upstream_notif_iter = NULL;
 730                         status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
 731                         goto end;
 732                 }
 733
 734                 if (notif_ts_ns <= youngest_ts_ns) {
 735                         *muxer_upstream_notif_iter =
 736                                 cur_muxer_upstream_notif_iter;
 737                         youngest_ts_ns = notif_ts_ns;
 738                         *ts_ns = youngest_ts_ns;
 739                 }
 740         }
 741
 742         if (!*muxer_upstream_notif_iter) {
 743                 status = BT_NOTIFICATION_ITERATOR_STATUS_END;
 744                 *ts_ns = INT64_MIN;
 745         }
 746
 747 end:
 748         return status;
 749 }
 750
 751 static
 752 enum bt_notification_iterator_status validate_muxer_upstream_notif_iter(
 753         struct muxer_upstream_notif_iter *muxer_upstream_notif_iter)
 754 {
 755         enum bt_notification_iterator_status status =
 756                 BT_NOTIFICATION_ITERATOR_STATUS_OK;
 757
 758         if (muxer_upstream_notif_iter->is_valid ||
 759                         !muxer_upstream_notif_iter->notif_iter) {
 760                 goto end;
 761         }
 762
 763         status = muxer_upstream_notif_iter_next(muxer_upstream_notif_iter);
 764
 765 end:
 766         return status;
 767 }
 768
 769 static
 770 enum bt_notification_iterator_status validate_muxer_upstream_notif_iters(
 771         struct muxer_notif_iter *muxer_notif_iter)
 772 {
 773         enum bt_notification_iterator_status status =
 774                 BT_NOTIFICATION_ITERATOR_STATUS_OK;
 775         size_t i;
 776
 777         for (i = 0; i < muxer_notif_iter->muxer_upstream_notif_iters->len; i++) {
 778                 struct muxer_upstream_notif_iter *muxer_upstream_notif_iter =
 779                         g_ptr_array_index(
 780                                 muxer_notif_iter->muxer_upstream_notif_iters,
 781                                 i);
 782
 783                 status = validate_muxer_upstream_notif_iter(
 784                         muxer_upstream_notif_iter);
 785                 if (status != BT_NOTIFICATION_ITERATOR_STATUS_OK) {
 786                         goto end;
 787                 }
 788
 789                 /*
 790                  * Remove this muxer upstream notification iterator
 791                  * if it's ended or canceled.
 792                  */
 793                 if (!muxer_upstream_notif_iter->notif_iter) {
 794                         /*
 795                          * Use g_ptr_array_remove_fast() because the
 796                          * order of those elements is not important.
 797                          */
 798                         g_ptr_array_remove_index_fast(
 799                                 muxer_notif_iter->muxer_upstream_notif_iters,
 800                                 i);
 801                         i--;
 802                 }
 803         }
 804
 805 end:
 806         return status;
 807 }
 808
 809 static
 810 struct bt_notification_iterator_next_return muxer_notif_iter_do_next(
 811                 struct muxer_comp *muxer_comp,
 812                 struct muxer_notif_iter *muxer_notif_iter)
 813 {
 814         struct muxer_upstream_notif_iter *muxer_upstream_notif_iter = NULL;
 815         struct bt_notification_iterator_next_return next_return = {
 816                 .notification = NULL,
 817                 .status = BT_NOTIFICATION_ITERATOR_STATUS_OK,
 818         };
 819         int64_t next_return_ts;
 820
 821         while (true) {
 822                 int ret = muxer_notif_iter_handle_newly_connected_ports(
 823                         muxer_notif_iter);
 824
 825                 if (ret) {
 826                         next_return.status =
 827                                 BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
 828                         goto end;
 829                 }
 830
 831                 next_return.status =
 832                         validate_muxer_upstream_notif_iters(muxer_notif_iter);
 833                 if (next_return.status != BT_NOTIFICATION_ITERATOR_STATUS_OK) {
 834                         goto end;
 835                 }
 836
 837                 /*
 838                  * At this point, we know that all the existing upstream
 839                  * notification iterators are valid. However the
 840                  * operations to validate them (during
 841                  * validate_muxer_upstream_notif_iters()) may have
 842                  * connected new ports. If no ports were connected
 843                  * during this operation, exit the loop.
 844                  */
 845                 if (!muxer_notif_iter->newly_connected_priv_ports) {
 846                         break;
 847                 }
 848         }
 849
 850         assert(!muxer_notif_iter->newly_connected_priv_ports);
 851
 852         /*
 853          * At this point we know that all the existing upstream
 854          * notification iterators are valid. We can find the one,
 855          * amongst those, of which the current notification is the
 856          * youngest.
 857          */
 858         next_return.status =
 859                 muxer_notif_iter_youngest_upstream_notif_iter(muxer_comp,
 860                         muxer_notif_iter, &muxer_upstream_notif_iter,
 861                         &next_return_ts);
 862         if (next_return.status < 0 ||
 863                         next_return.status == BT_NOTIFICATION_ITERATOR_STATUS_END ||
 864                         next_return.status == BT_NOTIFICATION_ITERATOR_STATUS_CANCELED) {
 865                 goto end;
 866         }
 867
 868         if (next_return_ts < muxer_notif_iter->last_returned_ts_ns) {
 869                 next_return.status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
 870                 goto end;
 871         }
 872
 873         assert(next_return.status == BT_NOTIFICATION_ITERATOR_STATUS_OK);
 874         assert(muxer_upstream_notif_iter);
 875         next_return.notification = bt_notification_iterator_get_notification(
 876                 muxer_upstream_notif_iter->notif_iter);
 877         assert(next_return.notification);
 878
 879         /*
 880          * We invalidate the upstream notification iterator so that, the
 881          * next time this function is called,
 882          * validate_muxer_upstream_notif_iters() will make it valid.
 883          */
 884         muxer_upstream_notif_iter->is_valid = false;
 885         muxer_notif_iter->last_returned_ts_ns = next_return_ts;
 886
 887 end:
 888         return next_return;
 889 }
 890
 891 static
 892 void destroy_muxer_notif_iter(struct muxer_notif_iter *muxer_notif_iter)
 893 {
 894         if (!muxer_notif_iter) {
 895                 return;
 896         }
 897
 898         if (muxer_notif_iter->muxer_upstream_notif_iters) {
 899                 g_ptr_array_free(
 900                         muxer_notif_iter->muxer_upstream_notif_iters, TRUE);
 901         }
 902
 903         g_list_free(muxer_notif_iter->newly_connected_priv_ports);
 904         g_free(muxer_notif_iter);
 905 }
 906
 907 static
 908 int muxer_notif_iter_init_newly_connected_ports(struct muxer_comp *muxer_comp,
 909                 struct muxer_notif_iter *muxer_notif_iter)
 910 {
 911         struct bt_component *comp;
 912         int64_t count;
 913         int64_t i;
 914         int ret = 0;
 915
 916         /*
 917          * Add the connected input ports to this muxer notification
 918          * iterator's list of newly connected ports. They will be
 919          * handled by muxer_notif_iter_handle_newly_connected_ports().
 920          */
 921         comp = bt_component_from_private_component(muxer_comp->priv_comp);
 922         assert(comp);
 923         count = bt_component_filter_get_input_port_count(comp);
 924         if (count < 0) {
 925                 goto end;
 926         }
 927
 928         for (i = 0; i < count; i++) {
 929                 struct bt_private_port *priv_port =
 930                         bt_private_component_filter_get_input_private_port_by_index(
 931                                 muxer_comp->priv_comp, i);
 932                 struct bt_port *port;
 933
 934                 assert(priv_port);
 935                 port = bt_port_from_private_port(priv_port);
 936                 assert(port);
 937
 938                 if (!bt_port_is_connected(port)) {
 939                         bt_put(priv_port);
 940                         bt_put(port);
 941                         continue;
 942                 }
 943
 944                 bt_put(port);
 945                 bt_put(priv_port);
 946                 muxer_notif_iter->newly_connected_priv_ports =
 947                         g_list_append(
 948                                 muxer_notif_iter->newly_connected_priv_ports,
 949                                 priv_port);
 950                 if (!muxer_notif_iter->newly_connected_priv_ports) {
 951                         ret = -1;
 952                         goto end;
 953                 }
 954         }
 955
 956 end:
 957         bt_put(comp);
 958         return ret;
 959 }
 960
 961 BT_HIDDEN
 962 enum bt_notification_iterator_status muxer_notif_iter_init(
 963                 struct bt_private_notification_iterator *priv_notif_iter,
 964                 struct bt_private_port *output_priv_port)
 965 {
 966         struct muxer_comp *muxer_comp = NULL;
 967         struct muxer_notif_iter *muxer_notif_iter = NULL;
 968         struct bt_private_component *priv_comp = NULL;
 969         enum bt_notification_iterator_status status =
 970                 BT_NOTIFICATION_ITERATOR_STATUS_OK;
 971         int ret;
 972
 973         priv_comp = bt_private_notification_iterator_get_private_component(
 974                 priv_notif_iter);
 975         assert(priv_comp);
 976         muxer_comp = bt_private_component_get_user_data(priv_comp);
 977         assert(muxer_comp);
 978
 979         if (muxer_comp->initializing_muxer_notif_iter) {
 980                 /*
 981                  * Weird, unhandled situation detected: downstream
 982                  * creates a muxer notification iterator while creating
 983                  * another muxer notification iterator (same component).
 984                  */
 985                 goto error;
 986         }
 987
 988         muxer_comp->initializing_muxer_notif_iter = true;
 989         muxer_notif_iter = g_new0(struct muxer_notif_iter, 1);
 990         if (!muxer_notif_iter) {
 991                 goto error;
 992         }
 993
 994         muxer_notif_iter->last_returned_ts_ns = INT64_MIN;
 995         muxer_notif_iter->muxer_upstream_notif_iters =
 996                 g_ptr_array_new_with_free_func(
 997                         (GDestroyNotify) destroy_muxer_upstream_notif_iter);
 998         if (!muxer_notif_iter->muxer_upstream_notif_iters) {
 999                 goto error;
1000         }
1001
1002         /*
1003          * Add the muxer notification iterator to the component's array
1004          * of muxer notification iterators here because
1005          * muxer_notif_iter_init_newly_connected_ports() can cause
1006          * muxer_port_connected() to be called, which adds the newly
1007          * connected port to each muxer notification iterator's list of
1008          * newly connected ports.
1009          */
1010         g_ptr_array_add(muxer_comp->muxer_notif_iters, muxer_notif_iter);
1011         ret = muxer_notif_iter_init_newly_connected_ports(muxer_comp,
1012                 muxer_notif_iter);
1013         if (ret) {
1014                 goto error;
1015         }
1016
1017         ret = bt_private_notification_iterator_set_user_data(priv_notif_iter,
1018                 muxer_notif_iter);
1019         assert(ret == 0);
1020         goto end;
1021
1022 error:
1023         if (g_ptr_array_index(muxer_comp->muxer_notif_iters,
1024                         muxer_comp->muxer_notif_iters->len - 1) == muxer_notif_iter) {
1025                 g_ptr_array_remove_index(muxer_comp->muxer_notif_iters,
1026                         muxer_comp->muxer_notif_iters->len - 1);
1027         }
1028
1029         destroy_muxer_notif_iter(muxer_notif_iter);
1030         ret = bt_private_notification_iterator_set_user_data(priv_notif_iter,
1031                 NULL);
1032         assert(ret == 0);
1033         status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
1034
1035 end:
1036         muxer_comp->initializing_muxer_notif_iter = false;
1037         bt_put(priv_comp);
1038         return status;
1039 }
1040
1041 BT_HIDDEN
1042 void muxer_notif_iter_finalize(
1043                 struct bt_private_notification_iterator *priv_notif_iter)
1044 {
1045         struct muxer_notif_iter *muxer_notif_iter =
1046                 bt_private_notification_iterator_get_user_data(priv_notif_iter);
1047         struct bt_private_component *priv_comp = NULL;
1048         struct muxer_comp *muxer_comp = NULL;
1049
1050         priv_comp = bt_private_notification_iterator_get_private_component(
1051                 priv_notif_iter);
1052         assert(priv_comp);
1053         muxer_comp = bt_private_component_get_user_data(priv_comp);
1054
1055         if (muxer_comp) {
1056                 (void) g_ptr_array_remove_fast(muxer_comp->muxer_notif_iters,
1057                         muxer_notif_iter);
1058                 destroy_muxer_notif_iter(muxer_notif_iter);
1059         }
1060
1061         bt_put(priv_comp);
1062 }
1063
1064 BT_HIDDEN
1065 struct bt_notification_iterator_next_return muxer_notif_iter_next(
1066                 struct bt_private_notification_iterator *priv_notif_iter)
1067 {
1068         struct bt_notification_iterator_next_return next_ret;
1069         struct muxer_notif_iter *muxer_notif_iter =
1070                 bt_private_notification_iterator_get_user_data(priv_notif_iter);
1071         struct bt_private_component *priv_comp = NULL;
1072         struct muxer_comp *muxer_comp = NULL;
1073
1074         assert(muxer_notif_iter);
1075         priv_comp = bt_private_notification_iterator_get_private_component(
1076                 priv_notif_iter);
1077         assert(priv_comp);
1078         muxer_comp = bt_private_component_get_user_data(priv_comp);
1079         assert(muxer_comp);
1080
1081         /* Are we in an error state set elsewhere? */
1082         if (unlikely(muxer_comp->error)) {
1083                 next_ret.notification = NULL;
1084                 next_ret.status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
1085                 goto end;
1086         }
1087
1088         next_ret = muxer_notif_iter_do_next(muxer_comp, muxer_notif_iter);
1089
1090 end:
1091         bt_put(priv_comp);
1092         return next_ret;
1093 }
1094
1095 BT_HIDDEN
1096 void muxer_port_connected(
1097                 struct bt_private_component *priv_comp,
1098                 struct bt_private_port *self_private_port,
1099                 struct bt_port *other_port)
1100 {
1101         struct bt_port *self_port =
1102                 bt_port_from_private_port(self_private_port);
1103         struct muxer_comp *muxer_comp =
1104                 bt_private_component_get_user_data(priv_comp);
1105         size_t i;
1106         int ret;
1107
1108         assert(self_port);
1109         assert(muxer_comp);
1110
1111         if (bt_port_get_type(self_port) == BT_PORT_TYPE_OUTPUT) {
1112                 goto end;
1113         }
1114
1115         for (i = 0; i < muxer_comp->muxer_notif_iters->len; i++) {
1116                 struct muxer_notif_iter *muxer_notif_iter =
1117                         g_ptr_array_index(muxer_comp->muxer_notif_iters, i);
1118
1119                 /*
1120                  * Add this port to the list of newly connected ports
1121                  * for this muxer notification iterator. We append at
1122                  * the end of this list while
1123                  * muxer_notif_iter_handle_newly_connected_ports()
1124                  * removes the nodes from the beginning.
1125                  *
1126                  * The list node owns the private port.
1127                  */
1128                 muxer_notif_iter->newly_connected_priv_ports =
1129                         g_list_append(
1130                                 muxer_notif_iter->newly_connected_priv_ports,
1131                                 self_private_port);
1132                 if (!muxer_notif_iter->newly_connected_priv_ports) {
1133                         /* Put reference taken by bt_get() above */
1134                         muxer_comp->error = true;
1135                         goto end;
1136                 }
1137         }
1138
1139         /* One less available input port */
1140         muxer_comp->available_input_ports--;
1141         ret = ensure_available_input_port(priv_comp);
1142         if (ret) {
1143                 /*
1144                  * Only way to report an error later since this
1145                  * method does not return anything.
1146                  */
1147                 muxer_comp->error = true;
1148                 goto end;
1149         }
1150
1151 end:
1152         bt_put(self_port);
1153 }
1154
1155 BT_HIDDEN
1156 void muxer_port_disconnected(struct bt_private_component *priv_comp,
1157                 struct bt_private_port *priv_port)
1158 {
1159         struct bt_port *port = bt_port_from_private_port(priv_port);
1160         struct muxer_comp *muxer_comp =
1161                 bt_private_component_get_user_data(priv_comp);
1162
1163         assert(port);
1164         assert(muxer_comp);
1165
1166         /*
1167          * There's nothing special to do when a port is disconnected
1168          * because this component deals with upstream notification
1169          * iterators which were already created thanks to connected
1170          * ports. The fact that the port is disconnected does not cancel
1171          * the upstream notification iterators created using its
1172          * connection: they still exist, even if the connection is dead.
1173          * The only way to remove an upstream notification iterator is
1174          * for its "next" operation to return
1175          * BT_NOTIFICATION_ITERATOR_STATUS_END.
1176          */
1177         if (bt_port_get_type(port) == BT_PORT_TYPE_INPUT) {
1178                 /* One more available input port */
1179                 muxer_comp->available_input_ports++;
1180         }
1181
1182         bt_put(port);
1183 }