src/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 #define BT_LOG_TAG "PLUGIN/FLT.UTILS.MUXER"
  24 #include "logging.h"
  25
  26 #include "common/macros.h"
  27 #include "compat/uuid.h"
  28 #include <babeltrace2/babeltrace.h>
  29 #include "lib/value.h"
  30 #include "lib/graph/component.h"
  31 #include "lib/graph/message/iterator.h"
  32 #include "lib/graph/connection.h"
  33 #include <glib.h>
  34 #include <stdbool.h>
  35 #include <inttypes.h>
  36 #include "common/assert.h"
  37 #include "common/common.h"
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 #include "muxer.h"
  42
  43 #define ASSUME_ABSOLUTE_CLOCK_CLASSES_PARAM_NAME        "assume-absolute-clock-classes"
  44
  45 struct muxer_comp {
  46         /* Weak ref */
  47         bt_self_component_filter *self_comp;
  48
  49         unsigned int next_port_num;
  50         size_t available_input_ports;
  51         bool initializing_muxer_msg_iter;
  52         bool assume_absolute_clock_classes;
  53 };
  54
  55 struct muxer_upstream_msg_iter {
  56         /* Owned by this, NULL if ended */
  57         bt_self_component_port_input_message_iterator *msg_iter;
  58
  59         /* Contains `const bt_message *`, owned by this */
  60         GQueue *msgs;
  61 };
  62
  63 enum muxer_msg_iter_clock_class_expectation {
  64         MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_ANY = 0,
  65         MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_NONE,
  66         MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_ABSOLUTE,
  67         MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_SPEC_UUID,
  68         MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_NO_UUID,
  69 };
  70
  71 struct muxer_msg_iter {
  72         /*
  73          * Array of struct muxer_upstream_msg_iter * (owned by this).
  74          *
  75          * NOTE: This array is searched in linearly to find the youngest
  76          * current message. Keep this until benchmarks confirm that
  77          * another data structure is faster than this for our typical
  78          * use cases.
  79          */
  80         GPtrArray *active_muxer_upstream_msg_iters;
  81
  82         /*
  83          * Array of struct muxer_upstream_msg_iter * (owned by this).
  84          *
  85          * We move ended message iterators from
  86          * `active_muxer_upstream_msg_iters` to this array so as to be
  87          * able to restore them when seeking.
  88          */
  89         GPtrArray *ended_muxer_upstream_msg_iters;
  90
  91         /* Last time returned in a message */
  92         int64_t last_returned_ts_ns;
  93
  94         /* Clock class expectation state */
  95         enum muxer_msg_iter_clock_class_expectation clock_class_expectation;
  96
  97         /*
  98          * Expected clock class UUID, only valid when
  99          * clock_class_expectation is
 100          * MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_SPEC_UUID.
 101          */
 102         unsigned char expected_clock_class_uuid[BABELTRACE_UUID_LEN];
 103 };
 104
 105 static
 106 void empty_message_queue(struct muxer_upstream_msg_iter *upstream_msg_iter)
 107 {
 108         const bt_message *msg;
 109
 110         while ((msg = g_queue_pop_head(upstream_msg_iter->msgs))) {
 111                 bt_message_put_ref(msg);
 112         }
 113 }
 114
 115 static
 116 void destroy_muxer_upstream_msg_iter(
 117                 struct muxer_upstream_msg_iter *muxer_upstream_msg_iter)
 118 {
 119         if (!muxer_upstream_msg_iter) {
 120                 return;
 121         }
 122
 123         BT_LOGD("Destroying muxer's upstream message iterator wrapper: "
 124                 "addr=%p, msg-iter-addr=%p, queue-len=%u",
 125                 muxer_upstream_msg_iter,
 126                 muxer_upstream_msg_iter->msg_iter,
 127                 muxer_upstream_msg_iter->msgs->length);
 128         bt_self_component_port_input_message_iterator_put_ref(
 129                 muxer_upstream_msg_iter->msg_iter);
 130
 131         if (muxer_upstream_msg_iter->msgs) {
 132                 empty_message_queue(muxer_upstream_msg_iter);
 133                 g_queue_free(muxer_upstream_msg_iter->msgs);
 134         }
 135
 136         g_free(muxer_upstream_msg_iter);
 137 }
 138
 139 static
 140 int muxer_msg_iter_add_upstream_msg_iter(struct muxer_msg_iter *muxer_msg_iter,
 141                 bt_self_component_port_input_message_iterator *self_msg_iter)
 142 {
 143         int ret = 0;
 144         struct muxer_upstream_msg_iter *muxer_upstream_msg_iter =
 145                 g_new0(struct muxer_upstream_msg_iter, 1);
 146
 147         if (!muxer_upstream_msg_iter) {
 148                 BT_LOGE_STR("Failed to allocate one muxer's upstream message iterator wrapper.");
 149                 goto error;
 150         }
 151
 152         muxer_upstream_msg_iter->msg_iter = self_msg_iter;
 153         bt_self_component_port_input_message_iterator_get_ref(muxer_upstream_msg_iter->msg_iter);
 154         muxer_upstream_msg_iter->msgs = g_queue_new();
 155         if (!muxer_upstream_msg_iter->msgs) {
 156                 BT_LOGE_STR("Failed to allocate a GQueue.");
 157                 goto error;
 158         }
 159
 160         g_ptr_array_add(muxer_msg_iter->active_muxer_upstream_msg_iters,
 161                 muxer_upstream_msg_iter);
 162         BT_LOGD("Added muxer's upstream message iterator wrapper: "
 163                 "addr=%p, muxer-msg-iter-addr=%p, msg-iter-addr=%p",
 164                 muxer_upstream_msg_iter, muxer_msg_iter,
 165                 self_msg_iter);
 166
 167         goto end;
 168
 169 error:
 170         g_free(muxer_upstream_msg_iter);
 171         ret = -1;
 172
 173 end:
 174         return ret;
 175 }
 176
 177 static
 178 bt_self_component_status add_available_input_port(
 179                 bt_self_component_filter *self_comp)
 180 {
 181         struct muxer_comp *muxer_comp = bt_self_component_get_data(
 182                 bt_self_component_filter_as_self_component(self_comp));
 183         bt_self_component_status status = BT_SELF_COMPONENT_STATUS_OK;
 184         GString *port_name = NULL;
 185
 186         BT_ASSERT(muxer_comp);
 187         port_name = g_string_new("in");
 188         if (!port_name) {
 189                 BT_LOGE_STR("Failed to allocate a GString.");
 190                 status = BT_SELF_COMPONENT_STATUS_NOMEM;
 191                 goto end;
 192         }
 193
 194         g_string_append_printf(port_name, "%u", muxer_comp->next_port_num);
 195         status = bt_self_component_filter_add_input_port(
 196                 self_comp, port_name->str, NULL, NULL);
 197         if (status != BT_SELF_COMPONENT_STATUS_OK) {
 198                 BT_LOGE("Cannot add input port to muxer component: "
 199                         "port-name=\"%s\", comp-addr=%p, status=%s",
 200                         port_name->str, self_comp,
 201                         bt_self_component_status_string(status));
 202                 goto end;
 203         }
 204
 205         muxer_comp->available_input_ports++;
 206         muxer_comp->next_port_num++;
 207         BT_LOGI("Added one input port to muxer component: "
 208                 "port-name=\"%s\", comp-addr=%p",
 209                 port_name->str, self_comp);
 210
 211 end:
 212         if (port_name) {
 213                 g_string_free(port_name, TRUE);
 214         }
 215
 216         return status;
 217 }
 218
 219 static
 220 bt_self_component_status create_output_port(
 221                 bt_self_component_filter *self_comp)
 222 {
 223         return bt_self_component_filter_add_output_port(
 224                 self_comp, "out", NULL, NULL);
 225 }
 226
 227 static
 228 void destroy_muxer_comp(struct muxer_comp *muxer_comp)
 229 {
 230         if (!muxer_comp) {
 231                 return;
 232         }
 233
 234         g_free(muxer_comp);
 235 }
 236
 237 static
 238 bt_value *get_default_params(void)
 239 {
 240         bt_value *params;
 241         int ret;
 242
 243         params = bt_value_map_create();
 244         if (!params) {
 245                 BT_LOGE_STR("Cannot create a map value object.");
 246                 goto error;
 247         }
 248
 249         ret = bt_value_map_insert_bool_entry(params,
 250                 ASSUME_ABSOLUTE_CLOCK_CLASSES_PARAM_NAME, false);
 251         if (ret) {
 252                 BT_LOGE_STR("Cannot add boolean value to map value object.");
 253                 goto error;
 254         }
 255
 256         goto end;
 257
 258 error:
 259         BT_VALUE_PUT_REF_AND_RESET(params);
 260
 261 end:
 262         return params;
 263 }
 264
 265 static
 266 int configure_muxer_comp(struct muxer_comp *muxer_comp,
 267                 const bt_value *params)
 268 {
 269         bt_value *default_params = NULL;
 270         bt_value *real_params = NULL;
 271         const bt_value *assume_absolute_clock_classes = NULL;
 272         int ret = 0;
 273         bt_bool bool_val;
 274
 275         default_params = get_default_params();
 276         if (!default_params) {
 277                 BT_LOGE("Cannot get default parameters: "
 278                         "muxer-comp-addr=%p", muxer_comp);
 279                 goto error;
 280         }
 281
 282         ret = bt_value_map_extend(default_params, params, &real_params);
 283         if (ret) {
 284                 BT_LOGE("Cannot extend default parameters map value: "
 285                         "muxer-comp-addr=%p, def-params-addr=%p, "
 286                         "params-addr=%p", muxer_comp, default_params,
 287                         params);
 288                 goto error;
 289         }
 290
 291         assume_absolute_clock_classes = bt_value_map_borrow_entry_value(real_params,
 292                                                                         ASSUME_ABSOLUTE_CLOCK_CLASSES_PARAM_NAME);
 293         if (assume_absolute_clock_classes &&
 294                         !bt_value_is_bool(assume_absolute_clock_classes)) {
 295                 BT_LOGE("Expecting a boolean value for the `%s` parameter: "
 296                         "muxer-comp-addr=%p, value-type=%s",
 297                         ASSUME_ABSOLUTE_CLOCK_CLASSES_PARAM_NAME, muxer_comp,
 298                         bt_common_value_type_string(
 299                                 bt_value_get_type(assume_absolute_clock_classes)));
 300                 goto error;
 301         }
 302
 303         bool_val = bt_value_bool_get(assume_absolute_clock_classes);
 304         muxer_comp->assume_absolute_clock_classes = (bool) bool_val;
 305         BT_LOGI("Configured muxer component: muxer-comp-addr=%p, "
 306                 "assume-absolute-clock-classes=%d",
 307                 muxer_comp, muxer_comp->assume_absolute_clock_classes);
 308         goto end;
 309
 310 error:
 311         ret = -1;
 312
 313 end:
 314         bt_value_put_ref(default_params);
 315         bt_value_put_ref(real_params);
 316         return ret;
 317 }
 318
 319 BT_HIDDEN
 320 bt_self_component_status muxer_init(
 321                 bt_self_component_filter *self_comp,
 322                 const bt_value *params, void *init_data)
 323 {
 324         int ret;
 325         bt_self_component_status status = BT_SELF_COMPONENT_STATUS_OK;
 326         struct muxer_comp *muxer_comp = g_new0(struct muxer_comp, 1);
 327
 328         BT_LOGI("Initializing muxer component: "
 329                 "comp-addr=%p, params-addr=%p", self_comp, params);
 330
 331         if (!muxer_comp) {
 332                 BT_LOGE_STR("Failed to allocate one muxer component.");
 333                 goto error;
 334         }
 335
 336         ret = configure_muxer_comp(muxer_comp, params);
 337         if (ret) {
 338                 BT_LOGE("Cannot configure muxer component: "
 339                         "muxer-comp-addr=%p, params-addr=%p",
 340                         muxer_comp, params);
 341                 goto error;
 342         }
 343
 344         muxer_comp->self_comp = self_comp;
 345         bt_self_component_set_data(
 346                 bt_self_component_filter_as_self_component(self_comp),
 347                 muxer_comp);
 348         status = add_available_input_port(self_comp);
 349         if (status != BT_SELF_COMPONENT_STATUS_OK) {
 350                 BT_LOGE("Cannot ensure that at least one muxer component's input port is available: "
 351                         "muxer-comp-addr=%p, status=%s",
 352                         muxer_comp,
 353                         bt_self_component_status_string(status));
 354                 goto error;
 355         }
 356
 357         status = create_output_port(self_comp);
 358         if (status) {
 359                 BT_LOGE("Cannot create muxer component's output port: "
 360                         "muxer-comp-addr=%p, status=%s",
 361                         muxer_comp,
 362                         bt_self_component_status_string(status));
 363                 goto error;
 364         }
 365
 366         BT_LOGI("Initialized muxer component: "
 367                 "comp-addr=%p, params-addr=%p, muxer-comp-addr=%p",
 368                 self_comp, params, muxer_comp);
 369
 370         goto end;
 371
 372 error:
 373         destroy_muxer_comp(muxer_comp);
 374         bt_self_component_set_data(
 375                 bt_self_component_filter_as_self_component(self_comp),
 376                 NULL);
 377
 378         if (status == BT_SELF_COMPONENT_STATUS_OK) {
 379                 status = BT_SELF_COMPONENT_STATUS_ERROR;
 380         }
 381
 382 end:
 383         return status;
 384 }
 385
 386 BT_HIDDEN
 387 void muxer_finalize(bt_self_component_filter *self_comp)
 388 {
 389         struct muxer_comp *muxer_comp = bt_self_component_get_data(
 390                 bt_self_component_filter_as_self_component(self_comp));
 391
 392         BT_LOGI("Finalizing muxer component: comp-addr=%p",
 393                 self_comp);
 394         destroy_muxer_comp(muxer_comp);
 395 }
 396
 397 static
 398 bt_self_component_port_input_message_iterator *
 399 create_msg_iter_on_input_port(bt_self_component_port_input *self_port)
 400 {
 401         const bt_port *port = bt_self_component_port_as_port(
 402                 bt_self_component_port_input_as_self_component_port(
 403                         self_port));
 404         bt_self_component_port_input_message_iterator *msg_iter =
 405                 NULL;
 406
 407         BT_ASSERT(port);
 408         BT_ASSERT(bt_port_is_connected(port));
 409
 410         // TODO: Advance the iterator to >= the time of the latest
 411         //       returned message by the muxer message
 412         //       iterator which creates it.
 413         msg_iter = bt_self_component_port_input_message_iterator_create(
 414                 self_port);
 415         if (!msg_iter) {
 416                 BT_LOGE("Cannot create upstream message iterator on input port: "
 417                         "port-addr=%p, port-name=\"%s\"",
 418                         port, bt_port_get_name(port));
 419                 goto end;
 420         }
 421
 422         BT_LOGI("Created upstream message iterator on input port: "
 423                 "port-addr=%p, port-name=\"%s\", msg-iter-addr=%p",
 424                 port, bt_port_get_name(port), msg_iter);
 425
 426 end:
 427         return msg_iter;
 428 }
 429
 430 static
 431 bt_self_message_iterator_status muxer_upstream_msg_iter_next(
 432                 struct muxer_upstream_msg_iter *muxer_upstream_msg_iter,
 433                 bool *is_ended)
 434 {
 435         bt_self_message_iterator_status status;
 436         bt_message_iterator_status input_port_iter_status;
 437         bt_message_array_const msgs;
 438         uint64_t i;
 439         uint64_t count;
 440
 441         BT_LOGD("Calling upstream message iterator's \"next\" method: "
 442                 "muxer-upstream-msg-iter-wrap-addr=%p, msg-iter-addr=%p",
 443                 muxer_upstream_msg_iter,
 444                 muxer_upstream_msg_iter->msg_iter);
 445         input_port_iter_status = bt_self_component_port_input_message_iterator_next(
 446                 muxer_upstream_msg_iter->msg_iter, &msgs, &count);
 447         BT_LOGD("Upstream message iterator's \"next\" method returned: "
 448                 "status=%s", bt_message_iterator_status_string(input_port_iter_status));
 449
 450         switch (input_port_iter_status) {
 451         case BT_MESSAGE_ITERATOR_STATUS_OK:
 452                 /*
 453                  * Message iterator's current message is
 454                  * valid: it must be considered for muxing operations.
 455                  */
 456                 BT_LOGD_STR("Validated upstream message iterator wrapper.");
 457                 BT_ASSERT(count > 0);
 458
 459                 /* Move messages to our queue */
 460                 for (i = 0; i < count; i++) {
 461                         /*
 462                          * Push to tail in order; other side
 463                          * (muxer_msg_iter_do_next_one()) consumes
 464                          * from the head first.
 465                          */
 466                         g_queue_push_tail(muxer_upstream_msg_iter->msgs,
 467                                 (void *) msgs[i]);
 468                 }
 469                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
 470                 break;
 471         case BT_MESSAGE_ITERATOR_STATUS_AGAIN:
 472                 /*
 473                  * Message iterator's current message is not
 474                  * valid anymore. Return
 475                  * BT_MESSAGE_ITERATOR_STATUS_AGAIN immediately.
 476                  */
 477                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_AGAIN;
 478                 break;
 479         case BT_MESSAGE_ITERATOR_STATUS_END:    /* Fall-through. */
 480                 /*
 481                  * Message iterator reached the end: release it. It
 482                  * won't be considered again to find the youngest
 483                  * message.
 484                  */
 485                 *is_ended = true;
 486                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
 487                 break;
 488         default:
 489                 /* Error or unsupported status code */
 490                 BT_LOGE("Error or unsupported status code: "
 491                         "status-code=%d", input_port_iter_status);
 492                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_ERROR;
 493                 break;
 494         }
 495
 496         return status;
 497 }
 498
 499 static
 500 int get_msg_ts_ns(struct muxer_comp *muxer_comp,
 501                 struct muxer_msg_iter *muxer_msg_iter,
 502                 const bt_message *msg, int64_t last_returned_ts_ns,
 503                 int64_t *ts_ns)
 504 {
 505         const bt_clock_snapshot *clock_snapshot = NULL;
 506         int ret = 0;
 507         bt_message_stream_activity_clock_snapshot_state sa_cs_state;
 508         const bt_stream_class *stream_class = NULL;
 509         bt_message_type msg_type;
 510
 511         BT_ASSERT(msg);
 512         BT_ASSERT(ts_ns);
 513         BT_LOGD("Getting message's timestamp: "
 514                 "muxer-msg-iter-addr=%p, msg-addr=%p, "
 515                 "last-returned-ts=%" PRId64,
 516                 muxer_msg_iter, msg, last_returned_ts_ns);
 517
 518         if (G_UNLIKELY(muxer_msg_iter->clock_class_expectation ==
 519                         MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_NONE)) {
 520                 *ts_ns = last_returned_ts_ns;
 521                 goto end;
 522         }
 523
 524         msg_type = bt_message_get_type(msg);
 525
 526         if (G_UNLIKELY(msg_type == BT_MESSAGE_TYPE_PACKET_BEGINNING)) {
 527                 stream_class = bt_stream_borrow_class_const(
 528                         bt_packet_borrow_stream_const(
 529                                 bt_message_packet_beginning_borrow_packet_const(
 530                                         msg)));
 531         } else if (G_UNLIKELY(msg_type == BT_MESSAGE_TYPE_PACKET_END)) {
 532                 stream_class = bt_stream_borrow_class_const(
 533                         bt_packet_borrow_stream_const(
 534                                 bt_message_packet_end_borrow_packet_const(
 535                                         msg)));
 536         } else if (G_UNLIKELY(msg_type == BT_MESSAGE_TYPE_DISCARDED_EVENTS)) {
 537                 stream_class = bt_stream_borrow_class_const(
 538                         bt_message_discarded_events_borrow_stream_const(msg));
 539         } else if (G_UNLIKELY(msg_type == BT_MESSAGE_TYPE_DISCARDED_PACKETS)) {
 540                 stream_class = bt_stream_borrow_class_const(
 541                         bt_message_discarded_packets_borrow_stream_const(msg));
 542         }
 543
 544         switch (msg_type) {
 545         case BT_MESSAGE_TYPE_EVENT:
 546                 BT_ASSERT(bt_message_event_borrow_stream_class_default_clock_class_const(
 547                                 msg));
 548                 clock_snapshot = bt_message_event_borrow_default_clock_snapshot_const(
 549                         msg);
 550                 break;
 551         case BT_MESSAGE_TYPE_PACKET_BEGINNING:
 552                 if (bt_stream_class_packets_have_beginning_default_clock_snapshot(
 553                                 stream_class)) {
 554                         clock_snapshot = bt_message_packet_beginning_borrow_default_clock_snapshot_const(
 555                                 msg);
 556                 } else {
 557                         goto no_clock_snapshot;
 558                 }
 559
 560                 break;
 561         case BT_MESSAGE_TYPE_PACKET_END:
 562                 if (bt_stream_class_packets_have_end_default_clock_snapshot(
 563                                 stream_class)) {
 564                         clock_snapshot = bt_message_packet_end_borrow_default_clock_snapshot_const(
 565                                 msg);
 566                 } else {
 567                         goto no_clock_snapshot;
 568                 }
 569
 570                 break;
 571         case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
 572                 if (bt_stream_class_discarded_events_have_default_clock_snapshots(
 573                                 stream_class)) {
 574                         clock_snapshot = bt_message_discarded_events_borrow_beginning_default_clock_snapshot_const(
 575                                 msg);
 576                 } else {
 577                         goto no_clock_snapshot;
 578                 }
 579
 580                 break;
 581         case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
 582                 if (bt_stream_class_discarded_packets_have_default_clock_snapshots(
 583                                 stream_class)) {
 584                         clock_snapshot = bt_message_discarded_packets_borrow_beginning_default_clock_snapshot_const(
 585                                 msg);
 586                 } else {
 587                         goto no_clock_snapshot;
 588                 }
 589
 590                 break;
 591         case BT_MESSAGE_TYPE_STREAM_ACTIVITY_BEGINNING:
 592                 BT_ASSERT(bt_message_stream_activity_beginning_borrow_stream_class_default_clock_class_const(
 593                                 msg));
 594                 sa_cs_state = bt_message_stream_activity_beginning_borrow_default_clock_snapshot_const(
 595                         msg, &clock_snapshot);
 596                 if (sa_cs_state != BT_MESSAGE_STREAM_ACTIVITY_CLOCK_SNAPSHOT_STATE_KNOWN) {
 597                         goto no_clock_snapshot;
 598                 }
 599
 600                 break;
 601         case BT_MESSAGE_TYPE_STREAM_ACTIVITY_END:
 602                 BT_ASSERT(bt_message_stream_activity_end_borrow_stream_class_default_clock_class_const(
 603                                 msg));
 604                 sa_cs_state = bt_message_stream_activity_end_borrow_default_clock_snapshot_const(
 605                         msg, &clock_snapshot);
 606                 if (sa_cs_state != BT_MESSAGE_STREAM_ACTIVITY_CLOCK_SNAPSHOT_STATE_KNOWN) {
 607                         goto no_clock_snapshot;
 608                 }
 609
 610                 break;
 611         case BT_MESSAGE_TYPE_MESSAGE_ITERATOR_INACTIVITY:
 612                 clock_snapshot = bt_message_message_iterator_inactivity_borrow_default_clock_snapshot_const(
 613                         msg);
 614                 break;
 615         default:
 616                 /* All the other messages have a higher priority */
 617                 BT_LOGD_STR("Message has no timestamp: using the last returned timestamp.");
 618                 *ts_ns = last_returned_ts_ns;
 619                 goto end;
 620         }
 621
 622         ret = bt_clock_snapshot_get_ns_from_origin(clock_snapshot, ts_ns);
 623         if (ret) {
 624                 BT_LOGE("Cannot get nanoseconds from Epoch of clock snapshot: "
 625                         "clock-snapshot-addr=%p", clock_snapshot);
 626                 goto error;
 627         }
 628
 629         goto end;
 630
 631 no_clock_snapshot:
 632         BT_LOGD_STR("Message's default clock snapshot is missing: "
 633                 "using the last returned timestamp.");
 634         *ts_ns = last_returned_ts_ns;
 635         goto end;
 636
 637 error:
 638         ret = -1;
 639
 640 end:
 641         if (ret == 0) {
 642                 BT_LOGD("Found message's timestamp: "
 643                         "muxer-msg-iter-addr=%p, msg-addr=%p, "
 644                         "last-returned-ts=%" PRId64 ", ts=%" PRId64,
 645                         muxer_msg_iter, msg, last_returned_ts_ns,
 646                         *ts_ns);
 647         }
 648
 649         return ret;
 650 }
 651
 652 static inline
 653 int validate_clock_class(struct muxer_msg_iter *muxer_msg_iter,
 654                 struct muxer_comp *muxer_comp,
 655                 const bt_clock_class *clock_class)
 656 {
 657         int ret = 0;
 658         const unsigned char *cc_uuid;
 659         const char *cc_name;
 660
 661         BT_ASSERT(clock_class);
 662         cc_uuid = bt_clock_class_get_uuid(clock_class);
 663         cc_name = bt_clock_class_get_name(clock_class);
 664
 665         if (muxer_msg_iter->clock_class_expectation ==
 666                         MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_ANY) {
 667                 /*
 668                  * This is the first clock class that this muxer
 669                  * message iterator encounters. Its properties
 670                  * determine what to expect for the whole lifetime of
 671                  * the iterator without a true
 672                  * `assume-absolute-clock-classes` parameter.
 673                  */
 674                 if (bt_clock_class_origin_is_unix_epoch(clock_class)) {
 675                         /* Expect absolute clock classes */
 676                         muxer_msg_iter->clock_class_expectation =
 677                                 MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_ABSOLUTE;
 678                 } else {
 679                         if (cc_uuid) {
 680                                 /*
 681                                  * Expect non-absolute clock classes
 682                                  * with a specific UUID.
 683                                  */
 684                                 muxer_msg_iter->clock_class_expectation =
 685                                         MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_SPEC_UUID;
 686                                 memcpy(muxer_msg_iter->expected_clock_class_uuid,
 687                                         cc_uuid, BABELTRACE_UUID_LEN);
 688                         } else {
 689                                 /*
 690                                  * Expect non-absolute clock classes
 691                                  * with no UUID.
 692                                  */
 693                                 muxer_msg_iter->clock_class_expectation =
 694                                         MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_NO_UUID;
 695                         }
 696                 }
 697         }
 698
 699         if (!muxer_comp->assume_absolute_clock_classes) {
 700                 switch (muxer_msg_iter->clock_class_expectation) {
 701                 case MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_ABSOLUTE:
 702                         if (!bt_clock_class_origin_is_unix_epoch(clock_class)) {
 703                                 BT_LOGE("Expecting an absolute clock class, "
 704                                         "but got a non-absolute one: "
 705                                         "clock-class-addr=%p, clock-class-name=\"%s\"",
 706                                         clock_class, cc_name);
 707                                 goto error;
 708                         }
 709                         break;
 710                 case MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_NO_UUID:
 711                         if (bt_clock_class_origin_is_unix_epoch(clock_class)) {
 712                                 BT_LOGE("Expecting a non-absolute clock class with no UUID, "
 713                                         "but got an absolute one: "
 714                                         "clock-class-addr=%p, clock-class-name=\"%s\"",
 715                                         clock_class, cc_name);
 716                                 goto error;
 717                         }
 718
 719                         if (cc_uuid) {
 720                                 BT_LOGE("Expecting a non-absolute clock class with no UUID, "
 721                                         "but got one with a UUID: "
 722                                         "clock-class-addr=%p, clock-class-name=\"%s\", "
 723                                         "uuid=\"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\"",
 724                                         clock_class, cc_name,
 725                                         (unsigned int) cc_uuid[0],
 726                                         (unsigned int) cc_uuid[1],
 727                                         (unsigned int) cc_uuid[2],
 728                                         (unsigned int) cc_uuid[3],
 729                                         (unsigned int) cc_uuid[4],
 730                                         (unsigned int) cc_uuid[5],
 731                                         (unsigned int) cc_uuid[6],
 732                                         (unsigned int) cc_uuid[7],
 733                                         (unsigned int) cc_uuid[8],
 734                                         (unsigned int) cc_uuid[9],
 735                                         (unsigned int) cc_uuid[10],
 736                                         (unsigned int) cc_uuid[11],
 737                                         (unsigned int) cc_uuid[12],
 738                                         (unsigned int) cc_uuid[13],
 739                                         (unsigned int) cc_uuid[14],
 740                                         (unsigned int) cc_uuid[15]);
 741                                 goto error;
 742                         }
 743                         break;
 744                 case MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_SPEC_UUID:
 745                         if (bt_clock_class_origin_is_unix_epoch(clock_class)) {
 746                                 BT_LOGE("Expecting a non-absolute clock class with a specific UUID, "
 747                                         "but got an absolute one: "
 748                                         "clock-class-addr=%p, clock-class-name=\"%s\"",
 749                                         clock_class, cc_name);
 750                                 goto error;
 751                         }
 752
 753                         if (!cc_uuid) {
 754                                 BT_LOGE("Expecting a non-absolute clock class with a specific UUID, "
 755                                         "but got one with no UUID: "
 756                                         "clock-class-addr=%p, clock-class-name=\"%s\"",
 757                                         clock_class, cc_name);
 758                                 goto error;
 759                         }
 760
 761                         if (memcmp(muxer_msg_iter->expected_clock_class_uuid,
 762                                         cc_uuid, BABELTRACE_UUID_LEN) != 0) {
 763                                 BT_LOGE("Expecting a non-absolute clock class with a specific UUID, "
 764                                         "but got one with different UUID: "
 765                                         "clock-class-addr=%p, clock-class-name=\"%s\", "
 766                                         "expected-uuid=\"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\", "
 767                                         "uuid=\"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\"",
 768                                         clock_class, cc_name,
 769                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[0],
 770                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[1],
 771                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[2],
 772                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[3],
 773                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[4],
 774                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[5],
 775                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[6],
 776                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[7],
 777                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[8],
 778                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[9],
 779                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[10],
 780                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[11],
 781                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[12],
 782                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[13],
 783                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[14],
 784                                         (unsigned int) muxer_msg_iter->expected_clock_class_uuid[15],
 785                                         (unsigned int) cc_uuid[0],
 786                                         (unsigned int) cc_uuid[1],
 787                                         (unsigned int) cc_uuid[2],
 788                                         (unsigned int) cc_uuid[3],
 789                                         (unsigned int) cc_uuid[4],
 790                                         (unsigned int) cc_uuid[5],
 791                                         (unsigned int) cc_uuid[6],
 792                                         (unsigned int) cc_uuid[7],
 793                                         (unsigned int) cc_uuid[8],
 794                                         (unsigned int) cc_uuid[9],
 795                                         (unsigned int) cc_uuid[10],
 796                                         (unsigned int) cc_uuid[11],
 797                                         (unsigned int) cc_uuid[12],
 798                                         (unsigned int) cc_uuid[13],
 799                                         (unsigned int) cc_uuid[14],
 800                                         (unsigned int) cc_uuid[15]);
 801                                 goto error;
 802                         }
 803                         break;
 804                 case MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_NONE:
 805                         BT_LOGE("Expecting no clock class, but got one: "
 806                                 "clock-class-addr=%p, clock-class-name=\"%s\"",
 807                                 clock_class, cc_name);
 808                         goto error;
 809                 default:
 810                         /* Unexpected */
 811                         BT_LOGF("Unexpected clock class expectation: "
 812                                 "expectation-code=%d",
 813                                 muxer_msg_iter->clock_class_expectation);
 814                         abort();
 815                 }
 816         }
 817
 818         goto end;
 819
 820 error:
 821         ret = -1;
 822
 823 end:
 824         return ret;
 825 }
 826
 827 static inline
 828 int validate_new_stream_clock_class(struct muxer_msg_iter *muxer_msg_iter,
 829                 struct muxer_comp *muxer_comp, const bt_stream *stream)
 830 {
 831         int ret = 0;
 832         const bt_stream_class *stream_class =
 833                 bt_stream_borrow_class_const(stream);
 834         const bt_clock_class *clock_class =
 835                 bt_stream_class_borrow_default_clock_class_const(stream_class);
 836
 837         if (!clock_class) {
 838                 if (muxer_msg_iter->clock_class_expectation ==
 839                         MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_ANY) {
 840                         /* Expect no clock class */
 841                         muxer_msg_iter->clock_class_expectation =
 842                                 MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_NONE;
 843                 } else {
 844                         BT_LOGE("Expecting stream class with a default clock class: "
 845                                 "stream-class-addr=%p, stream-class-name=\"%s\", "
 846                                 "stream-class-id=%" PRIu64,
 847                                 stream_class, bt_stream_class_get_name(stream_class),
 848                                 bt_stream_class_get_id(stream_class));
 849                         ret = -1;
 850                 }
 851
 852                 goto end;
 853         }
 854
 855         ret = validate_clock_class(muxer_msg_iter, muxer_comp, clock_class);
 856
 857 end:
 858         return ret;
 859 }
 860
 861 /*
 862  * This function finds the youngest available message amongst the
 863  * non-ended upstream message iterators and returns the upstream
 864  * message iterator which has it, or
 865  * BT_MESSAGE_ITERATOR_STATUS_END if there's no available
 866  * message.
 867  *
 868  * This function does NOT:
 869  *
 870  * * Update any upstream message iterator.
 871  * * Check the upstream message iterators to retry.
 872  *
 873  * On sucess, this function sets *muxer_upstream_msg_iter to the
 874  * upstream message iterator of which the current message is
 875  * the youngest, and sets *ts_ns to its time.
 876  */
 877 static
 878 bt_self_message_iterator_status
 879 muxer_msg_iter_youngest_upstream_msg_iter(
 880                 struct muxer_comp *muxer_comp,
 881                 struct muxer_msg_iter *muxer_msg_iter,
 882                 struct muxer_upstream_msg_iter **muxer_upstream_msg_iter,
 883                 int64_t *ts_ns)
 884 {
 885         size_t i;
 886         int ret;
 887         int64_t youngest_ts_ns = INT64_MAX;
 888         bt_self_message_iterator_status status =
 889                 BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
 890
 891         BT_ASSERT(muxer_comp);
 892         BT_ASSERT(muxer_msg_iter);
 893         BT_ASSERT(muxer_upstream_msg_iter);
 894         *muxer_upstream_msg_iter = NULL;
 895
 896         for (i = 0; i < muxer_msg_iter->active_muxer_upstream_msg_iters->len;
 897                         i++) {
 898                 const bt_message *msg;
 899                 struct muxer_upstream_msg_iter *cur_muxer_upstream_msg_iter =
 900                         g_ptr_array_index(
 901                                 muxer_msg_iter->active_muxer_upstream_msg_iters,
 902                                 i);
 903                 int64_t msg_ts_ns;
 904
 905                 if (!cur_muxer_upstream_msg_iter->msg_iter) {
 906                         /* This upstream message iterator is ended */
 907                         BT_LOGV("Skipping ended upstream message iterator: "
 908                                 "muxer-upstream-msg-iter-wrap-addr=%p",
 909                                 cur_muxer_upstream_msg_iter);
 910                         continue;
 911                 }
 912
 913                 BT_ASSERT(cur_muxer_upstream_msg_iter->msgs->length > 0);
 914                 msg = g_queue_peek_head(cur_muxer_upstream_msg_iter->msgs);
 915                 BT_ASSERT(msg);
 916
 917                 if (G_UNLIKELY(bt_message_get_type(msg) ==
 918                                 BT_MESSAGE_TYPE_STREAM_BEGINNING)) {
 919                         ret = validate_new_stream_clock_class(
 920                                 muxer_msg_iter, muxer_comp,
 921                                 bt_message_stream_beginning_borrow_stream_const(
 922                                         msg));
 923                         if (ret) {
 924                                 /*
 925                                  * validate_new_stream_clock_class() logs
 926                                  * errors.
 927                                  */
 928                                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_ERROR;
 929                                 goto end;
 930                         }
 931                 } else if (G_UNLIKELY(bt_message_get_type(msg) ==
 932                                 BT_MESSAGE_TYPE_MESSAGE_ITERATOR_INACTIVITY)) {
 933                         const bt_clock_snapshot *cs;
 934
 935                         cs = bt_message_message_iterator_inactivity_borrow_default_clock_snapshot_const(
 936                                 msg);
 937                         ret = validate_clock_class(muxer_msg_iter, muxer_comp,
 938                                 bt_clock_snapshot_borrow_clock_class_const(cs));
 939                         if (ret) {
 940                                 /* validate_clock_class() logs errors */
 941                                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_ERROR;
 942                                 goto end;
 943                         }
 944                 }
 945
 946                 ret = get_msg_ts_ns(muxer_comp, muxer_msg_iter, msg,
 947                         muxer_msg_iter->last_returned_ts_ns, &msg_ts_ns);
 948                 if (ret) {
 949                         /* get_msg_ts_ns() logs errors */
 950                         *muxer_upstream_msg_iter = NULL;
 951                         status = BT_SELF_MESSAGE_ITERATOR_STATUS_ERROR;
 952                         goto end;
 953                 }
 954
 955                 if (msg_ts_ns <= youngest_ts_ns) {
 956                         *muxer_upstream_msg_iter =
 957                                 cur_muxer_upstream_msg_iter;
 958                         youngest_ts_ns = msg_ts_ns;
 959                         *ts_ns = youngest_ts_ns;
 960                 }
 961         }
 962
 963         if (!*muxer_upstream_msg_iter) {
 964                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_END;
 965                 *ts_ns = INT64_MIN;
 966         }
 967
 968 end:
 969         return status;
 970 }
 971
 972 static
 973 bt_self_message_iterator_status validate_muxer_upstream_msg_iter(
 974         struct muxer_upstream_msg_iter *muxer_upstream_msg_iter,
 975         bool *is_ended)
 976 {
 977         bt_self_message_iterator_status status =
 978                 BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
 979
 980         BT_LOGD("Validating muxer's upstream message iterator wrapper: "
 981                 "muxer-upstream-msg-iter-wrap-addr=%p",
 982                 muxer_upstream_msg_iter);
 983
 984         if (muxer_upstream_msg_iter->msgs->length > 0 ||
 985                         !muxer_upstream_msg_iter->msg_iter) {
 986                 BT_LOGD("Already valid or not considered: "
 987                         "queue-len=%u, upstream-msg-iter-addr=%p",
 988                         muxer_upstream_msg_iter->msgs->length,
 989                         muxer_upstream_msg_iter->msg_iter);
 990                 goto end;
 991         }
 992
 993         /* muxer_upstream_msg_iter_next() logs details/errors */
 994         status = muxer_upstream_msg_iter_next(muxer_upstream_msg_iter,
 995                 is_ended);
 996
 997 end:
 998         return status;
 999 }
1000
1001 static
1002 bt_self_message_iterator_status validate_muxer_upstream_msg_iters(
1003                 struct muxer_msg_iter *muxer_msg_iter)
1004 {
1005         bt_self_message_iterator_status status =
1006                 BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
1007         size_t i;
1008
1009         BT_LOGD("Validating muxer's upstream message iterator wrappers: "
1010                 "muxer-msg-iter-addr=%p", muxer_msg_iter);
1011
1012         for (i = 0; i < muxer_msg_iter->active_muxer_upstream_msg_iters->len;
1013                         i++) {
1014                 bool is_ended = false;
1015                 struct muxer_upstream_msg_iter *muxer_upstream_msg_iter =
1016                         g_ptr_array_index(
1017                                 muxer_msg_iter->active_muxer_upstream_msg_iters,
1018                                 i);
1019
1020                 status = validate_muxer_upstream_msg_iter(
1021                         muxer_upstream_msg_iter, &is_ended);
1022                 if (status != BT_SELF_MESSAGE_ITERATOR_STATUS_OK) {
1023                         if (status < 0) {
1024                                 BT_LOGE("Cannot validate muxer's upstream message iterator wrapper: "
1025                                         "muxer-msg-iter-addr=%p, "
1026                                         "muxer-upstream-msg-iter-wrap-addr=%p",
1027                                         muxer_msg_iter,
1028                                         muxer_upstream_msg_iter);
1029                         } else {
1030                                 BT_LOGD("Cannot validate muxer's upstream message iterator wrapper: "
1031                                         "muxer-msg-iter-addr=%p, "
1032                                         "muxer-upstream-msg-iter-wrap-addr=%p",
1033                                         muxer_msg_iter,
1034                                         muxer_upstream_msg_iter);
1035                         }
1036
1037                         goto end;
1038                 }
1039
1040                 /*
1041                  * Move this muxer upstream message iterator to the
1042                  * array of ended iterators if it's ended.
1043                  */
1044                 if (G_UNLIKELY(is_ended)) {
1045                         BT_LOGD("Muxer's upstream message iterator wrapper: ended or canceled: "
1046                                 "muxer-msg-iter-addr=%p, "
1047                                 "muxer-upstream-msg-iter-wrap-addr=%p",
1048                                 muxer_msg_iter, muxer_upstream_msg_iter);
1049                         g_ptr_array_add(
1050                                 muxer_msg_iter->ended_muxer_upstream_msg_iters,
1051                                 muxer_upstream_msg_iter);
1052                         muxer_msg_iter->active_muxer_upstream_msg_iters->pdata[i] = NULL;
1053
1054                         /*
1055                          * Use g_ptr_array_remove_fast() because the
1056                          * order of those elements is not important.
1057                          */
1058                         g_ptr_array_remove_index_fast(
1059                                 muxer_msg_iter->active_muxer_upstream_msg_iters,
1060                                 i);
1061                         i--;
1062                 }
1063         }
1064
1065 end:
1066         return status;
1067 }
1068
1069 static inline
1070 bt_self_message_iterator_status muxer_msg_iter_do_next_one(
1071                 struct muxer_comp *muxer_comp,
1072                 struct muxer_msg_iter *muxer_msg_iter,
1073                 const bt_message **msg)
1074 {
1075         bt_self_message_iterator_status status;
1076         struct muxer_upstream_msg_iter *muxer_upstream_msg_iter = NULL;
1077         int64_t next_return_ts;
1078
1079         status = validate_muxer_upstream_msg_iters(muxer_msg_iter);
1080         if (status != BT_SELF_MESSAGE_ITERATOR_STATUS_OK) {
1081                 /* validate_muxer_upstream_msg_iters() logs details */
1082                 goto end;
1083         }
1084
1085         /*
1086          * At this point we know that all the existing upstream
1087          * message iterators are valid. We can find the one,
1088          * amongst those, of which the current message is the
1089          * youngest.
1090          */
1091         status = muxer_msg_iter_youngest_upstream_msg_iter(muxer_comp,
1092                         muxer_msg_iter, &muxer_upstream_msg_iter,
1093                         &next_return_ts);
1094         if (status < 0 || status == BT_SELF_MESSAGE_ITERATOR_STATUS_END) {
1095                 if (status < 0) {
1096                         BT_LOGE("Cannot find the youngest upstream message iterator wrapper: "
1097                                 "status=%s",
1098                                 bt_common_self_message_iterator_status_string(status));
1099                 } else {
1100                         BT_LOGD("Cannot find the youngest upstream message iterator wrapper: "
1101                                 "status=%s",
1102                                 bt_common_self_message_iterator_status_string(status));
1103                 }
1104
1105                 goto end;
1106         }
1107
1108         if (next_return_ts < muxer_msg_iter->last_returned_ts_ns) {
1109                 BT_LOGE("Youngest upstream message iterator wrapper's timestamp is less than muxer's message iterator's last returned timestamp: "
1110                         "muxer-msg-iter-addr=%p, ts=%" PRId64 ", "
1111                         "last-returned-ts=%" PRId64,
1112                         muxer_msg_iter, next_return_ts,
1113                         muxer_msg_iter->last_returned_ts_ns);
1114                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_ERROR;
1115                 goto end;
1116         }
1117
1118         BT_LOGD("Found youngest upstream message iterator wrapper: "
1119                 "muxer-msg-iter-addr=%p, "
1120                 "muxer-upstream-msg-iter-wrap-addr=%p, "
1121                 "ts=%" PRId64,
1122                 muxer_msg_iter, muxer_upstream_msg_iter, next_return_ts);
1123         BT_ASSERT(status == BT_SELF_MESSAGE_ITERATOR_STATUS_OK);
1124         BT_ASSERT(muxer_upstream_msg_iter);
1125
1126         /*
1127          * Consume from the queue's head: other side
1128          * (muxer_upstream_msg_iter_next()) writes to the tail.
1129          */
1130         *msg = g_queue_pop_head(muxer_upstream_msg_iter->msgs);
1131         BT_ASSERT(*msg);
1132         muxer_msg_iter->last_returned_ts_ns = next_return_ts;
1133
1134 end:
1135         return status;
1136 }
1137
1138 static
1139 bt_self_message_iterator_status muxer_msg_iter_do_next(
1140                 struct muxer_comp *muxer_comp,
1141                 struct muxer_msg_iter *muxer_msg_iter,
1142                 bt_message_array_const msgs, uint64_t capacity,
1143                 uint64_t *count)
1144 {
1145         bt_self_message_iterator_status status =
1146                 BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
1147         uint64_t i = 0;
1148
1149         while (i < capacity && status == BT_SELF_MESSAGE_ITERATOR_STATUS_OK) {
1150                 status = muxer_msg_iter_do_next_one(muxer_comp,
1151                         muxer_msg_iter, &msgs[i]);
1152                 if (status == BT_SELF_MESSAGE_ITERATOR_STATUS_OK) {
1153                         i++;
1154                 }
1155         }
1156
1157         if (i > 0) {
1158                 /*
1159                  * Even if muxer_msg_iter_do_next_one() returned
1160                  * something else than
1161                  * BT_MESSAGE_ITERATOR_STATUS_OK, we accumulated
1162                  * message objects in the output message
1163                  * array, so we need to return
1164                  * BT_MESSAGE_ITERATOR_STATUS_OK so that they are
1165                  * transfered to downstream. This other status occurs
1166                  * again the next time muxer_msg_iter_do_next() is
1167                  * called, possibly without any accumulated
1168                  * message, in which case we'll return it.
1169                  */
1170                 *count = i;
1171                 status = BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
1172         }
1173
1174         return status;
1175 }
1176
1177 static
1178 void destroy_muxer_msg_iter(struct muxer_msg_iter *muxer_msg_iter)
1179 {
1180         if (!muxer_msg_iter) {
1181                 return;
1182         }
1183
1184         BT_LOGD("Destroying muxer component's message iterator: "
1185                 "muxer-msg-iter-addr=%p", muxer_msg_iter);
1186
1187         if (muxer_msg_iter->active_muxer_upstream_msg_iters) {
1188                 BT_LOGD_STR("Destroying muxer's active upstream message iterator wrappers.");
1189                 g_ptr_array_free(
1190                         muxer_msg_iter->active_muxer_upstream_msg_iters, TRUE);
1191         }
1192
1193         if (muxer_msg_iter->ended_muxer_upstream_msg_iters) {
1194                 BT_LOGD_STR("Destroying muxer's ended upstream message iterator wrappers.");
1195                 g_ptr_array_free(
1196                         muxer_msg_iter->ended_muxer_upstream_msg_iters, TRUE);
1197         }
1198
1199         g_free(muxer_msg_iter);
1200 }
1201
1202 static
1203 int muxer_msg_iter_init_upstream_iterators(struct muxer_comp *muxer_comp,
1204                 struct muxer_msg_iter *muxer_msg_iter)
1205 {
1206         int64_t count;
1207         int64_t i;
1208         int ret = 0;
1209
1210         count = bt_component_filter_get_input_port_count(
1211                 bt_self_component_filter_as_component_filter(
1212                         muxer_comp->self_comp));
1213         if (count < 0) {
1214                 BT_LOGD("No input port to initialize for muxer component's message iterator: "
1215                         "muxer-comp-addr=%p, muxer-msg-iter-addr=%p",
1216                         muxer_comp, muxer_msg_iter);
1217                 goto end;
1218         }
1219
1220         for (i = 0; i < count; i++) {
1221                 bt_self_component_port_input_message_iterator *upstream_msg_iter;
1222                 bt_self_component_port_input *self_port =
1223                         bt_self_component_filter_borrow_input_port_by_index(
1224                                 muxer_comp->self_comp, i);
1225                 const bt_port *port;
1226
1227                 BT_ASSERT(self_port);
1228                 port = bt_self_component_port_as_port(
1229                         bt_self_component_port_input_as_self_component_port(
1230                                 self_port));
1231                 BT_ASSERT(port);
1232
1233                 if (!bt_port_is_connected(port)) {
1234                         /* Skip non-connected port */
1235                         continue;
1236                 }
1237
1238                 upstream_msg_iter = create_msg_iter_on_input_port(self_port);
1239                 if (!upstream_msg_iter) {
1240                         /* create_msg_iter_on_input_port() logs errors */
1241                         BT_ASSERT(!upstream_msg_iter);
1242                         ret = -1;
1243                         goto end;
1244                 }
1245
1246                 ret = muxer_msg_iter_add_upstream_msg_iter(muxer_msg_iter,
1247                         upstream_msg_iter);
1248                 bt_self_component_port_input_message_iterator_put_ref(
1249                         upstream_msg_iter);
1250                 if (ret) {
1251                         /* muxer_msg_iter_add_upstream_msg_iter() logs errors */
1252                         goto end;
1253                 }
1254         }
1255
1256 end:
1257         return ret;
1258 }
1259
1260 BT_HIDDEN
1261 bt_self_message_iterator_status muxer_msg_iter_init(
1262                 bt_self_message_iterator *self_msg_iter,
1263                 bt_self_component_filter *self_comp,
1264                 bt_self_component_port_output *port)
1265 {
1266         struct muxer_comp *muxer_comp = NULL;
1267         struct muxer_msg_iter *muxer_msg_iter = NULL;
1268         bt_self_message_iterator_status status =
1269                 BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
1270         int ret;
1271
1272         muxer_comp = bt_self_component_get_data(
1273                 bt_self_component_filter_as_self_component(self_comp));
1274         BT_ASSERT(muxer_comp);
1275         BT_LOGD("Initializing muxer component's message iterator: "
1276                 "comp-addr=%p, muxer-comp-addr=%p, msg-iter-addr=%p",
1277                 self_comp, muxer_comp, self_msg_iter);
1278
1279         if (muxer_comp->initializing_muxer_msg_iter) {
1280                 /*
1281                  * Weird, unhandled situation detected: downstream
1282                  * creates a muxer message iterator while creating
1283                  * another muxer message iterator (same component).
1284                  */
1285                 BT_LOGE("Recursive initialization of muxer component's message iterator: "
1286                         "comp-addr=%p, muxer-comp-addr=%p, msg-iter-addr=%p",
1287                         self_comp, muxer_comp, self_msg_iter);
1288                 goto error;
1289         }
1290
1291         muxer_comp->initializing_muxer_msg_iter = true;
1292         muxer_msg_iter = g_new0(struct muxer_msg_iter, 1);
1293         if (!muxer_msg_iter) {
1294                 BT_LOGE_STR("Failed to allocate one muxer component's message iterator.");
1295                 goto error;
1296         }
1297
1298         muxer_msg_iter->last_returned_ts_ns = INT64_MIN;
1299         muxer_msg_iter->active_muxer_upstream_msg_iters =
1300                 g_ptr_array_new_with_free_func(
1301                         (GDestroyNotify) destroy_muxer_upstream_msg_iter);
1302         if (!muxer_msg_iter->active_muxer_upstream_msg_iters) {
1303                 BT_LOGE_STR("Failed to allocate a GPtrArray.");
1304                 goto error;
1305         }
1306
1307         muxer_msg_iter->ended_muxer_upstream_msg_iters =
1308                 g_ptr_array_new_with_free_func(
1309                         (GDestroyNotify) destroy_muxer_upstream_msg_iter);
1310         if (!muxer_msg_iter->ended_muxer_upstream_msg_iters) {
1311                 BT_LOGE_STR("Failed to allocate a GPtrArray.");
1312                 goto error;
1313         }
1314
1315         ret = muxer_msg_iter_init_upstream_iterators(muxer_comp,
1316                 muxer_msg_iter);
1317         if (ret) {
1318                 BT_LOGE("Cannot initialize connected input ports for muxer component's message iterator: "
1319                         "comp-addr=%p, muxer-comp-addr=%p, "
1320                         "muxer-msg-iter-addr=%p, msg-iter-addr=%p, ret=%d",
1321                         self_comp, muxer_comp, muxer_msg_iter,
1322                         self_msg_iter, ret);
1323                 goto error;
1324         }
1325
1326         bt_self_message_iterator_set_data(self_msg_iter, muxer_msg_iter);
1327         BT_LOGD("Initialized muxer component's message iterator: "
1328                 "comp-addr=%p, muxer-comp-addr=%p, muxer-msg-iter-addr=%p, "
1329                 "msg-iter-addr=%p",
1330                 self_comp, muxer_comp, muxer_msg_iter, self_msg_iter);
1331         goto end;
1332
1333 error:
1334         destroy_muxer_msg_iter(muxer_msg_iter);
1335         bt_self_message_iterator_set_data(self_msg_iter, NULL);
1336         status = BT_SELF_MESSAGE_ITERATOR_STATUS_ERROR;
1337
1338 end:
1339         muxer_comp->initializing_muxer_msg_iter = false;
1340         return status;
1341 }
1342
1343 BT_HIDDEN
1344 void muxer_msg_iter_finalize(bt_self_message_iterator *self_msg_iter)
1345 {
1346         struct muxer_msg_iter *muxer_msg_iter =
1347                 bt_self_message_iterator_get_data(self_msg_iter);
1348         bt_self_component *self_comp = NULL;
1349         struct muxer_comp *muxer_comp = NULL;
1350
1351         self_comp = bt_self_message_iterator_borrow_component(
1352                 self_msg_iter);
1353         BT_ASSERT(self_comp);
1354         muxer_comp = bt_self_component_get_data(self_comp);
1355         BT_LOGD("Finalizing muxer component's message iterator: "
1356                 "comp-addr=%p, muxer-comp-addr=%p, muxer-msg-iter-addr=%p, "
1357                 "msg-iter-addr=%p",
1358                 self_comp, muxer_comp, muxer_msg_iter, self_msg_iter);
1359
1360         if (muxer_msg_iter) {
1361                 destroy_muxer_msg_iter(muxer_msg_iter);
1362         }
1363 }
1364
1365 BT_HIDDEN
1366 bt_self_message_iterator_status muxer_msg_iter_next(
1367                 bt_self_message_iterator *self_msg_iter,
1368                 bt_message_array_const msgs, uint64_t capacity,
1369                 uint64_t *count)
1370 {
1371         bt_self_message_iterator_status status;
1372         struct muxer_msg_iter *muxer_msg_iter =
1373                 bt_self_message_iterator_get_data(self_msg_iter);
1374         bt_self_component *self_comp = NULL;
1375         struct muxer_comp *muxer_comp = NULL;
1376
1377         BT_ASSERT(muxer_msg_iter);
1378         self_comp = bt_self_message_iterator_borrow_component(
1379                 self_msg_iter);
1380         BT_ASSERT(self_comp);
1381         muxer_comp = bt_self_component_get_data(self_comp);
1382         BT_ASSERT(muxer_comp);
1383         BT_LOGV("Muxer component's message iterator's \"next\" method called: "
1384                 "comp-addr=%p, muxer-comp-addr=%p, muxer-msg-iter-addr=%p, "
1385                 "msg-iter-addr=%p",
1386                 self_comp, muxer_comp, muxer_msg_iter, self_msg_iter);
1387
1388         status = muxer_msg_iter_do_next(muxer_comp, muxer_msg_iter,
1389                 msgs, capacity, count);
1390         if (status < 0) {
1391                 BT_LOGE("Cannot get next message: "
1392                         "comp-addr=%p, muxer-comp-addr=%p, muxer-msg-iter-addr=%p, "
1393                         "msg-iter-addr=%p, status=%s",
1394                         self_comp, muxer_comp, muxer_msg_iter, self_msg_iter,
1395                         bt_common_self_message_iterator_status_string(status));
1396         } else {
1397                 BT_LOGV("Returning from muxer component's message iterator's \"next\" method: "
1398                         "status=%s",
1399                         bt_common_self_message_iterator_status_string(status));
1400         }
1401
1402         return status;
1403 }
1404
1405 BT_HIDDEN
1406 bt_self_component_status muxer_input_port_connected(
1407                 bt_self_component_filter *self_comp,
1408                 bt_self_component_port_input *self_port,
1409                 const bt_port_output *other_port)
1410 {
1411         bt_self_component_status status;
1412
1413         status = add_available_input_port(self_comp);
1414         if (status) {
1415                 /*
1416                  * Only way to report an error later since this
1417                  * method does not return anything.
1418                  */
1419                 BT_LOGE("Cannot add one muxer component's input port: "
1420                         "status=%s",
1421                         bt_self_component_status_string(status));
1422                 goto end;
1423         }
1424
1425 end:
1426         return status;
1427 }
1428
1429 static inline
1430 bt_bool muxer_upstream_msg_iters_can_all_seek_beginning(
1431                 GPtrArray *muxer_upstream_msg_iters)
1432 {
1433         uint64_t i;
1434         bt_bool ret = BT_TRUE;
1435
1436         for (i = 0; i < muxer_upstream_msg_iters->len; i++) {
1437                 struct muxer_upstream_msg_iter *upstream_msg_iter =
1438                         muxer_upstream_msg_iters->pdata[i];
1439
1440                 if (!bt_self_component_port_input_message_iterator_can_seek_beginning(
1441                                 upstream_msg_iter->msg_iter)) {
1442                         ret = BT_FALSE;
1443                         goto end;
1444                 }
1445         }
1446
1447 end:
1448         return ret;
1449 }
1450
1451 BT_HIDDEN
1452 bt_bool muxer_msg_iter_can_seek_beginning(
1453                 bt_self_message_iterator *self_msg_iter)
1454 {
1455         struct muxer_msg_iter *muxer_msg_iter =
1456                 bt_self_message_iterator_get_data(self_msg_iter);
1457         bt_bool ret = BT_TRUE;
1458
1459         if (!muxer_upstream_msg_iters_can_all_seek_beginning(
1460                         muxer_msg_iter->active_muxer_upstream_msg_iters)) {
1461                 ret = BT_FALSE;
1462                 goto end;
1463         }
1464
1465         if (!muxer_upstream_msg_iters_can_all_seek_beginning(
1466                         muxer_msg_iter->ended_muxer_upstream_msg_iters)) {
1467                 ret = BT_FALSE;
1468                 goto end;
1469         }
1470
1471 end:
1472         return ret;
1473 }
1474
1475 BT_HIDDEN
1476 bt_self_message_iterator_status muxer_msg_iter_seek_beginning(
1477                 bt_self_message_iterator *self_msg_iter)
1478 {
1479         struct muxer_msg_iter *muxer_msg_iter =
1480                 bt_self_message_iterator_get_data(self_msg_iter);
1481         bt_message_iterator_status status = BT_MESSAGE_ITERATOR_STATUS_OK;
1482         uint64_t i;
1483
1484         /* Seek all ended upstream iterators first */
1485         for (i = 0; i < muxer_msg_iter->ended_muxer_upstream_msg_iters->len;
1486                         i++) {
1487                 struct muxer_upstream_msg_iter *upstream_msg_iter =
1488                         muxer_msg_iter->ended_muxer_upstream_msg_iters->pdata[i];
1489
1490                 status = bt_self_component_port_input_message_iterator_seek_beginning(
1491                         upstream_msg_iter->msg_iter);
1492                 if (status != BT_MESSAGE_ITERATOR_STATUS_OK) {
1493                         goto end;
1494                 }
1495
1496                 empty_message_queue(upstream_msg_iter);
1497         }
1498
1499         /* Seek all previously active upstream iterators */
1500         for (i = 0; i < muxer_msg_iter->active_muxer_upstream_msg_iters->len;
1501                         i++) {
1502                 struct muxer_upstream_msg_iter *upstream_msg_iter =
1503                         muxer_msg_iter->active_muxer_upstream_msg_iters->pdata[i];
1504
1505                 status = bt_self_component_port_input_message_iterator_seek_beginning(
1506                         upstream_msg_iter->msg_iter);
1507                 if (status != BT_MESSAGE_ITERATOR_STATUS_OK) {
1508                         goto end;
1509                 }
1510
1511                 empty_message_queue(upstream_msg_iter);
1512         }
1513
1514         /* Make them all active */
1515         for (i = 0; i < muxer_msg_iter->ended_muxer_upstream_msg_iters->len;
1516                         i++) {
1517                 struct muxer_upstream_msg_iter *upstream_msg_iter =
1518                         muxer_msg_iter->ended_muxer_upstream_msg_iters->pdata[i];
1519
1520                 g_ptr_array_add(muxer_msg_iter->active_muxer_upstream_msg_iters,
1521                         upstream_msg_iter);
1522                 muxer_msg_iter->ended_muxer_upstream_msg_iters->pdata[i] = NULL;
1523         }
1524
1525         g_ptr_array_remove_range(muxer_msg_iter->ended_muxer_upstream_msg_iters,
1526                 0, muxer_msg_iter->ended_muxer_upstream_msg_iters->len);
1527         muxer_msg_iter->last_returned_ts_ns = INT64_MIN;
1528         muxer_msg_iter->clock_class_expectation =
1529                 MUXER_MSG_ITER_CLOCK_CLASS_EXPECTATION_ANY;
1530
1531 end:
1532         return (bt_self_message_iterator_status) status;
1533 }