src/lib/graph/iterator.c

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   5  * Copyright 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   6  */
   7
   8 #define BT_LOG_TAG "LIB/MSG-ITER"
   9 #include "lib/logging.h"
  10
  11 #include "compat/compiler.h"
  12 #include "compat/glib.h"
  13 #include "lib/trace-ir/clock-class.h"
  14 #include "lib/trace-ir/clock-snapshot.h"
  15 #include <babeltrace2/trace-ir/field.h>
  16 #include <babeltrace2/trace-ir/event.h>
  17 #include "lib/trace-ir/event.h"
  18 #include <babeltrace2/trace-ir/packet.h>
  19 #include "lib/trace-ir/packet.h"
  20 #include "lib/trace-ir/stream.h"
  21 #include <babeltrace2/trace-ir/clock-class.h>
  22 #include <babeltrace2/trace-ir/stream-class.h>
  23 #include <babeltrace2/trace-ir/stream.h>
  24 #include <babeltrace2/graph/connection.h>
  25 #include <babeltrace2/graph/component.h>
  26 #include <babeltrace2/graph/message.h>
  27 #include <babeltrace2/graph/self-component.h>
  28 #include <babeltrace2/graph/port.h>
  29 #include <babeltrace2/graph/graph.h>
  30 #include <babeltrace2/graph/message-iterator.h>
  31 #include <babeltrace2/types.h>
  32 #include "common/assert.h"
  33 #include "lib/assert-cond.h"
  34 #include <stdint.h>
  35 #include <inttypes.h>
  36 #include <stdbool.h>
  37 #include <stdlib.h>
  38
  39 #include "component-class.h"
  40 #include "component.h"
  41 #include "component-sink.h"
  42 #include "component-source.h"
  43 #include "connection.h"
  44 #include "graph.h"
  45 #include "message-iterator-class.h"
  46 #include "message/discarded-items.h"
  47 #include "message/event.h"
  48 #include "message/iterator.h"
  49 #include "message/message.h"
  50 #include "message/message-iterator-inactivity.h"
  51 #include "message/stream.h"
  52 #include "message/packet.h"
  53 #include "lib/func-status.h"
  54
  55 /*
  56  * TODO: Use graph's state (number of active iterators, etc.) and
  57  * possibly system specifications to make a better guess than this.
  58  */
  59 #define MSG_BATCH_SIZE  15
  60
  61 #define BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(_iter)                     \
  62         BT_ASSERT_PRE("has-state-to-seek",                              \
  63                 (_iter)->state == BT_MESSAGE_ITERATOR_STATE_ACTIVE ||   \
  64                 (_iter)->state == BT_MESSAGE_ITERATOR_STATE_ENDED ||    \
  65                 (_iter)->state == BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_AGAIN || \
  66                 (_iter)->state == BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_ERROR, \
  67                 "Message iterator is in the wrong state: %!+i", (_iter))
  68
  69 static inline
  70 void set_msg_iterator_state(struct bt_message_iterator *iterator,
  71                 enum bt_message_iterator_state state)
  72 {
  73         BT_ASSERT_DBG(iterator);
  74         BT_LIB_LOGD("Updating message iterator's state: new-state=%s",
  75                 bt_message_iterator_state_string(state));
  76         iterator->state = state;
  77 }
  78
  79 static
  80 void bt_message_iterator_destroy(struct bt_object *obj)
  81 {
  82         struct bt_message_iterator *iterator;
  83
  84         BT_ASSERT(obj);
  85
  86         /*
  87          * The message iterator's reference count is 0 if we're
  88          * here. Increment it to avoid a double-destroy (possibly
  89          * infinitely recursive). This could happen for example if the
  90          * message iterator's finalization function does
  91          * bt_object_get_ref() (or anything that causes
  92          * bt_object_get_ref() to be called) on itself (ref. count goes
  93          * from 0 to 1), and then bt_object_put_ref(): the reference
  94          * count would go from 1 to 0 again and this function would be
  95          * called again.
  96          */
  97         obj->ref_count++;
  98         iterator = (void *) obj;
  99         BT_LIB_LOGI("Destroying self component input port message iterator object: "
 100                 "%!+i", iterator);
 101         bt_message_iterator_try_finalize(iterator);
 102
 103         if (iterator->connection) {
 104                 /*
 105                  * Remove ourself from the originating connection so
 106                  * that it does not try to finalize a dangling pointer
 107                  * later.
 108                  */
 109                 bt_connection_remove_iterator(iterator->connection, iterator);
 110                 iterator->connection = NULL;
 111         }
 112
 113         if (iterator->auto_seek.msgs) {
 114                 while (!g_queue_is_empty(iterator->auto_seek.msgs)) {
 115                         bt_object_put_ref_no_null_check(
 116                                 g_queue_pop_tail(iterator->auto_seek.msgs));
 117                 }
 118
 119                 g_queue_free(iterator->auto_seek.msgs);
 120                 iterator->auto_seek.msgs = NULL;
 121         }
 122
 123         if (iterator->upstream_msg_iters) {
 124                 /*
 125                  * At this point the message iterator is finalized, so
 126                  * it's detached from any upstream message iterator.
 127                  */
 128                 BT_ASSERT(iterator->upstream_msg_iters->len == 0);
 129                 g_ptr_array_free(iterator->upstream_msg_iters, TRUE);
 130                 iterator->upstream_msg_iters = NULL;
 131         }
 132
 133         if (iterator->msgs) {
 134                 g_ptr_array_free(iterator->msgs, TRUE);
 135                 iterator->msgs = NULL;
 136         }
 137
 138         g_free(iterator);
 139 }
 140
 141 void bt_message_iterator_try_finalize(
 142                 struct bt_message_iterator *iterator)
 143 {
 144         uint64_t i;
 145         bool call_user_finalize = true;
 146
 147         BT_ASSERT(iterator);
 148
 149         switch (iterator->state) {
 150         case BT_MESSAGE_ITERATOR_STATE_NON_INITIALIZED:
 151                 /*
 152                  * If this function is called while the iterator is in the
 153                  * NON_INITIALIZED state, it means the user initialization
 154                  * method has either not been called, or has failed.  We
 155                  * therefore don't want to call the user finalization method.
 156                  * However, the initialization method might have created some
 157                  * upstream message iterators before failing, so we want to
 158                  * execute the rest of this function, which unlinks the related
 159                  * iterators.
 160                  */
 161                 call_user_finalize = false;
 162                 break;
 163         case BT_MESSAGE_ITERATOR_STATE_FINALIZED:
 164                 /* Already finalized */
 165                 BT_LIB_LOGD("Not finalizing message iterator: already finalized: "
 166                         "%!+i", iterator);
 167                 goto end;
 168         case BT_MESSAGE_ITERATOR_STATE_FINALIZING:
 169                 /* Finalizing */
 170                 BT_LIB_LOGF("Message iterator is already being finalized: "
 171                         "%!+i", iterator);
 172                 bt_common_abort();
 173         default:
 174                 break;
 175         }
 176
 177         BT_LIB_LOGD("Finalizing message iterator: %!+i", iterator);
 178         set_msg_iterator_state(iterator,
 179                 BT_MESSAGE_ITERATOR_STATE_FINALIZING);
 180         BT_ASSERT(iterator->upstream_component);
 181
 182         /* Call user-defined destroy method */
 183         if (call_user_finalize) {
 184                 typedef void (*method_t)(void *);
 185                 method_t method;
 186                 struct bt_component_class *comp_class =
 187                         iterator->upstream_component->class;
 188                 struct bt_component_class_with_iterator_class *class_with_iter_class;
 189
 190                 BT_ASSERT(bt_component_class_has_message_iterator_class(comp_class));
 191                 class_with_iter_class = container_of(comp_class,
 192                         struct bt_component_class_with_iterator_class, parent);
 193                 method = (method_t) class_with_iter_class->msg_iter_cls->methods.finalize;
 194
 195                 if (method) {
 196                         const bt_error *saved_error;
 197
 198                         saved_error = bt_current_thread_take_error();
 199
 200                         BT_LIB_LOGD("Calling user's finalization method: %!+i",
 201                                 iterator);
 202                         method(iterator);
 203                         BT_ASSERT_POST_NO_ERROR("bt_message_iterator_class_finalize_method");
 204
 205                         if (saved_error) {
 206                                 BT_CURRENT_THREAD_MOVE_ERROR_AND_RESET(saved_error);
 207                         }
 208                 }
 209         }
 210
 211         /* Detach upstream message iterators */
 212         for (i = 0; i < iterator->upstream_msg_iters->len; i++) {
 213                 struct bt_message_iterator *upstream_msg_iter =
 214                         iterator->upstream_msg_iters->pdata[i];
 215
 216                 upstream_msg_iter->downstream_msg_iter = NULL;
 217         }
 218
 219         g_ptr_array_set_size(iterator->upstream_msg_iters, 0);
 220
 221         /* Detach downstream message iterator */
 222         if (iterator->downstream_msg_iter) {
 223                 gboolean existed;
 224
 225                 BT_ASSERT(iterator->downstream_msg_iter->upstream_msg_iters);
 226                 existed = g_ptr_array_remove_fast(
 227                         iterator->downstream_msg_iter->upstream_msg_iters,
 228                         iterator);
 229                 BT_ASSERT(existed);
 230         }
 231
 232         iterator->upstream_component = NULL;
 233         iterator->upstream_port = NULL;
 234         set_msg_iterator_state(iterator,
 235                 BT_MESSAGE_ITERATOR_STATE_FINALIZED);
 236         BT_LIB_LOGD("Finalized message iterator: %!+i", iterator);
 237
 238 end:
 239         return;
 240 }
 241
 242 void bt_message_iterator_set_connection(
 243                 struct bt_message_iterator *iterator,
 244                 struct bt_connection *connection)
 245 {
 246         BT_ASSERT(iterator);
 247         iterator->connection = connection;
 248         BT_LIB_LOGI("Set message iterator's connection: "
 249                 "%![iter-]+i, %![conn-]+x", iterator, connection);
 250 }
 251
 252 static
 253 enum bt_message_iterator_can_seek_beginning_status can_seek_ns_from_origin_true(
 254                 struct bt_message_iterator *iterator __attribute__((unused)),
 255                 int64_t ns_from_origin __attribute__((unused)),
 256                 bt_bool *can_seek)
 257 {
 258         *can_seek = BT_TRUE;
 259
 260         return BT_FUNC_STATUS_OK;
 261 }
 262
 263 static
 264 enum bt_message_iterator_can_seek_beginning_status can_seek_beginning_true(
 265                 struct bt_message_iterator *iterator __attribute__((unused)),
 266                 bt_bool *can_seek)
 267 {
 268         *can_seek = BT_TRUE;
 269
 270         return BT_FUNC_STATUS_OK;
 271 }
 272
 273 static
 274 int create_self_component_input_port_message_iterator(
 275                 struct bt_self_message_iterator *self_downstream_msg_iter,
 276                 struct bt_self_component_port_input *self_port,
 277                 struct bt_message_iterator **message_iterator,
 278                 const char *api_func)
 279 {
 280         bt_message_iterator_class_initialize_method init_method = NULL;
 281         struct bt_message_iterator *iterator =
 282                 NULL;
 283         struct bt_message_iterator *downstream_msg_iter =
 284                 (void *) self_downstream_msg_iter;
 285         struct bt_port *port = (void *) self_port;
 286         struct bt_port *upstream_port;
 287         struct bt_component *comp;
 288         struct bt_component *upstream_comp;
 289         struct bt_component_class *upstream_comp_cls;
 290         struct bt_component_class_with_iterator_class *upstream_comp_cls_with_iter_cls;
 291         int status;
 292
 293         BT_ASSERT_PRE_NON_NULL_FROM_FUNC(api_func, "message-iterator-output",
 294                 message_iterator, "Created message iterator (output)");
 295         BT_ASSERT_PRE_NON_NULL_FROM_FUNC(api_func, "input-port", port,
 296                 "Input port");
 297         comp = bt_port_borrow_component_inline(port);
 298         BT_ASSERT_PRE_FROM_FUNC(api_func, "input-port-is-connected",
 299                 bt_port_is_connected(port),
 300                 "Input port is not connected: %![port-]+p", port);
 301         BT_ASSERT_PRE_FROM_FUNC(api_func, "input-port-has-component",
 302                 comp, "Input port is not part of a component: %![port-]+p",
 303                 port);
 304         BT_ASSERT(port->connection);
 305         upstream_port = port->connection->upstream_port;
 306         BT_ASSERT(upstream_port);
 307         upstream_comp = bt_port_borrow_component_inline(upstream_port);
 308         BT_ASSERT(upstream_comp);
 309         BT_ASSERT_PRE_FROM_FUNC(api_func, "graph-is-configured",
 310                 bt_component_borrow_graph(upstream_comp)->config_state ==
 311                         BT_GRAPH_CONFIGURATION_STATE_PARTIALLY_CONFIGURED ||
 312                 bt_component_borrow_graph(upstream_comp)->config_state ==
 313                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURED,
 314                 "Graph is not configured: %!+g",
 315                 bt_component_borrow_graph(upstream_comp));
 316         upstream_comp_cls = upstream_comp->class;
 317         BT_ASSERT(upstream_comp->class->type ==
 318                 BT_COMPONENT_CLASS_TYPE_SOURCE ||
 319                 upstream_comp->class->type ==
 320                 BT_COMPONENT_CLASS_TYPE_FILTER);
 321         BT_LIB_LOGI("Creating message iterator on self component input port: "
 322                 "%![up-comp-]+c, %![up-port-]+p", upstream_comp, upstream_port);
 323         iterator = g_new0(
 324                 struct bt_message_iterator, 1);
 325         if (!iterator) {
 326                 BT_LIB_LOGE_APPEND_CAUSE(
 327                         "Failed to allocate one self component input port "
 328                         "message iterator.");
 329                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 330                 goto error;
 331         }
 332
 333         bt_object_init_shared(&iterator->base,
 334                 bt_message_iterator_destroy);
 335         iterator->msgs = g_ptr_array_new();
 336         if (!iterator->msgs) {
 337                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GPtrArray.");
 338                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 339                 goto error;
 340         }
 341
 342         g_ptr_array_set_size(iterator->msgs, MSG_BATCH_SIZE);
 343         iterator->last_ns_from_origin = INT64_MIN;
 344         iterator->auto_seek.msgs = g_queue_new();
 345         if (!iterator->auto_seek.msgs) {
 346                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GQueue.");
 347                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 348                 goto error;
 349         }
 350
 351         iterator->upstream_msg_iters = g_ptr_array_new();
 352         if (!iterator->upstream_msg_iters) {
 353                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GPtrArray.");
 354                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 355                 goto error;
 356         }
 357
 358         iterator->upstream_component = upstream_comp;
 359         iterator->upstream_port = upstream_port;
 360         iterator->connection = iterator->upstream_port->connection;
 361         iterator->graph = bt_component_borrow_graph(upstream_comp);
 362         set_msg_iterator_state(iterator,
 363                 BT_MESSAGE_ITERATOR_STATE_NON_INITIALIZED);
 364
 365         /* Copy methods from the message iterator class to the message iterator. */
 366         BT_ASSERT(bt_component_class_has_message_iterator_class(upstream_comp_cls));
 367         upstream_comp_cls_with_iter_cls = container_of(upstream_comp_cls,
 368                 struct bt_component_class_with_iterator_class, parent);
 369
 370         iterator->methods.next =
 371                 (bt_message_iterator_next_method)
 372                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.next;
 373         iterator->methods.seek_ns_from_origin =
 374                 (bt_message_iterator_seek_ns_from_origin_method)
 375                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.seek_ns_from_origin;
 376         iterator->methods.seek_beginning =
 377                 (bt_message_iterator_seek_beginning_method)
 378                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.seek_beginning;
 379         iterator->methods.can_seek_ns_from_origin =
 380                 (bt_message_iterator_can_seek_ns_from_origin_method)
 381                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.can_seek_ns_from_origin;
 382         iterator->methods.can_seek_beginning =
 383                 (bt_message_iterator_can_seek_beginning_method)
 384                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.can_seek_beginning;
 385
 386         if (iterator->methods.seek_ns_from_origin &&
 387                         !iterator->methods.can_seek_ns_from_origin) {
 388                 iterator->methods.can_seek_ns_from_origin =
 389                         (bt_message_iterator_can_seek_ns_from_origin_method)
 390                                 can_seek_ns_from_origin_true;
 391         }
 392
 393         if (iterator->methods.seek_beginning &&
 394                         !iterator->methods.can_seek_beginning) {
 395                 iterator->methods.can_seek_beginning =
 396                         (bt_message_iterator_can_seek_beginning_method)
 397                                 can_seek_beginning_true;
 398         }
 399
 400         /* Call iterator's init method. */
 401         init_method = upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.initialize;
 402
 403         if (init_method) {
 404                 enum bt_message_iterator_class_initialize_method_status iter_status;
 405
 406                 BT_LIB_LOGD("Calling user's initialization method: %!+i", iterator);
 407                 iter_status = init_method(
 408                         (struct bt_self_message_iterator *) iterator,
 409                         &iterator->config,
 410                         (struct bt_self_component_port_output *) upstream_port);
 411                 BT_LOGD("User method returned: status=%s",
 412                         bt_common_func_status_string(iter_status));
 413                 BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(
 414                         "bt_message_iterator_class_initialize_method",
 415                         iter_status);
 416                 if (iter_status != BT_FUNC_STATUS_OK) {
 417                         BT_LIB_LOGW_APPEND_CAUSE(
 418                                 "Component input port message iterator initialization method failed: "
 419                                 "%![iter-]+i, status=%s",
 420                                 iterator,
 421                                 bt_common_func_status_string(iter_status));
 422                         status = iter_status;
 423                         goto error;
 424                 }
 425
 426                 iterator->config.frozen = true;
 427         }
 428
 429         if (downstream_msg_iter) {
 430                 /* Set this message iterator's downstream message iterator */
 431                 iterator->downstream_msg_iter = downstream_msg_iter;
 432
 433                 /*
 434                  * Add this message iterator to the downstream message
 435                  * iterator's array of upstream message iterators.
 436                  */
 437                 g_ptr_array_add(downstream_msg_iter->upstream_msg_iters,
 438                         iterator);
 439         }
 440
 441         set_msg_iterator_state(iterator,
 442                 BT_MESSAGE_ITERATOR_STATE_ACTIVE);
 443         g_ptr_array_add(port->connection->iterators, iterator);
 444         BT_LIB_LOGI("Created message iterator on self component input port: "
 445                 "%![up-port-]+p, %![up-comp-]+c, %![iter-]+i",
 446                 upstream_port, upstream_comp, iterator);
 447
 448         *message_iterator = iterator;
 449         status = BT_FUNC_STATUS_OK;
 450         goto end;
 451
 452 error:
 453         BT_OBJECT_PUT_REF_AND_RESET(iterator);
 454
 455 end:
 456         return status;
 457 }
 458
 459 BT_EXPORT
 460 bt_message_iterator_create_from_message_iterator_status
 461 bt_message_iterator_create_from_message_iterator(
 462                 struct bt_self_message_iterator *self_msg_iter,
 463                 struct bt_self_component_port_input *input_port,
 464                 struct bt_message_iterator **message_iterator)
 465 {
 466         BT_ASSERT_PRE_NO_ERROR();
 467         BT_ASSERT_PRE_MSG_ITER_NON_NULL(self_msg_iter);
 468         return create_self_component_input_port_message_iterator(self_msg_iter,
 469                 input_port, message_iterator, __func__);
 470 }
 471
 472 BT_EXPORT
 473 bt_message_iterator_create_from_sink_component_status
 474 bt_message_iterator_create_from_sink_component(
 475                 struct bt_self_component_sink *self_comp,
 476                 struct bt_self_component_port_input *input_port,
 477                 struct bt_message_iterator **message_iterator)
 478 {
 479         BT_ASSERT_PRE_NO_ERROR();
 480         BT_ASSERT_PRE_NON_NULL("sink-component", self_comp, "Sink component");
 481         return create_self_component_input_port_message_iterator(NULL,
 482                 input_port, message_iterator, __func__);
 483 }
 484
 485 BT_EXPORT
 486 void *bt_self_message_iterator_get_data(
 487                 const struct bt_self_message_iterator *self_iterator)
 488 {
 489         struct bt_message_iterator *iterator =
 490                 (void *) self_iterator;
 491
 492         BT_ASSERT_PRE_DEV_MSG_ITER_NON_NULL(iterator);
 493         return iterator->user_data;
 494 }
 495
 496 BT_EXPORT
 497 void bt_self_message_iterator_set_data(
 498                 struct bt_self_message_iterator *self_iterator, void *data)
 499 {
 500         struct bt_message_iterator *iterator =
 501                 (void *) self_iterator;
 502
 503         BT_ASSERT_PRE_DEV_MSG_ITER_NON_NULL(iterator);
 504         iterator->user_data = data;
 505         BT_LIB_LOGD("Set message iterator's user data: "
 506                 "%!+i, user-data-addr=%p", iterator, data);
 507 }
 508
 509 BT_EXPORT
 510 void bt_self_message_iterator_configuration_set_can_seek_forward(
 511                 bt_self_message_iterator_configuration *config,
 512                 bt_bool can_seek_forward)
 513 {
 514         BT_ASSERT_PRE_NON_NULL("message-iterator-configuration", config,
 515                 "Message iterator configuration");
 516         BT_ASSERT_PRE_DEV_HOT("message-iterator-configuration", config,
 517                 "Message iterator configuration", "");
 518
 519         config->can_seek_forward = can_seek_forward;
 520 }
 521
 522 /*
 523  * Validate that the default clock snapshot in `msg` doesn't make us go back in
 524  * time.
 525  */
 526
 527 BT_ASSERT_COND_DEV_FUNC
 528 static
 529 bool clock_snapshots_are_monotonic_one(
 530                 struct bt_message_iterator *iterator,
 531                 const bt_message *msg)
 532 {
 533         const struct bt_clock_snapshot *clock_snapshot = NULL;
 534         bt_message_type message_type = bt_message_get_type(msg);
 535         int64_t ns_from_origin;
 536         enum bt_clock_snapshot_get_ns_from_origin_status clock_snapshot_status;
 537
 538         /*
 539          * The default is true: if we can't figure out the clock snapshot
 540          * (or there is none), assume it is fine.
 541          */
 542         bool result = true;
 543
 544         switch (message_type) {
 545         case BT_MESSAGE_TYPE_EVENT:
 546         {
 547                 struct bt_message_event *event_msg = (struct bt_message_event *) msg;
 548                 clock_snapshot = event_msg->default_cs;
 549                 break;
 550         }
 551         case BT_MESSAGE_TYPE_MESSAGE_ITERATOR_INACTIVITY:
 552         {
 553                 struct bt_message_message_iterator_inactivity *inactivity_msg =
 554                         (struct bt_message_message_iterator_inactivity *) msg;
 555                 clock_snapshot = inactivity_msg->cs;
 556                 break;
 557         }
 558         case BT_MESSAGE_TYPE_PACKET_BEGINNING:
 559         case BT_MESSAGE_TYPE_PACKET_END:
 560         {
 561                 struct bt_message_packet *packet_msg = (struct bt_message_packet *) msg;
 562                 clock_snapshot = packet_msg->default_cs;
 563                 break;
 564         }
 565         case BT_MESSAGE_TYPE_STREAM_BEGINNING:
 566         case BT_MESSAGE_TYPE_STREAM_END:
 567         {
 568                 struct bt_message_stream *stream_msg = (struct bt_message_stream *) msg;
 569                 if (stream_msg->default_cs_state != BT_MESSAGE_STREAM_CLOCK_SNAPSHOT_STATE_KNOWN) {
 570                         goto end;
 571                 }
 572
 573                 clock_snapshot = stream_msg->default_cs;
 574                 break;
 575         }
 576         case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
 577         case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
 578         {
 579                 struct bt_message_discarded_items *discarded_msg =
 580                         (struct bt_message_discarded_items *) msg;
 581
 582                 clock_snapshot = discarded_msg->default_begin_cs;
 583                 break;
 584         }
 585         }
 586
 587         if (!clock_snapshot) {
 588                 goto end;
 589         }
 590
 591         clock_snapshot_status = bt_clock_snapshot_get_ns_from_origin(
 592                 clock_snapshot, &ns_from_origin);
 593         if (clock_snapshot_status != BT_FUNC_STATUS_OK) {
 594                 /*
 595                  * bt_clock_snapshot_get_ns_from_origin can return
 596                  * OVERFLOW_ERROR.  We don't really want to report an error to
 597                  * our caller, so just clear it.
 598                  */
 599                 bt_current_thread_clear_error();
 600                 goto end;
 601         }
 602
 603         result = ns_from_origin >= iterator->last_ns_from_origin;
 604         iterator->last_ns_from_origin = ns_from_origin;
 605 end:
 606         return result;
 607 }
 608
 609 BT_ASSERT_COND_DEV_FUNC
 610 static
 611 bool clock_snapshots_are_monotonic(
 612                 struct bt_message_iterator *iterator,
 613                 bt_message_array_const msgs, uint64_t msg_count)
 614 {
 615         uint64_t i;
 616         bool result;
 617
 618         for (i = 0; i < msg_count; i++) {
 619                 if (!clock_snapshots_are_monotonic_one(iterator, msgs[i])) {
 620                         result = false;
 621                         goto end;
 622                 }
 623         }
 624
 625         result = true;
 626
 627 end:
 628         return result;
 629 }
 630
 631 /*
 632  * When a new stream begins, verify that the clock class tied to this
 633  * stream is compatible with what we've seen before.
 634  */
 635
 636 BT_ASSERT_COND_DEV_FUNC
 637 static
 638 bool clock_classes_are_compatible_one(struct bt_message_iterator *iterator,
 639                 const struct bt_message *msg)
 640 {
 641         enum bt_message_type message_type = bt_message_get_type(msg);
 642         bool result;
 643
 644         if (message_type == BT_MESSAGE_TYPE_STREAM_BEGINNING) {
 645                 const struct bt_message_stream *stream_msg = (struct bt_message_stream *) msg;
 646                 const struct bt_clock_class *clock_class = stream_msg->stream->class->default_clock_class;
 647                 bt_uuid clock_class_uuid = NULL;
 648
 649                 if (clock_class) {
 650                         clock_class_uuid = bt_clock_class_get_uuid(clock_class);
 651                 }
 652
 653                 switch (iterator->clock_expectation.type) {
 654                 case CLOCK_EXPECTATION_UNSET:
 655                         /*
 656                          * This is the first time we see a message with a clock
 657                          * snapshot: record the properties of that clock, against
 658                          * which we'll compare the clock properties of the following
 659                          * messages.
 660                          */
 661
 662                         if (!clock_class) {
 663                                 iterator->clock_expectation.type = CLOCK_EXPECTATION_NONE;
 664                         } else if (bt_clock_class_origin_is_unix_epoch(clock_class)) {
 665                                 iterator->clock_expectation.type = CLOCK_EXPECTATION_ORIGIN_UNIX;
 666                         } else if (clock_class_uuid) {
 667                                 iterator->clock_expectation.type = CLOCK_EXPECTATION_ORIGIN_OTHER_UUID;
 668                                 bt_uuid_copy(iterator->clock_expectation.uuid, clock_class_uuid);
 669                         } else {
 670                                 iterator->clock_expectation.type = CLOCK_EXPECTATION_ORIGIN_OTHER_NO_UUID;
 671                         }
 672                         break;
 673
 674                 case CLOCK_EXPECTATION_NONE:
 675                         if (clock_class) {
 676                                 BT_ASSERT_COND_DEV_MSG(
 677                                         "Expecting no clock class, got one: %![cc-]+K",
 678                                         clock_class);
 679                                 result = false;
 680                                 goto end;
 681                         }
 682
 683                         break;
 684
 685                 case CLOCK_EXPECTATION_ORIGIN_UNIX:
 686                         if (!clock_class) {
 687                                 BT_ASSERT_COND_DEV_MSG(
 688                                         "Expecting a clock class, got none.");
 689                                 result = false;
 690                                 goto end;
 691                         }
 692
 693                         if (!bt_clock_class_origin_is_unix_epoch(clock_class)) {
 694                                 BT_ASSERT_COND_DEV_MSG(
 695                                         "Expecting a clock class with Unix epoch origin: %![cc-]+K",
 696                                         clock_class);
 697                                 result = false;
 698                                 goto end;
 699                         }
 700                         break;
 701
 702                 case CLOCK_EXPECTATION_ORIGIN_OTHER_UUID:
 703                         if (!clock_class) {
 704                                 BT_ASSERT_COND_DEV_MSG(
 705                                         "Expecting a clock class, got none.");
 706                                 result = false;
 707                                 goto end;
 708                         }
 709
 710                         if (bt_clock_class_origin_is_unix_epoch(clock_class)) {
 711                                 BT_ASSERT_COND_DEV_MSG(
 712                                         "Expecting a clock class without Unix epoch origin: %![cc-]+K",
 713                                         clock_class);
 714                                 result = false;
 715                                 goto end;
 716                         }
 717
 718                         if (!clock_class_uuid) {
 719                                 BT_ASSERT_COND_DEV_MSG(
 720                                         "Expecting a clock class with UUID: %![cc-]+K",
 721                                         clock_class);
 722                                 result = false;
 723                                 goto end;
 724                         }
 725
 726                         if (bt_uuid_compare(iterator->clock_expectation.uuid, clock_class_uuid)) {
 727                                 BT_ASSERT_COND_DEV_MSG(
 728                                         "Expecting a clock class with UUID, got one "
 729                                         "with a different UUID: %![cc-]+K, expected-uuid=%!u",
 730                                         clock_class, iterator->clock_expectation.uuid);
 731                                 result = false;
 732                                 goto end;
 733                         }
 734                         break;
 735
 736                 case CLOCK_EXPECTATION_ORIGIN_OTHER_NO_UUID:
 737                         if (!clock_class) {
 738                                 BT_ASSERT_COND_DEV_MSG(
 739                                         "Expecting a clock class, got none.");
 740                                 result = false;
 741                                 goto end;
 742                         }
 743
 744                         if (bt_clock_class_origin_is_unix_epoch(clock_class)) {
 745                                 BT_ASSERT_COND_DEV_MSG(
 746                                         "Expecting a clock class without Unix epoch origin: %![cc-]+K",
 747                                         clock_class);
 748                                 result = false;
 749                                 goto end;
 750                         }
 751
 752                         if (clock_class_uuid) {
 753                                 BT_ASSERT_COND_DEV_MSG(
 754                                         "Expecting a clock class without UUID: %![cc-]+K",
 755                                         clock_class);
 756                                 result = false;
 757                                 goto end;
 758                         }
 759                         break;
 760                 }
 761         }
 762
 763         result = true;
 764
 765 end:
 766         return result;
 767 }
 768
 769 BT_ASSERT_COND_DEV_FUNC
 770 static
 771 bool clock_classes_are_compatible(
 772                 struct bt_message_iterator *iterator,
 773                 bt_message_array_const msgs, uint64_t msg_count)
 774 {
 775         uint64_t i;
 776         bool result;
 777
 778         for (i = 0; i < msg_count; i++) {
 779                 if (!clock_classes_are_compatible_one(iterator, msgs[i])) {
 780                         result = false;
 781                         goto end;
 782                 }
 783         }
 784
 785         result = true;
 786
 787 end:
 788         return result;
 789 }
 790
 791 /*
 792  * Call the `next` method of the iterator.  Do some validation on the returned
 793  * messages.
 794  */
 795
 796 #define NEXT_METHOD_NAME        "bt_message_iterator_class_next_method"
 797
 798 static
 799 enum bt_message_iterator_class_next_method_status
 800 call_iterator_next_method(
 801                 struct bt_message_iterator *iterator,
 802                 bt_message_array_const msgs, uint64_t capacity, uint64_t *user_count)
 803 {
 804         enum bt_message_iterator_class_next_method_status status;
 805
 806         BT_ASSERT_DBG(iterator->methods.next);
 807         BT_LOGD_STR("Calling user's \"next\" method.");
 808         status = iterator->methods.next(iterator, msgs, capacity, user_count);
 809         BT_LOGD("User method returned: status=%s, msg-count=%" PRIu64,
 810                 bt_common_func_status_string(status), *user_count);
 811
 812         if (status == BT_FUNC_STATUS_OK) {
 813                 BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
 814                         "message-clock-classes-are-compatible",
 815                         clock_classes_are_compatible(iterator, msgs,
 816                                 *user_count),
 817                         "Clocks are not compatible");
 818                 BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
 819                         "message-clock-snapshots-are-monotonic",
 820                         clock_snapshots_are_monotonic(iterator, msgs,
 821                                 *user_count),
 822                         "Clock snapshots are not monotonic");
 823         }
 824
 825         BT_ASSERT_POST_DEV_NO_ERROR_IF_NO_ERROR_STATUS(NEXT_METHOD_NAME,
 826                 status);
 827
 828         return status;
 829 }
 830
 831 BT_EXPORT
 832 enum bt_message_iterator_next_status
 833 bt_message_iterator_next(
 834                 struct bt_message_iterator *iterator,
 835                 bt_message_array_const *msgs, uint64_t *user_count)
 836 {
 837         enum bt_message_iterator_next_status status = BT_FUNC_STATUS_OK;
 838
 839         BT_ASSERT_PRE_DEV_NO_ERROR();
 840         BT_ASSERT_PRE_DEV_MSG_ITER_NON_NULL(iterator);
 841         BT_ASSERT_PRE_DEV_NON_NULL("message-array-output", msgs,
 842                 "Message array (output)");
 843         BT_ASSERT_PRE_DEV_NON_NULL("user-count-output", user_count,
 844                 "Message count (output)");
 845         BT_ASSERT_PRE_DEV("message-iterator-is-active",
 846                 iterator->state == BT_MESSAGE_ITERATOR_STATE_ACTIVE,
 847                 "Message iterator's \"next\" called, but "
 848                 "message iterator is in the wrong state: %!+i", iterator);
 849         BT_ASSERT_DBG(iterator->upstream_component);
 850         BT_ASSERT_DBG(iterator->upstream_component->class);
 851         BT_ASSERT_PRE_DEV("graph-is-configured",
 852                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
 853                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
 854                 "Graph is not configured: %!+g",
 855                 bt_component_borrow_graph(iterator->upstream_component));
 856         BT_LIB_LOGD("Getting next self component input port "
 857                 "message iterator's messages: %!+i, batch-size=%u",
 858                 iterator, MSG_BATCH_SIZE);
 859
 860         /*
 861          * Call the user's "next" method to get the next messages
 862          * and status.
 863          */
 864         *user_count = 0;
 865         status = (int) call_iterator_next_method(iterator,
 866                 (void *) iterator->msgs->pdata, MSG_BATCH_SIZE,
 867                 user_count);
 868         BT_LOGD("User method returned: status=%s, msg-count=%" PRIu64,
 869                 bt_common_func_status_string(status), *user_count);
 870         if (status < 0) {
 871                 BT_LIB_LOGW_APPEND_CAUSE(
 872                         "Component input port message iterator's \"next\" method failed: "
 873                         "%![iter-]+i, status=%s",
 874                         iterator, bt_common_func_status_string(status));
 875                 goto end;
 876         }
 877
 878         /*
 879          * There is no way that this iterator could have been finalized
 880          * during its "next" method, as the only way to do this is to
 881          * put the last iterator's reference, and this can only be done
 882          * by its downstream owner.
 883          *
 884          * For the same reason, there is no way that this iterator could
 885          * have seeked (cannot seek a self message iterator).
 886          */
 887         BT_ASSERT_DBG(iterator->state ==
 888                 BT_MESSAGE_ITERATOR_STATE_ACTIVE);
 889
 890         switch (status) {
 891         case BT_FUNC_STATUS_OK:
 892                 BT_ASSERT_POST_DEV(NEXT_METHOD_NAME, "count-lteq-capacity",
 893                         *user_count <= MSG_BATCH_SIZE,
 894                         "Invalid returned message count: greater than "
 895                         "batch size: count=%" PRIu64 ", batch-size=%u",
 896                         *user_count, MSG_BATCH_SIZE);
 897                 *msgs = (void *) iterator->msgs->pdata;
 898                 break;
 899         case BT_FUNC_STATUS_AGAIN:
 900                 goto end;
 901         case BT_FUNC_STATUS_END:
 902                 set_msg_iterator_state(iterator,
 903                         BT_MESSAGE_ITERATOR_STATE_ENDED);
 904                 goto end;
 905         default:
 906                 /* Unknown non-error status */
 907                 bt_common_abort();
 908         }
 909
 910 end:
 911         return status;
 912 }
 913
 914 BT_EXPORT
 915 struct bt_component *
 916 bt_message_iterator_borrow_component(
 917                 struct bt_message_iterator *iterator)
 918 {
 919         BT_ASSERT_PRE_DEV_MSG_ITER_NON_NULL(iterator);
 920         return iterator->upstream_component;
 921 }
 922
 923 BT_EXPORT
 924 struct bt_self_component *bt_self_message_iterator_borrow_component(
 925                 struct bt_self_message_iterator *self_iterator)
 926 {
 927         struct bt_message_iterator *iterator =
 928                 (void *) self_iterator;
 929
 930         BT_ASSERT_PRE_DEV_MSG_ITER_NON_NULL(iterator);
 931         return (void *) iterator->upstream_component;
 932 }
 933
 934 BT_EXPORT
 935 struct bt_self_component_port_output *bt_self_message_iterator_borrow_port(
 936                 struct bt_self_message_iterator *self_iterator)
 937 {
 938         struct bt_message_iterator *iterator =
 939                 (void *) self_iterator;
 940
 941         BT_ASSERT_PRE_DEV_MSG_ITER_NON_NULL(iterator);
 942         return (void *) iterator->upstream_port;
 943 }
 944
 945 #define CAN_SEEK_NS_FROM_ORIGIN_METHOD_NAME                             \
 946         "bt_message_iterator_class_can_seek_ns_from_origin_method"
 947
 948 BT_EXPORT
 949 enum bt_message_iterator_can_seek_ns_from_origin_status
 950 bt_message_iterator_can_seek_ns_from_origin(
 951                 struct bt_message_iterator *iterator,
 952                 int64_t ns_from_origin, bt_bool *can_seek)
 953 {
 954         enum bt_message_iterator_can_seek_ns_from_origin_status status;
 955
 956         BT_ASSERT_PRE_NO_ERROR();
 957         BT_ASSERT_PRE_MSG_ITER_NON_NULL(iterator);
 958         BT_ASSERT_PRE_RES_OUT_NON_NULL(can_seek);
 959         BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(iterator);
 960         BT_ASSERT_PRE("graph-is-configured",
 961                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
 962                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
 963                 "Graph is not configured: %!+g",
 964                 bt_component_borrow_graph(iterator->upstream_component));
 965
 966         if (iterator->methods.can_seek_ns_from_origin) {
 967                 /*
 968                  * Initialize to an invalid value, so we can post-assert that
 969                  * the method returned a valid value.
 970                  */
 971                 *can_seek = -1;
 972
 973                 BT_LIB_LOGD("Calling user's \"can seek nanoseconds from origin\" method: %!+i",
 974                         iterator);
 975
 976                 status = (int) iterator->methods.can_seek_ns_from_origin(iterator,
 977                         ns_from_origin, can_seek);
 978
 979                 BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(
 980                         CAN_SEEK_NS_FROM_ORIGIN_METHOD_NAME, status);
 981
 982                 if (status != BT_FUNC_STATUS_OK) {
 983                         BT_LIB_LOGW_APPEND_CAUSE(
 984                                 "Component input port message iterator's \"can seek nanoseconds from origin\" method failed: "
 985                                 "%![iter-]+i, status=%s",
 986                                 iterator, bt_common_func_status_string(status));
 987                         goto end;
 988                 }
 989
 990                 BT_ASSERT_POST(CAN_SEEK_NS_FROM_ORIGIN_METHOD_NAME,
 991                         "valid-return-value",
 992                         *can_seek == BT_TRUE || *can_seek == BT_FALSE,
 993                         "Unexpected boolean value returned from user's \"can seek ns from origin\" method: val=%d, %![iter-]+i",
 994                         *can_seek, iterator);
 995
 996                 BT_LIB_LOGD(
 997                         "User's \"can seek nanoseconds from origin\" returned successfully: "
 998                         "%![iter-]+i, can-seek=%d",
 999                         iterator, *can_seek);
1000
1001                 if (*can_seek) {
1002                         goto end;
1003                 }
1004         }
1005
1006         /*
1007          * Automatic seeking fall back: if we can seek to the beginning and the
1008          * iterator supports forward seeking then we can automatically seek to
1009          * any timestamp.
1010          */
1011         status = (int) bt_message_iterator_can_seek_beginning(
1012                 iterator, can_seek);
1013         if (status != BT_FUNC_STATUS_OK) {
1014                 goto end;
1015         }
1016
1017         *can_seek = *can_seek && iterator->config.can_seek_forward;
1018
1019 end:
1020         return status;
1021 }
1022
1023 #define CAN_SEEK_BEGINNING_METHOD_NAME                                  \
1024         "bt_message_iterator_class_can_seek_beginning"
1025
1026 BT_EXPORT
1027 enum bt_message_iterator_can_seek_beginning_status
1028 bt_message_iterator_can_seek_beginning(
1029                 struct bt_message_iterator *iterator,
1030                 bt_bool *can_seek)
1031 {
1032         enum bt_message_iterator_can_seek_beginning_status status;
1033
1034         BT_ASSERT_PRE_NO_ERROR();
1035         BT_ASSERT_PRE_MSG_ITER_NON_NULL(iterator);
1036         BT_ASSERT_PRE_RES_OUT_NON_NULL(can_seek);
1037         BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(iterator);
1038         BT_ASSERT_PRE("graph-is-configured",
1039                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
1040                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
1041                 "Graph is not configured: %!+g",
1042                 bt_component_borrow_graph(iterator->upstream_component));
1043
1044         if (iterator->methods.can_seek_beginning) {
1045                 /*
1046                  * Initialize to an invalid value, so we can post-assert that
1047                  * the method returned a valid value.
1048                  */
1049                 *can_seek = -1;
1050
1051                 status = (int) iterator->methods.can_seek_beginning(iterator, can_seek);
1052
1053                 BT_ASSERT_POST(CAN_SEEK_BEGINNING_METHOD_NAME,
1054                         "valid-return-value",
1055                         status != BT_FUNC_STATUS_OK ||
1056                                 *can_seek == BT_TRUE ||
1057                                 *can_seek == BT_FALSE,
1058                         "Unexpected boolean value returned from user's \"can seek beginning\" method: val=%d, %![iter-]+i",
1059                         *can_seek, iterator);
1060                 BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(
1061                         CAN_SEEK_BEGINNING_METHOD_NAME, status);
1062         } else {
1063                 *can_seek = BT_FALSE;
1064                 status = BT_FUNC_STATUS_OK;
1065         }
1066
1067         return status;
1068 }
1069
1070 static inline
1071 void set_iterator_state_after_seeking(
1072                 struct bt_message_iterator *iterator,
1073                 int status)
1074 {
1075         enum bt_message_iterator_state new_state = 0;
1076
1077         /* Set iterator's state depending on seeking status */
1078         switch (status) {
1079         case BT_FUNC_STATUS_OK:
1080                 new_state = BT_MESSAGE_ITERATOR_STATE_ACTIVE;
1081                 break;
1082         case BT_FUNC_STATUS_AGAIN:
1083                 new_state = BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_AGAIN;
1084                 break;
1085         case BT_FUNC_STATUS_ERROR:
1086         case BT_FUNC_STATUS_MEMORY_ERROR:
1087                 new_state = BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_ERROR;
1088                 break;
1089         case BT_FUNC_STATUS_END:
1090                 new_state = BT_MESSAGE_ITERATOR_STATE_ENDED;
1091                 break;
1092         default:
1093                 bt_common_abort();
1094         }
1095
1096         set_msg_iterator_state(iterator, new_state);
1097 }
1098
1099 static
1100 void reset_iterator_expectations(
1101                 struct bt_message_iterator *iterator)
1102 {
1103         iterator->last_ns_from_origin = INT64_MIN;
1104         iterator->clock_expectation.type = CLOCK_EXPECTATION_UNSET;
1105 }
1106
1107 static
1108 bool message_iterator_can_seek_beginning(
1109                 struct bt_message_iterator *iterator)
1110 {
1111         enum bt_message_iterator_can_seek_beginning_status status;
1112         bt_bool can_seek;
1113
1114         status = bt_message_iterator_can_seek_beginning(
1115                 iterator, &can_seek);
1116         if (status != BT_FUNC_STATUS_OK) {
1117                 can_seek = BT_FALSE;
1118         }
1119
1120         return can_seek;
1121 }
1122
1123 #define SEEK_BEGINNING_METHOD_NAME                                      \
1124         "bt_message_iterator_class_seek_beginning_method"
1125
1126 BT_EXPORT
1127 enum bt_message_iterator_seek_beginning_status
1128 bt_message_iterator_seek_beginning(struct bt_message_iterator *iterator)
1129 {
1130         int status;
1131
1132         BT_ASSERT_PRE_NO_ERROR();
1133         BT_ASSERT_PRE_MSG_ITER_NON_NULL(iterator);
1134         BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(iterator);
1135         BT_ASSERT_PRE("graph-is-configured",
1136                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
1137                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
1138                 "Graph is not configured: %!+g",
1139                 bt_component_borrow_graph(iterator->upstream_component));
1140         BT_ASSERT_PRE("can-seek-beginning",
1141                 message_iterator_can_seek_beginning(iterator),
1142                 "Message iterator cannot seek beginning: %!+i", iterator);
1143
1144         /*
1145          * We are seeking, reset our expectations about how the following
1146          * messages should look like.
1147          */
1148         reset_iterator_expectations(iterator);
1149
1150         BT_LIB_LOGD("Calling user's \"seek beginning\" method: %!+i", iterator);
1151         set_msg_iterator_state(iterator,
1152                 BT_MESSAGE_ITERATOR_STATE_SEEKING);
1153         status = iterator->methods.seek_beginning(iterator);
1154         BT_LOGD("User method returned: status=%s",
1155                 bt_common_func_status_string(status));
1156         BT_ASSERT_POST(SEEK_BEGINNING_METHOD_NAME, "valid-status",
1157                 status == BT_FUNC_STATUS_OK ||
1158                 status == BT_FUNC_STATUS_ERROR ||
1159                 status == BT_FUNC_STATUS_MEMORY_ERROR ||
1160                 status == BT_FUNC_STATUS_AGAIN,
1161                 "Unexpected status: %![iter-]+i, status=%s",
1162                 iterator, bt_common_func_status_string(status));
1163         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(SEEK_BEGINNING_METHOD_NAME,
1164                 status);
1165         if (status < 0) {
1166                 BT_LIB_LOGW_APPEND_CAUSE(
1167                         "Component input port message iterator's \"seek beginning\" method failed: "
1168                         "%![iter-]+i, status=%s",
1169                         iterator, bt_common_func_status_string(status));
1170         }
1171
1172         set_iterator_state_after_seeking(iterator, status);
1173         return status;
1174 }
1175
1176 BT_EXPORT
1177 bt_bool
1178 bt_message_iterator_can_seek_forward(
1179                 bt_message_iterator *iterator)
1180 {
1181         BT_ASSERT_PRE_MSG_ITER_NON_NULL(iterator);
1182
1183         return iterator->config.can_seek_forward;
1184 }
1185
1186 /*
1187  * Structure used to record the state of a given stream during the fast-forward
1188  * phase of an auto-seek.
1189  */
1190 struct auto_seek_stream_state {
1191         /*
1192          * Value representing which step of this timeline we are at.
1193          *
1194          *      time --->
1195          *   [SB]  1  [PB]  2  [PE]  1  [SE]
1196          *
1197          * At each point in the timeline, the messages we need to replicate are:
1198          *
1199          *   1: Stream beginning
1200          *   2: Stream beginning, packet beginning
1201          *
1202          * Before "Stream beginning" and after "Stream end", we don't need to
1203          * replicate anything as the stream doesn't exist.
1204          */
1205         enum {
1206                 AUTO_SEEK_STREAM_STATE_STREAM_BEGAN,
1207                 AUTO_SEEK_STREAM_STATE_PACKET_BEGAN,
1208         } state;
1209
1210         /*
1211          * If `state` is AUTO_SEEK_STREAM_STATE_PACKET_BEGAN, the packet we are
1212          * in.  This is a weak reference, since the packet will always be
1213          * alive by the time we use it.
1214          */
1215         struct bt_packet *packet;
1216
1217         /* Have we see a message with a clock snapshot yet? */
1218         bool seen_clock_snapshot;
1219 };
1220
1221 static
1222 struct auto_seek_stream_state *create_auto_seek_stream_state(void)
1223 {
1224         return g_new0(struct auto_seek_stream_state, 1);
1225 }
1226
1227 static
1228 void destroy_auto_seek_stream_state(void *ptr)
1229 {
1230         g_free(ptr);
1231 }
1232
1233 static
1234 GHashTable *create_auto_seek_stream_states(void)
1235 {
1236         return g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL,
1237                 destroy_auto_seek_stream_state);
1238 }
1239
1240 static
1241 void destroy_auto_seek_stream_states(GHashTable *stream_states)
1242 {
1243         g_hash_table_destroy(stream_states);
1244 }
1245
1246 /*
1247  * Handle one message while we are in the fast-forward phase of an auto-seek.
1248  *
1249  * Sets `*got_first` to true if the message's timestamp is greater or equal to
1250  * `ns_from_origin`.  In other words, if this is the first message after our
1251  * seek point.
1252  *
1253  * `stream_states` is an hash table of `bt_stream *` (weak reference) to
1254  * `struct auto_seek_stream_state` used to keep the state of each stream
1255  * during the fast-forward.
1256  */
1257
1258 static inline
1259 int auto_seek_handle_message(
1260                 struct bt_message_iterator *iterator,
1261                 int64_t ns_from_origin, const struct bt_message *msg,
1262                 bool *got_first, GHashTable *stream_states)
1263 {
1264         int status = BT_FUNC_STATUS_OK;
1265         int64_t msg_ns_from_origin;
1266         const struct bt_clock_snapshot *clk_snapshot = NULL;
1267         int ret;
1268
1269         BT_ASSERT_DBG(msg);
1270         BT_ASSERT_DBG(got_first);
1271
1272         switch (msg->type) {
1273         case BT_MESSAGE_TYPE_EVENT:
1274         {
1275                 const struct bt_message_event *event_msg =
1276                         (const void *) msg;
1277
1278                 clk_snapshot = event_msg->default_cs;
1279                 BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
1280                         "event-message-has-default-clock-snapshot",
1281                         clk_snapshot,
1282                         "Event message has no default clock snapshot: %!+n",
1283                         event_msg);
1284                 break;
1285         }
1286         case BT_MESSAGE_TYPE_MESSAGE_ITERATOR_INACTIVITY:
1287         {
1288                 const struct bt_message_message_iterator_inactivity *inactivity_msg =
1289                         (const void *) msg;
1290
1291                 clk_snapshot = inactivity_msg->cs;
1292                 BT_ASSERT_DBG(clk_snapshot);
1293                 break;
1294         }
1295         case BT_MESSAGE_TYPE_PACKET_BEGINNING:
1296         case BT_MESSAGE_TYPE_PACKET_END:
1297         {
1298                 const struct bt_message_packet *packet_msg =
1299                         (const void *) msg;
1300
1301                 if (msg->type == BT_MESSAGE_TYPE_PACKET_BEGINNING
1302                                 && !packet_msg->packet->stream->class->packets_have_beginning_default_clock_snapshot) {
1303                         goto skip_msg;
1304                 }
1305
1306                 if (msg->type == BT_MESSAGE_TYPE_PACKET_END
1307                                 && !packet_msg->packet->stream->class->packets_have_end_default_clock_snapshot) {
1308                         goto skip_msg;
1309                 }
1310
1311                 clk_snapshot = packet_msg->default_cs;
1312                 BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
1313                         "packet-message-has-default-clock-snapshot",
1314                         clk_snapshot,
1315                         "Packet message has no default clock snapshot: %!+n",
1316                         packet_msg);
1317                 break;
1318         }
1319         case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
1320         case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
1321         {
1322                 struct bt_message_discarded_items *msg_disc_items =
1323                         (void *) msg;
1324
1325                 if (msg->type == BT_MESSAGE_TYPE_DISCARDED_EVENTS &&
1326                                 !msg_disc_items->stream->class->discarded_events_have_default_clock_snapshots) {
1327                         goto skip_msg;
1328                 }
1329
1330                 if (msg->type == BT_MESSAGE_TYPE_DISCARDED_PACKETS &&
1331                                 !msg_disc_items->stream->class->discarded_packets_have_default_clock_snapshots) {
1332                         goto skip_msg;
1333                 }
1334
1335                 BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
1336                         "discarded-events-packets-message-has-default-clock-snapshot",
1337                         msg_disc_items->default_begin_cs &&
1338                                 msg_disc_items->default_end_cs,
1339                         "Discarded events/packets message has no default clock snapshots: %!+n",
1340                         msg_disc_items);
1341                 ret = bt_clock_snapshot_get_ns_from_origin(
1342                         msg_disc_items->default_begin_cs,
1343                         &msg_ns_from_origin);
1344                 if (ret) {
1345                         status = BT_FUNC_STATUS_ERROR;
1346                         goto end;
1347                 }
1348
1349                 if (msg_ns_from_origin >= ns_from_origin) {
1350                         *got_first = true;
1351                         goto push_msg;
1352                 }
1353
1354                 ret = bt_clock_snapshot_get_ns_from_origin(
1355                         msg_disc_items->default_end_cs,
1356                         &msg_ns_from_origin);
1357                 if (ret) {
1358                         status = BT_FUNC_STATUS_ERROR;
1359                         goto end;
1360                 }
1361
1362                 if (msg_ns_from_origin >= ns_from_origin) {
1363                         /*
1364                          * The discarded items message's beginning time
1365                          * is before the requested seeking time, but its
1366                          * end time is after. Modify the message so as
1367                          * to set its beginning time to the requested
1368                          * seeking time, and make its item count unknown
1369                          * as we don't know if items were really
1370                          * discarded within the new time range.
1371                          */
1372                         uint64_t new_begin_raw_value = 0;
1373
1374                         ret = bt_clock_class_clock_value_from_ns_from_origin(
1375                                 msg_disc_items->default_end_cs->clock_class,
1376                                 ns_from_origin, &new_begin_raw_value);
1377                         if (ret) {
1378                                 status = BT_FUNC_STATUS_ERROR;
1379                                 goto end;
1380                         }
1381
1382                         bt_clock_snapshot_set_raw_value(
1383                                 msg_disc_items->default_begin_cs,
1384                                 new_begin_raw_value);
1385                         msg_disc_items->count.base.avail =
1386                                 BT_PROPERTY_AVAILABILITY_NOT_AVAILABLE;
1387
1388                         /*
1389                          * It is safe to push it because its beginning
1390                          * time is exactly the requested seeking time.
1391                          */
1392                         goto push_msg;
1393                 } else {
1394                         goto skip_msg;
1395                 }
1396         }
1397         case BT_MESSAGE_TYPE_STREAM_BEGINNING:
1398         case BT_MESSAGE_TYPE_STREAM_END:
1399         {
1400                 struct bt_message_stream *stream_msg =
1401                         (struct bt_message_stream *) msg;
1402
1403                 if (stream_msg->default_cs_state != BT_MESSAGE_STREAM_CLOCK_SNAPSHOT_STATE_KNOWN) {
1404                         /* Ignore */
1405                         goto skip_msg;
1406                 }
1407
1408                 clk_snapshot = stream_msg->default_cs;
1409                 break;
1410         }
1411         default:
1412                 bt_common_abort();
1413         }
1414
1415         BT_ASSERT_DBG(clk_snapshot);
1416         ret = bt_clock_snapshot_get_ns_from_origin(clk_snapshot,
1417                 &msg_ns_from_origin);
1418         if (ret) {
1419                 status = BT_FUNC_STATUS_ERROR;
1420                 goto end;
1421         }
1422
1423         if (msg_ns_from_origin >= ns_from_origin) {
1424                 *got_first = true;
1425                 goto push_msg;
1426         }
1427
1428 skip_msg:
1429         /* This message won't be sent downstream. */
1430         switch (msg->type) {
1431         case BT_MESSAGE_TYPE_STREAM_BEGINNING:
1432         {
1433                 const struct bt_message_stream *stream_msg = (const void *) msg;
1434                 struct auto_seek_stream_state *stream_state;
1435
1436                 /* Update stream's state: stream began. */
1437                 stream_state = create_auto_seek_stream_state();
1438                 if (!stream_state) {
1439                         status = BT_FUNC_STATUS_MEMORY_ERROR;
1440                         goto end;
1441                 }
1442
1443                 stream_state->state = AUTO_SEEK_STREAM_STATE_STREAM_BEGAN;
1444
1445                 if (stream_msg->default_cs_state == BT_MESSAGE_STREAM_CLOCK_SNAPSHOT_STATE_KNOWN) {
1446                         stream_state->seen_clock_snapshot = true;
1447                 }
1448
1449                 BT_ASSERT_DBG(!bt_g_hash_table_contains(stream_states, stream_msg->stream));
1450                 g_hash_table_insert(stream_states, stream_msg->stream, stream_state);
1451                 break;
1452         }
1453         case BT_MESSAGE_TYPE_PACKET_BEGINNING:
1454         {
1455                 const struct bt_message_packet *packet_msg =
1456                         (const void *) msg;
1457                 struct auto_seek_stream_state *stream_state;
1458
1459                 /* Update stream's state: packet began. */
1460                 stream_state = g_hash_table_lookup(stream_states, packet_msg->packet->stream);
1461                 BT_ASSERT_DBG(stream_state);
1462                 BT_ASSERT_DBG(stream_state->state == AUTO_SEEK_STREAM_STATE_STREAM_BEGAN);
1463                 stream_state->state = AUTO_SEEK_STREAM_STATE_PACKET_BEGAN;
1464                 BT_ASSERT_DBG(!stream_state->packet);
1465                 stream_state->packet = packet_msg->packet;
1466
1467                 if (packet_msg->packet->stream->class->packets_have_beginning_default_clock_snapshot) {
1468                         stream_state->seen_clock_snapshot = true;
1469                 }
1470
1471                 break;
1472         }
1473         case BT_MESSAGE_TYPE_EVENT:
1474         {
1475                 const struct bt_message_event *event_msg = (const void *) msg;
1476                 struct auto_seek_stream_state *stream_state;
1477
1478                 stream_state = g_hash_table_lookup(stream_states,
1479                         event_msg->event->stream);
1480                 BT_ASSERT_DBG(stream_state);
1481
1482                 // HELPME: are we sure that event messages have clock snapshots at this point?
1483                 stream_state->seen_clock_snapshot = true;
1484
1485                 break;
1486         }
1487         case BT_MESSAGE_TYPE_PACKET_END:
1488         {
1489                 const struct bt_message_packet *packet_msg =
1490                         (const void *) msg;
1491                 struct auto_seek_stream_state *stream_state;
1492
1493                 /* Update stream's state: packet ended. */
1494                 stream_state = g_hash_table_lookup(stream_states, packet_msg->packet->stream);
1495                 BT_ASSERT_DBG(stream_state);
1496                 BT_ASSERT_DBG(stream_state->state == AUTO_SEEK_STREAM_STATE_PACKET_BEGAN);
1497                 stream_state->state = AUTO_SEEK_STREAM_STATE_STREAM_BEGAN;
1498                 BT_ASSERT_DBG(stream_state->packet);
1499                 stream_state->packet = NULL;
1500
1501                 if (packet_msg->packet->stream->class->packets_have_end_default_clock_snapshot) {
1502                         stream_state->seen_clock_snapshot = true;
1503                 }
1504
1505                 break;
1506         }
1507         case BT_MESSAGE_TYPE_STREAM_END:
1508         {
1509                 const struct bt_message_stream *stream_msg = (const void *) msg;
1510                 struct auto_seek_stream_state *stream_state;
1511
1512                 stream_state = g_hash_table_lookup(stream_states, stream_msg->stream);
1513                 BT_ASSERT_DBG(stream_state);
1514                 BT_ASSERT_DBG(stream_state->state == AUTO_SEEK_STREAM_STATE_STREAM_BEGAN);
1515                 BT_ASSERT_DBG(!stream_state->packet);
1516
1517                 /* Update stream's state: this stream doesn't exist anymore. */
1518                 g_hash_table_remove(stream_states, stream_msg->stream);
1519                 break;
1520         }
1521         case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
1522         case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
1523         {
1524                 const struct bt_message_discarded_items *discarded_msg =
1525                         (const void *) msg;
1526                 struct auto_seek_stream_state *stream_state;
1527
1528                 stream_state = g_hash_table_lookup(stream_states, discarded_msg->stream);
1529                 BT_ASSERT_DBG(stream_state);
1530
1531                 if ((msg->type == BT_MESSAGE_TYPE_DISCARDED_EVENTS && discarded_msg->stream->class->discarded_events_have_default_clock_snapshots) ||
1532                         (msg->type == BT_MESSAGE_TYPE_DISCARDED_PACKETS && discarded_msg->stream->class->discarded_packets_have_default_clock_snapshots)) {
1533                         stream_state->seen_clock_snapshot = true;
1534                 }
1535
1536                 break;
1537         }
1538         default:
1539                 break;
1540         }
1541
1542         bt_object_put_ref_no_null_check(msg);
1543         msg = NULL;
1544         goto end;
1545
1546 push_msg:
1547         g_queue_push_tail(iterator->auto_seek.msgs, (void *) msg);
1548         msg = NULL;
1549
1550 end:
1551         BT_ASSERT_DBG(!msg || status != BT_FUNC_STATUS_OK);
1552         return status;
1553 }
1554
1555 static
1556 int find_message_ge_ns_from_origin(
1557                 struct bt_message_iterator *iterator,
1558                 int64_t ns_from_origin, GHashTable *stream_states)
1559 {
1560         int status = BT_FUNC_STATUS_OK;
1561         enum bt_message_iterator_state init_state =
1562                 iterator->state;
1563         const struct bt_message *messages[MSG_BATCH_SIZE];
1564         uint64_t user_count = 0;
1565         uint64_t i;
1566         bool got_first = false;
1567
1568         BT_ASSERT_DBG(iterator);
1569         memset(&messages[0], 0, sizeof(messages[0]) * MSG_BATCH_SIZE);
1570
1571         /*
1572          * Make this iterator temporarily active (not seeking) to call
1573          * the "next" method.
1574          */
1575         set_msg_iterator_state(iterator,
1576                 BT_MESSAGE_ITERATOR_STATE_ACTIVE);
1577
1578         BT_ASSERT_DBG(iterator->methods.next);
1579
1580         while (!got_first) {
1581                 /*
1582                  * Call the user's "next" method to get the next
1583                  * messages and status.
1584                  */
1585                 status = call_iterator_next_method(iterator,
1586                         &messages[0], MSG_BATCH_SIZE, &user_count);
1587                 BT_LOGD("User method returned: status=%s",
1588                         bt_common_func_status_string(status));
1589                 if (status < 0) {
1590                         BT_LIB_LOGW_APPEND_CAUSE(
1591                                 "Component input port message iterator's \"next\" method failed: "
1592                                 "%![iter-]+i, status=%s",
1593                                 iterator, bt_common_func_status_string(status));
1594                 }
1595
1596                 /*
1597                  * The user's "next" method must not do any action which
1598                  * would change the iterator's state.
1599                  */
1600                 BT_ASSERT_DBG(iterator->state ==
1601                         BT_MESSAGE_ITERATOR_STATE_ACTIVE);
1602
1603                 switch (status) {
1604                 case BT_FUNC_STATUS_OK:
1605                         BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
1606                                 "count-lteq-capacity",
1607                                 user_count <= MSG_BATCH_SIZE,
1608                                 "Invalid returned message count: greater than "
1609                                 "batch size: count=%" PRIu64 ", batch-size=%u",
1610                                 user_count, MSG_BATCH_SIZE);
1611                         break;
1612                 case BT_FUNC_STATUS_AGAIN:
1613                 case BT_FUNC_STATUS_ERROR:
1614                 case BT_FUNC_STATUS_MEMORY_ERROR:
1615                 case BT_FUNC_STATUS_END:
1616                         goto end;
1617                 default:
1618                         bt_common_abort();
1619                 }
1620
1621                 for (i = 0; i < user_count; i++) {
1622                         if (got_first) {
1623                                 g_queue_push_tail(iterator->auto_seek.msgs,
1624                                         (void *) messages[i]);
1625                                 messages[i] = NULL;
1626                                 continue;
1627                         }
1628
1629                         status = auto_seek_handle_message(iterator,
1630                                 ns_from_origin, messages[i], &got_first,
1631                                 stream_states);
1632                         if (status == BT_FUNC_STATUS_OK) {
1633                                 /* Message was either pushed or moved */
1634                                 messages[i] = NULL;
1635                         } else {
1636                                 goto end;
1637                         }
1638                 }
1639         }
1640
1641 end:
1642         for (i = 0; i < user_count; i++) {
1643                 if (messages[i]) {
1644                         bt_object_put_ref_no_null_check(messages[i]);
1645                 }
1646         }
1647
1648         set_msg_iterator_state(iterator, init_state);
1649         return status;
1650 }
1651
1652 /*
1653  * This function is installed as the iterator's next callback after we have
1654  * auto-seeked (seeked to the beginning and fast-forwarded) to send the
1655  * messages saved in iterator->auto_seek.msgs.  Once this is done, the original
1656  * next callback is put back.
1657  */
1658
1659 static
1660 enum bt_message_iterator_class_next_method_status post_auto_seek_next(
1661                 struct bt_message_iterator *iterator,
1662                 bt_message_array_const msgs, uint64_t capacity,
1663                 uint64_t *count)
1664 {
1665         BT_ASSERT(!g_queue_is_empty(iterator->auto_seek.msgs));
1666         *count = 0;
1667
1668         /*
1669          * Move auto-seek messages to the output array (which is this
1670          * iterator's base message array).
1671          */
1672         while (capacity > 0 && !g_queue_is_empty(iterator->auto_seek.msgs)) {
1673                 msgs[*count] = g_queue_pop_head(iterator->auto_seek.msgs);
1674                 capacity--;
1675                 (*count)++;
1676         }
1677
1678         BT_ASSERT(*count > 0);
1679
1680         if (g_queue_is_empty(iterator->auto_seek.msgs)) {
1681                 /* No more auto-seek messages, restore user's next callback. */
1682                 BT_ASSERT(iterator->auto_seek.original_next_callback);
1683                 iterator->methods.next = iterator->auto_seek.original_next_callback;
1684                 iterator->auto_seek.original_next_callback = NULL;
1685         }
1686
1687         return BT_FUNC_STATUS_OK;
1688 }
1689
1690 static inline
1691 int clock_raw_value_from_ns_from_origin(const bt_clock_class *clock_class,
1692                 int64_t ns_from_origin, uint64_t *raw_value)
1693 {
1694
1695         int64_t cc_offset_s = clock_class->offset_seconds;
1696         uint64_t cc_offset_cycles = clock_class->offset_cycles;
1697         uint64_t cc_freq = clock_class->frequency;
1698
1699         return bt_common_clock_value_from_ns_from_origin(cc_offset_s,
1700                 cc_offset_cycles, cc_freq, ns_from_origin, raw_value);
1701 }
1702
1703 static
1704 bool message_iterator_can_seek_ns_from_origin(
1705                 struct bt_message_iterator *iterator,
1706                 int64_t ns_from_origin)
1707 {
1708         enum bt_message_iterator_can_seek_ns_from_origin_status status;
1709         bt_bool can_seek;
1710
1711         status = bt_message_iterator_can_seek_ns_from_origin(
1712                 iterator, ns_from_origin, &can_seek);
1713         if (status != BT_FUNC_STATUS_OK) {
1714                 can_seek = BT_FALSE;
1715         }
1716
1717         return can_seek;
1718 }
1719
1720 #define SEEK_NS_FROM_ORIGIN_METHOD_NAME                                 \
1721         "bt_message_iterator_class_seek_ns_from_origin_method"
1722
1723
1724 BT_EXPORT
1725 enum bt_message_iterator_seek_ns_from_origin_status
1726 bt_message_iterator_seek_ns_from_origin(
1727                 struct bt_message_iterator *iterator,
1728                 int64_t ns_from_origin)
1729 {
1730         int status;
1731         GHashTable *stream_states = NULL;
1732         bt_bool can_seek_by_itself;
1733
1734         BT_ASSERT_PRE_NO_ERROR();
1735         BT_ASSERT_PRE_MSG_ITER_NON_NULL(iterator);
1736         BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(iterator);
1737         BT_ASSERT_PRE("graph-is-configured",
1738                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
1739                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
1740                 "Graph is not configured: %!+g",
1741                 bt_component_borrow_graph(iterator->upstream_component));
1742         /* The iterator must be able to seek ns from origin one way or another. */
1743         BT_ASSERT_PRE("can-seek-ns-from-origin",
1744                 message_iterator_can_seek_ns_from_origin(iterator, ns_from_origin),
1745                 "Message iterator cannot seek nanoseconds from origin: %!+i, "
1746                 "ns-from-origin=%" PRId64, iterator, ns_from_origin);
1747         set_msg_iterator_state(iterator,
1748                 BT_MESSAGE_ITERATOR_STATE_SEEKING);
1749
1750         /*
1751          * We are seeking, reset our expectations about how the following
1752          * messages should look like.
1753          */
1754         reset_iterator_expectations(iterator);
1755
1756         /* Check if the iterator can seek by itself.  If not we'll use autoseek. */
1757         if (iterator->methods.can_seek_ns_from_origin) {
1758                 bt_message_iterator_class_can_seek_ns_from_origin_method_status
1759                         can_seek_status;
1760
1761                 can_seek_status =
1762                         iterator->methods.can_seek_ns_from_origin(
1763                                 iterator, ns_from_origin, &can_seek_by_itself);
1764                 if (can_seek_status != BT_FUNC_STATUS_OK) {
1765                         status = can_seek_status;
1766                         goto end;
1767                 }
1768         } else {
1769                 can_seek_by_itself = false;
1770         }
1771
1772         if (can_seek_by_itself) {
1773                 /* The iterator knows how to seek to a particular time, let it handle this. */
1774                 BT_ASSERT(iterator->methods.seek_ns_from_origin);
1775                 BT_LIB_LOGD("Calling user's \"seek nanoseconds from origin\" method: "
1776                         "%![iter-]+i, ns=%" PRId64, iterator, ns_from_origin);
1777                 status = iterator->methods.seek_ns_from_origin(iterator,
1778                         ns_from_origin);
1779                 BT_LOGD("User method returned: status=%s",
1780                         bt_common_func_status_string(status));
1781                 BT_ASSERT_POST(SEEK_NS_FROM_ORIGIN_METHOD_NAME, "valid-status",
1782                         status == BT_FUNC_STATUS_OK ||
1783                         status == BT_FUNC_STATUS_ERROR ||
1784                         status == BT_FUNC_STATUS_MEMORY_ERROR ||
1785                         status == BT_FUNC_STATUS_AGAIN,
1786                         "Unexpected status: %![iter-]+i, status=%s",
1787                         iterator, bt_common_func_status_string(status));
1788                 BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(
1789                         SEEK_NS_FROM_ORIGIN_METHOD_NAME, status);
1790                 if (status < 0) {
1791                         BT_LIB_LOGW_APPEND_CAUSE(
1792                                 "Component input port message iterator's \"seek nanoseconds from origin\" method failed: "
1793                                 "%![iter-]+i, status=%s",
1794                                 iterator, bt_common_func_status_string(status));
1795                 }
1796         } else {
1797                 /*
1798                  * The iterator doesn't know how to seek by itself to a
1799                  * particular time.  We will seek to the beginning and fast
1800                  * forward to the right place.
1801                  */
1802                 enum bt_message_iterator_class_can_seek_beginning_method_status can_seek_status;
1803                 bt_bool can_seek_beginning;
1804
1805                 can_seek_status = iterator->methods.can_seek_beginning(iterator,
1806                         &can_seek_beginning);
1807                 BT_ASSERT(can_seek_status == BT_FUNC_STATUS_OK);
1808                 BT_ASSERT(can_seek_beginning);
1809                 BT_ASSERT(iterator->methods.seek_beginning);
1810                 BT_LIB_LOGD("Calling user's \"seek beginning\" method: %!+i",
1811                         iterator);
1812                 status = iterator->methods.seek_beginning(iterator);
1813                 BT_LOGD("User method returned: status=%s",
1814                         bt_common_func_status_string(status));
1815                 BT_ASSERT_POST(SEEK_BEGINNING_METHOD_NAME, "valid-status",
1816                         status == BT_FUNC_STATUS_OK ||
1817                         status == BT_FUNC_STATUS_ERROR ||
1818                         status == BT_FUNC_STATUS_MEMORY_ERROR ||
1819                         status == BT_FUNC_STATUS_AGAIN,
1820                         "Unexpected status: %![iter-]+i, status=%s",
1821                         iterator, bt_common_func_status_string(status));
1822                 if (status < 0) {
1823                         BT_LIB_LOGW_APPEND_CAUSE(
1824                                 "Component input port message iterator's \"seek beginning\" method failed: "
1825                                 "%![iter-]+i, status=%s",
1826                                 iterator, bt_common_func_status_string(status));
1827                 }
1828
1829                 switch (status) {
1830                 case BT_FUNC_STATUS_OK:
1831                         break;
1832                 case BT_FUNC_STATUS_ERROR:
1833                 case BT_FUNC_STATUS_MEMORY_ERROR:
1834                 case BT_FUNC_STATUS_AGAIN:
1835                         goto end;
1836                 default:
1837                         bt_common_abort();
1838                 }
1839
1840                 /*
1841                  * Find the first message which has a default clock
1842                  * snapshot greater than or equal to the requested
1843                  * seeking time, and move the received messages from
1844                  * this point in the batch to this iterator's auto-seek
1845                  * message queue.
1846                  */
1847                 while (!g_queue_is_empty(iterator->auto_seek.msgs)) {
1848                         bt_object_put_ref_no_null_check(
1849                                 g_queue_pop_tail(iterator->auto_seek.msgs));
1850                 }
1851
1852                 stream_states = create_auto_seek_stream_states();
1853                 if (!stream_states) {
1854                         BT_LIB_LOGE_APPEND_CAUSE(
1855                                 "Failed to allocate one GHashTable.");
1856                         status = BT_FUNC_STATUS_MEMORY_ERROR;
1857                         goto end;
1858                 }
1859
1860                 status = find_message_ge_ns_from_origin(iterator,
1861                         ns_from_origin, stream_states);
1862                 switch (status) {
1863                 case BT_FUNC_STATUS_OK:
1864                 case BT_FUNC_STATUS_END:
1865                 {
1866                         GHashTableIter iter;
1867                         gpointer key, value;
1868
1869                         /*
1870                          * If some streams exist at the seek time, prepend the
1871                          * required messages to put those streams in the right
1872                          * state.
1873                          */
1874                         g_hash_table_iter_init(&iter, stream_states);
1875                         while (g_hash_table_iter_next (&iter, &key, &value)) {
1876                                 const bt_stream *stream = key;
1877                                 struct auto_seek_stream_state *stream_state =
1878                                         (struct auto_seek_stream_state *) value;
1879                                 bt_message *msg;
1880                                 const bt_clock_class *clock_class = bt_stream_class_borrow_default_clock_class_const(
1881                                         bt_stream_borrow_class_const(stream));
1882                                 /* Initialize to silence maybe-uninitialized warning. */
1883                                 uint64_t raw_value = 0;
1884
1885                                 /*
1886                                  * If we haven't seen a message with a clock snapshot, we don't know if our seek time is within
1887                                  * the clock's range, so it wouldn't be safe to try to convert ns_from_origin to a clock value.
1888                                  *
1889                                  * Also, it would be a bit of a lie to generate a stream begin message with the seek time as its
1890                                  * clock snapshot, because we don't really know if the stream existed at that time.  If we have
1891                                  * seen a message with a clock snapshot in our seeking, then we are sure that the
1892                                  * seek time is not below the clock range, and we know the stream was active at that
1893                                  * time (and that we cut it short).
1894                                  */
1895                                 if (stream_state->seen_clock_snapshot) {
1896                                         if (clock_raw_value_from_ns_from_origin(clock_class, ns_from_origin, &raw_value) != 0) {
1897                                                 BT_LIB_LOGW("Could not convert nanoseconds from origin to clock value: ns-from-origin=%" PRId64 ", %![cc-]+K",
1898                                                         ns_from_origin, clock_class);
1899                                                 status = BT_FUNC_STATUS_ERROR;
1900                                                 goto end;
1901                                         }
1902                                 }
1903
1904                                 switch (stream_state->state) {
1905                                 case AUTO_SEEK_STREAM_STATE_PACKET_BEGAN:
1906                                         BT_ASSERT(stream_state->packet);
1907                                         BT_LIB_LOGD("Creating packet message: %![packet-]+a", stream_state->packet);
1908
1909                                         if (stream->class->packets_have_beginning_default_clock_snapshot) {
1910                                                 /*
1911                                                  * If we are in the PACKET_BEGAN state, it means we have seen a "packet beginning"
1912                                                  * message.  If "packet beginning" packets have clock snapshots, then we must have
1913                                                  * seen a clock snapshot.
1914                                                  */
1915                                                 BT_ASSERT(stream_state->seen_clock_snapshot);
1916
1917                                                 msg = bt_message_packet_beginning_create_with_default_clock_snapshot(
1918                                                         (bt_self_message_iterator *) iterator, stream_state->packet, raw_value);
1919                                         } else {
1920                                                 msg = bt_message_packet_beginning_create((bt_self_message_iterator *) iterator,
1921                                                                 stream_state->packet);
1922                                         }
1923
1924                                         if (!msg) {
1925                                                 status = BT_FUNC_STATUS_MEMORY_ERROR;
1926                                                 goto end;
1927                                         }
1928
1929                                         g_queue_push_head(iterator->auto_seek.msgs, msg);
1930                                         msg = NULL;
1931                                         /* fall-thru */
1932
1933                                 case AUTO_SEEK_STREAM_STATE_STREAM_BEGAN:
1934                                         msg = bt_message_stream_beginning_create(
1935                                                 (bt_self_message_iterator *) iterator, stream);
1936                                         if (!msg) {
1937                                                 status = BT_FUNC_STATUS_MEMORY_ERROR;
1938                                                 goto end;
1939                                         }
1940
1941                                         if (stream_state->seen_clock_snapshot) {
1942                                                 bt_message_stream_beginning_set_default_clock_snapshot(msg, raw_value);
1943                                         }
1944
1945                                         g_queue_push_head(iterator->auto_seek.msgs, msg);
1946                                         msg = NULL;
1947                                         break;
1948                                 }
1949                         }
1950
1951                         /*
1952                          * If there are messages in the auto-seek
1953                          * message queue, replace the user's "next"
1954                          * method with a custom, temporary "next" method
1955                          * which returns them.
1956                          */
1957                         if (!g_queue_is_empty(iterator->auto_seek.msgs)) {
1958                                 BT_ASSERT(!iterator->auto_seek.original_next_callback);
1959                                 iterator->auto_seek.original_next_callback = iterator->methods.next;
1960
1961                                 iterator->methods.next =
1962                                         (bt_message_iterator_next_method)
1963                                                 post_auto_seek_next;
1964                         }
1965
1966                         /*
1967                          * `BT_FUNC_STATUS_END` becomes
1968                          * `BT_FUNC_STATUS_OK`: the next
1969                          * time this iterator's "next" method is called,
1970                          * it will return
1971                          * `BT_FUNC_STATUS_END`.
1972                          */
1973                         status = BT_FUNC_STATUS_OK;
1974                         break;
1975                 }
1976                 case BT_FUNC_STATUS_ERROR:
1977                 case BT_FUNC_STATUS_MEMORY_ERROR:
1978                 case BT_FUNC_STATUS_AGAIN:
1979                         goto end;
1980                 default:
1981                         bt_common_abort();
1982                 }
1983         }
1984
1985         /*
1986          * The following messages returned by the next method (including
1987          * post_auto_seek_next) must be after (or at) `ns_from_origin`.
1988          */
1989         iterator->last_ns_from_origin = ns_from_origin;
1990
1991 end:
1992         if (stream_states) {
1993                 destroy_auto_seek_stream_states(stream_states);
1994                 stream_states = NULL;
1995         }
1996
1997         set_iterator_state_after_seeking(iterator, status);
1998         return status;
1999 }
2000
2001 BT_EXPORT
2002 bt_bool bt_self_message_iterator_is_interrupted(
2003                 const struct bt_self_message_iterator *self_msg_iter)
2004 {
2005         const struct bt_message_iterator *iterator =
2006                 (const void *) self_msg_iter;
2007
2008         BT_ASSERT_PRE_MSG_ITER_NON_NULL(iterator);
2009         return (bt_bool) bt_graph_is_interrupted(iterator->graph);
2010 }
2011
2012 BT_EXPORT
2013 void bt_message_iterator_get_ref(
2014                 const struct bt_message_iterator *iterator)
2015 {
2016         bt_object_get_ref(iterator);
2017 }
2018
2019 BT_EXPORT
2020 void bt_message_iterator_put_ref(
2021                 const struct bt_message_iterator *iterator)
2022 {
2023         bt_object_put_ref(iterator);
2024 }