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