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 #ifdef BT_DEV_MODE
  70 struct per_stream_state
  71 {
  72         bt_packet *cur_packet;
  73 };
  74 #endif
  75
  76 static void
  77 clear_per_stream_state (struct bt_message_iterator *iterator)
  78 {
  79 #ifdef BT_DEV_MODE
  80         g_hash_table_remove_all(iterator->per_stream_state);
  81 #else
  82         BT_USE_EXPR(iterator);
  83 #endif
  84 }
  85
  86 static inline
  87 void set_msg_iterator_state(struct bt_message_iterator *iterator,
  88                 enum bt_message_iterator_state state)
  89 {
  90         BT_ASSERT_DBG(iterator);
  91         BT_LIB_LOGD("Updating message iterator's state: new-state=%s",
  92                 bt_message_iterator_state_string(state));
  93         iterator->state = state;
  94 }
  95
  96 static
  97 void bt_message_iterator_destroy(struct bt_object *obj)
  98 {
  99         struct bt_message_iterator *iterator;
 100
 101         BT_ASSERT(obj);
 102
 103         /*
 104          * The message iterator's reference count is 0 if we're
 105          * here. Increment it to avoid a double-destroy (possibly
 106          * infinitely recursive). This could happen for example if the
 107          * message iterator's finalization function does
 108          * bt_object_get_ref() (or anything that causes
 109          * bt_object_get_ref() to be called) on itself (ref. count goes
 110          * from 0 to 1), and then bt_object_put_ref(): the reference
 111          * count would go from 1 to 0 again and this function would be
 112          * called again.
 113          */
 114         obj->ref_count++;
 115         iterator = (void *) obj;
 116         BT_LIB_LOGI("Destroying self component input port message iterator object: "
 117                 "%!+i", iterator);
 118         bt_message_iterator_try_finalize(iterator);
 119
 120         if (iterator->connection) {
 121                 /*
 122                  * Remove ourself from the originating connection so
 123                  * that it does not try to finalize a dangling pointer
 124                  * later.
 125                  */
 126                 bt_connection_remove_iterator(iterator->connection, iterator);
 127                 iterator->connection = NULL;
 128         }
 129
 130         if (iterator->auto_seek.msgs) {
 131                 while (!g_queue_is_empty(iterator->auto_seek.msgs)) {
 132                         bt_object_put_ref_no_null_check(
 133                                 g_queue_pop_tail(iterator->auto_seek.msgs));
 134                 }
 135
 136                 g_queue_free(iterator->auto_seek.msgs);
 137                 iterator->auto_seek.msgs = NULL;
 138         }
 139
 140         if (iterator->upstream_msg_iters) {
 141                 /*
 142                  * At this point the message iterator is finalized, so
 143                  * it's detached from any upstream message iterator.
 144                  */
 145                 BT_ASSERT(iterator->upstream_msg_iters->len == 0);
 146                 g_ptr_array_free(iterator->upstream_msg_iters, TRUE);
 147                 iterator->upstream_msg_iters = NULL;
 148         }
 149
 150         if (iterator->msgs) {
 151                 g_ptr_array_free(iterator->msgs, TRUE);
 152                 iterator->msgs = NULL;
 153         }
 154
 155 #ifdef BT_DEV_MODE
 156         g_hash_table_destroy(iterator->per_stream_state);
 157 #endif
 158
 159         g_free(iterator);
 160 }
 161
 162 void bt_message_iterator_try_finalize(
 163                 struct bt_message_iterator *iterator)
 164 {
 165         uint64_t i;
 166         bool call_user_finalize = true;
 167
 168         BT_ASSERT(iterator);
 169
 170         switch (iterator->state) {
 171         case BT_MESSAGE_ITERATOR_STATE_NON_INITIALIZED:
 172                 /*
 173                  * If this function is called while the iterator is in the
 174                  * NON_INITIALIZED state, it means the user initialization
 175                  * method has either not been called, or has failed.  We
 176                  * therefore don't want to call the user finalization method.
 177                  * However, the initialization method might have created some
 178                  * upstream message iterators before failing, so we want to
 179                  * execute the rest of this function, which unlinks the related
 180                  * iterators.
 181                  */
 182                 call_user_finalize = false;
 183                 break;
 184         case BT_MESSAGE_ITERATOR_STATE_FINALIZED:
 185                 /* Already finalized */
 186                 BT_LIB_LOGD("Not finalizing message iterator: already finalized: "
 187                         "%!+i", iterator);
 188                 goto end;
 189         case BT_MESSAGE_ITERATOR_STATE_FINALIZING:
 190                 /* Finalizing */
 191                 BT_LIB_LOGF("Message iterator is already being finalized: "
 192                         "%!+i", iterator);
 193                 bt_common_abort();
 194         default:
 195                 break;
 196         }
 197
 198         BT_LIB_LOGD("Finalizing message iterator: %!+i", iterator);
 199         set_msg_iterator_state(iterator,
 200                 BT_MESSAGE_ITERATOR_STATE_FINALIZING);
 201         BT_ASSERT(iterator->upstream_component);
 202
 203         /* Call user-defined destroy method */
 204         if (call_user_finalize) {
 205                 typedef void (*method_t)(void *);
 206                 method_t method;
 207                 struct bt_component_class *comp_class =
 208                         iterator->upstream_component->class;
 209                 struct bt_component_class_with_iterator_class *class_with_iter_class;
 210
 211                 BT_ASSERT(bt_component_class_has_message_iterator_class(comp_class));
 212                 class_with_iter_class = container_of(comp_class,
 213                         struct bt_component_class_with_iterator_class, parent);
 214                 method = (method_t) class_with_iter_class->msg_iter_cls->methods.finalize;
 215
 216                 if (method) {
 217                         const bt_error *saved_error;
 218
 219                         saved_error = bt_current_thread_take_error();
 220
 221                         BT_LIB_LOGD("Calling user's finalization method: %!+i",
 222                                 iterator);
 223                         method(iterator);
 224                         BT_ASSERT_POST_NO_ERROR("bt_message_iterator_class_finalize_method");
 225
 226                         if (saved_error) {
 227                                 BT_CURRENT_THREAD_MOVE_ERROR_AND_RESET(saved_error);
 228                         }
 229                 }
 230         }
 231
 232         /* Detach upstream message iterators */
 233         for (i = 0; i < iterator->upstream_msg_iters->len; i++) {
 234                 struct bt_message_iterator *upstream_msg_iter =
 235                         iterator->upstream_msg_iters->pdata[i];
 236
 237                 upstream_msg_iter->downstream_msg_iter = NULL;
 238         }
 239
 240         g_ptr_array_set_size(iterator->upstream_msg_iters, 0);
 241
 242         /* Detach downstream message iterator */
 243         if (iterator->downstream_msg_iter) {
 244                 gboolean existed;
 245
 246                 BT_ASSERT(iterator->downstream_msg_iter->upstream_msg_iters);
 247                 existed = g_ptr_array_remove_fast(
 248                         iterator->downstream_msg_iter->upstream_msg_iters,
 249                         iterator);
 250                 BT_ASSERT(existed);
 251         }
 252
 253         iterator->upstream_component = NULL;
 254         iterator->upstream_port = NULL;
 255         set_msg_iterator_state(iterator,
 256                 BT_MESSAGE_ITERATOR_STATE_FINALIZED);
 257         BT_LIB_LOGD("Finalized message iterator: %!+i", iterator);
 258
 259 end:
 260         return;
 261 }
 262
 263 void bt_message_iterator_set_connection(
 264                 struct bt_message_iterator *iterator,
 265                 struct bt_connection *connection)
 266 {
 267         BT_ASSERT(iterator);
 268         iterator->connection = connection;
 269         BT_LIB_LOGI("Set message iterator's connection: "
 270                 "%![iter-]+i, %![conn-]+x", iterator, connection);
 271 }
 272
 273 static
 274 enum bt_message_iterator_can_seek_beginning_status can_seek_ns_from_origin_true(
 275                 struct bt_message_iterator *iterator __attribute__((unused)),
 276                 int64_t ns_from_origin __attribute__((unused)),
 277                 bt_bool *can_seek)
 278 {
 279         *can_seek = BT_TRUE;
 280
 281         return BT_FUNC_STATUS_OK;
 282 }
 283
 284 static
 285 enum bt_message_iterator_can_seek_beginning_status can_seek_beginning_true(
 286                 struct bt_message_iterator *iterator __attribute__((unused)),
 287                 bt_bool *can_seek)
 288 {
 289         *can_seek = BT_TRUE;
 290
 291         return BT_FUNC_STATUS_OK;
 292 }
 293
 294 static
 295 int create_self_component_input_port_message_iterator(
 296                 struct bt_self_message_iterator *self_downstream_msg_iter,
 297                 struct bt_self_component_port_input *self_port,
 298                 struct bt_message_iterator **message_iterator,
 299                 const char *api_func)
 300 {
 301         bt_message_iterator_class_initialize_method init_method = NULL;
 302         struct bt_message_iterator *iterator =
 303                 NULL;
 304         struct bt_message_iterator *downstream_msg_iter =
 305                 (void *) self_downstream_msg_iter;
 306         struct bt_port *port = (void *) self_port;
 307         struct bt_port *upstream_port;
 308         struct bt_component *comp;
 309         struct bt_component *upstream_comp;
 310         struct bt_component_class *upstream_comp_cls;
 311         struct bt_component_class_with_iterator_class *upstream_comp_cls_with_iter_cls;
 312         int status;
 313
 314         BT_ASSERT_PRE_NON_NULL_FROM_FUNC(api_func, "message-iterator-output",
 315                 message_iterator, "Created message iterator (output)");
 316         BT_ASSERT_PRE_NON_NULL_FROM_FUNC(api_func, "input-port", port,
 317                 "Input port");
 318         comp = bt_port_borrow_component_inline(port);
 319         BT_ASSERT_PRE_FROM_FUNC(api_func, "input-port-is-connected",
 320                 bt_port_is_connected(port),
 321                 "Input port is not connected: %![port-]+p", port);
 322         BT_ASSERT_PRE_FROM_FUNC(api_func, "input-port-has-component",
 323                 comp, "Input port is not part of a component: %![port-]+p",
 324                 port);
 325         BT_ASSERT(port->connection);
 326         upstream_port = port->connection->upstream_port;
 327         BT_ASSERT(upstream_port);
 328         upstream_comp = bt_port_borrow_component_inline(upstream_port);
 329         BT_ASSERT(upstream_comp);
 330         BT_ASSERT_PRE_FROM_FUNC(api_func, "graph-is-configured",
 331                 bt_component_borrow_graph(upstream_comp)->config_state ==
 332                         BT_GRAPH_CONFIGURATION_STATE_PARTIALLY_CONFIGURED ||
 333                 bt_component_borrow_graph(upstream_comp)->config_state ==
 334                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURED,
 335                 "Graph is not configured: %!+g",
 336                 bt_component_borrow_graph(upstream_comp));
 337         upstream_comp_cls = upstream_comp->class;
 338         BT_ASSERT(upstream_comp->class->type ==
 339                 BT_COMPONENT_CLASS_TYPE_SOURCE ||
 340                 upstream_comp->class->type ==
 341                 BT_COMPONENT_CLASS_TYPE_FILTER);
 342         BT_LIB_LOGI("Creating message iterator on self component input port: "
 343                 "%![up-comp-]+c, %![up-port-]+p", upstream_comp, upstream_port);
 344         iterator = g_new0(
 345                 struct bt_message_iterator, 1);
 346         if (!iterator) {
 347                 BT_LIB_LOGE_APPEND_CAUSE(
 348                         "Failed to allocate one self component input port "
 349                         "message iterator.");
 350                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 351                 goto error;
 352         }
 353
 354         bt_object_init_shared(&iterator->base,
 355                 bt_message_iterator_destroy);
 356         iterator->msgs = g_ptr_array_new();
 357         if (!iterator->msgs) {
 358                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GPtrArray.");
 359                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 360                 goto error;
 361         }
 362
 363         g_ptr_array_set_size(iterator->msgs, MSG_BATCH_SIZE);
 364         iterator->last_ns_from_origin = INT64_MIN;
 365
 366 #ifdef BT_DEV_MODE
 367         /* The per-stream state is only used for dev assertions right now. */
 368         iterator->per_stream_state = g_hash_table_new_full(
 369                 g_direct_hash,
 370                 g_direct_equal,
 371                 NULL,
 372                 g_free);
 373 #endif
 374
 375         iterator->auto_seek.msgs = g_queue_new();
 376         if (!iterator->auto_seek.msgs) {
 377                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GQueue.");
 378                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 379                 goto error;
 380         }
 381
 382         iterator->upstream_msg_iters = g_ptr_array_new();
 383         if (!iterator->upstream_msg_iters) {
 384                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GPtrArray.");
 385                 status = BT_FUNC_STATUS_MEMORY_ERROR;
 386                 goto error;
 387         }
 388
 389         iterator->upstream_component = upstream_comp;
 390         iterator->upstream_port = upstream_port;
 391         iterator->connection = iterator->upstream_port->connection;
 392         iterator->graph = bt_component_borrow_graph(upstream_comp);
 393         set_msg_iterator_state(iterator,
 394                 BT_MESSAGE_ITERATOR_STATE_NON_INITIALIZED);
 395
 396         /* Copy methods from the message iterator class to the message iterator. */
 397         BT_ASSERT(bt_component_class_has_message_iterator_class(upstream_comp_cls));
 398         upstream_comp_cls_with_iter_cls = container_of(upstream_comp_cls,
 399                 struct bt_component_class_with_iterator_class, parent);
 400
 401         iterator->methods.next =
 402                 (bt_message_iterator_next_method)
 403                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.next;
 404         iterator->methods.seek_ns_from_origin =
 405                 (bt_message_iterator_seek_ns_from_origin_method)
 406                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.seek_ns_from_origin;
 407         iterator->methods.seek_beginning =
 408                 (bt_message_iterator_seek_beginning_method)
 409                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.seek_beginning;
 410         iterator->methods.can_seek_ns_from_origin =
 411                 (bt_message_iterator_can_seek_ns_from_origin_method)
 412                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.can_seek_ns_from_origin;
 413         iterator->methods.can_seek_beginning =
 414                 (bt_message_iterator_can_seek_beginning_method)
 415                         upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.can_seek_beginning;
 416
 417         if (iterator->methods.seek_ns_from_origin &&
 418                         !iterator->methods.can_seek_ns_from_origin) {
 419                 iterator->methods.can_seek_ns_from_origin =
 420                         (bt_message_iterator_can_seek_ns_from_origin_method)
 421                                 can_seek_ns_from_origin_true;
 422         }
 423
 424         if (iterator->methods.seek_beginning &&
 425                         !iterator->methods.can_seek_beginning) {
 426                 iterator->methods.can_seek_beginning =
 427                         (bt_message_iterator_can_seek_beginning_method)
 428                                 can_seek_beginning_true;
 429         }
 430
 431         /* Call iterator's init method. */
 432         init_method = upstream_comp_cls_with_iter_cls->msg_iter_cls->methods.initialize;
 433
 434         if (init_method) {
 435                 enum bt_message_iterator_class_initialize_method_status iter_status;
 436
 437                 BT_LIB_LOGD("Calling user's initialization method: %!+i", iterator);
 438                 iter_status = init_method(
 439                         (struct bt_self_message_iterator *) iterator,
 440                         &iterator->config,
 441                         (struct bt_self_component_port_output *) upstream_port);
 442                 BT_LOGD("User method returned: status=%s",
 443                         bt_common_func_status_string(iter_status));
 444                 BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(
 445                         "bt_message_iterator_class_initialize_method",
 446                         iter_status);
 447                 if (iter_status != BT_FUNC_STATUS_OK) {
 448                         BT_LIB_LOGW_APPEND_CAUSE(
 449                                 "Component input port message iterator initialization method failed: "
 450                                 "%![iter-]+i, status=%s",
 451                                 iterator,
 452                                 bt_common_func_status_string(iter_status));
 453                         status = iter_status;
 454                         goto error;
 455                 }
 456
 457                 iterator->config.frozen = true;
 458         }
 459
 460         if (downstream_msg_iter) {
 461                 /* Set this message iterator's downstream message iterator */
 462                 iterator->downstream_msg_iter = downstream_msg_iter;
 463
 464                 /*
 465                  * Add this message iterator to the downstream message
 466                  * iterator's array of upstream message iterators.
 467                  */
 468                 g_ptr_array_add(downstream_msg_iter->upstream_msg_iters,
 469                         iterator);
 470         }
 471
 472         set_msg_iterator_state(iterator,
 473                 BT_MESSAGE_ITERATOR_STATE_ACTIVE);
 474         g_ptr_array_add(port->connection->iterators, iterator);
 475         BT_LIB_LOGI("Created message iterator on self component input port: "
 476                 "%![up-port-]+p, %![up-comp-]+c, %![iter-]+i",
 477                 upstream_port, upstream_comp, iterator);
 478
 479         *message_iterator = iterator;
 480         status = BT_FUNC_STATUS_OK;
 481         goto end;
 482
 483 error:
 484         BT_OBJECT_PUT_REF_AND_RESET(iterator);
 485
 486 end:
 487         return status;
 488 }
 489
 490 BT_EXPORT
 491 bt_message_iterator_create_from_message_iterator_status
 492 bt_message_iterator_create_from_message_iterator(
 493                 struct bt_self_message_iterator *self_msg_iter,
 494                 struct bt_self_component_port_input *input_port,
 495                 struct bt_message_iterator **message_iterator)
 496 {
 497         BT_ASSERT_PRE_NO_ERROR();
 498         BT_ASSERT_PRE_MSG_ITER_NON_NULL(self_msg_iter);
 499         return create_self_component_input_port_message_iterator(self_msg_iter,
 500                 input_port, message_iterator, __func__);
 501 }
 502
 503 BT_EXPORT
 504 bt_message_iterator_create_from_sink_component_status
 505 bt_message_iterator_create_from_sink_component(
 506                 struct bt_self_component_sink *self_comp,
 507                 struct bt_self_component_port_input *input_port,
 508                 struct bt_message_iterator **message_iterator)
 509 {
 510         BT_ASSERT_PRE_NO_ERROR();
 511         BT_ASSERT_PRE_NON_NULL("sink-component", self_comp, "Sink component");
 512         return create_self_component_input_port_message_iterator(NULL,
 513                 input_port, message_iterator, __func__);
 514 }
 515
 516 BT_EXPORT
 517 void *bt_self_message_iterator_get_data(
 518                 const struct bt_self_message_iterator *self_iterator)
 519 {
 520         struct bt_message_iterator *iterator =
 521                 (void *) self_iterator;
 522
 523         BT_ASSERT_PRE_DEV_MSG_ITER_NON_NULL(iterator);
 524         return iterator->user_data;
 525 }
 526
 527 BT_EXPORT
 528 void bt_self_message_iterator_set_data(
 529                 struct bt_self_message_iterator *self_iterator, void *data)
 530 {
 531         struct bt_message_iterator *iterator =
 532                 (void *) self_iterator;
 533
 534         BT_ASSERT_PRE_DEV_MSG_ITER_NON_NULL(iterator);
 535         iterator->user_data = data;
 536         BT_LIB_LOGD("Set message iterator's user data: "
 537                 "%!+i, user-data-addr=%p", iterator, data);
 538 }
 539
 540 BT_EXPORT
 541 void bt_self_message_iterator_configuration_set_can_seek_forward(
 542                 bt_self_message_iterator_configuration *config,
 543                 bt_bool can_seek_forward)
 544 {
 545         BT_ASSERT_PRE_NON_NULL("message-iterator-configuration", config,
 546                 "Message iterator configuration");
 547         BT_ASSERT_PRE_DEV_HOT("message-iterator-configuration", config,
 548                 "Message iterator configuration", "");
 549
 550         config->can_seek_forward = can_seek_forward;
 551 }
 552
 553 /*
 554  * Validate that the default clock snapshot in `msg` doesn't make us go back in
 555  * time.
 556  */
 557
 558 BT_ASSERT_COND_DEV_FUNC
 559 static
 560 bool clock_snapshots_are_monotonic_one(
 561                 struct bt_message_iterator *iterator,
 562                 const bt_message *msg)
 563 {
 564         const struct bt_clock_snapshot *clock_snapshot = NULL;
 565         bt_message_type message_type = bt_message_get_type(msg);
 566         int64_t ns_from_origin;
 567         enum bt_clock_snapshot_get_ns_from_origin_status clock_snapshot_status;
 568
 569         /*
 570          * The default is true: if we can't figure out the clock snapshot
 571          * (or there is none), assume it is fine.
 572          */
 573         bool result = true;
 574
 575         switch (message_type) {
 576         case BT_MESSAGE_TYPE_EVENT:
 577         {
 578                 struct bt_message_event *event_msg = (struct bt_message_event *) msg;
 579                 clock_snapshot = event_msg->default_cs;
 580                 break;
 581         }
 582         case BT_MESSAGE_TYPE_MESSAGE_ITERATOR_INACTIVITY:
 583         {
 584                 struct bt_message_message_iterator_inactivity *inactivity_msg =
 585                         (struct bt_message_message_iterator_inactivity *) msg;
 586                 clock_snapshot = inactivity_msg->cs;
 587                 break;
 588         }
 589         case BT_MESSAGE_TYPE_PACKET_BEGINNING:
 590         case BT_MESSAGE_TYPE_PACKET_END:
 591         {
 592                 struct bt_message_packet *packet_msg = (struct bt_message_packet *) msg;
 593                 clock_snapshot = packet_msg->default_cs;
 594                 break;
 595         }
 596         case BT_MESSAGE_TYPE_STREAM_BEGINNING:
 597         case BT_MESSAGE_TYPE_STREAM_END:
 598         {
 599                 struct bt_message_stream *stream_msg = (struct bt_message_stream *) msg;
 600                 if (stream_msg->default_cs_state != BT_MESSAGE_STREAM_CLOCK_SNAPSHOT_STATE_KNOWN) {
 601                         goto end;
 602                 }
 603
 604                 clock_snapshot = stream_msg->default_cs;
 605                 break;
 606         }
 607         case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
 608         case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
 609         {
 610                 struct bt_message_discarded_items *discarded_msg =
 611                         (struct bt_message_discarded_items *) msg;
 612
 613                 clock_snapshot = discarded_msg->default_begin_cs;
 614                 break;
 615         }
 616         }
 617
 618         if (!clock_snapshot) {
 619                 goto end;
 620         }
 621
 622         clock_snapshot_status = bt_clock_snapshot_get_ns_from_origin(
 623                 clock_snapshot, &ns_from_origin);
 624         if (clock_snapshot_status != BT_FUNC_STATUS_OK) {
 625                 /*
 626                  * bt_clock_snapshot_get_ns_from_origin can return
 627                  * OVERFLOW_ERROR.  We don't really want to report an error to
 628                  * our caller, so just clear it.
 629                  */
 630                 bt_current_thread_clear_error();
 631                 goto end;
 632         }
 633
 634         result = ns_from_origin >= iterator->last_ns_from_origin;
 635         iterator->last_ns_from_origin = ns_from_origin;
 636 end:
 637         return result;
 638 }
 639
 640 BT_ASSERT_COND_DEV_FUNC
 641 static
 642 bool clock_snapshots_are_monotonic(
 643                 struct bt_message_iterator *iterator,
 644                 bt_message_array_const msgs, uint64_t msg_count)
 645 {
 646         uint64_t i;
 647         bool result;
 648
 649         for (i = 0; i < msg_count; i++) {
 650                 if (!clock_snapshots_are_monotonic_one(iterator, msgs[i])) {
 651                         result = false;
 652                         goto end;
 653                 }
 654         }
 655
 656         result = true;
 657
 658 end:
 659         return result;
 660 }
 661
 662 /*
 663  * When a new stream begins, verify that the clock class tied to this
 664  * stream is compatible with what we've seen before.
 665  */
 666
 667 BT_ASSERT_COND_DEV_FUNC
 668 static
 669 bool clock_classes_are_compatible_one(struct bt_message_iterator *iterator,
 670                 const struct bt_message *msg)
 671 {
 672         enum bt_message_type message_type = bt_message_get_type(msg);
 673         bool result;
 674
 675         if (message_type == BT_MESSAGE_TYPE_STREAM_BEGINNING) {
 676                 const struct bt_message_stream *stream_msg = (struct bt_message_stream *) msg;
 677                 const struct bt_clock_class *clock_class = stream_msg->stream->class->default_clock_class;
 678                 bt_uuid clock_class_uuid = NULL;
 679
 680                 if (clock_class) {
 681                         clock_class_uuid = bt_clock_class_get_uuid(clock_class);
 682                 }
 683
 684                 switch (iterator->clock_expectation.type) {
 685                 case CLOCK_EXPECTATION_UNSET:
 686                         /*
 687                          * This is the first time we see a message with a clock
 688                          * snapshot: record the properties of that clock, against
 689                          * which we'll compare the clock properties of the following
 690                          * messages.
 691                          */
 692
 693                         if (!clock_class) {
 694                                 iterator->clock_expectation.type = CLOCK_EXPECTATION_NONE;
 695                         } else if (bt_clock_class_origin_is_unix_epoch(clock_class)) {
 696                                 iterator->clock_expectation.type = CLOCK_EXPECTATION_ORIGIN_UNIX;
 697                         } else if (clock_class_uuid) {
 698                                 iterator->clock_expectation.type = CLOCK_EXPECTATION_ORIGIN_OTHER_UUID;
 699                                 bt_uuid_copy(iterator->clock_expectation.uuid, clock_class_uuid);
 700                         } else {
 701                                 iterator->clock_expectation.type = CLOCK_EXPECTATION_ORIGIN_OTHER_NO_UUID;
 702                         }
 703                         break;
 704
 705                 case CLOCK_EXPECTATION_NONE:
 706                         if (clock_class) {
 707                                 BT_ASSERT_COND_DEV_MSG(
 708                                         "Expecting no clock class, got one: %![cc-]+K",
 709                                         clock_class);
 710                                 result = false;
 711                                 goto end;
 712                         }
 713
 714                         break;
 715
 716                 case CLOCK_EXPECTATION_ORIGIN_UNIX:
 717                         if (!clock_class) {
 718                                 BT_ASSERT_COND_DEV_MSG(
 719                                         "Expecting a clock class, got none.");
 720                                 result = false;
 721                                 goto end;
 722                         }
 723
 724                         if (!bt_clock_class_origin_is_unix_epoch(clock_class)) {
 725                                 BT_ASSERT_COND_DEV_MSG(
 726                                         "Expecting a clock class with Unix epoch origin: %![cc-]+K",
 727                                         clock_class);
 728                                 result = false;
 729                                 goto end;
 730                         }
 731                         break;
 732
 733                 case CLOCK_EXPECTATION_ORIGIN_OTHER_UUID:
 734                         if (!clock_class) {
 735                                 BT_ASSERT_COND_DEV_MSG(
 736                                         "Expecting a clock class, got none.");
 737                                 result = false;
 738                                 goto end;
 739                         }
 740
 741                         if (bt_clock_class_origin_is_unix_epoch(clock_class)) {
 742                                 BT_ASSERT_COND_DEV_MSG(
 743                                         "Expecting a clock class without Unix epoch origin: %![cc-]+K",
 744                                         clock_class);
 745                                 result = false;
 746                                 goto end;
 747                         }
 748
 749                         if (!clock_class_uuid) {
 750                                 BT_ASSERT_COND_DEV_MSG(
 751                                         "Expecting a clock class with UUID: %![cc-]+K",
 752                                         clock_class);
 753                                 result = false;
 754                                 goto end;
 755                         }
 756
 757                         if (bt_uuid_compare(iterator->clock_expectation.uuid, clock_class_uuid)) {
 758                                 BT_ASSERT_COND_DEV_MSG(
 759                                         "Expecting a clock class with UUID, got one "
 760                                         "with a different UUID: %![cc-]+K, expected-uuid=%!u",
 761                                         clock_class, iterator->clock_expectation.uuid);
 762                                 result = false;
 763                                 goto end;
 764                         }
 765                         break;
 766
 767                 case CLOCK_EXPECTATION_ORIGIN_OTHER_NO_UUID:
 768                         if (!clock_class) {
 769                                 BT_ASSERT_COND_DEV_MSG(
 770                                         "Expecting a clock class, got none.");
 771                                 result = false;
 772                                 goto end;
 773                         }
 774
 775                         if (bt_clock_class_origin_is_unix_epoch(clock_class)) {
 776                                 BT_ASSERT_COND_DEV_MSG(
 777                                         "Expecting a clock class without Unix epoch origin: %![cc-]+K",
 778                                         clock_class);
 779                                 result = false;
 780                                 goto end;
 781                         }
 782
 783                         if (clock_class_uuid) {
 784                                 BT_ASSERT_COND_DEV_MSG(
 785                                         "Expecting a clock class without UUID: %![cc-]+K",
 786                                         clock_class);
 787                                 result = false;
 788                                 goto end;
 789                         }
 790                         break;
 791                 }
 792         }
 793
 794         result = true;
 795
 796 end:
 797         return result;
 798 }
 799
 800 BT_ASSERT_COND_DEV_FUNC
 801 static
 802 bool clock_classes_are_compatible(
 803                 struct bt_message_iterator *iterator,
 804                 bt_message_array_const msgs, uint64_t msg_count)
 805 {
 806         uint64_t i;
 807         bool result;
 808
 809         for (i = 0; i < msg_count; i++) {
 810                 if (!clock_classes_are_compatible_one(iterator, msgs[i])) {
 811                         result = false;
 812                         goto end;
 813                 }
 814         }
 815
 816         result = true;
 817
 818 end:
 819         return result;
 820 }
 821
 822 #ifdef BT_DEV_MODE
 823 static
 824 const bt_stream *get_stream_from_msg(const struct bt_message *msg)
 825 {
 826         struct bt_stream *stream;
 827
 828         switch (msg->type) {
 829         case BT_MESSAGE_TYPE_STREAM_BEGINNING:
 830         case BT_MESSAGE_TYPE_STREAM_END:
 831         {
 832                 struct bt_message_stream *msg_stream =
 833                         (struct bt_message_stream *) msg;
 834                 stream = msg_stream->stream;
 835                 break;
 836         }
 837         case BT_MESSAGE_TYPE_EVENT:
 838         {
 839                 struct bt_message_event *msg_event =
 840                         (struct bt_message_event *) msg;
 841                 stream = msg_event->event->stream;
 842                 break;
 843         }
 844         case BT_MESSAGE_TYPE_PACKET_BEGINNING:
 845         case BT_MESSAGE_TYPE_PACKET_END:
 846         {
 847                 struct bt_message_packet *msg_packet =
 848                         (struct bt_message_packet *) msg;
 849                 stream = msg_packet->packet->stream;
 850                 break;
 851         }
 852         case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
 853         case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
 854         {
 855                 struct bt_message_discarded_items *msg_discarded =
 856                         (struct bt_message_discarded_items *) msg;
 857                 stream = msg_discarded->stream;
 858                 break;
 859         }
 860         case BT_MESSAGE_TYPE_MESSAGE_ITERATOR_INACTIVITY:
 861                 stream = NULL;
 862                 break;
 863         default:
 864                 bt_common_abort();
 865         }
 866
 867         return stream;
 868 }
 869
 870 static
 871 struct per_stream_state *get_per_stream_state(
 872                 struct bt_message_iterator *iterator,
 873                 const struct bt_stream *stream)
 874 {
 875         struct per_stream_state *state = g_hash_table_lookup(
 876                 iterator->per_stream_state, stream);
 877
 878         if (!state) {
 879                 state = g_new0(struct per_stream_state, 1);
 880                 g_hash_table_insert(iterator->per_stream_state,
 881                         (gpointer) stream, state);
 882         }
 883
 884         return state;
 885 }
 886 #endif
 887
 888 #define NEXT_METHOD_NAME        "bt_message_iterator_class_next_method"
 889
 890 #ifdef BT_DEV_MODE
 891 static
 892 void assert_post_dev_expected_packet(struct bt_message_iterator *iterator,
 893                 const struct bt_message *msg)
 894 {
 895         const bt_stream *stream = get_stream_from_msg(msg);
 896         struct per_stream_state *state;
 897         const bt_packet *actual_packet = NULL;
 898         const bt_packet *expected_packet = NULL;
 899
 900         if (!stream) {
 901                 goto end;
 902         }
 903
 904         state = get_per_stream_state(iterator, stream);
 905
 906         switch (msg->type) {
 907         case BT_MESSAGE_TYPE_EVENT:
 908         {
 909                 const struct bt_message_event *msg_event =
 910                         (const struct bt_message_event *) msg;
 911
 912                 actual_packet = msg_event->event->packet;
 913                 expected_packet = state->cur_packet;
 914                 break;
 915         }
 916         case BT_MESSAGE_TYPE_PACKET_BEGINNING:
 917         {
 918                 const struct bt_message_packet *msg_packet =
 919                         (const struct bt_message_packet *) msg;
 920
 921                 BT_ASSERT(!state->cur_packet);
 922                 state->cur_packet = msg_packet->packet;
 923                 break;
 924         }
 925         case BT_MESSAGE_TYPE_PACKET_END:
 926         {
 927                 const struct bt_message_packet *msg_packet =
 928                         (const struct bt_message_packet *) msg;
 929
 930                 actual_packet = msg_packet->packet;
 931                 expected_packet = state->cur_packet;
 932                 BT_ASSERT(state->cur_packet);
 933                 state->cur_packet = NULL;
 934                 break;
 935         }
 936         default:
 937                 break;
 938         }
 939
 940         BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
 941                 "message-packet-is-expected",
 942                 actual_packet == expected_packet,
 943                 "Message's packet is not expected: %![stream-]s, %![iterator-]i, "
 944                 "%![message-]n, %![received-packet-]a, %![expected-packet-]a",
 945                 stream, iterator, msg, actual_packet, expected_packet);
 946
 947 end:
 948         return;
 949 }
 950
 951 static
 952 void assert_post_dev_next(
 953                 struct bt_message_iterator *iterator,
 954                 bt_message_iterator_class_next_method_status status,
 955                 bt_message_array_const msgs, uint64_t msg_count)
 956 {
 957         if (status == BT_MESSAGE_ITERATOR_CLASS_NEXT_METHOD_STATUS_OK) {
 958                 uint64_t i;
 959
 960                 for (i = 0; i < msg_count; i++) {
 961                         assert_post_dev_expected_packet(iterator, msgs[i]);
 962                 }
 963         }
 964 }
 965 #endif
 966
 967 /*
 968  * Call the `next` method of the iterator.  Do some validation on the returned
 969  * messages.
 970  */
 971
 972 static
 973 enum bt_message_iterator_class_next_method_status
 974 call_iterator_next_method(
 975                 struct bt_message_iterator *iterator,
 976                 bt_message_array_const msgs, uint64_t capacity, uint64_t *user_count)
 977 {
 978         enum bt_message_iterator_class_next_method_status status;
 979
 980         BT_ASSERT_DBG(iterator->methods.next);
 981         BT_LOGD_STR("Calling user's \"next\" method.");
 982         status = iterator->methods.next(iterator, msgs, capacity, user_count);
 983         BT_LOGD("User method returned: status=%s, msg-count=%" PRIu64,
 984                 bt_common_func_status_string(status), *user_count);
 985
 986         if (status == BT_FUNC_STATUS_OK) {
 987                 BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
 988                         "message-clock-classes-are-compatible",
 989                         clock_classes_are_compatible(iterator, msgs,
 990                                 *user_count),
 991                         "Clocks are not compatible");
 992                 BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
 993                         "message-clock-snapshots-are-monotonic",
 994                         clock_snapshots_are_monotonic(iterator, msgs,
 995                                 *user_count),
 996                         "Clock snapshots are not monotonic");
 997         }
 998
 999 #ifdef BT_DEV_MODE
1000         assert_post_dev_next(iterator, status, msgs, *user_count);
1001 #endif
1002
1003         BT_ASSERT_POST_DEV_NO_ERROR_IF_NO_ERROR_STATUS(NEXT_METHOD_NAME,
1004                 status);
1005
1006         return status;
1007 }
1008
1009 BT_EXPORT
1010 enum bt_message_iterator_next_status
1011 bt_message_iterator_next(
1012                 struct bt_message_iterator *iterator,
1013                 bt_message_array_const *msgs, uint64_t *user_count)
1014 {
1015         enum bt_message_iterator_next_status status = BT_FUNC_STATUS_OK;
1016
1017         BT_ASSERT_PRE_DEV_NO_ERROR();
1018         BT_ASSERT_PRE_DEV_MSG_ITER_NON_NULL(iterator);
1019         BT_ASSERT_PRE_DEV_NON_NULL("message-array-output", msgs,
1020                 "Message array (output)");
1021         BT_ASSERT_PRE_DEV_NON_NULL("user-count-output", user_count,
1022                 "Message count (output)");
1023         BT_ASSERT_PRE_DEV("message-iterator-is-active",
1024                 iterator->state == BT_MESSAGE_ITERATOR_STATE_ACTIVE,
1025                 "Message iterator's \"next\" called, but "
1026                 "message iterator is in the wrong state: %!+i", iterator);
1027         BT_ASSERT_DBG(iterator->upstream_component);
1028         BT_ASSERT_DBG(iterator->upstream_component->class);
1029         BT_ASSERT_PRE_DEV("graph-is-configured",
1030                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
1031                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
1032                 "Graph is not configured: %!+g",
1033                 bt_component_borrow_graph(iterator->upstream_component));
1034         BT_LIB_LOGD("Getting next self component input port "
1035                 "message iterator's messages: %!+i, batch-size=%u",
1036                 iterator, MSG_BATCH_SIZE);
1037
1038         /*
1039          * Call the user's "next" method to get the next messages
1040          * and status.
1041          */
1042         *user_count = 0;
1043         status = (int) call_iterator_next_method(iterator,
1044                 (void *) iterator->msgs->pdata, MSG_BATCH_SIZE,
1045                 user_count);
1046         BT_LOGD("User method returned: status=%s, msg-count=%" PRIu64,
1047                 bt_common_func_status_string(status), *user_count);
1048         if (status < 0) {
1049                 BT_LIB_LOGW_APPEND_CAUSE(
1050                         "Component input port message iterator's \"next\" method failed: "
1051                         "%![iter-]+i, status=%s",
1052                         iterator, bt_common_func_status_string(status));
1053                 goto end;
1054         }
1055
1056         /*
1057          * There is no way that this iterator could have been finalized
1058          * during its "next" method, as the only way to do this is to
1059          * put the last iterator's reference, and this can only be done
1060          * by its downstream owner.
1061          *
1062          * For the same reason, there is no way that this iterator could
1063          * have seeked (cannot seek a self message iterator).
1064          */
1065         BT_ASSERT_DBG(iterator->state ==
1066                 BT_MESSAGE_ITERATOR_STATE_ACTIVE);
1067
1068         switch (status) {
1069         case BT_FUNC_STATUS_OK:
1070                 BT_ASSERT_POST_DEV(NEXT_METHOD_NAME, "count-lteq-capacity",
1071                         *user_count <= MSG_BATCH_SIZE,
1072                         "Invalid returned message count: greater than "
1073                         "batch size: count=%" PRIu64 ", batch-size=%u",
1074                         *user_count, MSG_BATCH_SIZE);
1075                 *msgs = (void *) iterator->msgs->pdata;
1076                 break;
1077         case BT_FUNC_STATUS_AGAIN:
1078                 goto end;
1079         case BT_FUNC_STATUS_END:
1080                 set_msg_iterator_state(iterator,
1081                         BT_MESSAGE_ITERATOR_STATE_ENDED);
1082                 goto end;
1083         default:
1084                 /* Unknown non-error status */
1085                 bt_common_abort();
1086         }
1087
1088 end:
1089         return status;
1090 }
1091
1092 BT_EXPORT
1093 struct bt_component *
1094 bt_message_iterator_borrow_component(
1095                 struct bt_message_iterator *iterator)
1096 {
1097         BT_ASSERT_PRE_DEV_MSG_ITER_NON_NULL(iterator);
1098         return iterator->upstream_component;
1099 }
1100
1101 BT_EXPORT
1102 struct bt_self_component *bt_self_message_iterator_borrow_component(
1103                 struct bt_self_message_iterator *self_iterator)
1104 {
1105         struct bt_message_iterator *iterator =
1106                 (void *) self_iterator;
1107
1108         BT_ASSERT_PRE_DEV_MSG_ITER_NON_NULL(iterator);
1109         return (void *) iterator->upstream_component;
1110 }
1111
1112 BT_EXPORT
1113 struct bt_self_component_port_output *bt_self_message_iterator_borrow_port(
1114                 struct bt_self_message_iterator *self_iterator)
1115 {
1116         struct bt_message_iterator *iterator =
1117                 (void *) self_iterator;
1118
1119         BT_ASSERT_PRE_DEV_MSG_ITER_NON_NULL(iterator);
1120         return (void *) iterator->upstream_port;
1121 }
1122
1123 #define CAN_SEEK_NS_FROM_ORIGIN_METHOD_NAME                             \
1124         "bt_message_iterator_class_can_seek_ns_from_origin_method"
1125
1126 BT_EXPORT
1127 enum bt_message_iterator_can_seek_ns_from_origin_status
1128 bt_message_iterator_can_seek_ns_from_origin(
1129                 struct bt_message_iterator *iterator,
1130                 int64_t ns_from_origin, bt_bool *can_seek)
1131 {
1132         enum bt_message_iterator_can_seek_ns_from_origin_status status;
1133
1134         BT_ASSERT_PRE_NO_ERROR();
1135         BT_ASSERT_PRE_MSG_ITER_NON_NULL(iterator);
1136         BT_ASSERT_PRE_RES_OUT_NON_NULL(can_seek);
1137         BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(iterator);
1138         BT_ASSERT_PRE("graph-is-configured",
1139                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
1140                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
1141                 "Graph is not configured: %!+g",
1142                 bt_component_borrow_graph(iterator->upstream_component));
1143
1144         if (iterator->methods.can_seek_ns_from_origin) {
1145                 /*
1146                  * Initialize to an invalid value, so we can post-assert that
1147                  * the method returned a valid value.
1148                  */
1149                 *can_seek = -1;
1150
1151                 BT_LIB_LOGD("Calling user's \"can seek nanoseconds from origin\" method: %!+i",
1152                         iterator);
1153
1154                 status = (int) iterator->methods.can_seek_ns_from_origin(iterator,
1155                         ns_from_origin, can_seek);
1156
1157                 BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(
1158                         CAN_SEEK_NS_FROM_ORIGIN_METHOD_NAME, status);
1159
1160                 if (status != BT_FUNC_STATUS_OK) {
1161                         BT_LIB_LOGW_APPEND_CAUSE(
1162                                 "Component input port message iterator's \"can seek nanoseconds from origin\" method failed: "
1163                                 "%![iter-]+i, status=%s",
1164                                 iterator, bt_common_func_status_string(status));
1165                         goto end;
1166                 }
1167
1168                 BT_ASSERT_POST(CAN_SEEK_NS_FROM_ORIGIN_METHOD_NAME,
1169                         "valid-return-value",
1170                         *can_seek == BT_TRUE || *can_seek == BT_FALSE,
1171                         "Unexpected boolean value returned from user's \"can seek ns from origin\" method: val=%d, %![iter-]+i",
1172                         *can_seek, iterator);
1173
1174                 BT_LIB_LOGD(
1175                         "User's \"can seek nanoseconds from origin\" returned successfully: "
1176                         "%![iter-]+i, can-seek=%d",
1177                         iterator, *can_seek);
1178
1179                 if (*can_seek) {
1180                         goto end;
1181                 }
1182         }
1183
1184         /*
1185          * Automatic seeking fall back: if we can seek to the beginning and the
1186          * iterator supports forward seeking then we can automatically seek to
1187          * any timestamp.
1188          */
1189         status = (int) bt_message_iterator_can_seek_beginning(
1190                 iterator, can_seek);
1191         if (status != BT_FUNC_STATUS_OK) {
1192                 goto end;
1193         }
1194
1195         *can_seek = *can_seek && iterator->config.can_seek_forward;
1196
1197 end:
1198         return status;
1199 }
1200
1201 #define CAN_SEEK_BEGINNING_METHOD_NAME                                  \
1202         "bt_message_iterator_class_can_seek_beginning"
1203
1204 BT_EXPORT
1205 enum bt_message_iterator_can_seek_beginning_status
1206 bt_message_iterator_can_seek_beginning(
1207                 struct bt_message_iterator *iterator,
1208                 bt_bool *can_seek)
1209 {
1210         enum bt_message_iterator_can_seek_beginning_status status;
1211
1212         BT_ASSERT_PRE_NO_ERROR();
1213         BT_ASSERT_PRE_MSG_ITER_NON_NULL(iterator);
1214         BT_ASSERT_PRE_RES_OUT_NON_NULL(can_seek);
1215         BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(iterator);
1216         BT_ASSERT_PRE("graph-is-configured",
1217                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
1218                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
1219                 "Graph is not configured: %!+g",
1220                 bt_component_borrow_graph(iterator->upstream_component));
1221
1222         if (iterator->methods.can_seek_beginning) {
1223                 /*
1224                  * Initialize to an invalid value, so we can post-assert that
1225                  * the method returned a valid value.
1226                  */
1227                 *can_seek = -1;
1228
1229                 status = (int) iterator->methods.can_seek_beginning(iterator, can_seek);
1230
1231                 BT_ASSERT_POST(CAN_SEEK_BEGINNING_METHOD_NAME,
1232                         "valid-return-value",
1233                         status != BT_FUNC_STATUS_OK ||
1234                                 *can_seek == BT_TRUE ||
1235                                 *can_seek == BT_FALSE,
1236                         "Unexpected boolean value returned from user's \"can seek beginning\" method: val=%d, %![iter-]+i",
1237                         *can_seek, iterator);
1238                 BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(
1239                         CAN_SEEK_BEGINNING_METHOD_NAME, status);
1240         } else {
1241                 *can_seek = BT_FALSE;
1242                 status = BT_FUNC_STATUS_OK;
1243         }
1244
1245         return status;
1246 }
1247
1248 static inline
1249 void set_iterator_state_after_seeking(
1250                 struct bt_message_iterator *iterator,
1251                 int status)
1252 {
1253         enum bt_message_iterator_state new_state = 0;
1254
1255         /* Set iterator's state depending on seeking status */
1256         switch (status) {
1257         case BT_FUNC_STATUS_OK:
1258                 new_state = BT_MESSAGE_ITERATOR_STATE_ACTIVE;
1259                 break;
1260         case BT_FUNC_STATUS_AGAIN:
1261                 new_state = BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_AGAIN;
1262                 break;
1263         case BT_FUNC_STATUS_ERROR:
1264         case BT_FUNC_STATUS_MEMORY_ERROR:
1265                 new_state = BT_MESSAGE_ITERATOR_STATE_LAST_SEEKING_RETURNED_ERROR;
1266                 break;
1267         case BT_FUNC_STATUS_END:
1268                 new_state = BT_MESSAGE_ITERATOR_STATE_ENDED;
1269                 break;
1270         default:
1271                 bt_common_abort();
1272         }
1273
1274         set_msg_iterator_state(iterator, new_state);
1275 }
1276
1277 static
1278 void reset_iterator_expectations(
1279                 struct bt_message_iterator *iterator)
1280 {
1281         iterator->last_ns_from_origin = INT64_MIN;
1282         iterator->clock_expectation.type = CLOCK_EXPECTATION_UNSET;
1283 }
1284
1285 static
1286 bool message_iterator_can_seek_beginning(
1287                 struct bt_message_iterator *iterator)
1288 {
1289         enum bt_message_iterator_can_seek_beginning_status status;
1290         bt_bool can_seek;
1291
1292         status = bt_message_iterator_can_seek_beginning(
1293                 iterator, &can_seek);
1294         if (status != BT_FUNC_STATUS_OK) {
1295                 can_seek = BT_FALSE;
1296         }
1297
1298         return can_seek;
1299 }
1300
1301 #define SEEK_BEGINNING_METHOD_NAME                                      \
1302         "bt_message_iterator_class_seek_beginning_method"
1303
1304 BT_EXPORT
1305 enum bt_message_iterator_seek_beginning_status
1306 bt_message_iterator_seek_beginning(struct bt_message_iterator *iterator)
1307 {
1308         int status;
1309
1310         BT_ASSERT_PRE_NO_ERROR();
1311         BT_ASSERT_PRE_MSG_ITER_NON_NULL(iterator);
1312         BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(iterator);
1313         BT_ASSERT_PRE("graph-is-configured",
1314                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
1315                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
1316                 "Graph is not configured: %!+g",
1317                 bt_component_borrow_graph(iterator->upstream_component));
1318         BT_ASSERT_PRE("can-seek-beginning",
1319                 message_iterator_can_seek_beginning(iterator),
1320                 "Message iterator cannot seek beginning: %!+i", iterator);
1321
1322         /*
1323          * We are seeking, reset our expectations about how the following
1324          * messages should look like.
1325          */
1326         reset_iterator_expectations(iterator);
1327
1328         BT_LIB_LOGD("Calling user's \"seek beginning\" method: %!+i", iterator);
1329         set_msg_iterator_state(iterator,
1330                 BT_MESSAGE_ITERATOR_STATE_SEEKING);
1331         status = iterator->methods.seek_beginning(iterator);
1332         BT_LOGD("User method returned: status=%s",
1333                 bt_common_func_status_string(status));
1334         BT_ASSERT_POST(SEEK_BEGINNING_METHOD_NAME, "valid-status",
1335                 status == BT_FUNC_STATUS_OK ||
1336                 status == BT_FUNC_STATUS_ERROR ||
1337                 status == BT_FUNC_STATUS_MEMORY_ERROR ||
1338                 status == BT_FUNC_STATUS_AGAIN,
1339                 "Unexpected status: %![iter-]+i, status=%s",
1340                 iterator, bt_common_func_status_string(status));
1341         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(SEEK_BEGINNING_METHOD_NAME,
1342                 status);
1343         if (status < 0) {
1344                 BT_LIB_LOGW_APPEND_CAUSE(
1345                         "Component input port message iterator's \"seek beginning\" method failed: "
1346                         "%![iter-]+i, status=%s",
1347                         iterator, bt_common_func_status_string(status));
1348         }
1349
1350         clear_per_stream_state(iterator);
1351
1352         set_iterator_state_after_seeking(iterator, status);
1353         return status;
1354 }
1355
1356 BT_EXPORT
1357 bt_bool
1358 bt_message_iterator_can_seek_forward(
1359                 bt_message_iterator *iterator)
1360 {
1361         BT_ASSERT_PRE_MSG_ITER_NON_NULL(iterator);
1362
1363         return iterator->config.can_seek_forward;
1364 }
1365
1366 /*
1367  * Structure used to record the state of a given stream during the fast-forward
1368  * phase of an auto-seek.
1369  */
1370 struct auto_seek_stream_state {
1371         /*
1372          * Value representing which step of this timeline we are at.
1373          *
1374          *      time --->
1375          *   [SB]  1  [PB]  2  [PE]  1  [SE]
1376          *
1377          * At each point in the timeline, the messages we need to replicate are:
1378          *
1379          *   1: Stream beginning
1380          *   2: Stream beginning, packet beginning
1381          *
1382          * Before "Stream beginning" and after "Stream end", we don't need to
1383          * replicate anything as the stream doesn't exist.
1384          */
1385         enum {
1386                 AUTO_SEEK_STREAM_STATE_STREAM_BEGAN,
1387                 AUTO_SEEK_STREAM_STATE_PACKET_BEGAN,
1388         } state;
1389
1390         /*
1391          * If `state` is AUTO_SEEK_STREAM_STATE_PACKET_BEGAN, the packet we are
1392          * in.  This is a weak reference, since the packet will always be
1393          * alive by the time we use it.
1394          */
1395         struct bt_packet *packet;
1396
1397         /* Have we see a message with a clock snapshot yet? */
1398         bool seen_clock_snapshot;
1399 };
1400
1401 static
1402 struct auto_seek_stream_state *create_auto_seek_stream_state(void)
1403 {
1404         return g_new0(struct auto_seek_stream_state, 1);
1405 }
1406
1407 static
1408 void destroy_auto_seek_stream_state(void *ptr)
1409 {
1410         g_free(ptr);
1411 }
1412
1413 static
1414 GHashTable *create_auto_seek_stream_states(void)
1415 {
1416         return g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL,
1417                 destroy_auto_seek_stream_state);
1418 }
1419
1420 static
1421 void destroy_auto_seek_stream_states(GHashTable *stream_states)
1422 {
1423         g_hash_table_destroy(stream_states);
1424 }
1425
1426 /*
1427  * Handle one message while we are in the fast-forward phase of an auto-seek.
1428  *
1429  * Sets `*got_first` to true if the message's timestamp is greater or equal to
1430  * `ns_from_origin`.  In other words, if this is the first message after our
1431  * seek point.
1432  *
1433  * `stream_states` is an hash table of `bt_stream *` (weak reference) to
1434  * `struct auto_seek_stream_state` used to keep the state of each stream
1435  * during the fast-forward.
1436  */
1437
1438 static inline
1439 int auto_seek_handle_message(
1440                 struct bt_message_iterator *iterator,
1441                 int64_t ns_from_origin, const struct bt_message *msg,
1442                 bool *got_first, GHashTable *stream_states)
1443 {
1444         int status = BT_FUNC_STATUS_OK;
1445         int64_t msg_ns_from_origin;
1446         const struct bt_clock_snapshot *clk_snapshot = NULL;
1447         int ret;
1448
1449         BT_ASSERT_DBG(msg);
1450         BT_ASSERT_DBG(got_first);
1451
1452         switch (msg->type) {
1453         case BT_MESSAGE_TYPE_EVENT:
1454         {
1455                 const struct bt_message_event *event_msg =
1456                         (const void *) msg;
1457
1458                 clk_snapshot = event_msg->default_cs;
1459                 BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
1460                         "event-message-has-default-clock-snapshot",
1461                         clk_snapshot,
1462                         "Event message has no default clock snapshot: %!+n",
1463                         event_msg);
1464                 break;
1465         }
1466         case BT_MESSAGE_TYPE_MESSAGE_ITERATOR_INACTIVITY:
1467         {
1468                 const struct bt_message_message_iterator_inactivity *inactivity_msg =
1469                         (const void *) msg;
1470
1471                 clk_snapshot = inactivity_msg->cs;
1472                 BT_ASSERT_DBG(clk_snapshot);
1473                 break;
1474         }
1475         case BT_MESSAGE_TYPE_PACKET_BEGINNING:
1476         case BT_MESSAGE_TYPE_PACKET_END:
1477         {
1478                 const struct bt_message_packet *packet_msg =
1479                         (const void *) msg;
1480
1481                 if (msg->type == BT_MESSAGE_TYPE_PACKET_BEGINNING
1482                                 && !packet_msg->packet->stream->class->packets_have_beginning_default_clock_snapshot) {
1483                         goto skip_msg;
1484                 }
1485
1486                 if (msg->type == BT_MESSAGE_TYPE_PACKET_END
1487                                 && !packet_msg->packet->stream->class->packets_have_end_default_clock_snapshot) {
1488                         goto skip_msg;
1489                 }
1490
1491                 clk_snapshot = packet_msg->default_cs;
1492                 BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
1493                         "packet-message-has-default-clock-snapshot",
1494                         clk_snapshot,
1495                         "Packet message has no default clock snapshot: %!+n",
1496                         packet_msg);
1497                 break;
1498         }
1499         case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
1500         case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
1501         {
1502                 struct bt_message_discarded_items *msg_disc_items =
1503                         (void *) msg;
1504
1505                 if (msg->type == BT_MESSAGE_TYPE_DISCARDED_EVENTS &&
1506                                 !msg_disc_items->stream->class->discarded_events_have_default_clock_snapshots) {
1507                         goto skip_msg;
1508                 }
1509
1510                 if (msg->type == BT_MESSAGE_TYPE_DISCARDED_PACKETS &&
1511                                 !msg_disc_items->stream->class->discarded_packets_have_default_clock_snapshots) {
1512                         goto skip_msg;
1513                 }
1514
1515                 BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
1516                         "discarded-events-packets-message-has-default-clock-snapshot",
1517                         msg_disc_items->default_begin_cs &&
1518                                 msg_disc_items->default_end_cs,
1519                         "Discarded events/packets message has no default clock snapshots: %!+n",
1520                         msg_disc_items);
1521                 ret = bt_clock_snapshot_get_ns_from_origin(
1522                         msg_disc_items->default_begin_cs,
1523                         &msg_ns_from_origin);
1524                 if (ret) {
1525                         status = BT_FUNC_STATUS_ERROR;
1526                         goto end;
1527                 }
1528
1529                 if (msg_ns_from_origin >= ns_from_origin) {
1530                         *got_first = true;
1531                         goto push_msg;
1532                 }
1533
1534                 ret = bt_clock_snapshot_get_ns_from_origin(
1535                         msg_disc_items->default_end_cs,
1536                         &msg_ns_from_origin);
1537                 if (ret) {
1538                         status = BT_FUNC_STATUS_ERROR;
1539                         goto end;
1540                 }
1541
1542                 if (msg_ns_from_origin >= ns_from_origin) {
1543                         /*
1544                          * The discarded items message's beginning time
1545                          * is before the requested seeking time, but its
1546                          * end time is after. Modify the message so as
1547                          * to set its beginning time to the requested
1548                          * seeking time, and make its item count unknown
1549                          * as we don't know if items were really
1550                          * discarded within the new time range.
1551                          */
1552                         uint64_t new_begin_raw_value = 0;
1553
1554                         ret = bt_clock_class_clock_value_from_ns_from_origin(
1555                                 msg_disc_items->default_end_cs->clock_class,
1556                                 ns_from_origin, &new_begin_raw_value);
1557                         if (ret) {
1558                                 status = BT_FUNC_STATUS_ERROR;
1559                                 goto end;
1560                         }
1561
1562                         bt_clock_snapshot_set_raw_value(
1563                                 msg_disc_items->default_begin_cs,
1564                                 new_begin_raw_value);
1565                         msg_disc_items->count.base.avail =
1566                                 BT_PROPERTY_AVAILABILITY_NOT_AVAILABLE;
1567
1568                         /*
1569                          * It is safe to push it because its beginning
1570                          * time is exactly the requested seeking time.
1571                          */
1572                         goto push_msg;
1573                 } else {
1574                         goto skip_msg;
1575                 }
1576         }
1577         case BT_MESSAGE_TYPE_STREAM_BEGINNING:
1578         case BT_MESSAGE_TYPE_STREAM_END:
1579         {
1580                 struct bt_message_stream *stream_msg =
1581                         (struct bt_message_stream *) msg;
1582
1583                 if (stream_msg->default_cs_state != BT_MESSAGE_STREAM_CLOCK_SNAPSHOT_STATE_KNOWN) {
1584                         /* Ignore */
1585                         goto skip_msg;
1586                 }
1587
1588                 clk_snapshot = stream_msg->default_cs;
1589                 break;
1590         }
1591         default:
1592                 bt_common_abort();
1593         }
1594
1595         BT_ASSERT_DBG(clk_snapshot);
1596         ret = bt_clock_snapshot_get_ns_from_origin(clk_snapshot,
1597                 &msg_ns_from_origin);
1598         if (ret) {
1599                 status = BT_FUNC_STATUS_ERROR;
1600                 goto end;
1601         }
1602
1603         if (msg_ns_from_origin >= ns_from_origin) {
1604                 *got_first = true;
1605                 goto push_msg;
1606         }
1607
1608 skip_msg:
1609         /* This message won't be sent downstream. */
1610         switch (msg->type) {
1611         case BT_MESSAGE_TYPE_STREAM_BEGINNING:
1612         {
1613                 const struct bt_message_stream *stream_msg = (const void *) msg;
1614                 struct auto_seek_stream_state *stream_state;
1615
1616                 /* Update stream's state: stream began. */
1617                 stream_state = create_auto_seek_stream_state();
1618                 if (!stream_state) {
1619                         status = BT_FUNC_STATUS_MEMORY_ERROR;
1620                         goto end;
1621                 }
1622
1623                 stream_state->state = AUTO_SEEK_STREAM_STATE_STREAM_BEGAN;
1624
1625                 if (stream_msg->default_cs_state == BT_MESSAGE_STREAM_CLOCK_SNAPSHOT_STATE_KNOWN) {
1626                         stream_state->seen_clock_snapshot = true;
1627                 }
1628
1629                 BT_ASSERT_DBG(!bt_g_hash_table_contains(stream_states, stream_msg->stream));
1630                 g_hash_table_insert(stream_states, stream_msg->stream, stream_state);
1631                 break;
1632         }
1633         case BT_MESSAGE_TYPE_PACKET_BEGINNING:
1634         {
1635                 const struct bt_message_packet *packet_msg =
1636                         (const void *) msg;
1637                 struct auto_seek_stream_state *stream_state;
1638
1639                 /* Update stream's state: packet began. */
1640                 stream_state = g_hash_table_lookup(stream_states, packet_msg->packet->stream);
1641                 BT_ASSERT_DBG(stream_state);
1642                 BT_ASSERT_DBG(stream_state->state == AUTO_SEEK_STREAM_STATE_STREAM_BEGAN);
1643                 stream_state->state = AUTO_SEEK_STREAM_STATE_PACKET_BEGAN;
1644                 BT_ASSERT_DBG(!stream_state->packet);
1645                 stream_state->packet = packet_msg->packet;
1646
1647                 if (packet_msg->packet->stream->class->packets_have_beginning_default_clock_snapshot) {
1648                         stream_state->seen_clock_snapshot = true;
1649                 }
1650
1651                 break;
1652         }
1653         case BT_MESSAGE_TYPE_EVENT:
1654         {
1655                 const struct bt_message_event *event_msg = (const void *) msg;
1656                 struct auto_seek_stream_state *stream_state;
1657
1658                 stream_state = g_hash_table_lookup(stream_states,
1659                         event_msg->event->stream);
1660                 BT_ASSERT_DBG(stream_state);
1661
1662                 // HELPME: are we sure that event messages have clock snapshots at this point?
1663                 stream_state->seen_clock_snapshot = true;
1664
1665                 break;
1666         }
1667         case BT_MESSAGE_TYPE_PACKET_END:
1668         {
1669                 const struct bt_message_packet *packet_msg =
1670                         (const void *) msg;
1671                 struct auto_seek_stream_state *stream_state;
1672
1673                 /* Update stream's state: packet ended. */
1674                 stream_state = g_hash_table_lookup(stream_states, packet_msg->packet->stream);
1675                 BT_ASSERT_DBG(stream_state);
1676                 BT_ASSERT_DBG(stream_state->state == AUTO_SEEK_STREAM_STATE_PACKET_BEGAN);
1677                 stream_state->state = AUTO_SEEK_STREAM_STATE_STREAM_BEGAN;
1678                 BT_ASSERT_DBG(stream_state->packet);
1679                 stream_state->packet = NULL;
1680
1681                 if (packet_msg->packet->stream->class->packets_have_end_default_clock_snapshot) {
1682                         stream_state->seen_clock_snapshot = true;
1683                 }
1684
1685                 break;
1686         }
1687         case BT_MESSAGE_TYPE_STREAM_END:
1688         {
1689                 const struct bt_message_stream *stream_msg = (const void *) msg;
1690                 struct auto_seek_stream_state *stream_state;
1691
1692                 stream_state = g_hash_table_lookup(stream_states, stream_msg->stream);
1693                 BT_ASSERT_DBG(stream_state);
1694                 BT_ASSERT_DBG(stream_state->state == AUTO_SEEK_STREAM_STATE_STREAM_BEGAN);
1695                 BT_ASSERT_DBG(!stream_state->packet);
1696
1697                 /* Update stream's state: this stream doesn't exist anymore. */
1698                 g_hash_table_remove(stream_states, stream_msg->stream);
1699                 break;
1700         }
1701         case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
1702         case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
1703         {
1704                 const struct bt_message_discarded_items *discarded_msg =
1705                         (const void *) msg;
1706                 struct auto_seek_stream_state *stream_state;
1707
1708                 stream_state = g_hash_table_lookup(stream_states, discarded_msg->stream);
1709                 BT_ASSERT_DBG(stream_state);
1710
1711                 if ((msg->type == BT_MESSAGE_TYPE_DISCARDED_EVENTS && discarded_msg->stream->class->discarded_events_have_default_clock_snapshots) ||
1712                         (msg->type == BT_MESSAGE_TYPE_DISCARDED_PACKETS && discarded_msg->stream->class->discarded_packets_have_default_clock_snapshots)) {
1713                         stream_state->seen_clock_snapshot = true;
1714                 }
1715
1716                 break;
1717         }
1718         default:
1719                 break;
1720         }
1721
1722         bt_object_put_ref_no_null_check(msg);
1723         msg = NULL;
1724         goto end;
1725
1726 push_msg:
1727         g_queue_push_tail(iterator->auto_seek.msgs, (void *) msg);
1728         msg = NULL;
1729
1730 end:
1731         BT_ASSERT_DBG(!msg || status != BT_FUNC_STATUS_OK);
1732         return status;
1733 }
1734
1735 static
1736 int find_message_ge_ns_from_origin(
1737                 struct bt_message_iterator *iterator,
1738                 int64_t ns_from_origin, GHashTable *stream_states)
1739 {
1740         int status = BT_FUNC_STATUS_OK;
1741         enum bt_message_iterator_state init_state =
1742                 iterator->state;
1743         const struct bt_message *messages[MSG_BATCH_SIZE];
1744         uint64_t user_count = 0;
1745         uint64_t i;
1746         bool got_first = false;
1747
1748         BT_ASSERT_DBG(iterator);
1749         memset(&messages[0], 0, sizeof(messages[0]) * MSG_BATCH_SIZE);
1750
1751         /*
1752          * Make this iterator temporarily active (not seeking) to call
1753          * the "next" method.
1754          */
1755         set_msg_iterator_state(iterator,
1756                 BT_MESSAGE_ITERATOR_STATE_ACTIVE);
1757
1758         BT_ASSERT_DBG(iterator->methods.next);
1759
1760         while (!got_first) {
1761                 /*
1762                  * Call the user's "next" method to get the next
1763                  * messages and status.
1764                  */
1765                 status = call_iterator_next_method(iterator,
1766                         &messages[0], MSG_BATCH_SIZE, &user_count);
1767                 BT_LOGD("User method returned: status=%s",
1768                         bt_common_func_status_string(status));
1769                 if (status < 0) {
1770                         BT_LIB_LOGW_APPEND_CAUSE(
1771                                 "Component input port message iterator's \"next\" method failed: "
1772                                 "%![iter-]+i, status=%s",
1773                                 iterator, bt_common_func_status_string(status));
1774                 }
1775
1776                 /*
1777                  * The user's "next" method must not do any action which
1778                  * would change the iterator's state.
1779                  */
1780                 BT_ASSERT_DBG(iterator->state ==
1781                         BT_MESSAGE_ITERATOR_STATE_ACTIVE);
1782
1783                 switch (status) {
1784                 case BT_FUNC_STATUS_OK:
1785                         BT_ASSERT_POST_DEV(NEXT_METHOD_NAME,
1786                                 "count-lteq-capacity",
1787                                 user_count <= MSG_BATCH_SIZE,
1788                                 "Invalid returned message count: greater than "
1789                                 "batch size: count=%" PRIu64 ", batch-size=%u",
1790                                 user_count, MSG_BATCH_SIZE);
1791                         break;
1792                 case BT_FUNC_STATUS_AGAIN:
1793                 case BT_FUNC_STATUS_ERROR:
1794                 case BT_FUNC_STATUS_MEMORY_ERROR:
1795                 case BT_FUNC_STATUS_END:
1796                         goto end;
1797                 default:
1798                         bt_common_abort();
1799                 }
1800
1801                 for (i = 0; i < user_count; i++) {
1802                         if (got_first) {
1803                                 g_queue_push_tail(iterator->auto_seek.msgs,
1804                                         (void *) messages[i]);
1805                                 messages[i] = NULL;
1806                                 continue;
1807                         }
1808
1809                         status = auto_seek_handle_message(iterator,
1810                                 ns_from_origin, messages[i], &got_first,
1811                                 stream_states);
1812                         if (status == BT_FUNC_STATUS_OK) {
1813                                 /* Message was either pushed or moved */
1814                                 messages[i] = NULL;
1815                         } else {
1816                                 goto end;
1817                         }
1818                 }
1819         }
1820
1821 end:
1822         for (i = 0; i < user_count; i++) {
1823                 if (messages[i]) {
1824                         bt_object_put_ref_no_null_check(messages[i]);
1825                 }
1826         }
1827
1828         set_msg_iterator_state(iterator, init_state);
1829         return status;
1830 }
1831
1832 /*
1833  * This function is installed as the iterator's next callback after we have
1834  * auto-seeked (seeked to the beginning and fast-forwarded) to send the
1835  * messages saved in iterator->auto_seek.msgs.  Once this is done, the original
1836  * next callback is put back.
1837  */
1838
1839 static
1840 enum bt_message_iterator_class_next_method_status post_auto_seek_next(
1841                 struct bt_message_iterator *iterator,
1842                 bt_message_array_const msgs, uint64_t capacity,
1843                 uint64_t *count)
1844 {
1845         BT_ASSERT(!g_queue_is_empty(iterator->auto_seek.msgs));
1846         *count = 0;
1847
1848         /*
1849          * Move auto-seek messages to the output array (which is this
1850          * iterator's base message array).
1851          */
1852         while (capacity > 0 && !g_queue_is_empty(iterator->auto_seek.msgs)) {
1853                 msgs[*count] = g_queue_pop_head(iterator->auto_seek.msgs);
1854                 capacity--;
1855                 (*count)++;
1856         }
1857
1858         BT_ASSERT(*count > 0);
1859
1860         if (g_queue_is_empty(iterator->auto_seek.msgs)) {
1861                 /* No more auto-seek messages, restore user's next callback. */
1862                 BT_ASSERT(iterator->auto_seek.original_next_callback);
1863                 iterator->methods.next = iterator->auto_seek.original_next_callback;
1864                 iterator->auto_seek.original_next_callback = NULL;
1865         }
1866
1867         return BT_FUNC_STATUS_OK;
1868 }
1869
1870 static inline
1871 int clock_raw_value_from_ns_from_origin(const bt_clock_class *clock_class,
1872                 int64_t ns_from_origin, uint64_t *raw_value)
1873 {
1874
1875         int64_t cc_offset_s = clock_class->offset_seconds;
1876         uint64_t cc_offset_cycles = clock_class->offset_cycles;
1877         uint64_t cc_freq = clock_class->frequency;
1878
1879         return bt_common_clock_value_from_ns_from_origin(cc_offset_s,
1880                 cc_offset_cycles, cc_freq, ns_from_origin, raw_value);
1881 }
1882
1883 static
1884 bool message_iterator_can_seek_ns_from_origin(
1885                 struct bt_message_iterator *iterator,
1886                 int64_t ns_from_origin)
1887 {
1888         enum bt_message_iterator_can_seek_ns_from_origin_status status;
1889         bt_bool can_seek;
1890
1891         status = bt_message_iterator_can_seek_ns_from_origin(
1892                 iterator, ns_from_origin, &can_seek);
1893         if (status != BT_FUNC_STATUS_OK) {
1894                 can_seek = BT_FALSE;
1895         }
1896
1897         return can_seek;
1898 }
1899
1900 #define SEEK_NS_FROM_ORIGIN_METHOD_NAME                                 \
1901         "bt_message_iterator_class_seek_ns_from_origin_method"
1902
1903
1904 BT_EXPORT
1905 enum bt_message_iterator_seek_ns_from_origin_status
1906 bt_message_iterator_seek_ns_from_origin(
1907                 struct bt_message_iterator *iterator,
1908                 int64_t ns_from_origin)
1909 {
1910         int status;
1911         GHashTable *stream_states = NULL;
1912         bt_bool can_seek_by_itself;
1913
1914         BT_ASSERT_PRE_NO_ERROR();
1915         BT_ASSERT_PRE_MSG_ITER_NON_NULL(iterator);
1916         BT_ASSERT_PRE_ITER_HAS_STATE_TO_SEEK(iterator);
1917         BT_ASSERT_PRE("graph-is-configured",
1918                 bt_component_borrow_graph(iterator->upstream_component)->config_state !=
1919                         BT_GRAPH_CONFIGURATION_STATE_CONFIGURING,
1920                 "Graph is not configured: %!+g",
1921                 bt_component_borrow_graph(iterator->upstream_component));
1922         /* The iterator must be able to seek ns from origin one way or another. */
1923         BT_ASSERT_PRE("can-seek-ns-from-origin",
1924                 message_iterator_can_seek_ns_from_origin(iterator, ns_from_origin),
1925                 "Message iterator cannot seek nanoseconds from origin: %!+i, "
1926                 "ns-from-origin=%" PRId64, iterator, ns_from_origin);
1927         set_msg_iterator_state(iterator,
1928                 BT_MESSAGE_ITERATOR_STATE_SEEKING);
1929
1930         /*
1931          * We are seeking, reset our expectations about how the following
1932          * messages should look like.
1933          */
1934         reset_iterator_expectations(iterator);
1935
1936         /* Check if the iterator can seek by itself.  If not we'll use autoseek. */
1937         if (iterator->methods.can_seek_ns_from_origin) {
1938                 bt_message_iterator_class_can_seek_ns_from_origin_method_status
1939                         can_seek_status;
1940
1941                 can_seek_status =
1942                         iterator->methods.can_seek_ns_from_origin(
1943                                 iterator, ns_from_origin, &can_seek_by_itself);
1944                 if (can_seek_status != BT_FUNC_STATUS_OK) {
1945                         status = can_seek_status;
1946                         goto end;
1947                 }
1948         } else {
1949                 can_seek_by_itself = false;
1950         }
1951
1952         if (can_seek_by_itself) {
1953                 /* The iterator knows how to seek to a particular time, let it handle this. */
1954                 BT_ASSERT(iterator->methods.seek_ns_from_origin);
1955                 BT_LIB_LOGD("Calling user's \"seek nanoseconds from origin\" method: "
1956                         "%![iter-]+i, ns=%" PRId64, iterator, ns_from_origin);
1957                 status = iterator->methods.seek_ns_from_origin(iterator,
1958                         ns_from_origin);
1959                 BT_LOGD("User method returned: status=%s",
1960                         bt_common_func_status_string(status));
1961                 BT_ASSERT_POST(SEEK_NS_FROM_ORIGIN_METHOD_NAME, "valid-status",
1962                         status == BT_FUNC_STATUS_OK ||
1963                         status == BT_FUNC_STATUS_ERROR ||
1964                         status == BT_FUNC_STATUS_MEMORY_ERROR ||
1965                         status == BT_FUNC_STATUS_AGAIN,
1966                         "Unexpected status: %![iter-]+i, status=%s",
1967                         iterator, bt_common_func_status_string(status));
1968                 BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(
1969                         SEEK_NS_FROM_ORIGIN_METHOD_NAME, status);
1970                 if (status < 0) {
1971                         BT_LIB_LOGW_APPEND_CAUSE(
1972                                 "Component input port message iterator's \"seek nanoseconds from origin\" method failed: "
1973                                 "%![iter-]+i, status=%s",
1974                                 iterator, bt_common_func_status_string(status));
1975                 }
1976         } else {
1977                 /*
1978                  * The iterator doesn't know how to seek by itself to a
1979                  * particular time.  We will seek to the beginning and fast
1980                  * forward to the right place.
1981                  */
1982                 enum bt_message_iterator_class_can_seek_beginning_method_status can_seek_status;
1983                 bt_bool can_seek_beginning;
1984
1985                 can_seek_status = iterator->methods.can_seek_beginning(iterator,
1986                         &can_seek_beginning);
1987                 BT_ASSERT(can_seek_status == BT_FUNC_STATUS_OK);
1988                 BT_ASSERT(can_seek_beginning);
1989                 BT_ASSERT(iterator->methods.seek_beginning);
1990                 BT_LIB_LOGD("Calling user's \"seek beginning\" method: %!+i",
1991                         iterator);
1992                 status = iterator->methods.seek_beginning(iterator);
1993                 BT_LOGD("User method returned: status=%s",
1994                         bt_common_func_status_string(status));
1995                 BT_ASSERT_POST(SEEK_BEGINNING_METHOD_NAME, "valid-status",
1996                         status == BT_FUNC_STATUS_OK ||
1997                         status == BT_FUNC_STATUS_ERROR ||
1998                         status == BT_FUNC_STATUS_MEMORY_ERROR ||
1999                         status == BT_FUNC_STATUS_AGAIN,
2000                         "Unexpected status: %![iter-]+i, status=%s",
2001                         iterator, bt_common_func_status_string(status));
2002                 if (status < 0) {
2003                         BT_LIB_LOGW_APPEND_CAUSE(
2004                                 "Component input port message iterator's \"seek beginning\" method failed: "
2005                                 "%![iter-]+i, status=%s",
2006                                 iterator, bt_common_func_status_string(status));
2007                 }
2008
2009                 clear_per_stream_state(iterator);
2010
2011                 switch (status) {
2012                 case BT_FUNC_STATUS_OK:
2013                         break;
2014                 case BT_FUNC_STATUS_ERROR:
2015                 case BT_FUNC_STATUS_MEMORY_ERROR:
2016                 case BT_FUNC_STATUS_AGAIN:
2017                         goto end;
2018                 default:
2019                         bt_common_abort();
2020                 }
2021
2022                 /*
2023                  * Find the first message which has a default clock
2024                  * snapshot greater than or equal to the requested
2025                  * seeking time, and move the received messages from
2026                  * this point in the batch to this iterator's auto-seek
2027                  * message queue.
2028                  */
2029                 while (!g_queue_is_empty(iterator->auto_seek.msgs)) {
2030                         bt_object_put_ref_no_null_check(
2031                                 g_queue_pop_tail(iterator->auto_seek.msgs));
2032                 }
2033
2034                 stream_states = create_auto_seek_stream_states();
2035                 if (!stream_states) {
2036                         BT_LIB_LOGE_APPEND_CAUSE(
2037                                 "Failed to allocate one GHashTable.");
2038                         status = BT_FUNC_STATUS_MEMORY_ERROR;
2039                         goto end;
2040                 }
2041
2042                 status = find_message_ge_ns_from_origin(iterator,
2043                         ns_from_origin, stream_states);
2044                 switch (status) {
2045                 case BT_FUNC_STATUS_OK:
2046                 case BT_FUNC_STATUS_END:
2047                 {
2048                         GHashTableIter iter;
2049                         gpointer key, value;
2050
2051                         /*
2052                          * If some streams exist at the seek time, prepend the
2053                          * required messages to put those streams in the right
2054                          * state.
2055                          */
2056                         g_hash_table_iter_init(&iter, stream_states);
2057                         while (g_hash_table_iter_next (&iter, &key, &value)) {
2058                                 const bt_stream *stream = key;
2059                                 struct auto_seek_stream_state *stream_state =
2060                                         (struct auto_seek_stream_state *) value;
2061                                 bt_message *msg;
2062                                 const bt_clock_class *clock_class = bt_stream_class_borrow_default_clock_class_const(
2063                                         bt_stream_borrow_class_const(stream));
2064                                 /* Initialize to silence maybe-uninitialized warning. */
2065                                 uint64_t raw_value = 0;
2066
2067                                 /*
2068                                  * If we haven't seen a message with a clock snapshot, we don't know if our seek time is within
2069                                  * the clock's range, so it wouldn't be safe to try to convert ns_from_origin to a clock value.
2070                                  *
2071                                  * Also, it would be a bit of a lie to generate a stream begin message with the seek time as its
2072                                  * clock snapshot, because we don't really know if the stream existed at that time.  If we have
2073                                  * seen a message with a clock snapshot in our seeking, then we are sure that the
2074                                  * seek time is not below the clock range, and we know the stream was active at that
2075                                  * time (and that we cut it short).
2076                                  */
2077                                 if (stream_state->seen_clock_snapshot) {
2078                                         if (clock_raw_value_from_ns_from_origin(clock_class, ns_from_origin, &raw_value) != 0) {
2079                                                 BT_LIB_LOGW("Could not convert nanoseconds from origin to clock value: ns-from-origin=%" PRId64 ", %![cc-]+K",
2080                                                         ns_from_origin, clock_class);
2081                                                 status = BT_FUNC_STATUS_ERROR;
2082                                                 goto end;
2083                                         }
2084                                 }
2085
2086                                 switch (stream_state->state) {
2087                                 case AUTO_SEEK_STREAM_STATE_PACKET_BEGAN:
2088                                         BT_ASSERT(stream_state->packet);
2089                                         BT_LIB_LOGD("Creating packet message: %![packet-]+a", stream_state->packet);
2090
2091                                         if (stream->class->packets_have_beginning_default_clock_snapshot) {
2092                                                 /*
2093                                                  * If we are in the PACKET_BEGAN state, it means we have seen a "packet beginning"
2094                                                  * message.  If "packet beginning" packets have clock snapshots, then we must have
2095                                                  * seen a clock snapshot.
2096                                                  */
2097                                                 BT_ASSERT(stream_state->seen_clock_snapshot);
2098
2099                                                 msg = bt_message_packet_beginning_create_with_default_clock_snapshot(
2100                                                         (bt_self_message_iterator *) iterator, stream_state->packet, raw_value);
2101                                         } else {
2102                                                 msg = bt_message_packet_beginning_create((bt_self_message_iterator *) iterator,
2103                                                                 stream_state->packet);
2104                                         }
2105
2106                                         if (!msg) {
2107                                                 status = BT_FUNC_STATUS_MEMORY_ERROR;
2108                                                 goto end;
2109                                         }
2110
2111                                         g_queue_push_head(iterator->auto_seek.msgs, msg);
2112                                         msg = NULL;
2113                                         /* fall-thru */
2114
2115                                 case AUTO_SEEK_STREAM_STATE_STREAM_BEGAN:
2116                                         msg = bt_message_stream_beginning_create(
2117                                                 (bt_self_message_iterator *) iterator, stream);
2118                                         if (!msg) {
2119                                                 status = BT_FUNC_STATUS_MEMORY_ERROR;
2120                                                 goto end;
2121                                         }
2122
2123                                         if (stream_state->seen_clock_snapshot) {
2124                                                 bt_message_stream_beginning_set_default_clock_snapshot(msg, raw_value);
2125                                         }
2126
2127                                         g_queue_push_head(iterator->auto_seek.msgs, msg);
2128                                         msg = NULL;
2129                                         break;
2130                                 }
2131                         }
2132
2133                         /*
2134                          * If there are messages in the auto-seek
2135                          * message queue, replace the user's "next"
2136                          * method with a custom, temporary "next" method
2137                          * which returns them.
2138                          */
2139                         if (!g_queue_is_empty(iterator->auto_seek.msgs)) {
2140                                 BT_ASSERT(!iterator->auto_seek.original_next_callback);
2141                                 iterator->auto_seek.original_next_callback = iterator->methods.next;
2142
2143                                 iterator->methods.next =
2144                                         (bt_message_iterator_next_method)
2145                                                 post_auto_seek_next;
2146                         }
2147
2148                         /*
2149                          * `BT_FUNC_STATUS_END` becomes
2150                          * `BT_FUNC_STATUS_OK`: the next
2151                          * time this iterator's "next" method is called,
2152                          * it will return
2153                          * `BT_FUNC_STATUS_END`.
2154                          */
2155                         status = BT_FUNC_STATUS_OK;
2156                         break;
2157                 }
2158                 case BT_FUNC_STATUS_ERROR:
2159                 case BT_FUNC_STATUS_MEMORY_ERROR:
2160                 case BT_FUNC_STATUS_AGAIN:
2161                         goto end;
2162                 default:
2163                         bt_common_abort();
2164                 }
2165         }
2166
2167         clear_per_stream_state(iterator);
2168
2169         /*
2170          * The following messages returned by the next method (including
2171          * post_auto_seek_next) must be after (or at) `ns_from_origin`.
2172          */
2173         iterator->last_ns_from_origin = ns_from_origin;
2174
2175 end:
2176         if (stream_states) {
2177                 destroy_auto_seek_stream_states(stream_states);
2178                 stream_states = NULL;
2179         }
2180
2181         set_iterator_state_after_seeking(iterator, status);
2182         return status;
2183 }
2184
2185 BT_EXPORT
2186 bt_bool bt_self_message_iterator_is_interrupted(
2187                 const struct bt_self_message_iterator *self_msg_iter)
2188 {
2189         const struct bt_message_iterator *iterator =
2190                 (const void *) self_msg_iter;
2191
2192         BT_ASSERT_PRE_MSG_ITER_NON_NULL(iterator);
2193         return (bt_bool) bt_graph_is_interrupted(iterator->graph);
2194 }
2195
2196 BT_EXPORT
2197 void bt_message_iterator_get_ref(
2198                 const struct bt_message_iterator *iterator)
2199 {
2200         bt_object_get_ref(iterator);
2201 }
2202
2203 BT_EXPORT
2204 void bt_message_iterator_put_ref(
2205                 const struct bt_message_iterator *iterator)
2206 {
2207         bt_object_put_ref(iterator);
2208 }