src/lib/graph/iterator.c

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