src/lib/graph/iterator.c

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