sync/engine/sync_scheduler_impl.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "sync/engine/sync_scheduler_impl.h"
   6
   7 #include <algorithm>
   8 #include <cstring>
   9
  10 #include "base/auto_reset.h"
  11 #include "base/bind.h"
  12 #include "base/bind_helpers.h"
  13 #include "base/compiler_specific.h"
  14 #include "base/location.h"
  15 #include "base/logging.h"
  16 #include "base/message_loop/message_loop.h"
  17 #include "sync/engine/backoff_delay_provider.h"
  18 #include "sync/engine/syncer.h"
  19 #include "sync/protocol/proto_enum_conversions.h"
  20 #include "sync/protocol/sync.pb.h"
  21 #include "sync/util/data_type_histogram.h"
  22 #include "sync/util/logging.h"
  23
  24 using base::TimeDelta;
  25 using base::TimeTicks;
  26
  27 namespace syncer {
  28
  29 using sessions::SyncSession;
  30 using sessions::SyncSessionSnapshot;
  31 using sync_pb::GetUpdatesCallerInfo;
  32
  33 namespace {
  34
  35 bool ShouldRequestEarlyExit(const SyncProtocolError& error) {
  36   switch (error.error_type) {
  37     case SYNC_SUCCESS:
  38     case MIGRATION_DONE:
  39     case THROTTLED:
  40     case TRANSIENT_ERROR:
  41       return false;
  42     case NOT_MY_BIRTHDAY:
  43     case CLEAR_PENDING:
  44     case DISABLED_BY_ADMIN:
  45     case USER_ROLLBACK:
  46       // If we send terminate sync early then |sync_cycle_ended| notification
  47       // would not be sent. If there were no actions then |ACTIONABLE_ERROR|
  48       // notification wouldnt be sent either. Then the UI layer would be left
  49       // waiting forever. So assert we would send something.
  50       DCHECK_NE(error.action, UNKNOWN_ACTION);
  51       return true;
  52     case INVALID_CREDENTIAL:
  53       // The notification for this is handled by PostAndProcessHeaders|.
  54       // Server does no have to send any action for this.
  55       return true;
  56     // Make the default a NOTREACHED. So if a new error is introduced we
  57     // think about its expected functionality.
  58     default:
  59       NOTREACHED();
  60       return false;
  61   }
  62 }
  63
  64 bool IsActionableError(
  65     const SyncProtocolError& error) {
  66   return (error.action != UNKNOWN_ACTION);
  67 }
  68 }  // namespace
  69
  70 ConfigurationParams::ConfigurationParams()
  71     : source(GetUpdatesCallerInfo::UNKNOWN) {}
  72 ConfigurationParams::ConfigurationParams(
  73     const sync_pb::GetUpdatesCallerInfo::GetUpdatesSource& source,
  74     ModelTypeSet types_to_download,
  75     const ModelSafeRoutingInfo& routing_info,
  76     const base::Closure& ready_task,
  77     const base::Closure& retry_task)
  78     : source(source),
  79       types_to_download(types_to_download),
  80       routing_info(routing_info),
  81       ready_task(ready_task),
  82       retry_task(retry_task) {
  83   DCHECK(!ready_task.is_null());
  84   DCHECK(!retry_task.is_null());
  85 }
  86 ConfigurationParams::~ConfigurationParams() {}
  87
  88 SyncSchedulerImpl::WaitInterval::WaitInterval()
  89     : mode(UNKNOWN) {}
  90
  91 SyncSchedulerImpl::WaitInterval::WaitInterval(Mode mode, TimeDelta length)
  92     : mode(mode), length(length) {}
  93
  94 SyncSchedulerImpl::WaitInterval::~WaitInterval() {}
  95
  96 #define ENUM_CASE(x) case x: return #x; break;
  97
  98 const char* SyncSchedulerImpl::WaitInterval::GetModeString(Mode mode) {
  99   switch (mode) {
 100     ENUM_CASE(UNKNOWN);
 101     ENUM_CASE(EXPONENTIAL_BACKOFF);
 102     ENUM_CASE(THROTTLED);
 103   }
 104   NOTREACHED();
 105   return "";
 106 }
 107
 108 GetUpdatesCallerInfo::GetUpdatesSource GetUpdatesFromNudgeSource(
 109     NudgeSource source) {
 110   switch (source) {
 111     case NUDGE_SOURCE_NOTIFICATION:
 112       return GetUpdatesCallerInfo::NOTIFICATION;
 113     case NUDGE_SOURCE_LOCAL:
 114       return GetUpdatesCallerInfo::LOCAL;
 115     case NUDGE_SOURCE_LOCAL_REFRESH:
 116       return GetUpdatesCallerInfo::DATATYPE_REFRESH;
 117     case NUDGE_SOURCE_UNKNOWN:
 118       return GetUpdatesCallerInfo::UNKNOWN;
 119     default:
 120       NOTREACHED();
 121       return GetUpdatesCallerInfo::UNKNOWN;
 122   }
 123 }
 124
 125 // Helper macros to log with the syncer thread name; useful when there
 126 // are multiple syncer threads involved.
 127
 128 #define SLOG(severity) LOG(severity) << name_ << ": "
 129
 130 #define SDVLOG(verbose_level) DVLOG(verbose_level) << name_ << ": "
 131
 132 #define SDVLOG_LOC(from_here, verbose_level)             \
 133   DVLOG_LOC(from_here, verbose_level) << name_ << ": "
 134
 135 namespace {
 136
 137 const int kDefaultSessionsCommitDelaySeconds = 10;
 138
 139 bool IsConfigRelatedUpdateSourceValue(
 140     GetUpdatesCallerInfo::GetUpdatesSource source) {
 141   switch (source) {
 142     case GetUpdatesCallerInfo::RECONFIGURATION:
 143     case GetUpdatesCallerInfo::MIGRATION:
 144     case GetUpdatesCallerInfo::NEW_CLIENT:
 145     case GetUpdatesCallerInfo::NEWLY_SUPPORTED_DATATYPE:
 146       return true;
 147     default:
 148       return false;
 149   }
 150 }
 151
 152 }  // namespace
 153
 154 SyncSchedulerImpl::SyncSchedulerImpl(const std::string& name,
 155                                      BackoffDelayProvider* delay_provider,
 156                                      sessions::SyncSessionContext* context,
 157                                      Syncer* syncer)
 158     : name_(name),
 159       started_(false),
 160       syncer_short_poll_interval_seconds_(
 161           TimeDelta::FromSeconds(kDefaultShortPollIntervalSeconds)),
 162       syncer_long_poll_interval_seconds_(
 163           TimeDelta::FromSeconds(kDefaultLongPollIntervalSeconds)),
 164       sessions_commit_delay_(
 165           TimeDelta::FromSeconds(kDefaultSessionsCommitDelaySeconds)),
 166       mode_(NORMAL_MODE),
 167       delay_provider_(delay_provider),
 168       syncer_(syncer),
 169       session_context_(context),
 170       no_scheduling_allowed_(false),
 171       do_poll_after_credentials_updated_(false),
 172       next_sync_session_job_priority_(NORMAL_PRIORITY),
 173       weak_ptr_factory_(this),
 174       weak_ptr_factory_for_weak_handle_(this) {
 175   weak_handle_this_ = MakeWeakHandle(
 176       weak_ptr_factory_for_weak_handle_.GetWeakPtr());
 177 }
 178
 179 SyncSchedulerImpl::~SyncSchedulerImpl() {
 180   DCHECK(CalledOnValidThread());
 181   Stop();
 182 }
 183
 184 void SyncSchedulerImpl::OnCredentialsUpdated() {
 185   DCHECK(CalledOnValidThread());
 186
 187   if (HttpResponse::SYNC_AUTH_ERROR ==
 188       session_context_->connection_manager()->server_status()) {
 189     OnServerConnectionErrorFixed();
 190   }
 191 }
 192
 193 void SyncSchedulerImpl::OnConnectionStatusChange() {
 194   if (HttpResponse::CONNECTION_UNAVAILABLE  ==
 195       session_context_->connection_manager()->server_status()) {
 196     // Optimistically assume that the connection is fixed and try
 197     // connecting.
 198     OnServerConnectionErrorFixed();
 199   }
 200 }
 201
 202 void SyncSchedulerImpl::OnServerConnectionErrorFixed() {
 203   // There could be a pending nudge or configuration job in several cases:
 204   //
 205   // 1. We're in exponential backoff.
 206   // 2. We're silenced / throttled.
 207   // 3. A nudge was saved previously due to not having a valid auth token.
 208   // 4. A nudge was scheduled + saved while in configuration mode.
 209   //
 210   // In all cases except (2), we want to retry contacting the server. We
 211   // call TryCanaryJob to achieve this, and note that nothing -- not even a
 212   // canary job -- can bypass a THROTTLED WaitInterval. The only thing that
 213   // has the authority to do that is the Unthrottle timer.
 214   TryCanaryJob();
 215 }
 216
 217 void SyncSchedulerImpl::Start(Mode mode) {
 218   DCHECK(CalledOnValidThread());
 219   std::string thread_name = base::MessageLoop::current()->thread_name();
 220   if (thread_name.empty())
 221     thread_name = "<Main thread>";
 222   SDVLOG(2) << "Start called from thread "
 223             << thread_name << " with mode " << GetModeString(mode);
 224   if (!started_) {
 225     started_ = true;
 226     SendInitialSnapshot();
 227   }
 228
 229   DCHECK(!session_context_->account_name().empty());
 230   DCHECK(syncer_.get());
 231   Mode old_mode = mode_;
 232   mode_ = mode;
 233   AdjustPolling(UPDATE_INTERVAL);  // Will kick start poll timer if needed.
 234
 235   if (old_mode != mode_ && mode_ == NORMAL_MODE) {
 236     // We just got back to normal mode.  Let's try to run the work that was
 237     // queued up while we were configuring.
 238
 239     // Update our current time before checking IsRetryRequired().
 240     nudge_tracker_.SetSyncCycleStartTime(base::TimeTicks::Now());
 241     if (nudge_tracker_.IsSyncRequired() && CanRunNudgeJobNow(NORMAL_PRIORITY)) {
 242       TrySyncSessionJob();
 243     }
 244   }
 245 }
 246
 247 ModelTypeSet SyncSchedulerImpl::GetEnabledAndUnthrottledTypes() {
 248   ModelTypeSet enabled_types = session_context_->GetEnabledTypes();
 249   ModelTypeSet enabled_protocol_types =
 250       Intersection(ProtocolTypes(), enabled_types);
 251   ModelTypeSet throttled_types = nudge_tracker_.GetThrottledTypes();
 252   return Difference(enabled_protocol_types, throttled_types);
 253 }
 254
 255 void SyncSchedulerImpl::SendInitialSnapshot() {
 256   DCHECK(CalledOnValidThread());
 257   scoped_ptr<SyncSession> dummy(SyncSession::Build(session_context_, this));
 258   SyncCycleEvent event(SyncCycleEvent::STATUS_CHANGED);
 259   event.snapshot = dummy->TakeSnapshot();
 260   FOR_EACH_OBSERVER(SyncEngineEventListener,
 261                     *session_context_->listeners(),
 262                     OnSyncCycleEvent(event));
 263 }
 264
 265 namespace {
 266
 267 // Helper to extract the routing info corresponding to types in
 268 // |types_to_download| from |current_routes|.
 269 void BuildModelSafeParams(
 270     ModelTypeSet types_to_download,
 271     const ModelSafeRoutingInfo& current_routes,
 272     ModelSafeRoutingInfo* result_routes) {
 273   for (ModelTypeSet::Iterator iter = types_to_download.First(); iter.Good();
 274        iter.Inc()) {
 275     ModelType type = iter.Get();
 276     ModelSafeRoutingInfo::const_iterator route = current_routes.find(type);
 277     DCHECK(route != current_routes.end());
 278     ModelSafeGroup group = route->second;
 279     (*result_routes)[type] = group;
 280   }
 281 }
 282
 283 }  // namespace.
 284
 285 void SyncSchedulerImpl::ScheduleConfiguration(
 286     const ConfigurationParams& params) {
 287   DCHECK(CalledOnValidThread());
 288   DCHECK(IsConfigRelatedUpdateSourceValue(params.source));
 289   DCHECK_EQ(CONFIGURATION_MODE, mode_);
 290   DCHECK(!params.ready_task.is_null());
 291   CHECK(started_) << "Scheduler must be running to configure.";
 292   SDVLOG(2) << "Reconfiguring syncer.";
 293
 294   // Only one configuration is allowed at a time. Verify we're not waiting
 295   // for a pending configure job.
 296   DCHECK(!pending_configure_params_);
 297
 298   ModelSafeRoutingInfo restricted_routes;
 299   BuildModelSafeParams(params.types_to_download,
 300                        params.routing_info,
 301                        &restricted_routes);
 302   session_context_->SetRoutingInfo(restricted_routes);
 303
 304   // Only reconfigure if we have types to download.
 305   if (!params.types_to_download.Empty()) {
 306     pending_configure_params_.reset(new ConfigurationParams(params));
 307     TrySyncSessionJob();
 308   } else {
 309     SDVLOG(2) << "No change in routing info, calling ready task directly.";
 310     params.ready_task.Run();
 311   }
 312 }
 313
 314 bool SyncSchedulerImpl::CanRunJobNow(JobPriority priority) {
 315   DCHECK(CalledOnValidThread());
 316   if (wait_interval_ && wait_interval_->mode == WaitInterval::THROTTLED) {
 317     SDVLOG(1) << "Unable to run a job because we're throttled.";
 318     return false;
 319   }
 320
 321   if (wait_interval_
 322       && wait_interval_->mode == WaitInterval::EXPONENTIAL_BACKOFF
 323       && priority != CANARY_PRIORITY) {
 324     SDVLOG(1) << "Unable to run a job because we're backing off.";
 325     return false;
 326   }
 327
 328   if (session_context_->connection_manager()->HasInvalidAuthToken()) {
 329     SDVLOG(1) << "Unable to run a job because we have no valid auth token.";
 330     return false;
 331   }
 332
 333   return true;
 334 }
 335
 336 bool SyncSchedulerImpl::CanRunNudgeJobNow(JobPriority priority) {
 337   DCHECK(CalledOnValidThread());
 338
 339   if (!CanRunJobNow(priority)) {
 340     SDVLOG(1) << "Unable to run a nudge job right now";
 341     return false;
 342   }
 343
 344   const ModelTypeSet enabled_types = session_context_->GetEnabledTypes();
 345   if (nudge_tracker_.GetThrottledTypes().HasAll(enabled_types)) {
 346     SDVLOG(1) << "Not running a nudge because we're fully type throttled.";
 347     return false;
 348   }
 349
 350   if (mode_ == CONFIGURATION_MODE) {
 351     SDVLOG(1) << "Not running nudge because we're in configuration mode.";
 352     return false;
 353   }
 354
 355   return true;
 356 }
 357
 358 void SyncSchedulerImpl::ScheduleLocalNudge(
 359     const TimeDelta& desired_delay,
 360     ModelTypeSet types,
 361     const tracked_objects::Location& nudge_location) {
 362   DCHECK(CalledOnValidThread());
 363   DCHECK(!types.Empty());
 364
 365   SDVLOG_LOC(nudge_location, 2)
 366       << "Scheduling sync because of local change to "
 367       << ModelTypeSetToString(types);
 368   UpdateNudgeTimeRecords(types);
 369   nudge_tracker_.RecordLocalChange(types);
 370   ScheduleNudgeImpl(desired_delay, nudge_location);
 371 }
 372
 373 void SyncSchedulerImpl::ScheduleLocalRefreshRequest(
 374     const TimeDelta& desired_delay,
 375     ModelTypeSet types,
 376     const tracked_objects::Location& nudge_location) {
 377   DCHECK(CalledOnValidThread());
 378   DCHECK(!types.Empty());
 379
 380   SDVLOG_LOC(nudge_location, 2)
 381       << "Scheduling sync because of local refresh request for "
 382       << ModelTypeSetToString(types);
 383   nudge_tracker_.RecordLocalRefreshRequest(types);
 384   ScheduleNudgeImpl(desired_delay, nudge_location);
 385 }
 386
 387 void SyncSchedulerImpl::ScheduleInvalidationNudge(
 388     const TimeDelta& desired_delay,
 389     syncer::ModelType model_type,
 390     scoped_ptr<InvalidationInterface> invalidation,
 391     const tracked_objects::Location& nudge_location) {
 392   DCHECK(CalledOnValidThread());
 393
 394   SDVLOG_LOC(nudge_location, 2)
 395       << "Scheduling sync because we received invalidation for "
 396       << ModelTypeToString(model_type);
 397   nudge_tracker_.RecordRemoteInvalidation(model_type, invalidation.Pass());
 398   ScheduleNudgeImpl(desired_delay, nudge_location);
 399 }
 400
 401 // TODO(zea): Consider adding separate throttling/backoff for datatype
 402 // refresh requests.
 403 void SyncSchedulerImpl::ScheduleNudgeImpl(
 404     const TimeDelta& delay,
 405     const tracked_objects::Location& nudge_location) {
 406   DCHECK(CalledOnValidThread());
 407
 408   if (no_scheduling_allowed_) {
 409     NOTREACHED() << "Illegal to schedule job while session in progress.";
 410     return;
 411   }
 412
 413   if (!started_) {
 414     SDVLOG_LOC(nudge_location, 2)
 415         << "Dropping nudge, scheduler is not running.";
 416     return;
 417   }
 418
 419   SDVLOG_LOC(nudge_location, 2)
 420       << "In ScheduleNudgeImpl with delay "
 421       << delay.InMilliseconds() << " ms";
 422
 423   if (!CanRunNudgeJobNow(NORMAL_PRIORITY))
 424     return;
 425
 426   TimeTicks incoming_run_time = TimeTicks::Now() + delay;
 427   if (!scheduled_nudge_time_.is_null() &&
 428     (scheduled_nudge_time_ < incoming_run_time)) {
 429     // Old job arrives sooner than this one.  Don't reschedule it.
 430     return;
 431   }
 432
 433   // Either there is no existing nudge in flight or the incoming nudge should be
 434   // made to arrive first (preempt) the existing nudge.  We reschedule in either
 435   // case.
 436   SDVLOG_LOC(nudge_location, 2)
 437       << "Scheduling a nudge with "
 438       << delay.InMilliseconds() << " ms delay";
 439   scheduled_nudge_time_ = incoming_run_time;
 440   pending_wakeup_timer_.Start(
 441       nudge_location,
 442       delay,
 443       base::Bind(&SyncSchedulerImpl::PerformDelayedNudge,
 444                  weak_ptr_factory_.GetWeakPtr()));
 445 }
 446
 447 const char* SyncSchedulerImpl::GetModeString(SyncScheduler::Mode mode) {
 448   switch (mode) {
 449     ENUM_CASE(CONFIGURATION_MODE);
 450     ENUM_CASE(NORMAL_MODE);
 451   }
 452   return "";
 453 }
 454
 455 void SyncSchedulerImpl::DoNudgeSyncSessionJob(JobPriority priority) {
 456   DCHECK(CalledOnValidThread());
 457   DCHECK(CanRunNudgeJobNow(priority));
 458
 459   DVLOG(2) << "Will run normal mode sync cycle with types "
 460            << ModelTypeSetToString(session_context_->GetEnabledTypes());
 461   scoped_ptr<SyncSession> session(SyncSession::Build(session_context_, this));
 462   bool premature_exit = !syncer_->NormalSyncShare(
 463       GetEnabledAndUnthrottledTypes(),
 464       nudge_tracker_,
 465       session.get());
 466   AdjustPolling(FORCE_RESET);
 467   // Don't run poll job till the next time poll timer fires.
 468   do_poll_after_credentials_updated_ = false;
 469
 470   bool success = !premature_exit
 471       && !sessions::HasSyncerError(
 472           session->status_controller().model_neutral_state());
 473
 474   if (success) {
 475     // That cycle took care of any outstanding work we had.
 476     SDVLOG(2) << "Nudge succeeded.";
 477     nudge_tracker_.RecordSuccessfulSyncCycle();
 478     scheduled_nudge_time_ = base::TimeTicks();
 479
 480     // If we're here, then we successfully reached the server.  End all backoff.
 481     wait_interval_.reset();
 482     NotifyRetryTime(base::Time());
 483   } else {
 484     HandleFailure(session->status_controller().model_neutral_state());
 485   }
 486 }
 487
 488 void SyncSchedulerImpl::DoConfigurationSyncSessionJob(JobPriority priority) {
 489   DCHECK(CalledOnValidThread());
 490   DCHECK_EQ(mode_, CONFIGURATION_MODE);
 491   DCHECK(pending_configure_params_ != NULL);
 492
 493   if (!CanRunJobNow(priority)) {
 494     SDVLOG(2) << "Unable to run configure job right now.";
 495     if (!pending_configure_params_->retry_task.is_null()) {
 496       pending_configure_params_->retry_task.Run();
 497       pending_configure_params_->retry_task.Reset();
 498     }
 499     return;
 500   }
 501
 502   SDVLOG(2) << "Will run configure SyncShare with types "
 503             << ModelTypeSetToString(session_context_->GetEnabledTypes());
 504   scoped_ptr<SyncSession> session(SyncSession::Build(session_context_, this));
 505   bool premature_exit = !syncer_->ConfigureSyncShare(
 506       pending_configure_params_->types_to_download,
 507       pending_configure_params_->source,
 508       session.get());
 509   AdjustPolling(FORCE_RESET);
 510   // Don't run poll job till the next time poll timer fires.
 511   do_poll_after_credentials_updated_ = false;
 512
 513   bool success = !premature_exit
 514       && !sessions::HasSyncerError(
 515           session->status_controller().model_neutral_state());
 516
 517   if (success) {
 518     SDVLOG(2) << "Configure succeeded.";
 519     pending_configure_params_->ready_task.Run();
 520     pending_configure_params_.reset();
 521
 522     // If we're here, then we successfully reached the server.  End all backoff.
 523     wait_interval_.reset();
 524     NotifyRetryTime(base::Time());
 525   } else {
 526     HandleFailure(session->status_controller().model_neutral_state());
 527     // Sync cycle might receive response from server that causes scheduler to
 528     // stop and draws pending_configure_params_ invalid.
 529     if (started_ && !pending_configure_params_->retry_task.is_null()) {
 530       pending_configure_params_->retry_task.Run();
 531       pending_configure_params_->retry_task.Reset();
 532     }
 533   }
 534 }
 535
 536 void SyncSchedulerImpl::HandleFailure(
 537     const sessions::ModelNeutralState& model_neutral_state) {
 538   if (IsCurrentlyThrottled()) {
 539     SDVLOG(2) << "Was throttled during previous sync cycle.";
 540     RestartWaiting();
 541   } else if (!IsBackingOff()) {
 542     // Setup our backoff if this is our first such failure.
 543     TimeDelta length = delay_provider_->GetDelay(
 544         delay_provider_->GetInitialDelay(model_neutral_state));
 545     wait_interval_.reset(
 546         new WaitInterval(WaitInterval::EXPONENTIAL_BACKOFF, length));
 547     SDVLOG(2) << "Sync cycle failed.  Will back off for "
 548         << wait_interval_->length.InMilliseconds() << "ms.";
 549     RestartWaiting();
 550   }
 551 }
 552
 553 void SyncSchedulerImpl::DoPollSyncSessionJob() {
 554   base::AutoReset<bool> protector(&no_scheduling_allowed_, true);
 555
 556   SDVLOG(2) << "Polling with types "
 557             << ModelTypeSetToString(GetEnabledAndUnthrottledTypes());
 558   scoped_ptr<SyncSession> session(SyncSession::Build(session_context_, this));
 559   syncer_->PollSyncShare(
 560       GetEnabledAndUnthrottledTypes(),
 561       session.get());
 562
 563   AdjustPolling(FORCE_RESET);
 564
 565   if (IsCurrentlyThrottled()) {
 566     SDVLOG(2) << "Poll request got us throttled.";
 567     // The OnSilencedUntil() call set up the WaitInterval for us.  All we need
 568     // to do is start the timer.
 569     RestartWaiting();
 570   }
 571 }
 572
 573 void SyncSchedulerImpl::UpdateNudgeTimeRecords(ModelTypeSet types) {
 574   DCHECK(CalledOnValidThread());
 575   base::TimeTicks now = TimeTicks::Now();
 576   // Update timing information for how often datatypes are triggering nudges.
 577   for (ModelTypeSet::Iterator iter = types.First(); iter.Good(); iter.Inc()) {
 578     base::TimeTicks previous = last_local_nudges_by_model_type_[iter.Get()];
 579     last_local_nudges_by_model_type_[iter.Get()] = now;
 580     if (previous.is_null())
 581       continue;
 582
 583 #define PER_DATA_TYPE_MACRO(type_str) \
 584     SYNC_FREQ_HISTOGRAM("Sync.Freq" type_str, now - previous);
 585     SYNC_DATA_TYPE_HISTOGRAM(iter.Get());
 586 #undef PER_DATA_TYPE_MACRO
 587   }
 588 }
 589
 590 TimeDelta SyncSchedulerImpl::GetPollInterval() {
 591   return (!session_context_->notifications_enabled() ||
 592           !session_context_->ShouldFetchUpdatesBeforeCommit()) ?
 593       syncer_short_poll_interval_seconds_ :
 594       syncer_long_poll_interval_seconds_;
 595 }
 596
 597 void SyncSchedulerImpl::AdjustPolling(PollAdjustType type) {
 598   DCHECK(CalledOnValidThread());
 599
 600   TimeDelta poll = GetPollInterval();
 601   bool rate_changed = !poll_timer_.IsRunning() ||
 602                        poll != poll_timer_.GetCurrentDelay();
 603
 604   if (type == FORCE_RESET) {
 605     last_poll_reset_ = base::TimeTicks::Now();
 606     if (!rate_changed)
 607       poll_timer_.Reset();
 608   }
 609
 610   if (!rate_changed)
 611     return;
 612
 613   // Adjust poll rate.
 614   poll_timer_.Stop();
 615   poll_timer_.Start(FROM_HERE, poll, this,
 616                     &SyncSchedulerImpl::PollTimerCallback);
 617 }
 618
 619 void SyncSchedulerImpl::RestartWaiting() {
 620   CHECK(wait_interval_.get());
 621   DCHECK(wait_interval_->length >= TimeDelta::FromSeconds(0));
 622   NotifyRetryTime(base::Time::Now() + wait_interval_->length);
 623   SDVLOG(2) << "Starting WaitInterval timer of length "
 624       << wait_interval_->length.InMilliseconds() << "ms.";
 625   if (wait_interval_->mode == WaitInterval::THROTTLED) {
 626     pending_wakeup_timer_.Start(
 627         FROM_HERE,
 628         wait_interval_->length,
 629         base::Bind(&SyncSchedulerImpl::Unthrottle,
 630                    weak_ptr_factory_.GetWeakPtr()));
 631   } else {
 632     pending_wakeup_timer_.Start(
 633         FROM_HERE,
 634         wait_interval_->length,
 635         base::Bind(&SyncSchedulerImpl::ExponentialBackoffRetry,
 636                    weak_ptr_factory_.GetWeakPtr()));
 637   }
 638 }
 639
 640 void SyncSchedulerImpl::Stop() {
 641   DCHECK(CalledOnValidThread());
 642   SDVLOG(2) << "Stop called";
 643
 644   // Kill any in-flight method calls.
 645   weak_ptr_factory_.InvalidateWeakPtrs();
 646   wait_interval_.reset();
 647   NotifyRetryTime(base::Time());
 648   poll_timer_.Stop();
 649   pending_wakeup_timer_.Stop();
 650   pending_configure_params_.reset();
 651   if (started_)
 652     started_ = false;
 653 }
 654
 655 // This is the only place where we invoke DoSyncSessionJob with canary
 656 // privileges.  Everyone else should use NORMAL_PRIORITY.
 657 void SyncSchedulerImpl::TryCanaryJob() {
 658   next_sync_session_job_priority_ = CANARY_PRIORITY;
 659   TrySyncSessionJob();
 660 }
 661
 662 void SyncSchedulerImpl::TrySyncSessionJob() {
 663   // Post call to TrySyncSessionJobImpl on current thread. Later request for
 664   // access token will be here.
 665   base::MessageLoop::current()->PostTask(FROM_HERE, base::Bind(
 666       &SyncSchedulerImpl::TrySyncSessionJobImpl,
 667       weak_ptr_factory_.GetWeakPtr()));
 668 }
 669
 670 void SyncSchedulerImpl::TrySyncSessionJobImpl() {
 671   JobPriority priority = next_sync_session_job_priority_;
 672   next_sync_session_job_priority_ = NORMAL_PRIORITY;
 673
 674   nudge_tracker_.SetSyncCycleStartTime(base::TimeTicks::Now());
 675
 676   DCHECK(CalledOnValidThread());
 677   if (mode_ == CONFIGURATION_MODE) {
 678     if (pending_configure_params_) {
 679       SDVLOG(2) << "Found pending configure job";
 680       DoConfigurationSyncSessionJob(priority);
 681     }
 682   } else if (CanRunNudgeJobNow(priority)) {
 683     if (nudge_tracker_.IsSyncRequired()) {
 684       SDVLOG(2) << "Found pending nudge job";
 685       DoNudgeSyncSessionJob(priority);
 686     } else if (do_poll_after_credentials_updated_ ||
 687         ((base::TimeTicks::Now() - last_poll_reset_) >= GetPollInterval())) {
 688       DoPollSyncSessionJob();
 689       // Poll timer fires infrequently. Usually by this time access token is
 690       // already expired and poll job will fail with auth error. Set flag to
 691       // retry poll once ProfileSyncService gets new access token, TryCanaryJob
 692       // will be called after access token is retrieved.
 693       if (HttpResponse::SYNC_AUTH_ERROR ==
 694           session_context_->connection_manager()->server_status()) {
 695         do_poll_after_credentials_updated_ = true;
 696       }
 697     }
 698   }
 699
 700   if (priority == CANARY_PRIORITY) {
 701     // If this is canary job then whatever result was don't run poll job till
 702     // the next time poll timer fires.
 703     do_poll_after_credentials_updated_ = false;
 704   }
 705
 706   if (IsBackingOff() && !pending_wakeup_timer_.IsRunning()) {
 707     // If we succeeded, our wait interval would have been cleared.  If it hasn't
 708     // been cleared, then we should increase our backoff interval and schedule
 709     // another retry.
 710     TimeDelta length = delay_provider_->GetDelay(wait_interval_->length);
 711     wait_interval_.reset(
 712       new WaitInterval(WaitInterval::EXPONENTIAL_BACKOFF, length));
 713     SDVLOG(2) << "Sync cycle failed.  Will back off for "
 714         << wait_interval_->length.InMilliseconds() << "ms.";
 715     RestartWaiting();
 716   }
 717 }
 718
 719 void SyncSchedulerImpl::PollTimerCallback() {
 720   DCHECK(CalledOnValidThread());
 721   if (no_scheduling_allowed_) {
 722     // The no_scheduling_allowed_ flag is set by a function-scoped AutoReset in
 723     // functions that are called only on the sync thread.  This function is also
 724     // called only on the sync thread, and only when it is posted by an expiring
 725     // timer.  If we find that no_scheduling_allowed_ is set here, then
 726     // something is very wrong.  Maybe someone mistakenly called us directly, or
 727     // mishandled the book-keeping for no_scheduling_allowed_.
 728     NOTREACHED() << "Illegal to schedule job while session in progress.";
 729     return;
 730   }
 731
 732   TrySyncSessionJob();
 733 }
 734
 735 void SyncSchedulerImpl::RetryTimerCallback() {
 736   TrySyncSessionJob();
 737 }
 738
 739 void SyncSchedulerImpl::Unthrottle() {
 740   DCHECK(CalledOnValidThread());
 741   DCHECK_EQ(WaitInterval::THROTTLED, wait_interval_->mode);
 742
 743   // We're no longer throttled, so clear the wait interval.
 744   wait_interval_.reset();
 745   NotifyRetryTime(base::Time());
 746   NotifyThrottledTypesChanged(nudge_tracker_.GetThrottledTypes());
 747
 748   // We treat this as a 'canary' in the sense that it was originally scheduled
 749   // to run some time ago, failed, and we now want to retry, versus a job that
 750   // was just created (e.g via ScheduleNudgeImpl). The main implication is
 751   // that we're careful to update routing info (etc) with such potentially
 752   // stale canary jobs.
 753   TryCanaryJob();
 754 }
 755
 756 void SyncSchedulerImpl::TypeUnthrottle(base::TimeTicks unthrottle_time) {
 757   DCHECK(CalledOnValidThread());
 758   nudge_tracker_.UpdateTypeThrottlingState(unthrottle_time);
 759   NotifyThrottledTypesChanged(nudge_tracker_.GetThrottledTypes());
 760
 761   if (nudge_tracker_.IsAnyTypeThrottled()) {
 762     const base::TimeTicks now = base::TimeTicks::Now();
 763     base::TimeDelta time_until_next_unthrottle =
 764         nudge_tracker_.GetTimeUntilNextUnthrottle(now);
 765     type_unthrottle_timer_.Start(
 766         FROM_HERE,
 767         time_until_next_unthrottle,
 768         base::Bind(&SyncSchedulerImpl::TypeUnthrottle,
 769                    weak_ptr_factory_.GetWeakPtr(),
 770                    now + time_until_next_unthrottle));
 771   }
 772
 773   // Maybe this is a good time to run a nudge job.  Let's try it.
 774   if (nudge_tracker_.IsSyncRequired() && CanRunNudgeJobNow(NORMAL_PRIORITY))
 775     TrySyncSessionJob();
 776 }
 777
 778 void SyncSchedulerImpl::PerformDelayedNudge() {
 779   // Circumstances may have changed since we scheduled this delayed nudge.
 780   // We must check to see if it's OK to run the job before we do so.
 781   if (CanRunNudgeJobNow(NORMAL_PRIORITY))
 782     TrySyncSessionJob();
 783
 784   // We're not responsible for setting up any retries here.  The functions that
 785   // first put us into a state that prevents successful sync cycles (eg. global
 786   // throttling, type throttling, network errors, transient errors) will also
 787   // setup the appropriate retry logic (eg. retry after timeout, exponential
 788   // backoff, retry when the network changes).
 789 }
 790
 791 void SyncSchedulerImpl::ExponentialBackoffRetry() {
 792   TryCanaryJob();
 793 }
 794
 795 void SyncSchedulerImpl::NotifyRetryTime(base::Time retry_time) {
 796   FOR_EACH_OBSERVER(SyncEngineEventListener,
 797                     *session_context_->listeners(),
 798                     OnRetryTimeChanged(retry_time));
 799 }
 800
 801 void SyncSchedulerImpl::NotifyThrottledTypesChanged(ModelTypeSet types) {
 802   FOR_EACH_OBSERVER(SyncEngineEventListener,
 803                     *session_context_->listeners(),
 804                     OnThrottledTypesChanged(types));
 805 }
 806
 807 bool SyncSchedulerImpl::IsBackingOff() const {
 808   DCHECK(CalledOnValidThread());
 809   return wait_interval_.get() && wait_interval_->mode ==
 810       WaitInterval::EXPONENTIAL_BACKOFF;
 811 }
 812
 813 void SyncSchedulerImpl::OnThrottled(const base::TimeDelta& throttle_duration) {
 814   DCHECK(CalledOnValidThread());
 815   wait_interval_.reset(new WaitInterval(WaitInterval::THROTTLED,
 816                                         throttle_duration));
 817   NotifyRetryTime(base::Time::Now() + wait_interval_->length);
 818   NotifyThrottledTypesChanged(ModelTypeSet::All());
 819 }
 820
 821 void SyncSchedulerImpl::OnTypesThrottled(
 822     ModelTypeSet types,
 823     const base::TimeDelta& throttle_duration) {
 824   base::TimeTicks now = base::TimeTicks::Now();
 825
 826   nudge_tracker_.SetTypesThrottledUntil(types, throttle_duration, now);
 827   base::TimeDelta time_until_next_unthrottle =
 828       nudge_tracker_.GetTimeUntilNextUnthrottle(now);
 829   type_unthrottle_timer_.Start(
 830       FROM_HERE,
 831       time_until_next_unthrottle,
 832       base::Bind(&SyncSchedulerImpl::TypeUnthrottle,
 833                  weak_ptr_factory_.GetWeakPtr(),
 834                  now + time_until_next_unthrottle));
 835   NotifyThrottledTypesChanged(nudge_tracker_.GetThrottledTypes());
 836 }
 837
 838 bool SyncSchedulerImpl::IsCurrentlyThrottled() {
 839   DCHECK(CalledOnValidThread());
 840   return wait_interval_.get() && wait_interval_->mode ==
 841       WaitInterval::THROTTLED;
 842 }
 843
 844 void SyncSchedulerImpl::OnReceivedShortPollIntervalUpdate(
 845     const base::TimeDelta& new_interval) {
 846   DCHECK(CalledOnValidThread());
 847   syncer_short_poll_interval_seconds_ = new_interval;
 848 }
 849
 850 void SyncSchedulerImpl::OnReceivedLongPollIntervalUpdate(
 851     const base::TimeDelta& new_interval) {
 852   DCHECK(CalledOnValidThread());
 853   syncer_long_poll_interval_seconds_ = new_interval;
 854 }
 855
 856 void SyncSchedulerImpl::OnReceivedSessionsCommitDelay(
 857     const base::TimeDelta& new_delay) {
 858   DCHECK(CalledOnValidThread());
 859   sessions_commit_delay_ = new_delay;
 860 }
 861
 862 void SyncSchedulerImpl::OnReceivedClientInvalidationHintBufferSize(int size) {
 863   if (size > 0)
 864     nudge_tracker_.SetHintBufferSize(size);
 865   else
 866     NOTREACHED() << "Hint buffer size should be > 0.";
 867 }
 868
 869 void SyncSchedulerImpl::OnSyncProtocolError(
 870     const SyncProtocolError& sync_protocol_error) {
 871   DCHECK(CalledOnValidThread());
 872   if (ShouldRequestEarlyExit(sync_protocol_error)) {
 873     SDVLOG(2) << "Sync Scheduler requesting early exit.";
 874     Stop();
 875   }
 876   if (IsActionableError(sync_protocol_error)) {
 877     SDVLOG(2) << "OnActionableError";
 878     FOR_EACH_OBSERVER(SyncEngineEventListener,
 879                       *session_context_->listeners(),
 880                       OnActionableError(sync_protocol_error));
 881   }
 882 }
 883
 884 void SyncSchedulerImpl::OnReceivedGuRetryDelay(const base::TimeDelta& delay) {
 885   nudge_tracker_.SetNextRetryTime(TimeTicks::Now() + delay);
 886   retry_timer_.Start(FROM_HERE, delay, this,
 887                      &SyncSchedulerImpl::RetryTimerCallback);
 888 }
 889
 890 void SyncSchedulerImpl::OnReceivedMigrationRequest(ModelTypeSet types) {
 891     FOR_EACH_OBSERVER(SyncEngineEventListener,
 892                       *session_context_->listeners(),
 893                       OnMigrationRequested(types));
 894 }
 895
 896 void SyncSchedulerImpl::SetNotificationsEnabled(bool notifications_enabled) {
 897   DCHECK(CalledOnValidThread());
 898   session_context_->set_notifications_enabled(notifications_enabled);
 899   if (notifications_enabled)
 900     nudge_tracker_.OnInvalidationsEnabled();
 901   else
 902     nudge_tracker_.OnInvalidationsDisabled();
 903 }
 904
 905 base::TimeDelta SyncSchedulerImpl::GetSessionsCommitDelay() const {
 906   DCHECK(CalledOnValidThread());
 907   return sessions_commit_delay_;
 908 }
 909
 910 #undef SDVLOG_LOC
 911
 912 #undef SDVLOG
 913
 914 #undef SLOG
 915
 916 #undef ENUM_CASE
 917
 918 }  // namespace syncer