MetricsService: ensure in-memory/pref execution phase are in sync

components/metrics/metrics_service.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 //------------------------------------------------------------------------------
 // Description of the life cycle of a instance of MetricsService.
 //
 //  OVERVIEW
 //
 // A MetricsService instance is typically created at application startup.  It is
@@ skipping 204 matching lines @@
       return BAD_REQUEST;
     default:
       return UNKNOWN_FAILURE;
   }
 }
 
 #if defined(OS_ANDROID) || defined(OS_IOS)
 void MarkAppCleanShutdownAndCommit(CleanExitBeacon* clean_exit_beacon,
                                    PrefService* local_state) {
   clean_exit_beacon->WriteBeaconValue(true);
+  // Note: the in-memory MetricsService::execution_phase_ is not updated.
   local_state->SetInteger(prefs::kStabilityExecutionPhase,
                           MetricsService::SHUTDOWN_COMPLETE);
   // Start writing right away (write happens on a different thread).
   local_state->CommitPendingWrite();
 }
 #endif  // defined(OS_ANDROID) || defined(OS_IOS)
 
 }  // namespace
 
 // static
@@ skipping 238 matching lines @@
     PushPendingLogsToPersistentStorage();
     // Persisting logs closes the current log, so start recording a new log
     // immediately to capture any background work that might be done before the
     // process is killed.
     OpenNewLog();
   }
 }
 
 void MetricsService::OnAppEnterForeground() {
   clean_exit_beacon_.WriteBeaconValue(false);
+  // Restore the execution phase stored in prefs.

[Alexei Svitkine (slow), 2016/11/24 21:20:20]

Nit: Mention MarkAppCleanShutdownAndCommit() here.

[manzagop (departed), 2016/11/24 22:40:42]

Done.

+  local_state_->SetInteger(prefs::kStabilityExecutionPhase, execution_phase_);
   StartSchedulerIfNecessary();
 }
 #else
 void MetricsService::LogNeedForCleanShutdown() {
   clean_exit_beacon_.WriteBeaconValue(false);
   // Redundant setting to be sure we call for a clean shutdown.
   clean_shutdown_status_ = NEED_TO_SHUTDOWN;
 }
 #endif  // defined(OS_ANDROID) || defined(OS_IOS)
 
@@ skipping 21 matching lines @@
 void MetricsService::ClearSavedStabilityMetrics() {
   for (MetricsProvider* provider : metrics_providers_)
     provider->ClearSavedStabilityMetrics();
 
   // Reset the prefs that are managed by MetricsService/MetricsLog directly.
   local_state_->SetInteger(prefs::kStabilityBreakpadRegistrationSuccess, 0);
   local_state_->SetInteger(prefs::kStabilityBreakpadRegistrationFail, 0);
   local_state_->SetInteger(prefs::kStabilityCrashCount, 0);
   local_state_->SetInteger(prefs::kStabilityDebuggerPresent, 0);
   local_state_->SetInteger(prefs::kStabilityDebuggerNotPresent, 0);
-  local_state_->SetInteger(prefs::kStabilityExecutionPhase,
-                           UNINITIALIZED_PHASE);
+  local_state_->SetInteger(prefs::kStabilityExecutionPhase, execution_phase_);

[Alexei Svitkine (slow), 2016/11/24 21:20:20]

I'm not sure this makes sense. Maybe better to just not set it?

[manzagop (departed), 2016/11/24 22:40:42]

Done.

The value needs to be preserved up to when it's consumed in
MetricsService::InitializeMetricsState.
https://cs.chromium.org/chromium/src/components/metrics/metrics_service.cc?sq...

But it's different from the other metrics, in that it's not an accumulation
metric.

After that, it gets shortly after overwritten to START_METRICS_RECORDING (and
this period it outside the uma crash mechanism coverage).
https://cs.chromium.org/chromium/src/components/metrics/metrics_service.cc?sq...

So I think it's fine to not set it.

   local_state_->SetInteger(prefs::kStabilityIncompleteSessionEndCount, 0);
   local_state_->SetInteger(prefs::kStabilityLaunchCount, 0);
   local_state_->SetBoolean(prefs::kStabilitySessionEndCompleted, true);
   local_state_->SetInteger(prefs::kStabilityDeferredCount, 0);
   // Note: kStabilityDiscardCount is not cleared as its intent is to measure
   // the number of times data is discarded, even across versions.
   local_state_->SetInteger(prefs::kStabilityVersionMismatchCount, 0);
 }
 
 void MetricsService::PushExternalLog(const std::string& log) {
@@ skipping 668 matching lines @@
     provider->RecordInitialHistogramSnapshots(&histogram_snapshot_manager_);
 }
 
 void MetricsService::LogCleanShutdown() {
   // Redundant setting to assure that we always reset this value at shutdown
   // (and that we don't use some alternate path, and not call LogCleanShutdown).
   clean_shutdown_status_ = CLEANLY_SHUTDOWN;
   client_->OnLogCleanShutdown();
   clean_exit_beacon_.WriteBeaconValue(true);
   RecordCurrentState(local_state_);
-  local_state_->SetInteger(prefs::kStabilityExecutionPhase,
-                           MetricsService::SHUTDOWN_COMPLETE);
+  SetExecutionPhase(MetricsService::SHUTDOWN_COMPLETE, local_state_);
 }
 
 void MetricsService::RecordBooleanPrefValue(const char* path, bool value) {
   DCHECK(IsSingleThreaded());
   local_state_->SetBoolean(path, value);
   RecordCurrentState(local_state_);
 }
 
 void MetricsService::RecordCurrentState(PrefService* pref) {
   pref->SetInt64(prefs::kStabilityLastTimestampSec,
                  base::Time::Now().ToTimeT());
 }
 
 void MetricsService::SkipAndDiscardUpload() {
   log_manager_.DiscardStagedLog();
   scheduler_->UploadCancelled();
   log_upload_in_progress_ = false;
 }
 
 }  // namespace metrics