Added asynchronous notification of readiness to the StatisticsProvider, and

chrome/browser/metrics/metrics_service.cc

 // Copyright (c) 2012 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
@@ skipping 71 matching lines @@
 //    SENDING_OLD_LOGS,       // Sending unsent logs from previous session.
 //    SENDING_CURRENT_LOGS,   // Sending standard current logs as they accrue.
 //
 // In more detail, we have:
 //
 //    INITIALIZED,            // Constructor was called.
 // The MS has been constructed, but has taken no actions to compose the
 // initial log.
 //
 //    INIT_TASK_SCHEDULED,    // Waiting for deferred init tasks to complete.
-// Typically about 30 seconds after startup, a task is sent to a second thread
-// (the file thread) to perform deferred (lower priority and slower)
-// initialization steps such as getting the list of plugins.  That task will
-// (when complete) make an async callback (via a Task) to indicate the
-// completion.
+// Typically about 30 seconds after startup, a task is posted to perform
+// deferred (lower priority and slower) initialization steps such as getting the
+// list of plugins.  That task will (when complete) make an async callback (via
+// a Task) to indicate the completion.
 //
 //    INIT_TASK_DONE,         // Waiting for timer to send initial log.
 // The callback has arrived, and it is now possible for an initial log to be
 // created.  This callback typically arrives back less than one second after
 // the deferred init task is dispatched.
 //
 //    INITIAL_LOG_READY,      // Initial log generated, and waiting for reply.
 // This state is entered only after an initial log has been composed, and
 // prepared for transmission.  It is also the case that any previously unsent
 // logs have been loaded into instance variables for possible transmission.
@@ skipping 133 matching lines @@
 const size_t kUploadLogAvoidRetransmitSize = 50000;
 
 // Interval, in minutes, between state saves.
 const int kSaveStateIntervalMinutes = 5;
 
 // Used to indicate that the response code is currently not set at all --
 // RESPONSE_CODE_INVALID can sometimes be returned in response to a request if,
 // e.g., the server is down.
 const int kNoResponseCode = content::URLFetcher::RESPONSE_CODE_INVALID - 1;
 
+// Used to indicate that a report was generated before the hardware_class
+// property was available from the StatisticsProvider. This is used to identify
+// faulty reports from Chrome OS clients.
+const char kHardwareClassNotReady[] = "(not ready)";
+
 }
 
 // static
 MetricsService::ShutdownCleanliness MetricsService::clean_shutdown_status_ =
     MetricsService::CLEANLY_SHUTDOWN;
 
 // This is used to quickly log stats from child process related notifications in
 // MetricsService::child_stats_buffer_.  The buffer's contents are transferred
 // out when Local State is periodically saved.  The information is then
 // reported to the UMA server on next launch.
@@ skipping 487 matching lines @@
   size_t switch_count = command_line->GetSwitches().size();
   UMA_HISTOGRAM_COUNTS_100("Chrome.CommandLineFlagCount", switch_count);
   UMA_HISTOGRAM_COUNTS_100("Chrome.CommandLineUncommonFlagCount",
                            switch_count - common_commands);
 
   // Kick off the process of saving the state (so the uptime numbers keep
   // getting updated) every n minutes.
   ScheduleNextStateSave();
 }
 
-// static
-void MetricsService::InitTaskGetHardwareClass(
-    base::WeakPtr<MetricsService> self,
-    base::MessageLoopProxy* target_loop) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-
-  std::string hardware_class;
+void MetricsService::OnStatisticsProviderReady() {
 #if defined(OS_CHROMEOS)
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   chromeos::system::StatisticsProvider::GetInstance()->GetMachineStatistic(
-      "hardware_class", &hardware_class);
-#endif  // OS_CHROMEOS
-
-  target_loop->PostTask(FROM_HERE,
-      base::Bind(&MetricsService::OnInitTaskGotHardwareClass,
-          self, hardware_class));
+      "hardware_class", &hardware_class_);
+#endif
 }
 
-void MetricsService::OnInitTaskGotHardwareClass(
-    const std::string& hardware_class) {
+void MetricsService::InitTaskGetPluginInfo() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK_EQ(state_, INIT_TASK_SCHEDULED);
-  hardware_class_ = hardware_class;
 
   // Start the next part of the init task: loading plugin information.
   PluginService::GetInstance()->GetPlugins(
       base::Bind(&MetricsService::OnInitTaskGotPluginInfo,
-          self_ptr_factory_.GetWeakPtr()));
+                 self_ptr_factory_.GetWeakPtr()));
 }
 
 void MetricsService::OnInitTaskGotPluginInfo(
     const std::vector<webkit::WebPluginInfo>& plugins) {
   DCHECK_EQ(state_, INIT_TASK_SCHEDULED);
   plugins_ = plugins;
 
   if (state_ == INIT_TASK_SCHEDULED)
     state_ = INIT_TASK_DONE;
 }
@@ skipping 34 matching lines @@
 void MetricsService::StartRecording() {
   if (log_manager_.current_log())
     return;
 
   log_manager_.BeginLoggingWithLog(new MetricsLog(client_id_, session_id_),
                                    MetricsLogManager::ONGOING_LOG);
   if (state_ == INITIALIZED) {
     // We only need to schedule that run once.
     state_ = INIT_TASK_SCHEDULED;
 
-    // Schedules a task on the file thread for execution of slower
-    // initialization steps (such as plugin list generation) necessary
-    // for sending the initial log.  This avoids blocking the main UI
-    // thread.
-    BrowserThread::PostDelayedTask(
-        BrowserThread::FILE,
+#if defined(OS_CHROMEOS)
+    // The hardware class can only be retrieved once the StatisticsProvider is
+    // ready. This usually happens early enough, but can take longer on some
+    // faulty hardware. Use a temporary special marker to identify those cases.
+    hardware_class_ = kHardwareClassNotReady;

[Ilya Sherman, 2012/04/20 21:18:37]

nit: Any reason not to initialize this in the constructor?

[Joao da Silva, 2012/04/23 09:36:50]

Done.

+    chromeos::system::StatisticsProvider::GetInstance()->WhenReady(
+        base::Bind(&MetricsService::OnStatisticsProviderReady,
+                   self_ptr_factory_.GetWeakPtr()));
+#endif
+
+    // Schedules a delayed task for execution of slower initialization steps
+    // (such as plugin list generation) necessary for sending the initial log.
+    MessageLoop::current()->PostDelayedTask(
         FROM_HERE,
-        base::Bind(&MetricsService::InitTaskGetHardwareClass,
-            self_ptr_factory_.GetWeakPtr(),
-            MessageLoop::current()->message_loop_proxy()),
+        base::Bind(&MetricsService::InitTaskGetPluginInfo,
+                   self_ptr_factory_.GetWeakPtr()),
         base::TimeDelta::FromSeconds(kInitializationDelaySeconds));
   }
 }
 
 void MetricsService::StopRecording() {
   if (!log_manager_.current_log())
     return;
 
   // TODO(jar): Integrate bounds on log recording more consistently, so that we
   // can stop recording logs that are too big much sooner.
@@ skipping 813 matching lines @@
   if (local_state) {
     const PrefService::Preference* uma_pref =
         local_state->FindPreference(prefs::kMetricsReportingEnabled);
     if (uma_pref) {
       bool success = uma_pref->GetValue()->GetAsBoolean(&result);
       DCHECK(success);
     }
   }
   return result;
 }