Added retry policy

chrome/browser/chromeos/login/enrollment/enrollment_screen.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.
 
 #include "chrome/browser/chromeos/login/enrollment/enrollment_screen.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/command_line.h"
@@ skipping 34 matching lines @@
 
 namespace {
 
 const char * const kMetricEnrollmentTimeCancel =
     "Enterprise.EnrollmentTime.Cancel";
 const char * const kMetricEnrollmentTimeFailure =
     "Enterprise.EnrollmentTime.Failure";
 const char * const kMetricEnrollmentTimeSuccess =
     "Enterprise.EnrollmentTime.Success";
 
+// Retry policy constants.
+const int INITIAL_DELAY_MS = 4 * 1000;  // 4 seconds

[xiyuan, 2017/02/03 23:34:14]

nit: constant should be name as kTheConstantName, like the above. And chromium
code prefers to use constexpr in new code.

i.e.
constexpr int kInitialDelayMs = 4 * 1000;  // 4 seconds

[kumarniranjan, 2017/02/06 21:38:24]

Done.

+const double MULTIPLY_FACTOR = 1.5;
+const double JITTER_FACTOR = 0.1;            // +/- 10% jitter
+const int64_t MAX_DELAY_MS = 8 * 60 * 1000;  // 8 minutes
+
+// Helper function. Returns true if we are using Hands Off Enrollment.
+bool UsingHandsOffEnrollment() {
+  return policy::DeviceCloudPolicyManagerChromeOS::
+             GetZeroTouchEnrollmentMode() ==
+         policy::ZeroTouchEnrollmentMode::HANDS_OFF;
+}
+
 }  // namespace
 
 namespace chromeos {
 
 // static
 EnrollmentScreen* EnrollmentScreen::Get(ScreenManager* manager) {
   return static_cast<EnrollmentScreen*>(
       manager->GetScreen(OobeScreen::SCREEN_OOBE_ENROLLMENT));
 }
 
 EnrollmentScreen::EnrollmentScreen(BaseScreenDelegate* base_screen_delegate,
                                    EnrollmentScreenActor* actor)
     : BaseScreen(base_screen_delegate, OobeScreen::SCREEN_OOBE_ENROLLMENT),
       actor_(actor),
-      weak_ptr_factory_(this) {}
+      weak_ptr_factory_(this) {
+  retry_policy_.num_errors_to_ignore = 0;
+  retry_policy_.initial_delay_ms = INITIAL_DELAY_MS;
+  retry_policy_.multiply_factor = MULTIPLY_FACTOR;
+  retry_policy_.jitter_factor = JITTER_FACTOR;
+  retry_policy_.maximum_backoff_ms = MAX_DELAY_MS;
+  retry_policy_.entry_lifetime_ms = -1;
+  retry_policy_.always_use_initial_delay = true;
+  retry_backoff_.reset(new net::BackoffEntry(&retry_policy_));
+}
 
 EnrollmentScreen::~EnrollmentScreen() {
   DCHECK(!enrollment_helper_ || g_browser_process->IsShuttingDown());
 }
 
 void EnrollmentScreen::SetParameters(
     const policy::EnrollmentConfig& enrollment_config,
     pairing_chromeos::ControllerPairingController* shark_controller) {
   enrollment_config_ = enrollment_config;
   switch (enrollment_config_.auth_mechanism) {
@@ skipping 103 matching lines @@
   // TODO(rsorokin): Move ShowAdJoin after STEP_REGISTRATION
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           chromeos::switches::kEnableAd)) {
     actor_->ShowAdJoin();
   } else {
     OnAdJoined("");
   }
 }
 
 void EnrollmentScreen::OnRetry() {
+  retry_task_.Cancel();
+  ProcessRetry();
+}
+
+void EnrollmentScreen::AutomaticRetry() {
+  retry_backoff_->InformOfRequest(false);
+  retry_task_.Reset(base::Bind(&EnrollmentScreen::ProcessRetry,
+                               weak_ptr_factory_.GetWeakPtr()));
+
+  base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+      FROM_HERE, retry_task_.callback(), retry_backoff_->GetTimeUntilRelease());
+}
+
+void EnrollmentScreen::ProcessRetry() {
+  num_retries_++;

[xiyuan, 2017/02/03 23:34:14]

nit: use pre-increment,
i.e.
  ++num_retries_;

[kumarniranjan, 2017/02/06 21:38:24]

Done.

+  LOG(WARNING) << "Enrollment retry " << num_retries_;
   Show();
 }
 
 void EnrollmentScreen::OnCancel() {
   if (AdvanceToNextAuth()) {
     Show();
     return;
   }
 
   UMA(policy::kMetricEnrollmentCancelled);
@@ skipping 33 matching lines @@
 void EnrollmentScreen::OnEnrollmentError(policy::EnrollmentStatus status) {
   // TODO(pbond): remove this LOG once http://crbug.com/586961 is fixed.
   LOG(WARNING) << "Enrollment error occured: status=" << status.status()
                << " http status=" << status.http_status()
                << " DM status=" << status.client_status();
   RecordEnrollmentErrorMetrics();
   // If the DM server does not have a device pre-provisioned for attestation-
   // based enrollment and we have a fallback authentication, show it.
   if (status.status() == policy::EnrollmentStatus::REGISTRATION_FAILED &&
       status.client_status() == policy::DM_STATUS_SERVICE_DEVICE_NOT_FOUND &&
-      current_auth_ == AUTH_ATTESTATION && AdvanceToNextAuth())
+      current_auth_ == AUTH_ATTESTATION && AdvanceToNextAuth()) {
     Show();
-  else
+  } else {
     actor_->ShowEnrollmentStatus(status);
+    if (UsingHandsOffEnrollment())
+      AutomaticRetry();
+  }
 }
 
 void EnrollmentScreen::OnOtherError(
     EnterpriseEnrollmentHelper::OtherError error) {
   RecordEnrollmentErrorMetrics();
   actor_->ShowOtherError(error);
+  if (UsingHandsOffEnrollment())
+    AutomaticRetry();
 }
 
 void EnrollmentScreen::OnDeviceEnrolled(const std::string& additional_token) {
   // TODO(pbond): remove this LOG once http://crbug.com/586961 is fixed.
   LOG(WARNING) << "Device is successfully enrolled.";
   if (!additional_token.empty())
     SendEnrollmentAuthToken(additional_token);
 
   enrollment_helper_->GetDeviceAttributeUpdatePermission();
 }
@@ skipping 50 matching lines @@
   std::string location = policy ? policy->annotated_location() : std::string();
   actor_->ShowAttributePromptScreen(asset_id, location);
 }
 
 void EnrollmentScreen::SendEnrollmentAuthToken(const std::string& token) {
   DCHECK(shark_controller_);
   shark_controller_->OnAuthenticationDone(enrolling_user_domain_, token);
 }
 
 void EnrollmentScreen::ShowEnrollmentStatusOnSuccess() {
+  retry_backoff_->InformOfRequest(true);
   if (elapsed_timer_)
     UMA_ENROLLMENT_TIME(kMetricEnrollmentTimeSuccess, elapsed_timer_);
   actor_->ShowEnrollmentStatus(
       policy::EnrollmentStatus::ForStatus(policy::EnrollmentStatus::SUCCESS));
 }
 
 void EnrollmentScreen::UMA(policy::MetricEnrollment sample) {
   EnrollmentUMA(sample, config_.mode);
 }
 
 void EnrollmentScreen::ShowSigninScreen() {
   actor_->Show();
   actor_->ShowSigninScreen();
 }
 
 void EnrollmentScreen::RecordEnrollmentErrorMetrics() {
   enrollment_failed_once_ = true;
   //  TODO(drcrash): Maybe create multiple metrics (http://crbug.com/640313)?
   if (elapsed_timer_)
     UMA_ENROLLMENT_TIME(kMetricEnrollmentTimeFailure, elapsed_timer_);
 }
 
 }  // namespace chromeos