chromeos: Don't spam logs with tlsdate D-Bus errors at boot.

chromeos/dbus/system_clock_client.cc

 // Copyright (c) 2013 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 "chromeos/dbus/system_clock_client.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "dbus/bus.h"
 #include "dbus/message.h"
 #include "dbus/object_path.h"
 #include "dbus/object_proxy.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"
 
 namespace chromeos {
 
 // The SystemClockClient implementation used in production.
 class SystemClockClientImpl : public SystemClockClient {
  public:
   SystemClockClientImpl()
       : can_set_time_(false),
-        can_set_time_initialized_(false),
-        system_clock_proxy_(NULL),
+        system_clock_proxy_(nullptr),
         weak_ptr_factory_(this) {}
 
   ~SystemClockClientImpl() override {}
 
   void AddObserver(Observer* observer) override {
     observers_.AddObserver(observer);
   }
 
   void RemoveObserver(Observer* observer) override {
     observers_.RemoveObserver(observer);
@@ skipping 14 matching lines @@
                                     dbus::ObjectProxy::EmptyResponseCallback());
   }
 
   bool CanSetTime() override { return can_set_time_; }
 
  protected:
   void Init(dbus::Bus* bus) override {
     system_clock_proxy_ = bus->GetObjectProxy(
         system_clock::kSystemClockServiceName,
         dbus::ObjectPath(system_clock::kSystemClockServicePath));
-
-    // Check whether the system clock can be set.
-    GetCanSet();
-
-    // Monitor the D-Bus signal for TimeUpdated changes.
     system_clock_proxy_->ConnectToSignal(
         system_clock::kSystemClockInterface,
         system_clock::kSystemClockUpdated,
         base::Bind(&SystemClockClientImpl::TimeUpdatedReceived,
                    weak_ptr_factory_.GetWeakPtr()),
         base::Bind(&SystemClockClientImpl::TimeUpdatedConnected,
                    weak_ptr_factory_.GetWeakPtr()));
+    system_clock_proxy_->WaitForServiceToBeAvailable(
+        base::Bind(&SystemClockClientImpl::ProxyAvailabilityChanged,
+                   weak_ptr_factory_.GetWeakPtr()));
   }
 
  private:
+  void ProxyAvailabilityChanged(bool service_is_available) {

[Daniel Erat, 2016/08/11 01:15:46]

i should rename this and change the code. this is actually only called once,
when the service becomes available. (it's unlikely that it'll ever see a false
argument.)

[michaelpg, 2016/08/11 03:21:08]

what would make the service unavailable after the timeout? (and how long is the
timeout?)

+    VLOG(1) << "D-Bus proxy is " << (service_is_available ? "" : "un")
+            << "available";
+
+    if (service_is_available) {
+      GetCanSet();
+    } else if (can_set_time_) {
+      can_set_time_ = false;
+      FOR_EACH_OBSERVER(Observer, observers_,
+                        SystemClockCanSetTimeChanged(can_set_time_));
+    }
+  }
+
   // Called when a TimeUpdated signal is received.
   void TimeUpdatedReceived(dbus::Signal* signal) {
     VLOG(1) << "TimeUpdated signal received: " << signal->ToString();
     dbus::MessageReader reader(signal);
     FOR_EACH_OBSERVER(Observer, observers_, SystemClockUpdated());
 
     // Check if the system clock can be changed now.
     GetCanSet();
   }
 
@@ skipping 12 matching lines @@
       return;
     }
 
     dbus::MessageReader reader(response);
     bool can_set_time;
     if (!reader.PopBool(&can_set_time)) {
       LOG(ERROR) << "CanSetTime response invalid: " << response->ToString();
       return;
     }
 
-    // Nothing to do if the CanSetTime response hasn't changed.
-    if (can_set_time_initialized_ && can_set_time_ == can_set_time)
-      return;
-
-    can_set_time_initialized_ = true;
-    can_set_time_ = can_set_time;
-
-    FOR_EACH_OBSERVER(
-        Observer, observers_, SystemClockCanSetTimeChanged(can_set_time));
+    if (can_set_time_ != can_set_time) {
+      can_set_time_ = can_set_time;
+      FOR_EACH_OBSERVER(Observer, observers_,
+                        SystemClockCanSetTimeChanged(can_set_time));
+    }
   }
 
   // Check whether the time can be set.
   void GetCanSet() {
     dbus::MethodCall method_call(system_clock::kSystemClockInterface,
                                  system_clock::kSystemClockCanSet);
     dbus::MessageWriter writer(&method_call);
     system_clock_proxy_->CallMethod(
-        &method_call,
-        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+        &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
         base::Bind(&SystemClockClientImpl::OnGetCanSet,
                    weak_ptr_factory_.GetWeakPtr()));
   }
 
   // Whether the time can be set. Value is false until the first
   // CanSetTime response is received.
   bool can_set_time_;
-  bool can_set_time_initialized_;
   dbus::ObjectProxy* system_clock_proxy_;
   base::ObserverList<Observer> observers_;
 
   base::WeakPtrFactory<SystemClockClientImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemClockClientImpl);
 };
 
-void SystemClockClient::Observer::SystemClockUpdated() {
-}
-
-void SystemClockClient::Observer::SystemClockCanSetTimeChanged(
-    bool can_set_time) {
-}
-
-SystemClockClient::SystemClockClient() {
-}
-
-SystemClockClient::~SystemClockClient() {
-}
-
 // static
 SystemClockClient* SystemClockClient::Create() {
   return new SystemClockClientImpl();
 }
 
+SystemClockClient::SystemClockClient() {}
+
 }  // namespace chromeos