Shill: Delay the ConnectToSignal call until an observer is added.

chromeos/dbus/shill_client_helper.cc

Index: chromeos/dbus/shill_client_helper.cc
diff --git a/chromeos/dbus/shill_client_helper.cc b/chromeos/dbus/shill_client_helper.cc
index c83bfe0b9d3530f1c9f859eeba37beb225e625d7..d9a491287d37a641473a9f635827d026f3d60510 100644
--- a/chromeos/dbus/shill_client_helper.cc
+++ b/chromeos/dbus/shill_client_helper.cc
@@ -35,6 +35,13 @@ ShillClientHelper::~ShillClientHelper() {
 
 void ShillClientHelper::AddPropertyChangedObserver(
     ShillPropertyChangedObserver* observer) {
+  // Excecutes all the pending MonitorPropertyChanged calls.
+  for (std::vector<std::string>::iterator it = monitored_interfaces_.begin();
+      it != monitored_interfaces_.end(); ++it) {
+    MonitorPropertyChangedInternal(*it);
+  }
+  monitored_interfaces_.clear();
+
   observer_list_.AddObserver(observer);
 }
 
@@ -45,6 +52,16 @@ void ShillClientHelper::RemovePropertyChangedObserver(
 
 void ShillClientHelper::MonitorPropertyChanged(
     const std::string& interface_name) {
+  if (observer_list_.size() > 0)

[hashimoto, 2013/02/13 04:01:31]

nit: if-statement without curly braces are not allowed for multiple line cases.

[deymo, 2013/02/13 05:41:07]

Done.

+    // Effectively monitor the PropertyChanged now.
+    MonitorPropertyChangedInternal(interface_name);
+  else
+    // Delay the ConnectToSignal until an observer is added.
+    monitored_interfaces_.push_back(interface_name);
+}
+
+void ShillClientHelper::MonitorPropertyChangedInternal(
+    const std::string& interface_name) {
   // We are not using dbus::PropertySet to monitor PropertyChanged signal
   // because the interface is not "org.freedesktop.DBus.Properties".
   proxy_->ConnectToSignal(interface_name,