libbrillo: Resets property update callback on UnregisterProperty

BUG=chromium:812468
TEST=Unit test added

Change-Id: I797852ffc456894d845b388feff1de56b922e49b
Reviewed-on: https://chromium-review.googlesource.com/974907
Commit-Ready: Sonny Sasaka <sonnysasaka@chromium.org>
Tested-by: Sonny Sasaka <sonnysasaka@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>

3 files changed, 12 insertions, 0 deletions

diff --git a/brillo/dbus/exported_property_set.cc b/brillo/dbus/exported_property_set.cc
index 31a99be..018843e 100644
--- a/brillo/dbus/exported_property_set.cc
+++ b/brillo/dbus/exported_property_set.cc
@@ -61,6 +61,7 @@ void ExportedPropertySet::UnregisterProperty(const std::string& interface_name,
   auto prop_iter = prop_map.find(property_name);
   CHECK(prop_iter != prop_map.end())
       << "Property '" << property_name << "' doesn't exist";
+  prop_iter->second->ClearUpdateCallback();
   prop_map.erase(prop_iter);
 }
 
@@ -170,6 +171,10 @@ void ExportedPropertyBase::SetUpdateCallback(const OnUpdateCallback& cb) {
   on_update_callback_ = cb;
 }
 
+void ExportedPropertyBase::ClearUpdateCallback() {
+  on_update_callback_.Reset();
+}
+
 void ExportedPropertyBase::SetAccessMode(
     ExportedPropertyBase::Access access_mode) {
   access_mode_ = access_mode;
diff --git a/brillo/dbus/exported_property_set.h b/brillo/dbus/exported_property_set.h
index 3d4b14b..61ea08a 100644
--- a/brillo/dbus/exported_property_set.h
+++ b/brillo/dbus/exported_property_set.h
@@ -71,6 +71,9 @@ class BRILLO_EXPORT ExportedPropertyBase {
   // interface of the exported object.
   virtual void SetUpdateCallback(const OnUpdateCallback& cb);
 
+  // Clears the update callback that was previously set with SetUpdateCallback.
+  virtual void ClearUpdateCallback();
+
   // Returns the contained value as Any.
   virtual brillo::Any GetValue() const = 0;
 
diff --git a/brillo/dbus/exported_property_set_unittest.cc b/brillo/dbus/exported_property_set_unittest.cc
index 4c03aef..93aceb4 100644
--- a/brillo/dbus/exported_property_set_unittest.cc
+++ b/brillo/dbus/exported_property_set_unittest.cc
@@ -342,6 +342,10 @@ TEST_F(ExportedPropertySetTest, GetRemovedProperty) {
 
   auto response = GetPropertyOnInterface(kTestInterface1, kBoolPropName);
   ASSERT_EQ(DBUS_ERROR_UNKNOWN_PROPERTY, response->GetErrorName());
+
+  // Signal should not be emitted for removed property.
+  EXPECT_CALL(*mock_exported_object_, SendSignal(_)).Times(0);
+  p_->bool_prop_.SetValue(true);
 }
 
 TEST_F(ExportedPropertySetTest, GetWorksWithBool) {