Checkable: Extract parents directly from dependency groups

lib/icinga/checkable-dependency.cpp

@@ -250,12 +250,8 @@ bool Checkable::AffectsChildren() const
 std::set<Checkable::Ptr> Checkable::GetParents() const
 {
 	std::set<Checkable::Ptr> parents;
-
+	for (auto& dependencyGroup : GetDependencyGroups()) {
-	for (const Dependency::Ptr& dep : GetDependencies()) {
+		dependencyGroup->LoadParents(parents);
-		Checkable::Ptr parent = dep->GetParent();
-
-		if (parent && parent.get() != this)
-			parents.insert(parent);
 	}
 
 	return parents;

lib/icinga/dependency-group.cpp

@@ -133,6 +133,20 @@ std::vector<Dependency::Ptr> DependencyGroup::GetDependenciesForChild(const Chec
 	return dependencies;
 }
 
+/**
+ * Load all parent Checkables of the current dependency group.
+ *
+ * @param parents The set to load the parent Checkables into.
+ */
+void DependencyGroup::LoadParents(std::set<Checkable::Ptr>& parents) const
+{
+	std::lock_guard lock(m_Mutex);
+	for (auto& [compositeKey, children] : m_Members) {
+		ASSERT(!children.empty()); // We should never have an empty map for any given key at any given time.
+		parents.insert(std::get<0>(compositeKey));
+	}
+}
+
 /**
  * Retrieve the number of dependency objects in the current dependency group.
  *

lib/icinga/dependency.hpp

@@ -155,6 +155,7 @@ public:
 	void AddDependency(const Dependency::Ptr& dependency);
 	void RemoveDependency(const Dependency::Ptr& dependency);
 	std::vector<Dependency::Ptr> GetDependenciesForChild(const Checkable* child) const;
+	void LoadParents(std::set<Checkable::Ptr>& parents) const;
 	size_t GetDependenciesCount() const;
 
 	void SetIcingaDBIdentifier(const String& identifier);