Introduce CheckResultProducerComponent

Author: Al2Klimov

lib/remote/CMakeLists.txt

@@ -13,6 +13,7 @@ set(remote_SOURCES
   apilistener.cpp apilistener.hpp apilistener-ti.hpp apilistener-configsync.cpp apilistener-filesync.cpp
   apilistener-authority.cpp
   apiuser.cpp apiuser.hpp apiuser-ti.hpp
+  crproducer.cpp crproducer.hpp
   configfileshandler.cpp configfileshandler.hpp
   configobjectslock.cpp configobjectslock.hpp
   configobjectutility.cpp configobjectutility.hpp

lib/remote/crproducer.cpp

@@ -0,0 +1,47 @@
+/* Icinga 2 | (c) 2025 Icinga GmbH | GPLv2+ */
+
+#include "remote/crproducer.hpp"
+
+using namespace icinga;
+
+bool CheckResultProducerComponent::try_lock_shared() noexcept
+{
+	std::unique_lock lock (m_Mutex);
+
+	if (m_InstanceIsActive) {
+		++m_ProcessingCheckResults;
+		return true;
+	}
+
+	return false;
+}
+
+void CheckResultProducerComponent::unlock_shared() noexcept
+{
+	std::unique_lock lock (m_Mutex);
+
+	if (!--m_ProcessingCheckResults && !m_InstanceIsActive) {
+		m_CV.notify_all();
+	}
+}
+
+/**
+ * Allow processing check results.
+ */
+void CheckResultProducerComponent::Start()
+{
+	std::unique_lock lock (m_Mutex);
+
+	m_InstanceIsActive = true;
+}
+
+/**
+ * Disallow processing new check results, wait for all currently processed ones to finish.
+ */
+void CheckResultProducerComponent::Stop()
+{
+	std::unique_lock lock (m_Mutex);
+
+	m_InstanceIsActive = false;
+	m_CV.wait(lock, [this] { return !m_ProcessingCheckResults; });
+}

lib/remote/crproducer.hpp

@@ -0,0 +1,54 @@
+/* Icinga 2 | (c) 2025 Icinga GmbH | GPLv2+ */
+
+#pragma once
+
+#include "base/object.hpp"
+#include <condition_variable>
+#include <cstdint>
+#include <mutex>
+
+namespace icinga
+{
+
+/**
+ * A component that produces check results and hence is responsible for them, e.g. CheckerComponent.
+ * I.e. on its shutdown it has to clean up and/or wait for its own ongoing checks if any.
+ *
+ * @ingroup icinga
+ */
+class CheckResultProducer : virtual public Object
+{
+public:
+	DECLARE_PTR_TYPEDEFS(CheckResultProducer);
+
+	/**
+	 * Requests to delay the producer shutdown (if any) for a CheckResult to be processed.
+	 *
+	 * @return Whether request was accepted.
+	 */
+	virtual bool try_lock_shared() noexcept = 0;
+
+	/**
+	 * Releases one semaphore slot acquired for CheckResult processing.
+	 */
+	virtual void unlock_shared() noexcept = 0;
+};
+
+class CheckResultProducerComponent : public CheckResultProducer
+{
+public:
+	bool try_lock_shared() noexcept override;
+	void unlock_shared() noexcept override;
+
+protected:
+	void Start();
+	void Stop();
+
+private:
+	std::mutex m_Mutex;
+	std::condition_variable m_CV;
+	bool m_InstanceIsActive = false;
+	uint_fast32_t m_ProcessingCheckResults = 0;
+};
+
+}