Gracefully exit if Ctrl-C is pressed (#293)

* Feature: Gracefully exit if Ctrl-C is pressed
* Bugfix: Return error code on exit as set by application
* changelog

1 files changed, 41 insertions, 4 deletions

diff --git a/src/zenserver/zenserver.cpp b/src/zenserver/zenserver.cpp
index f9221ed0f..ce5e4e964 100644
--- a/src/zenserver/zenserver.cpp
+++ b/src/zenserver/zenserver.cpp
@@ -130,6 +130,16 @@ namespace zen {
 using namespace std::literals;
 
 namespace utils {
+	static std::atomic_uint32_t SignalCounter[NSIG] = {0};
+
+	static void SignalCallbackHandler(int SigNum)
+	{
+		if (SigNum >= 0 && SigNum < NSIG)
+		{
+			SignalCounter[SigNum].fetch_add(1);
+		}
+	}
+
 #if ZEN_USE_SENTRY
 	class sentry_sink final : public spdlog::sinks::base_sink<spdlog::details::null_mutex>
 	{
@@ -520,17 +530,36 @@ public:
 		EnsureIoRunner();
 	}
 
+	void EnqueueSigIntTimer()
+	{
+		m_SigIntTimer.expires_after(std::chrono::milliseconds(500));
+		m_SigIntTimer.async_wait([this](const asio::error_code&) { CheckSigInt(); });
+		EnsureIoRunner();
+	}
+
 	void CheckStateMarker()
 	{
 		std::filesystem::path StateMarkerPath = m_DataRoot / "state_marker";
 		if (!std::filesystem::exists(StateMarkerPath))
 		{
 			ZEN_ERROR("state marker at {} has been deleted, exiting", StateMarkerPath);
-			RequestExit(0);
+			RequestExit(1);
+			return;
 		}
 		EnqueueStateMarkerTimer();
 	}
 
+	void CheckSigInt()
+	{
+		if (utils::SignalCounter[SIGINT] > 0)
+		{
+			ZEN_INFO("SIGINT triggered (Ctrl+C), exiting");
+			RequestExit(128 + SIGINT);
+			return;
+		}
+		EnqueueSigIntTimer();
+	}
+
 	void CheckOwnerPid()
 	{
 		// Pick up any new "owner" processes
@@ -615,6 +644,7 @@ private:
 	asio::io_context				m_IoContext;
 	asio::steady_timer				m_PidCheckTimer{m_IoContext};
 	asio::steady_timer				m_StateMakerTimer{m_IoContext};
+	asio::steady_timer				m_SigIntTimer{m_IoContext};
 	zen::ProcessMonitor				m_ProcessMonitor;
 	zen::NamedMutex					m_ServerMutex;
 
@@ -686,6 +716,8 @@ ZenServer::OnReady()
 void
 ZenServer::InitializeState(const ZenServerOptions& ServerOptions)
 {
+	EnqueueSigIntTimer();
+
 	// Check root manifest to deal with schema versioning
 
 	bool		WipeState  = false;
@@ -1198,8 +1230,11 @@ ZenEntryPoint::Run()
 			ZEN_INFO("shutdown monitor thread waiting for shutdown signal '{}'", ShutdownEventName);
 			if (ShutdownEvent->Wait())
 			{
-				ZEN_INFO("shutdown signal received");
-				Server.RequestExit(0);
+				if (!IsApplicationExitRequested())
+				{
+					ZEN_INFO("shutdown signal received");
+					Server.RequestExit(0);
+				}
 			}
 			else
 			{
@@ -1235,7 +1270,7 @@ ZenEntryPoint::Run()
 
 	ShutdownLogging();
 
-	return 0;
+	return ApplicationExitCode();
 }
 
 }  // namespace zen
@@ -1306,6 +1341,8 @@ main(int argc, char* argv[])
 	}
 #endif
 
+	signal(SIGINT, utils::SignalCallbackHandler);
+
 	try
 	{
 		ZenServerOptions ServerOptions;