From a742e64e4d0bd7030746c3d409865808307e7ad4 Mon Sep 17 00:00:00 2001
From: Jean Flach <jean-marcel.flach@icinga.com>
Date: Wed, 14 Mar 2018 10:01:11 +0100
Subject: [PATCH] Fix reload handling

Make sure we have written the new PID before letting it take over.
---
 lib/base/application.cpp  | 34 +++++++++++++++-------------------
 lib/cli/daemoncommand.cpp |  9 ++++++++-
 2 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/lib/base/application.cpp b/lib/base/application.cpp
index 6f0f9d660..f28946abd 100644
--- a/lib/base/application.cpp
+++ b/lib/base/application.cpp
@@ -90,25 +90,7 @@ void Application::Stop(bool runtimeRemoved)
 	WSACleanup();
 #endif /* _WIN32 */
 
-	// Getting a shutdown-signal when a restart is in progress usually
-	// means that the restart succeeded and the new process wants to take
-	// over. Write the PID of the new process to the pidfile before this
-	// process exits to keep systemd happy.
-	if (l_Restarting) {
-		try {
-			UpdatePidFile(GetPidPath(), m_ReloadProcess);
-		} catch (const std::exception&) {
-			/* abort restart */
-			Log(LogCritical, "Application", "Cannot update PID file. Aborting restart operation.");
-			return;
-		}
-
-		Log(LogDebug, "Application")
-			<< "Keeping pid  '" << m_ReloadProcess << "' open.";
-
-		ClosePidFile(false);
-	} else
-		ClosePidFile(true);
+	ClosePidFile(true);
 
 	ObjectImpl<Application>::Stop(runtimeRemoved);
 }
@@ -741,6 +723,20 @@ void Application::SigUsr2Handler(int)
 	sd_notifyf(0, "MAINPID=%lu", (unsigned long) m_ReloadProcess);
 #endif /* HAVE_SYSTEMD */
 
+	/* Write the PID of the new process to the pidfile before this
+	 * process exits to keep systemd happy.
+	 */
+	Application::Ptr instance = GetInstance();
+	try {
+		instance->UpdatePidFile(GetPidPath(), m_ReloadProcess);
+	} catch (const std::exception&) {
+		/* abort restart */
+		Log(LogCritical, "Application", "Cannot update PID file. Aborting restart operation.");
+		return;
+	}
+
+	instance->ClosePidFile(false);
+
 	Exit(0);
 }
 
diff --git a/lib/cli/daemoncommand.cpp b/lib/cli/daemoncommand.cpp
index 199fa67ff..5b34bc18d 100644
--- a/lib/cli/daemoncommand.cpp
+++ b/lib/cli/daemoncommand.cpp
@@ -262,10 +262,17 @@ int DaemonCommand::Run(const po::variables_map& vm, const std::vector<std::strin
 		Log(LogInformation, "cli", "Requesting to take over.");
 		int rc = kill(vm["reload-internal"].as<int>(), SIGUSR2);
 		if (rc) {
-			Log(LogCritical, "Application")
+			Log(LogCritical, "cli")
 				<< "Failed to send signal to \"" << vm["reload-internal"].as<int>() <<  "\" with " << strerror(errno);
 			return EXIT_FAILURE;
 		}
+
+		double start = Utility::GetTime();
+		while (kill(vm["reload-internal"].as<int>(), SIGCHLD) == 0)
+			Utility::Sleep(0.2);
+
+		Log(LogNotice, "cli")
+			<< "Waited for " << Utility::FormatDuration(Utility::GetTime() - start) << " on old process to exit.";
 	}
 #endif /* _WIN32 */