From 88b3b8ef1895dc0cb2b0a70141b2866ab8df1ce7 Mon Sep 17 00:00:00 2001
From: Dennis Klein <d.klein@gsi.de>
Date: Wed, 20 Sep 2017 18:10:56 +0200
Subject: [PATCH] FairMQ: Make sure --catch-signals is always handled

---
 fairmq/plugins/Control.cxx | 63 +++++++++++++++++++-------------------
 fairmq/plugins/Control.h   |  2 +-
 2 files changed, 33 insertions(+), 32 deletions(-)

diff --git a/fairmq/plugins/Control.cxx b/fairmq/plugins/Control.cxx
index 8babf320..0c2a4bb1 100644
--- a/fairmq/plugins/Control.cxx
+++ b/fairmq/plugins/Control.cxx
@@ -17,6 +17,7 @@ using namespace std;
 
 namespace
 {
+    // ugly global state, but std::signal gives us no other choice
     std::function<void(int)> gSignalHandlerClosure;
 
     extern "C" auto signal_handler(int signal) -> void
@@ -62,24 +63,24 @@ Control::Control(const string name, const Plugin::Version version, const string
             LOG(ERROR) << "Unrecognized control mode '" << control << "' requested. " << "Ignoring and falling back to static control mode.";
             fControllerThread = thread(&Control::StaticMode, this);
         }
-
-        LOG(DEBUG) << "catch-signals: " << GetProperty<int>("catch-signals");
-        if (GetProperty<int>("catch-signals") > 0)
-        {
-            gSignalHandlerClosure = bind(&Control::SignalHandler, this, placeholders::_1);
-            signal(SIGINT, signal_handler);
-            signal(SIGTERM, signal_handler);
-        }
-        else
-        {
-            LOG(WARN) << "Signal handling (e.g. Ctrl-C) has been deactivated.";
-        }
     }
     catch (PluginServices::DeviceControlError& e)
     {
         // If we are here, it means another plugin has taken control. That's fine, just print the exception message and do nothing else.
         LOG(DEBUG) << e.what();
     }
+
+    LOG(DEBUG) << "catch-signals: " << GetProperty<int>("catch-signals");
+    if (GetProperty<int>("catch-signals") > 0)
+    {
+        gSignalHandlerClosure = bind(&Control::SignalHandler, this, placeholders::_1);
+        signal(SIGINT, signal_handler);
+        signal(SIGTERM, signal_handler);
+    }
+    else
+    {
+        LOG(WARN) << "Signal handling (e.g. Ctrl-C) has been deactivated.";
+    }
 }
 
 auto ControlPluginProgramOptions() -> Plugin::ProgOptions
@@ -96,15 +97,6 @@ auto Control::InteractiveMode() -> void
 {
     try
     {
-        SubscribeToDeviceStateChange([&](DeviceState newState)
-        {
-            {
-                lock_guard<mutex> lock{fEventsMutex};
-                fEvents.push(newState);
-            }
-            fNewEvent.notify_one();
-        });
-
         RunStartupSequence();
 
         char input; // hold the user console input
@@ -226,15 +218,6 @@ auto Control::StaticMode() -> void
 {
     try
     {
-        SubscribeToDeviceStateChange([&](DeviceState newState)
-        {
-            {
-                lock_guard<mutex> lock{fEventsMutex};
-                fEvents.push(newState);
-            }
-            fNewEvent.notify_one();
-        });
-
         RunStartupSequence();
     
         {
@@ -261,7 +244,6 @@ auto Control::StaticMode() -> void
 
 auto Control::SignalHandler(int signal) -> void
 {
-
     if (!fDeviceTerminationRequested)
     {
         fDeviceTerminationRequested = true;
@@ -271,6 +253,16 @@ auto Control::SignalHandler(int signal) -> void
         LOG(INFO) << "Received device shutdown request (signal " << signal << ").";
         LOG(INFO) << "Waiting for graceful device shutdown. Hit Ctrl-C again to abort immediately.";
 
+        UnsubscribeFromDeviceStateChange(); // In case, static or interactive mode have subscribed already
+        SubscribeToDeviceStateChange([&](DeviceState newState)
+        {
+            {
+                lock_guard<mutex> lock{fEventsMutex};
+                fEvents.push(newState);
+            }
+            fNewEvent.notify_one();
+        });
+
         fSignalHandlerThread = thread(&Control::RunShutdownSequence, this);
     }
     else
@@ -317,6 +309,15 @@ auto Control::RunShutdownSequence() -> void
 
 auto Control::RunStartupSequence() -> void
 {
+    SubscribeToDeviceStateChange([&](DeviceState newState)
+    {
+        {
+            lock_guard<mutex> lock{fEventsMutex};
+            fEvents.push(newState);
+        }
+        fNewEvent.notify_one();
+    });
+
     ChangeDeviceState(DeviceStateTransition::InitDevice);
     while (WaitForNextState() != DeviceState::DeviceReady) {}
     ChangeDeviceState(DeviceStateTransition::InitTask);
diff --git a/fairmq/plugins/Control.h b/fairmq/plugins/Control.h
index 85a891aa..7b445c09 100644
--- a/fairmq/plugins/Control.h
+++ b/fairmq/plugins/Control.h
@@ -55,7 +55,7 @@ auto ControlPluginProgramOptions() -> Plugin::ProgOptions;
 REGISTER_FAIRMQ_PLUGIN(
     Control,                                     // Class name
     control,                                     // Plugin name (string, lower case chars only)
-    (Plugin::Version{1,0,0}),                    // Version
+    (Plugin::Version{1,0,1}),                    // Version
     "FairRootGroup <fairroot@gsi.de>",           // Maintainer
     "https://github.com/FairRootGroup/FairRoot", // Homepage
     ControlPluginProgramOptions                  // Free function which declares custom program options for the plugin