call prepare() for all Modules during server start up

include/Module.h

@@ -36,13 +36,14 @@ namespace ChimeraTK {
       /** Destructor */
       virtual ~Module();
 
-      /** Prepare the execution of the module. */
+      /** Prepare the execution of the module. This function is called before any module is started (including internal
+       *  modules like FanOuts) and before the initial values of the variables are pushed into the queues. */
       virtual void prepare() {};
 
       /** Execute the module. */
       virtual void run() {};
 
-      /** Terminate the module. Must be called before destruction, if run() was called previously. */
+      /** Terminate the module. Must/will be called before destruction, if run() was called previously. */
       virtual void terminate() {};
       
       /** Wait for receiving an update for any of the push-type variables in the group. Any poll-type variables are

src/Application.cc

@@ -129,6 +129,11 @@ void Application::run() {
         "Error: An instance of Application must have its applicationName set.");
   }
 
+  // prepare the modules
+  for(auto &module : getSubmoduleListRecursive()) {
+    module->prepare();
+  }
+
   // start the necessary threads for the FanOuts etc.
   for(auto &internalModule : internalModuleList) {
     internalModule->activate();
@@ -148,6 +153,7 @@ void Application::run() {
   for(auto &module : getSubmoduleListRecursive()) {
     module->run();
   }
+
 }
 
 /*********************************************************************************************************************/