change error notification at subsystem shutdown to use just a string*

(this allows to memoize the error message and call the termination
handler outside the catch block)

src/common/guifacade.cpp

@@ -136,7 +136,7 @@ namespace gui {
         
         
         void
-        closeGuiModule (lumiera::Error *)
+        closeGuiModule (std::string *)
           {
             Lock guard (this);
             if (!facade)

src/common/subsys.hpp

@@ -71,7 +71,7 @@ namespace lumiera {
     : private noncopyable
     {
     public:
-      typedef function<void(Error*)> SigTerm;
+      typedef function<void(string*)> SigTerm;
       
       virtual ~Subsys();
       

src/common/subsystem-runner.hpp

@@ -31,6 +31,7 @@
 
 #include <tr1/functional>
 #include <vector>
+#include <string>
 
 
 namespace lumiera {
@@ -39,6 +40,7 @@ namespace lumiera {
   using std::tr1::function;
   using std::tr1::placeholders::_1;
   using std::vector;
+  using std::string;
   using util::cStr;
   using util::isnil;
   using util::and_all;
@@ -172,12 +174,13 @@ namespace lumiera {
         }   }
       
       void
-      sigTerm (Subsys* susy, Error* problem) ///< called from subsystem on termination
+      sigTerm (Subsys* susy, string* problem) ///< called from subsystem on termination
         {
           ASSERT (susy);
           Lock sync (this);
-          triggerEmergency(problem);
+          triggerEmergency(!isnil (problem));
           INFO (operate, "Subsystem '%s' terminated.", cStr(*susy));
+          WARN_IF (!isnil(problem), operate, "Irregular shutdown caused by: %s", cStr(*problem));
           ERROR_IF (susy->isRunning(), lumiera, "Subsystem '%s' signals termination, "
                                                 "without resetting running state", cStr(*susy));
           removeall (running_, susy);

src/gui/guistart.cpp

@@ -89,7 +89,7 @@ namespace gui {
         
        ~GuiLifecycle ()
           {
-            reportOnTermination_(0);    /////////TODO: pass on error information
+            reportOnTermination_(&error_);             // inform main thread that the GUI has been shut down. 
           }
         
         

src/lib/util.hpp

@@ -60,6 +60,13 @@ namespace util {
     return !pContainer || pContainer->empty();
   }
   
+  template <class CONT>
+  inline bool
+  isnil (CONT* pContainer)
+  {
+    return !pContainer || pContainer->empty();
+  }
+  
   inline bool
   isnil (const char* pCStr)
   {

tests/lib/subsystem-runner-test.cpp

@@ -165,13 +165,14 @@ namespace lumiera {
               lumiera_error();   //  reset error state....
                                 //   Note: in real life this actually
                                //    would be an catched exception!
+              string problemReport (problemIndicator.what());
               
               {
                 Lock guard (this);
                 isUp_ = false;
                 
                 INFO (test, "thread %s terminates.", cStr(*this));
-                termination ("true"==runSpec? 0 : &problemIndicator);
+                termination ("true"==runSpec? 0 : &problemReport);
             } }