Maint 9.1.x issue4037 add flag

Buildings/Resources/C-Sources/cfdSendStopCommand.c

@@ -29,7 +29,7 @@ void cfdSendStopCommand(void *thread) {
   cosim->para->flag = 0;
 
   /* Wait for the feedback from FFD*/
- while(cosim->para->flag==0 && i<imax) {
+ while(cosim->started==1 && cosim->para->flag==0 && i<imax) {
     if(cosim->para->ffdError==1) {
       ModelicaError(cosim->ffd->msg);
     }
@@ -43,7 +43,7 @@ void cfdSendStopCommand(void *thread) {
     if(cosim->para->ffdError==1) {
       ModelicaError(cosim->ffd->msg);
     }
-    else {
+    else if (cosim->started==1) {
       ModelicaMessage("Successfully stopped the FFD simulation.\n");
     }
   }

Buildings/Resources/C-Sources/cfdStartCosimulation.c

@@ -230,6 +230,7 @@ int cfdStartCosimulation(const char *cfdFilNam, const char **name, const double
   | Implicitly launch DLL module.
   ****************************************************************************/
   ffd_dll(cosim);
+  cosim->started = 1;
 
   return 0;
 } /* End of cfdStartCosimulation()*/

Buildings/Resources/C-Sources/cfdcosim.c

@@ -98,6 +98,7 @@ void *cfdcosim() {
   cosim->modelica->shaConSig = NULL;
   cosim->modelica->shaAbsRad = NULL;
   cosim->ffd->TSha = NULL;
+  cosim->started = 0;
 
   return (void*) cosim;
 } /* End of cfdcosim()*/

Buildings/Resources/src/FastFluidDynamics/modelica_ffd_common.h

@@ -72,6 +72,7 @@ typedef struct {
 }ffdSharedData;
 
 typedef struct{
+  int started; /* Flag to indicate if the Co-simulation has started or not. */
   ParameterSharedData *para;
   ffdSharedData *ffd;
   ModelicaSharedData *modelica;