Make calling MPI_Finalize() at destruciotn of MPIManager switchable

src/core/mpi/Environment.h

@@ -48,8 +48,8 @@ int main( int argc, char ** argv )
 class Environment
 {
 public:
-   Environment( int & argc, char ** & argv, bool abortOnException = true ) {
-      MPIManager::instance()->initializeMPI( &argc, &argv, abortOnException );
+   Environment( int & argc, char ** & argv, bool abortOnException = true, bool finalizeOnDestruction=true ) {
+      MPIManager::instance()->initializeMPI( &argc, &argv, abortOnException, finalizeOnDestruction);
    }
    ~Environment() {
       MPIManager::instance()->finalizeMPI();

src/core/mpi/MPIManager.cpp

@@ -90,7 +90,7 @@ void MPIManager::abort()
 }
 
 
-void MPIManager::initializeMPI( int* argc, char*** argv, bool abortOnException )
+void MPIManager::initializeMPI( int* argc, char*** argv, bool abortOnException, bool finalizeOnDestruction )
 {
    WALBERLA_MPI_SECTION()
    {
@@ -111,6 +111,7 @@ void MPIManager::initializeMPI( int* argc, char*** argv, bool abortOnException )
 
       if( abortOnException )
          std::set_terminate( customTerminateHandler );
+      finalizeOnDestruction_ = finalizeOnDestruction;
    }
 }
 
@@ -122,7 +123,8 @@ void MPIManager::finalizeMPI()
       if( isMPIInitialized_ && !currentlyAborting_ )
       {
          isMPIInitialized_ = false;
-         MPI_Finalize();
+         if (finalizeOnDestruction_)
+           MPI_Finalize();
       }
    }
 }

src/core/mpi/MPIManager.h

@@ -63,8 +63,9 @@ public:
     * Configures the class, initializes numProcesses, worldRank
     * the rank and comm variables are still invalid, until custom communicator is set up
     * @param abortOnException if true, MPI_Abort is called in case of an uncaught exception
+    * @param finalizeOnDestruction if true, MPI_Finalize is called, when the instance is destructed.
     */
-   void initializeMPI( int* argc, char*** argv, bool abortOnException = true );
+   void initializeMPI( int* argc, char*** argv, bool abortOnException = true, bool finalizeOnDestruction=true);
 
    void finalizeMPI();
 
@@ -156,6 +157,8 @@ private:
 
    bool currentlyAborting_;
 
+   bool finalizeOnDestruction_;
+
    // Singleton
    MPIManager() : worldRank_(0), rank_(-1), numProcesses_(1), comm_(MPI_COMM_NULL),
                   isMPIInitialized_(false), cartesianSetup_(false), currentlyAborting_(false)