Gmsh should call MPI_Finalize only if Gmsh performed MPI_Init

src/common/GmshMessage.cpp

@@ -57,6 +57,7 @@
 
 int Msg::_commRank = 0;
 int Msg::_commSize = 1;
+bool Msg::_mpiInit = false;
 int Msg::_verbosity = 5;
 int Msg::_progressMeterStep = 10;
 std::atomic<int> Msg::_progressMeterCurrent(-1);
@@ -128,7 +129,10 @@ void Msg::Initialize(int argc, char **argv)
 #if defined(HAVE_MPI)
   int flag;
   MPI_Initialized(&flag);
-  if(!flag) MPI_Init(&argc, &argv);
+  if(!flag) {
+    MPI_Init(&argc, &argv);
+    _mpiInit = true;
+  }
   MPI_Comm_rank(MPI_COMM_WORLD, &_commRank);
   MPI_Comm_size(MPI_COMM_WORLD, &_commSize);
   MPI_Comm_set_errhandler(MPI_COMM_WORLD, MPI_ERRORS_RETURN);
@@ -208,10 +212,12 @@ void Msg::Finalize()
   //PetscFinalize();
 #endif
 #if defined(HAVE_MPI)
-  int finalized; // Some PETSc versions call MPI_FINALIZE
+  if(_mpiInit) {
+    int finalized;
     MPI_Finalized(&finalized);
     if (!finalized)
       MPI_Finalize();
+  }
 #endif
   FinalizeOnelab();
 }

src/common/GmshMessage.h

@@ -32,6 +32,8 @@ class Msg {
 private:
   // current cpu number and total number of cpus
   static int _commRank, _commSize;
+  // did Gmsh initialize MPI?
+  static bool _mpiInit;
   // verbosity level (0: silent except fatal errors, 1: +errors, 2: +warnings,
   // 3: +direct, 4: +info, 5 (=normal): +statusbar, 99: debug)
   static int _verbosity;