Fix MPI-related bugs

CMakeLists.txt

@@ -433,6 +433,7 @@ set(LIBOPENMC_FORTRAN_SRC
 )
 set(LIBOPENMC_CXX_SRC
   src/initialize.cpp
+  src/finalize.cpp
   src/hdf5_interface.cpp
   src/message_passing.cpp
   src/plot.cpp

src/api.F90

@@ -105,6 +105,11 @@ contains
   function openmc_finalize() result(err) bind(C)
     integer(C_INT) :: err
 
+    interface
+      subroutine openmc_free_bank() bind(C)
+      end subroutine openmc_free_bank
+    end interface
+
     ! Clear results
     err = openmc_reset()
 
@@ -170,6 +175,7 @@ contains
 #ifdef OPENMC_MPI
     ! Free all MPI types
     call MPI_TYPE_FREE(MPI_BANK, err)
+    call openmc_free_bank()
 #endif
 
   end function openmc_finalize

src/finalize.cpp

@@ -0,0 +1,10 @@
+#include "finalize.h"
+
+#include "message_passing.h"
+
+void openmc_free_bank()
+{
+#ifdef OPENMC_MPI
+  MPI_Type_free(&openmc::mpi::bank);
+#endif
+}

src/finalize.h

@@ -0,0 +1,6 @@
+#ifndef FINALIZE_H
+#define FINALIZE_H
+
+extern "C" void openmc_free_bank();
+
+#endif // FINALIZE_H

src/hdf5_interface.F90

@@ -1103,7 +1103,7 @@ contains
     character(*), intent(in), target   :: buffer(:)  ! read data to here
     logical,      intent(in), optional :: indep ! independent I/O
 
-    integer :: i
+    integer(HSIZE_T) :: i
     integer(HSIZE_T) :: dims(1)
     integer(C_SIZE_T) :: m, n
     logical(C_BOOL) :: indep_

src/initialize.cpp

@@ -71,7 +71,8 @@ void initialize_mpi(MPI_Comm intracomm)
 
   // Initialize MPI
   int flag;
-  if (!MPI_Initialized(&flag)) MPI_Init(nullptr, nullptr);
+  MPI_Initialized(&flag);
+  if (!flag) MPI_Init(nullptr, nullptr);
 
   // Determine number of processes and rank for each
   MPI_Comm_size(intracomm, &openmc::mpi::n_procs);

src/main.cpp

@@ -38,12 +38,14 @@ int main(int argc, char* argv[]) {
     err = openmc_calculate_volumes();
     break;
   }
+  if (err) openmc::fatal_error(openmc_err_msg);
 
   // Finalize and free up memory
-  openmc_finalize();
+  err = openmc_finalize();
+  if (err) openmc::fatal_error(openmc_err_msg);
 
   // If MPI is in use and enabled, terminate it
-#ifdef MPI
+#ifdef OPENMC_MPI
   MPI_Finalize();
 #endif
 }