Make micro_photon_xs available on C++ side

include/openmc/photon.h

@@ -22,16 +22,35 @@ public:
   int Z_; //! Atomic number
 };
 
+//==============================================================================
+//! Cached microscopic photon cross sections for a particular element at the
+//! current energy
+//==============================================================================
+
+struct ElementMicroXS {
+  int index_grid; //!< index on element energy grid
+  double last_E {0.0}; //!< last evaluated energy in [eV]
+  double interp_factor; //!< interpolation factor on energy grid
+  double total; //!< microscopic total photon xs
+  double coherent; //!< microscopic coherent xs
+  double incoherent; //!< microscopic incoherent xs
+  double photoelectric; //!< microscopic photoelectric xs
+  double pair_production; //!< microscopic pair production xs
+};
+
 //==============================================================================
 // Global variables
 //==============================================================================
 
 namespace data {
-
 extern std::vector<PhotonInteraction> elements;
-
 } // namespace data
 
+namespace simulation {
+extern ElementMicroXS* micro_photon_xs;
+#pragma omp threadprivate(micro_photon_xs)
+} // namespace simulation
+
 } // namespace openmc
 
 #endif // OPENMC_PHOTON_H

src/nuclide.cpp

@@ -5,6 +5,7 @@
 #include "openmc/error.h"
 #include "openmc/hdf5_interface.h"
 #include "openmc/message_passing.h"
+#include "openmc/photon.h"
 #include "openmc/random_lcg.h"
 #include "openmc/search.h"
 #include "openmc/settings.h"
@@ -935,12 +936,14 @@ extern "C" bool multipole_in_range(Nuclide* nuc, double E)
 extern "C" void nuclides_clear() { data::nuclides.clear(); }
 
 extern "C" NuclideMicroXS* micro_xs_ptr();
+extern "C" ElementMicroXS* micro_photon_xs_ptr();
 
 void set_micro_xs()
 {
 #pragma omp parallel
   {
     simulation::micro_xs = micro_xs_ptr();
+    simulation::micro_photon_xs = micro_photon_xs_ptr();
   }
 }
 

src/photon.cpp

@@ -9,11 +9,13 @@ namespace openmc {
 //==============================================================================
 
 namespace data {
-
 std::vector<PhotonInteraction> elements;
-
 } // namespace data
 
+namespace simulation {
+ElementMicroXS* micro_photon_xs;
+} // namespace simulation
+
 //==============================================================================
 // PhotonInteraction implementation
 //==============================================================================

src/photon_header.F90

@@ -1,5 +1,7 @@
 module photon_header
 
+  use, intrinsic :: ISO_C_BINDING
+
   use algorithm,        only: binary_search
   use constants
   use dict_header,      only: DictIntInt, DictCharInt
@@ -92,18 +94,18 @@ module photon_header
 ! particular element at the current energy
 !===============================================================================
 
-  type ElementMicroXS
-    integer :: index_grid      ! index on element energy grid
-    real(8) :: last_E = ZERO   ! last evaluated energy
-    real(8) :: interp_factor   ! interpolation factor on energy grid
-    real(8) :: total           ! microscropic total photon xs
-    real(8) :: coherent        ! microscopic coherent xs
-    real(8) :: incoherent      ! microscopic incoherent xs
-    real(8) :: photoelectric   ! microscopic photoelectric xs
-    real(8) :: pair_production ! microscopic pair production xs
+  type, bind(C) :: ElementMicroXS
+    integer(C_INT) :: index_grid      ! index on element energy grid
+    real(C_DOUBLE) :: last_E = ZERO   ! last evaluated energy
+    real(C_DOUBLE) :: interp_factor   ! interpolation factor on energy grid
+    real(C_DOUBLE) :: total           ! microscropic total photon xs
+    real(C_DOUBLE) :: coherent        ! microscopic coherent xs
+    real(C_DOUBLE) :: incoherent      ! microscopic incoherent xs
+    real(C_DOUBLE) :: photoelectric   ! microscopic photoelectric xs
+    real(C_DOUBLE) :: pair_production ! microscopic pair production xs
   end type ElementMicroXS
 
-  type(ElementMicroXS), allocatable :: micro_photon_xs(:) ! Cache for each element
+  type(ElementMicroXS), allocatable, target :: micro_photon_xs(:) ! Cache for each element
 !$omp threadprivate(micro_photon_xs)
 
 contains
@@ -517,4 +519,13 @@ contains
     if (allocated(ttb)) deallocate(ttb)
   end subroutine free_memory_photon
 
+  function micro_photon_xs_ptr() result(ptr) bind(C)
+    type(C_PTR) :: ptr
+    if (size(micro_photon_xs) > 0) then
+      ptr = C_LOC(micro_photon_xs(1))
+    else
+      ptr = C_NULL_PTR
+    end if
+  end function
+
 end module photon_header