Make sure autogenerated filter IDs are unique

openmc/capi/filter.py

@@ -45,6 +45,8 @@ _dll.openmc_filter_set_type.errcheck = _error_handler
 _dll.openmc_get_filter_index.argtypes = [c_int32, POINTER(c_int32)]
 _dll.openmc_get_filter_index.restype = c_int
 _dll.openmc_get_filter_index.errcheck = _error_handler
+_dll.openmc_get_free_filter_id.argtypes = [POINTER(c_int32)]
+_dll.openmc_get_free_filter_id.restype = None
 _dll.openmc_material_filter_get_bins.argtypes = [
     c_int32, POINTER(POINTER(c_int32)), POINTER(c_int32)]
 _dll.openmc_material_filter_get_bins.restype = c_int
@@ -253,4 +255,12 @@ class _FilterMapping(Mapping):
     def __repr__(self):
         return repr(dict(self))
 
+
 filters = _FilterMapping()
+
+
+def get_free_filter_id():
+    """Returns an ID number that has not been used by any other filters."""
+    id_ = c_int32()
+    _dll.openmc_get_free_filter_id(id_)
+    return id_.value

src/api.F90

@@ -51,6 +51,7 @@ module openmc_api
   public :: openmc_get_cell_index
   public :: openmc_get_keff
   public :: openmc_get_filter_index
+  public :: openmc_get_free_filter_id
   public :: openmc_get_material_index
   public :: openmc_get_nuclide_index
   public :: openmc_get_tally_index

src/cmfd_input.F90

@@ -261,7 +261,8 @@ contains
     integer :: i_filt_start, i_filt_end
     integer(C_INT32_T), allocatable :: filter_indices(:)
     integer(C_INT) :: err
-    integer :: i_filt      ! index in filters array
+    integer :: i_filt     ! index in filters array
+    integer :: filt_id
     integer :: iarray3(3) ! temp integer array
     real(8) :: rarray3(3) ! temp double array
     real(C_DOUBLE), allocatable :: energies(:)
@@ -381,14 +382,16 @@ contains
     ! Set up mesh filter
     i_filt = i_filt_start
     err = openmc_filter_set_type(i_filt, C_CHAR_'mesh' // C_NULL_CHAR)
-    err = openmc_filter_set_id(i_filt, i_filt)
+    call openmc_get_free_filter_id(filt_id)
+    err = openmc_filter_set_id(i_filt, filt_id)
     err = openmc_mesh_filter_set_mesh(i_filt, i_start)
 
     if (energy_filters) then
       ! Read and set incoming energy mesh filter
       i_filt = i_filt + 1
       err = openmc_filter_set_type(i_filt, C_CHAR_'energy' // C_NULL_CHAR)
-      err = openmc_filter_set_id(i_filt, i_filt)
+      call openmc_get_free_filter_id(filt_id)
+      err = openmc_filter_set_id(i_filt, filt_id)
 
       ! Get energies and set bins
       ng = node_word_count(node_mesh, "energy")
@@ -399,7 +402,8 @@ contains
       ! Read and set outgoing energy mesh filter
       i_filt = i_filt + 1
       err = openmc_filter_set_type(i_filt, C_CHAR_'energyout' // C_NULL_CHAR)
-      err = openmc_filter_set_id(i_filt, i_filt)
+      call openmc_get_free_filter_id(filt_id)
+      err = openmc_filter_set_id(i_filt, filt_id)
       err = openmc_energy_filter_set_bins(i_filt, ng, energies)
     end if
 
@@ -407,7 +411,8 @@ contains
     ! tallies use this filter and we need to change the dimension
     i_filt = i_filt + 1
     err = openmc_filter_set_type(i_filt, C_CHAR_'mesh' // C_NULL_CHAR)
-    err = openmc_filter_set_id(i_filt, i_filt)
+    call openmc_get_free_filter_id(filt_id)
+    err = openmc_filter_set_id(i_filt, filt_id)
     err = openmc_mesh_filter_set_mesh(i_filt, i_start)
 
     ! We need to increase the dimension by one since we also need

src/input_xml.F90

@@ -3146,7 +3146,9 @@ contains
               filters(i_filt_start) % obj % n_bins = product(m % dimension + 1)
 
               ! Set ID
-              err = openmc_filter_set_id(i_filt_start, i_filt_start)
+              call openmc_get_free_filter_id(filter_id)
+              err = openmc_filter_set_id(i_filt_start, filter_id)
+
 
               ! Add surface filter
               allocate(SurfaceFilter :: filters(i_filt_end) % obj)
@@ -3167,7 +3169,8 @@ contains
                 filt % current = .true.
 
                 ! Set ID
-                err = openmc_filter_set_id(i_filt_end, i_filt_end)
+                call openmc_get_free_filter_id(filter_id)
+                err = openmc_filter_set_id(i_filt_end, filter_id)
               end select
 
               ! Copy filter indices to resized array

src/tallies/tally_filter_header.F90

@@ -19,6 +19,7 @@ module tally_filter_header
   public :: openmc_filter_get_id
   public :: openmc_filter_set_id
   public :: openmc_get_filter_index
+  public :: openmc_get_free_filter_id
 
 !===============================================================================
 ! TALLYFILTERMATCH stores every valid bin and weight for a filter
@@ -122,6 +123,10 @@ module tally_filter_header
   ! Dictionary that maps user IDs to indices in 'filters'
   type(DictIntInt), public :: filter_dict
 
+  ! The largest filter ID that has been specified in the system.  This is useful
+  ! in case the code needs to find an ID for a new filter.
+  integer :: largest_filter_id
+
 contains
 
 !===============================================================================
@@ -140,6 +145,7 @@ contains
     n_filters = 0
     if (allocated(filters)) deallocate(filters)
     call filter_dict % clear()
+    largest_filter_id = 0
   end subroutine free_memory_tally_filter
 
 !===============================================================================
@@ -205,6 +211,7 @@ contains
       if (allocated(filters(index) % obj)) then
         filters(index) % obj % id = id
         call filter_dict % set(id, index)
+        if (id > largest_filter_id) largest_filter_id = id
 
         err = 0
       else
@@ -238,4 +245,12 @@ contains
     end if
   end function openmc_get_filter_index
 
+
+  subroutine openmc_get_free_filter_id(id) bind(C)
+    ! Returns an ID number that has not been used by any other filters.
+    integer(C_INT32_T), intent(out) :: id
+
+    id = largest_filter_id + 1
+  end subroutine openmc_get_free_filter_id
+
 end module tally_filter_header