Ability to restart from state point. Works in serial.

src/DEPENDENCIES

@@ -120,6 +120,7 @@ initialize.o: input_xml.o
 initialize.o: output.o
 initialize.o: random_lcg.o
 initialize.o: source.o
+initialize.o: state_point.o
 initialize.o: string.o
 initialize.o: tally.o
 initialize.o: tally_header.o
@@ -233,6 +234,7 @@ source.o: physics.o
 source.o: random_lcg.o
 source.o: string.o
 
+state_point.o: error.o
 state_point.o: global.o
 state_point.o: output.o
 state_point.o: string.o

src/criticality.F90

@@ -38,6 +38,13 @@ contains
     ! LOOP OVER BATCHES
     BATCH_LOOP: do current_batch = 1, n_batches
 
+       ! In a restart run, skip any batches that have already been simulated
+       if (restart_run .and. current_batch <= restart_batch) then
+          if (current_batch == n_inactive) tallies_on = .true.
+          if (current_batch > n_inactive) n_realizations = n_realizations + 1
+          cycle BATCH_LOOP
+       end if
+
        call initialize_batch()
 
        ! =======================================================================

src/fixed_source.F90

@@ -34,6 +34,12 @@ contains
     ! LOOP OVER BATCHES
     BATCH_LOOP: do current_batch = 1, n_batches
 
+       ! In a restart run, skip any batches that have already been simulated
+       if (restart_run .and. current_batch <= restart_batch) then
+          if (current_batch > n_inactive) n_realizations = n_realizations + 1
+          cycle BATCH_LOOP
+       end if
+
        call initialize_batch()
 
        ! Start timer for transport

src/global.F90

@@ -222,9 +222,13 @@ module global
   ! Mode to run in (fixed source, criticality, plotting, etc)
   integer :: run_mode = MODE_CRITICALITY
 
+  ! Restart run
+  logical :: restart_run = .false.
+  integer :: restart_batch
+
   character(MAX_FILE_LEN) :: path_input          ! Path to input file
   character(MAX_FILE_LEN) :: path_cross_sections ! Path to cross_sections.xml
-  character(MAX_FILE_LEN) :: path_source         ! Path to binary source
+  character(MAX_FILE_LEN) :: path_source = ''    ! Path to binary source
   character(MAX_FILE_LEN) :: path_state_point    ! Path to binary state point
 
   ! Message used in message/warning/fatal_error

src/initialize.F90

@@ -18,6 +18,7 @@ module initialize
                               create_xs_summary_file, print_version
   use random_lcg,       only: initialize_prng
   use source,           only: initialize_source
+  use state_point,      only: load_state_point
   use string,           only: to_str, str_to_int, starts_with, ends_with,      &
                               lower_case
   use tally,            only: create_tally_map
@@ -125,6 +126,10 @@ contains
           call allocate_banks()
           call initialize_source()
        end if
+
+       ! If this is a restart run, load the state point data and binary source
+       ! file
+       if (restart_run) call load_state_point()
     end if
 
     ! stop timer for initialization
@@ -260,6 +265,14 @@ contains
                      " command-line flag."
                 call fatal_error()
              end if
+          case ('-r', '-restart', '--restart')
+             i = i + 1
+             ! Read path for state point
+             path_state_point = argv(i)
+             restart_run = .true.
+
+             ! Set path for binary source file
+             path_source = 'source.' // path_state_point(9:10) // '.binary'
           case ('-?', '-help', '--help')
              call print_usage()
              stop

src/input_xml.F90

@@ -327,9 +327,6 @@ contains
           allocate(external_source % params_energy(2))
           external_source % params_energy = (/ 0.988_8, 2.249_8 /)
        end if
-
-       ! Set null path for source file
-       path_source = ""
     end if
 
     ! Survival biasing

src/output.F90

@@ -167,6 +167,7 @@ contains
        write(OUTPUT_UNIT,*)
        write(OUTPUT_UNIT,*) 'Options:'
        write(OUTPUT_UNIT,*) '  -p, --plot      Run in plotting mode'
+       write(OUTPUT_UNIT,*) '  -r, --restart   Restart a previous run'
        write(OUTPUT_UNIT,*) '  -v, --version   Show version information'
        write(OUTPUT_UNIT,*) '  -?, --help      Show this message'
     end if

src/state_point.F90

@@ -1,5 +1,6 @@
 module state_point
 
+  use error,  only: warning, fatal_error
   use global
   use output, only: write_message
   use string, only: to_str
@@ -44,6 +45,9 @@ contains
     ! Write out random number seed
     write(UNIT_STATE) seed
 
+    ! Write out keff information
+    write(UNIT_STATE) keff, keff_std
+
     ! Write out global tallies sum and sum_sq
     write(UNIT_STATE) N_GLOBAL_TALLIES
     write(UNIT_STATE) global_tallies(:) % sum
@@ -65,4 +69,94 @@ contains
 
   end subroutine create_state_point
 
+!===============================================================================
+! LOAD_STATE_POINT
+!===============================================================================
+
+  subroutine load_state_point()
+
+    integer :: i       ! loop index
+    integer :: temp(3) ! temporary variable
+
+    ! Write message
+    message = "Loading state point " // trim(path_state_point) // "..."
+    call write_message()
+
+    ! Open binary state point file for writing
+    open(UNIT=UNIT_STATE, FILE=path_state_point, STATUS='old', &
+         ACCESS='stream')
+
+    ! Raad revision number for state point file and make sure it matches with
+    ! current version
+    read(UNIT_STATE) temp(1)
+    if (temp(1) /= REVISION_STATEPOINT) then
+       message = "State point binary version does not match current version " &
+            // "in OpenMC."
+       call fatal_error()
+    end if
+    
+    ! Read OpenMC version
+    read(UNIT_STATE) temp(1:3)
+    if (temp(1) /= VERSION_MAJOR .or. temp(2) /= VERSION_MINOR &
+         .or. temp(3) /= VERSION_RELEASE) then
+       message = "State point file was created with a different version " // &
+            "of OpenMC."
+       call warning()
+    end if
+
+    ! Read and overwrite run information
+    read(UNIT_STATE) run_mode, n_particles, n_batches, &
+         n_inactive, gen_per_batch
+
+    ! Read batch number to restart at
+    read(UNIT_STATE) restart_batch
+
+    ! Read and overwrite random number seed
+    read(UNIT_STATE) seed
+
+    ! Write out keff information
+    read(UNIT_STATE) keff, keff_std
+
+    if (master) then
+       ! Read number of global tallies and make sure it matches
+       read(UNIT_STATE) temp(1)
+       if (temp(1) /= N_GLOBAL_TALLIES) then
+          message = "Number of global tallies does not match in state point."
+          call fatal_error()
+       end if
+
+       ! Read global tally data
+       read(UNIT_STATE) global_tallies(:) % sum
+       read(UNIT_STATE) global_tallies(:) % sum_sq
+
+       ! Read tally data 
+       if (current_batch > n_inactive) then
+          ! Read number of tallies and make sure it matches
+          read(UNIT_STATE) temp(1)
+          if (temp(1) /= n_tallies) then
+             message = "Number of tallies does not match in state point."
+             call fatal_error()
+          end if
+
+          do i = 1, n_tallies
+             ! Make sure dimensions match for tally filters and scores
+             read(UNIT_STATE) temp(1:2)
+             if (temp(1) /= size(tallies(i) % scores, 1) .or. &
+                  temp(2) /= size(tallies(i) % scores, 2)) then
+                message = "Tally dimensions do not match in state point."
+                call fatal_error()
+             end if
+
+             ! Read sum and sum squared
+             read(UNIT_STATE) tallies(i) % scores(:,:) % sum
+             read(UNIT_STATE) tallies(i) % scores(:,:) % sum_sq
+          end do
+       end if
+    end if
+
+    ! Close binary state point file
+    close(UNIT_STATE)
+
+  end subroutine load_state_point
+
 end module state_point