Restructure the offline driver.

There is now only one executable being built: either cable-mpi or cable, depending if MPI support is available or not. When MPI support is available, the code will now automatically run the serial driver if using only one MPI process, instead of stopping with an error like before.

CMakeLists.txt

@@ -59,6 +59,7 @@ add_library(
     src/offline/cable_plume_mip.F90
     src/offline/cable_read.F90
     src/offline/cable_site.F90
+    src/offline/cable_serial.F90
     src/offline/cable_soil_params.F90
     src/offline/cable_weathergenerator.F90
     src/offline/cable_write.F90
@@ -158,22 +159,24 @@ if(CABLE_MPI)
   target_link_libraries(cable_common PRIVATE MPI::MPI_Fortran)
 endif()
 
-add_executable(
-    cable
-    src/offline/cable_driver.F90
-)
-target_link_libraries(cable PRIVATE cable_common)
-install(TARGETS cable RUNTIME)
-
 if(CABLE_MPI)
     add_executable(
         cable-mpi
         src/offline/cable_mpicommon.F90
-        src/offline/cable_mpidrv.F90
         src/offline/cable_mpimaster.F90
         src/offline/cable_mpiworker.F90
         src/science/pop/pop_mpi.F90
+        src/offline/cable_offline_driver.F90
     )
     target_link_libraries(cable-mpi PRIVATE cable_common MPI::MPI_Fortran)
     install(TARGETS cable-mpi RUNTIME)
+else()
+    add_executable(
+        cable
+        src/offline/cable_mpimaster_stub.F90
+        src/offline/cable_mpiworker_stub.F90
+        src/offline/cable_offline_driver.F90
+    )
+    target_link_libraries(cable PRIVATE cable_common)
+    install(TARGETS cable RUNTIME)
 endif()

src/offline/cable_mpimaster_stub.F90

@@ -0,0 +1,32 @@
+!==============================================================================
+! This source code is part of the
+! Australian Community Atmosphere Biosphere Land Exchange (CABLE) model.
+! This work is licensed under the CSIRO Open Source Software License
+! Agreement (variation of the BSD / MIT License).
+!
+! You may not use this file except in compliance with this License.
+! A copy of the License (CSIRO_BSD_MIT_License_v2.0_CABLE.txt) is located
+! in each directory containing CABLE code.
+!
+! ==============================================================================
+! Purpose: Stub for the master driver when MPI is not available.
+!
+! ==============================================================================
+!
+MODULE cable_mpimaster
+  IMPLICIT NONE
+
+  PRIVATE
+  PUBLIC :: mpidrv_master
+
+CONTAINS
+
+  SUBROUTINE mpidrv_master(comm)
+    INTEGER, INTENT(IN) :: comm
+
+    ! This should never be called!
+    STOP
+
+  END SUBROUTINE mpidrv_master
+
+END MODULE cable_mpimaster

src/offline/cable_mpiworker_stub.F90

@@ -0,0 +1,32 @@
+!==============================================================================
+! This source code is part of the
+! Australian Community Atmosphere Biosphere Land Exchange (CABLE) model.
+! This work is licensed under the CSIRO Open Source Software License
+! Agreement (variation of the BSD / MIT License).
+!
+! You may not use this file except in compliance with this License.
+! A copy of the License (CSIRO_BSD_MIT_License_v2.0_CABLE.txt) is located
+! in each directory containing CABLE code.
+!
+! ==============================================================================
+! Purpose: Stub for the worker driver when MPI is not available.
+!
+! ==============================================================================
+!
+MODULE cable_mpiworker
+  IMPLICIT NONE
+
+  PRIVATE
+  PUBLIC :: mpidrv_worker
+
+CONTAINS
+
+  SUBROUTINE mpidrv_worker(comm)
+    INTEGER, INTENT(IN) :: comm
+
+    ! This should never be called!
+    STOP
+
+  END SUBROUTINE mpidrv_worker
+
+END MODULE cable_mpiworker

src/offline/cable_mpidrv.F90 → src/offline/cable_offline_driver.F90

@@ -8,20 +8,10 @@
 ! A copy of the License (CSIRO_BSD_MIT_License_v2.0_CABLE.txt) is located
 ! in each directory containing CABLE code.
 !
-! ==============================================================================
-! Purpose: Bare bones MPI driver for CABLE
-!
-! Contact: [email protected]
-!
-! History: MPI wrapper developed by Maciej Golebiewski (2012)
-!
-! ==============================================================================
-!
-PROGRAM mpi_driver
-  USE mpi
-  USE cable_mpi_mod, ONLY : mpi_grp_t, mpi_mod_init, mpi_mod_end, mpi_check_error
+PROGRAM cable_offline_driver
+  USE cable_mpi_mod, ONLY : mpi_grp_t, mpi_mod_init, mpi_mod_end
   USE cable_driver_init_mod
-
+  USE cable_serial
   USE cable_mpimaster
   USE cable_mpiworker
 
@@ -35,20 +25,19 @@ PROGRAM mpi_driver
 
   CALL cable_driver_init(mpi_grp)
 
-  IF (mpi_grp%size < 2) THEN
-    WRITE(*,*) 'This program needs at least 2 processes to run!'
-    CALL mpi_grp%abort()
-  END IF
-
-  IF (mpi_grp%rank == 0) THEN
-     CALL mpidrv_master (mpi_grp%comm)
+  IF (mpi_grp%size == 1) THEN
+    CALL serialdrv()
   ELSE
-     CALL mpidrv_worker (mpi_grp%comm)
+    IF (mpi_grp%rank == 0) THEN
+      CALL mpidrv_master(mpi_grp%comm)
+    ELSE
+      CALL mpidrv_worker(mpi_grp%comm)
+    END IF
   END IF
 
   CALL mpi_mod_end()
 
   CALL CPU_TIME(etime)
   PRINT *, 'Finished. ', etime, ' seconds needed for '
 
-END PROGRAM mpi_driver
+END PROGRAM cable_offline_driver

src/offline/cable_driver.F90 → src/offline/cable_serial.F90

@@ -58,8 +58,7 @@
 !              poolcnpOut.csv -- from CASA-CNP
 !==============================================================================
 
-PROGRAM cable_offline_driver
-  USE cable_mpi_mod, ONLY : mpi_grp_t, mpi_mod_init, mpi_mod_end
+MODULE cable_serial
   USE cable_driver_init_mod, ONLY : &
     cable_driver_init,              &
     vegparmnew,                     &
@@ -147,6 +146,14 @@ PROGRAM cable_offline_driver
 USE casa_offline_inout_module, ONLY : WRITE_CASA_RESTART_NC, WRITE_CASA_OUTPUT_NC 
   IMPLICIT NONE
 
+  PRIVATE
+  PUBLIC :: serialdrv
+
+CONTAINS
+
+SUBROUTINE serialdrv()
+
+
   ! CABLE namelist: model configuration, runtime/user switches
   !CHARACTER(LEN=200), PARAMETER :: CABLE_NAMELIST='cable.nml'
   ! try to read in namelist from command line argument
@@ -254,7 +261,7 @@ PROGRAM cable_offline_driver
        new_sumbal = 0.0, &
        new_sumfpn = 0.0, &
        new_sumfe = 0.0
-!For consistency w JAC
+  !For consistency w JAC
   REAL,ALLOCATABLE, SAVE :: c1(:,:)
   REAL,ALLOCATABLE, SAVE :: rhoch(:,:)
   REAL,ALLOCATABLE, SAVE :: xk(:,:)
@@ -263,26 +270,18 @@ PROGRAM cable_offline_driver
   INTEGER :: ioerror
   INTEGER :: count_bal = 0
 
-! for landuse
-integer     mlon,mlat, mpx
-real(r_2), dimension(:,:,:),   allocatable,  save  :: luc_atransit
-real(r_2), dimension(:,:),     allocatable,  save  :: luc_fharvw
-real(r_2), dimension(:,:,:),   allocatable,  save  :: luc_xluh2cable
-real(r_2), dimension(:),       allocatable,  save  :: arealand        
-integer,   dimension(:,:),     allocatable,  save  :: landmask
-integer,   dimension(:),       allocatable,  save  :: cstart,cend,nap
-real(r_2), dimension(:,:,:),   allocatable,  save  :: patchfrac_new
-
-  ! mpi group info
-  TYPE(mpi_grp_t) :: mpi_grp
+  ! for landuse
+  integer     mlon,mlat, mpx
+  real(r_2), dimension(:,:,:),   allocatable,  save  :: luc_atransit
+  real(r_2), dimension(:,:),     allocatable,  save  :: luc_fharvw
+  real(r_2), dimension(:,:,:),   allocatable,  save  :: luc_xluh2cable
+  real(r_2), dimension(:),       allocatable,  save  :: arealand
+  integer,   dimension(:,:),     allocatable,  save  :: landmask
+  integer,   dimension(:),       allocatable,  save  :: cstart,cend,nap
+  real(r_2), dimension(:,:,:),   allocatable,  save  :: patchfrac_new
 
 ! END header
 
-  CALL mpi_mod_init()
-  mpi_grp = mpi_grp_t()
-
-  CALL cable_driver_init(mpi_grp)
-
   cable_runtime%offline = .TRUE.
 
   ! Open, read and close the consistency check file.
@@ -1234,9 +1233,7 @@ PROGRAM cable_offline_driver
   CALL CPU_TIME(etime)
   PRINT *, 'Finished. ', etime, ' seconds needed for ', kend,' hours'
 
-  CALL mpi_mod_end()
-
-END PROGRAM cable_offline_driver
+END SUBROUTINE serialdrv
 
 
 SUBROUTINE prepareFiles(ncciy)
@@ -1372,3 +1369,5 @@ SUBROUTINE LUCdriver( casabiome,casapool, &
   CALL POPLUC_weights_transfer(POPLUC,POP,LUC_EXPT)
 
 END SUBROUTINE LUCdriver
+
+END MODULE cable_serial