Actual source code: ex16f.F90
petsc-3.13.6 2020-09-29
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      1: ! Tests calling PetscOptionsSetValue() before PetscInitialize(): Fortran Example

      3: program main
      4:  #include <petsc/finclude/petscsys.h>
      5:       use petscsys
      6:
      7:       implicit none
      8:       PetscErrorCode :: ierr
      9:       PetscMPIInt  ::  myRank,mySize
     10:       character(len=80) :: outputString
     11:
     12:       ! Every PETSc routine should begin with the PetscInitialize() routine.
     13:
     14:       call PetscOptionsSetValue(PETSC_NULL_OPTIONS,"-no_signal_handler","true",ierr)
     15:       call PetscInitialize(PETSC_NULL_CHARACTER,ierr)
     16:       if (ierr/=0) then
     17:         write(6,*) 'Unable to initialize PETSc'
     18:         stop
     19:       endif
     20:
     21:       ! Since when PetscInitialize() returns with an error the PETSc data structures
     22:       ! may not be set up hence we cannot call CHKERRA() hence directly return the error code.

     24:       ! Since PetscOptionsSetValue() is called before the PetscInitialize() we cannot call
     25:       ! CHKERRA() on the error code and just return it directly.
     26:
     27:       ! We can now change the communicator universe for PETSc

     29:       call MPI_Comm_size(MPI_COMM_WORLD,mySize,ierr); CHKERRA(ierr)
     30:       call MPI_Comm_rank(MPI_COMM_WORLD,myRank,ierr); CHKERRA(ierr)
     31:       write(outputString,*) 'Number of processors =',mySize,'rank =',myRank,'\n'
     32:       call PetscPrintf(PETSC_COMM_WORLD,outputString,ierr); CHKERRA(ierr)
     33:       call PetscFinalize(ierr)

     35: end program main

     37: !/*TEST
     38: !
     39: !   test:
     40: !      nsize: 2
     41: !      args: -options_view -get_total_flops
     42: !      filter: egrep -v "(malloc|display|nox|Total flops|saws_port_auto_select|vecscatter_mpi1|options_left|error_output_stdout|check_pointer_intensity|cuda_initialize|use_gpu_aware_mpi)"
     43: !
     44: !TEST*/