xref: /petsc/src/sys/tutorials/ex16.c (revision c4762a1b19cd2af06abeed90e8f9d34fb975dd94)
1*c4762a1bSJed Brown 
2*c4762a1bSJed Brown static char help[] = "Tests calling PetscOptionsSetValue() before PetscInitialize()\n\n";
3*c4762a1bSJed Brown 
4*c4762a1bSJed Brown /*T
5*c4762a1bSJed Brown    Concepts: introduction to PETSc;
6*c4762a1bSJed Brown    Concepts: printing^in parallel
7*c4762a1bSJed Brown    Processors: n
8*c4762a1bSJed Brown T*/
9*c4762a1bSJed Brown 
10*c4762a1bSJed Brown #include <petscsys.h>
11*c4762a1bSJed Brown int main(int argc,char **argv)
12*c4762a1bSJed Brown {
13*c4762a1bSJed Brown   PetscErrorCode ierr;
14*c4762a1bSJed Brown   PetscMPIInt    rank,size;
15*c4762a1bSJed Brown 
16*c4762a1bSJed Brown   /*
17*c4762a1bSJed Brown     Every PETSc routine should begin with the PetscInitialize() routine.
18*c4762a1bSJed Brown     argc, argv - These command line arguments are taken to extract the options
19*c4762a1bSJed Brown                  supplied to PETSc and options supplied to MPI.
20*c4762a1bSJed Brown     help       - When PETSc executable is invoked with the option -help,
21*c4762a1bSJed Brown                  it prints the various options that can be applied at
22*c4762a1bSJed Brown                  runtime.  The user can use the "help" variable place
23*c4762a1bSJed Brown                  additional help messages in this printout.
24*c4762a1bSJed Brown 
25*c4762a1bSJed Brown     Since when PetscInitialize() returns with an error the PETSc data structures
26*c4762a1bSJed Brown     may not be set up hence we cannot call CHKERRQ() hence directly return the error code.
27*c4762a1bSJed Brown 
28*c4762a1bSJed Brown     Since PetscOptionsSetValue() is called before the PetscInitialize() we cannot call
29*c4762a1bSJed Brown     CHKERRQ() on the error code and just return it directly.
30*c4762a1bSJed Brown   */
31*c4762a1bSJed Brown   ierr = PetscOptionsSetValue(NULL,"-no_signal_handler","true");if (ierr) return ierr;
32*c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
33*c4762a1bSJed Brown   ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
34*c4762a1bSJed Brown   ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
35*c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_WORLD,"Number of processors = %d, rank = %d\n",size,rank);CHKERRQ(ierr);
36*c4762a1bSJed Brown   ierr = PetscFinalize();
37*c4762a1bSJed Brown   return ierr;
38*c4762a1bSJed Brown }
39*c4762a1bSJed Brown 
40*c4762a1bSJed Brown 
41*c4762a1bSJed Brown /*TEST
42*c4762a1bSJed Brown 
43*c4762a1bSJed Brown    test:
44*c4762a1bSJed Brown       nsize: 2
45*c4762a1bSJed Brown       args: -options_view -get_total_flops
46*c4762a1bSJed Brown       filter: egrep -v "(cuda_initialize|malloc|display|nox|Total flops|saws_port_auto_select|vecscatter_mpi1|options_left|error_output_stdout|check_pointer_intensity)"
47*c4762a1bSJed Brown 
48*c4762a1bSJed Brown TEST*/
49