xref: /petsc/src/sys/tutorials/ex2f.F90 (revision c4762a1b19cd2af06abeed90e8f9d34fb975dd94)
1*c4762a1bSJed Brown! Synchronized printing: Fortran Example
2*c4762a1bSJed Brown
3*c4762a1bSJed Brown
4*c4762a1bSJed Brownprogram main
5*c4762a1bSJed Brown#include <petsc/finclude/petscsys.h>
6*c4762a1bSJed Brown      use petscsys
7*c4762a1bSJed Brown
8*c4762a1bSJed Brown      implicit none
9*c4762a1bSJed Brown      PetscErrorCode    :: ierr
10*c4762a1bSJed Brown      PetscMPIInt       :: myRank,mySize
11*c4762a1bSJed Brown      character(len=80) :: outputString
12*c4762a1bSJed Brown
13*c4762a1bSJed Brown      ! Every PETSc program should begin with the PetscInitialize() routine.
14*c4762a1bSJed Brown
15*c4762a1bSJed Brown      call PetscInitialize(PETSC_NULL_CHARACTER,ierr)
16*c4762a1bSJed Brown      if (ierr /= 0) then
17*c4762a1bSJed Brown        write(6,*) 'Unable to initialize PETSc'
18*c4762a1bSJed Brown        stop
19*c4762a1bSJed Brown      endif
20*c4762a1bSJed Brown
21*c4762a1bSJed Brown      ! The following MPI calls return the number of processes
22*c4762a1bSJed Brown      ! being used and the rank of this process in the group
23*c4762a1bSJed Brown
24*c4762a1bSJed Brown      call MPI_Comm_size(MPI_COMM_WORLD,mySize,ierr)
25*c4762a1bSJed Brown      CHKERRA(ierr)
26*c4762a1bSJed Brown      call MPI_Comm_rank(MPI_COMM_WORLD,myRank,ierr)
27*c4762a1bSJed Brown      CHKERRA(ierr)
28*c4762a1bSJed Brown
29*c4762a1bSJed Brown      ! Here we would like to print only one message that represents
30*c4762a1bSJed Brown      ! all the processes in the group
31*c4762a1bSJed Brown      write(outputString,*) 'No of Processors = ', mysize, ', rank = ',myRank,'\n'
32*c4762a1bSJed Brown      call PetscPrintf(PETSC_COMM_WORLD,outputString,ierr)
33*c4762a1bSJed Brown      CHKERRA(ierr)
34*c4762a1bSJed Brown
35*c4762a1bSJed Brown      write(outputString,*) myRank,'Synchronized Hello World\n'
36*c4762a1bSJed Brown      call PetscSynchronizedPrintf(PETSC_COMM_WORLD,outputString,ierr)
37*c4762a1bSJed Brown      CHKERRA(ierr)
38*c4762a1bSJed Brown      write(outputString,*) myRank,'Synchronized Hello World - Part II\n'
39*c4762a1bSJed Brown      call PetscSynchronizedPrintf(PETSC_COMM_WORLD,outputString,ierr)
40*c4762a1bSJed Brown      CHKERRA(ierr)
41*c4762a1bSJed Brown      call PetscSynchronizedFlush(PETSC_COMM_WORLD,PETSC_STDOUT,ierr)
42*c4762a1bSJed Brown      CHKERRA(ierr)
43*c4762a1bSJed Brown
44*c4762a1bSJed Brown      ! Here a barrier is used to separate the two program states.
45*c4762a1bSJed Brown      call MPI_Barrier(PETSC_COMM_WORLD,ierr)
46*c4762a1bSJed Brown      CHKERRA(ierr)
47*c4762a1bSJed Brown
48*c4762a1bSJed Brown      write(outputString,*) myRank,'Jumbled Hello World\n'
49*c4762a1bSJed Brown      call PetscPrintf(PETSC_COMM_SELF,outputString,ierr)
50*c4762a1bSJed Brown      CHKERRA(ierr)
51*c4762a1bSJed Brown
52*c4762a1bSJed Brown      call PetscFinalize(ierr)
53*c4762a1bSJed Brown      CHKERRA(ierr)
54*c4762a1bSJed Brown
55*c4762a1bSJed Brownend program main
56*c4762a1bSJed Brown
57*c4762a1bSJed Brown!/*TEST
58*c4762a1bSJed Brown!
59*c4762a1bSJed Brown!   test:
60*c4762a1bSJed Brown!
61*c4762a1bSJed Brown!TEST*/
62