xref: /petsc/src/sys/tutorials/ex2f.F90 (revision 8c8af28eefa46e3bea82adfa51baf2c790322ff8)
1c4762a1bSJed Brown! Synchronized printing: Fortran Example
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4c4762a1bSJed Brownprogram main
5c4762a1bSJed Brown#include <petsc/finclude/petscsys.h>
6*8c8af28eSPedro Ricardo C. Souza      use petscmpi  ! or mpi or mpi_f08
7c4762a1bSJed Brown      use petscsys
8c4762a1bSJed Brown
9c4762a1bSJed Brown      implicit none
10c4762a1bSJed Brown      PetscErrorCode                    :: ierr
11c4762a1bSJed Brown      PetscMPIInt                       :: myRank,mySize
1262ac926dSPierre Jolivet      character(len=PETSC_MAX_PATH_LEN) :: outputString
13c4762a1bSJed Brown
14c4762a1bSJed Brown      ! Every PETSc program should begin with the PetscInitialize() routine.
15c4762a1bSJed Brown
16c4762a1bSJed Brown      call PetscInitialize(PETSC_NULL_CHARACTER,ierr)
17c4762a1bSJed Brown      if (ierr /= 0) then
18c4762a1bSJed Brown        write(6,*) 'Unable to initialize PETSc'
19c4762a1bSJed Brown        stop
20c4762a1bSJed Brown      endif
21c4762a1bSJed Brown
22c4762a1bSJed Brown      ! The following MPI calls return the number of processes
23c4762a1bSJed Brown      ! being used and the rank of this process in the group
24c4762a1bSJed Brown
25c4762a1bSJed Brown      call MPI_Comm_size(MPI_COMM_WORLD,mySize,ierr)
26c4762a1bSJed Brown      CHKERRA(ierr)
27c4762a1bSJed Brown      call MPI_Comm_rank(MPI_COMM_WORLD,myRank,ierr)
28c4762a1bSJed Brown      CHKERRA(ierr)
29c4762a1bSJed Brown
30c4762a1bSJed Brown      ! Here we would like to print only one message that represents
31c4762a1bSJed Brown      ! all the processes in the group
32c4762a1bSJed Brown      write(outputString,*) 'No of Processors = ', mysize, ', rank = ',myRank,'\n'
33c4762a1bSJed Brown      call PetscPrintf(PETSC_COMM_WORLD,outputString,ierr)
34c4762a1bSJed Brown      CHKERRA(ierr)
35c4762a1bSJed Brown
36c4762a1bSJed Brown      write(outputString,*) myRank,'Synchronized Hello World\n'
37c4762a1bSJed Brown      call PetscSynchronizedPrintf(PETSC_COMM_WORLD,outputString,ierr)
38c4762a1bSJed Brown      CHKERRA(ierr)
39c4762a1bSJed Brown      write(outputString,*) myRank,'Synchronized Hello World - Part II\n'
40c4762a1bSJed Brown      call PetscSynchronizedPrintf(PETSC_COMM_WORLD,outputString,ierr)
41c4762a1bSJed Brown      CHKERRA(ierr)
42c4762a1bSJed Brown      call PetscSynchronizedFlush(PETSC_COMM_WORLD,PETSC_STDOUT,ierr)
43c4762a1bSJed Brown      CHKERRA(ierr)
44c4762a1bSJed Brown
45c4762a1bSJed Brown      ! Here a barrier is used to separate the two program states.
46c4762a1bSJed Brown      call MPI_Barrier(PETSC_COMM_WORLD,ierr)
47c4762a1bSJed Brown      CHKERRA(ierr)
48c4762a1bSJed Brown
49c4762a1bSJed Brown      write(outputString,*) myRank,'Jumbled Hello World\n'
50c4762a1bSJed Brown      call PetscPrintf(PETSC_COMM_SELF,outputString,ierr)
51c4762a1bSJed Brown      CHKERRA(ierr)
52c4762a1bSJed Brown
53c4762a1bSJed Brown      call PetscFinalize(ierr)
54c4762a1bSJed Brown      CHKERRA(ierr)
55c4762a1bSJed Brown
56c4762a1bSJed Brownend program main
57c4762a1bSJed Brown
58c4762a1bSJed Brown!/*TEST
59c4762a1bSJed Brown!
60c4762a1bSJed Brown!   test:
61c4762a1bSJed Brown!
62c4762a1bSJed Brown!TEST*/
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