xref: /petsc/src/sys/tutorials/ex2f.F90 (revision 62ac926ddc3e036a30b4ea12e742c29a0093bc2f)
1c4762a1bSJed Brown! Synchronized printing: Fortran Example
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4c4762a1bSJed Brownprogram main
5c4762a1bSJed Brown#include <petsc/finclude/petscsys.h>
6c4762a1bSJed Brown      use petscsys
7c4762a1bSJed Brown
8c4762a1bSJed Brown      implicit none
9c4762a1bSJed Brown      PetscErrorCode                    :: ierr
10c4762a1bSJed Brown      PetscMPIInt                       :: myRank,mySize
11*62ac926dSPierre Jolivet      character(len=PETSC_MAX_PATH_LEN) :: outputString
12c4762a1bSJed Brown
13c4762a1bSJed Brown      ! Every PETSc program should begin with the PetscInitialize() routine.
14c4762a1bSJed Brown
15c4762a1bSJed Brown      call PetscInitialize(PETSC_NULL_CHARACTER,ierr)
16c4762a1bSJed Brown      if (ierr /= 0) then
17c4762a1bSJed Brown        write(6,*) 'Unable to initialize PETSc'
18c4762a1bSJed Brown        stop
19c4762a1bSJed Brown      endif
20c4762a1bSJed Brown
21c4762a1bSJed Brown      ! The following MPI calls return the number of processes
22c4762a1bSJed Brown      ! being used and the rank of this process in the group
23c4762a1bSJed Brown
24c4762a1bSJed Brown      call MPI_Comm_size(MPI_COMM_WORLD,mySize,ierr)
25c4762a1bSJed Brown      CHKERRA(ierr)
26c4762a1bSJed Brown      call MPI_Comm_rank(MPI_COMM_WORLD,myRank,ierr)
27c4762a1bSJed Brown      CHKERRA(ierr)
28c4762a1bSJed Brown
29c4762a1bSJed Brown      ! Here we would like to print only one message that represents
30c4762a1bSJed Brown      ! all the processes in the group
31c4762a1bSJed Brown      write(outputString,*) 'No of Processors = ', mysize, ', rank = ',myRank,'\n'
32c4762a1bSJed Brown      call PetscPrintf(PETSC_COMM_WORLD,outputString,ierr)
33c4762a1bSJed Brown      CHKERRA(ierr)
34c4762a1bSJed Brown
35c4762a1bSJed Brown      write(outputString,*) myRank,'Synchronized Hello World\n'
36c4762a1bSJed Brown      call PetscSynchronizedPrintf(PETSC_COMM_WORLD,outputString,ierr)
37c4762a1bSJed Brown      CHKERRA(ierr)
38c4762a1bSJed Brown      write(outputString,*) myRank,'Synchronized Hello World - Part II\n'
39c4762a1bSJed Brown      call PetscSynchronizedPrintf(PETSC_COMM_WORLD,outputString,ierr)
40c4762a1bSJed Brown      CHKERRA(ierr)
41c4762a1bSJed Brown      call PetscSynchronizedFlush(PETSC_COMM_WORLD,PETSC_STDOUT,ierr)
42c4762a1bSJed Brown      CHKERRA(ierr)
43c4762a1bSJed Brown
44c4762a1bSJed Brown      ! Here a barrier is used to separate the two program states.
45c4762a1bSJed Brown      call MPI_Barrier(PETSC_COMM_WORLD,ierr)
46c4762a1bSJed Brown      CHKERRA(ierr)
47c4762a1bSJed Brown
48c4762a1bSJed Brown      write(outputString,*) myRank,'Jumbled Hello World\n'
49c4762a1bSJed Brown      call PetscPrintf(PETSC_COMM_SELF,outputString,ierr)
50c4762a1bSJed Brown      CHKERRA(ierr)
51c4762a1bSJed Brown
52c4762a1bSJed Brown      call PetscFinalize(ierr)
53c4762a1bSJed Brown      CHKERRA(ierr)
54c4762a1bSJed Brown
55c4762a1bSJed Brownend program main
56c4762a1bSJed Brown
57c4762a1bSJed Brown!/*TEST
58c4762a1bSJed Brown!
59c4762a1bSJed Brown!   test:
60c4762a1bSJed Brown!
61c4762a1bSJed Brown!TEST*/
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