xref: /petsc/src/sys/tutorials/ex2f.F90 (revision 749c190bad46ba447444c173d8c7a4080c70750e)
1c4762a1bSJed Brown! Synchronized printing: Fortran Example
2c4762a1bSJed Brown#include <petsc/finclude/petscsys.h>
3*c5e229c2SMartin Diehlprogram main
4c4762a1bSJed Brown  use petscsys
5c4762a1bSJed Brown
6c4762a1bSJed Brown  implicit none
7c4762a1bSJed Brown  PetscErrorCode                    :: ierr
8f8402805SBarry Smith  PetscMPIInt                       :: rank, size
962ac926dSPierre Jolivet  character(len=PETSC_MAX_PATH_LEN) :: outputString
10c4762a1bSJed Brown
11c4762a1bSJed Brown  ! Every PETSc program should begin with the PetscInitialize() routine.
12c4762a1bSJed Brown
13d8606c27SBarry Smith  PetscCallA(PetscInitialize(ierr))
14c4762a1bSJed Brown
15c4762a1bSJed Brown  ! The following MPI calls return the number of processes
16c4762a1bSJed Brown  ! being used and the rank of this process in the group
17c4762a1bSJed Brown
18f8402805SBarry Smith  PetscCallMPIA(MPI_Comm_size(MPI_COMM_WORLD, size, ierr))
19f8402805SBarry Smith  PetscCallMPIA(MPI_Comm_rank(MPI_COMM_WORLD, rank, ierr))
20c4762a1bSJed Brown
21c4762a1bSJed Brown  ! Here we would like to print only one message that represents
22c4762a1bSJed Brown  ! all the processes in the group
23f8402805SBarry Smith  write (outputString, *) 'No of Processors = ', size, ', rank = ', rank, '\n'
24f8402805SBarry Smith  PetscCallA(PetscPrintf(PETSC_COMM_WORLD, outputString, ierr))
25c4762a1bSJed Brown
26f8402805SBarry Smith  write (outputString, *) rank, 'Synchronized Hello World\n'
27f8402805SBarry Smith  PetscCallA(PetscSynchronizedPrintf(PETSC_COMM_WORLD, outputString, ierr))
28f8402805SBarry Smith
29f8402805SBarry Smith  write (outputString, *) rank, 'Synchronized Hello World - Part II\n'
30f8402805SBarry Smith  PetscCallA(PetscSynchronizedPrintf(PETSC_COMM_WORLD, outputString, ierr))
31f8402805SBarry Smith  PetscCallA(PetscSynchronizedFlush(PETSC_COMM_WORLD, PETSC_STDOUT, ierr))
32f8402805SBarry Smith
33c4762a1bSJed Brown  ! Here a barrier is used to separate the two program states.
34f8402805SBarry Smith  PetscCallMPIA(MPI_Barrier(PETSC_COMM_WORLD, ierr))
35c4762a1bSJed Brown
36f8402805SBarry Smith  write (outputString, *) rank, 'Jumbled Hello World\n'
37f8402805SBarry Smith  PetscCallA(PetscPrintf(PETSC_COMM_SELF, outputString, ierr))
38c4762a1bSJed Brown
39f8402805SBarry Smith  PetscCallA(PetscFinalize(ierr))
40c4762a1bSJed Brownend program main
41c4762a1bSJed Brown
42c4762a1bSJed Brown!/*TEST
43c4762a1bSJed Brown!
44c4762a1bSJed Brown!   test:
45c4762a1bSJed Brown!
46c4762a1bSJed Brown!TEST*/
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