xref: /petsc/src/sys/tutorials/ex2f.F90 (revision f84028053d197aff3fdf060e86d88b3f1b0f0110)
1c4762a1bSJed Brown! Synchronized printing: Fortran Example
2c4762a1bSJed Brown
3c4762a1bSJed Brownprogram main
4c4762a1bSJed Brown#include <petsc/finclude/petscsys.h>
58c8af28eSPedro Ricardo C. Souza      use petscmpi  ! or mpi or mpi_f08
6c4762a1bSJed Brown      use petscsys
7c4762a1bSJed Brown
8c4762a1bSJed Brown      implicit none
9c4762a1bSJed Brown      PetscErrorCode                    :: ierr
10*f8402805SBarry Smith      PetscMPIInt                       :: rank,size
1162ac926dSPierre Jolivet      character(len=PETSC_MAX_PATH_LEN) :: outputString
12c4762a1bSJed Brown
13c4762a1bSJed Brown      ! Every PETSc program should begin with the PetscInitialize() routine.
14c4762a1bSJed Brown
15*f8402805SBarry Smith      PetscCallA(PetscInitialize(PETSC_NULL_CHARACTER,ierr))
16c4762a1bSJed Brown
17c4762a1bSJed Brown      ! The following MPI calls return the number of processes
18c4762a1bSJed Brown      ! being used and the rank of this process in the group
19c4762a1bSJed Brown
20*f8402805SBarry Smith      PetscCallMPIA(MPI_Comm_size(MPI_COMM_WORLD,size,ierr))
21*f8402805SBarry Smith      PetscCallMPIA(MPI_Comm_rank(MPI_COMM_WORLD,rank,ierr))
22c4762a1bSJed Brown
23c4762a1bSJed Brown      ! Here we would like to print only one message that represents
24c4762a1bSJed Brown      ! all the processes in the group
25*f8402805SBarry Smith      write(outputString,*) 'No of Processors = ', size, ', rank = ',rank,'\n'
26*f8402805SBarry Smith      PetscCallA(PetscPrintf(PETSC_COMM_WORLD,outputString,ierr))
27c4762a1bSJed Brown
28*f8402805SBarry Smith      write(outputString,*) rank,'Synchronized Hello World\n'
29*f8402805SBarry Smith      PetscCallA(PetscSynchronizedPrintf(PETSC_COMM_WORLD,outputString,ierr))
30*f8402805SBarry Smith
31*f8402805SBarry Smith      write(outputString,*) rank,'Synchronized Hello World - Part II\n'
32*f8402805SBarry Smith      PetscCallA(PetscSynchronizedPrintf(PETSC_COMM_WORLD,outputString,ierr))
33*f8402805SBarry Smith      PetscCallA(PetscSynchronizedFlush(PETSC_COMM_WORLD,PETSC_STDOUT,ierr))
34*f8402805SBarry Smith
35c4762a1bSJed Brown
36c4762a1bSJed Brown      ! Here a barrier is used to separate the two program states.
37*f8402805SBarry Smith      PetscCallMPIA(MPI_Barrier(PETSC_COMM_WORLD,ierr))
38c4762a1bSJed Brown
39*f8402805SBarry Smith      write(outputString,*) rank,'Jumbled Hello World\n'
40*f8402805SBarry Smith      PetscCallA(PetscPrintf(PETSC_COMM_SELF,outputString,ierr))
41c4762a1bSJed Brown
42*f8402805SBarry Smith      PetscCallA(PetscFinalize(ierr))
43c4762a1bSJed Brownend program main
44c4762a1bSJed Brown
45c4762a1bSJed Brown!/*TEST
46c4762a1bSJed Brown!
47c4762a1bSJed Brown!   test:
48c4762a1bSJed Brown!
49c4762a1bSJed Brown!TEST*/
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