Actual source code: ex45.cxx


  2: static char help[] = "Demonstrates call PETSc first and then Trilinos in the same program.\n\n";

  4: /*
  5:    Example obtained from: http://trilinos.org/docs/dev/packages/tpetra/doc/html/Tpetra_Lesson01.html
  6: */

  8: #include <petscsys.h>
  9: #include <Teuchos_DefaultMpiComm.hpp> // wrapper for MPI_Comm
 10: #include <Tpetra_Version.hpp>         // Tpetra version string

 12: // Do something with the given communicator.  In this case, we just
 13: // print Tpetra's version to stdout on Process 0 in the given
 14: // communicator.
 15: void exampleRoutine(const Teuchos::RCP<const Teuchos::Comm<int>> &comm)
 16: {
 17:   if (comm->getRank() == 0) {
 18:     // On (MPI) Process 0, print out the Tpetra software version.
 19:     std::cout << Tpetra::version() << std::endl << std::endl;
 20:   }
 21: }

 23: int main(int argc, char **argv)
 24: {
 25:   // These "using" declarations make the code more concise, in that
 26:   // you don't have to write the namespace along with the class or
 27:   // object name.  This is especially helpful with commonly used
 28:   // things like std::endl or Teuchos::RCP.
 29:   using std::cout;
 30:   using std::endl;
 31:   using Teuchos::Comm;
 32:   using Teuchos::MpiComm;
 33:   using Teuchos::RCP;
 34:   using Teuchos::rcp;

 36:   /*
 37:     Every PETSc routine should begin with the PetscInitialize() routine.
 38:     argc, argv - These command line arguments are taken to extract the options
 39:                  supplied to PETSc and options supplied to MPI.
 40:     help       - When PETSc executable is invoked with the option -help,
 41:                  it prints the various options that can be applied at
 42:                  runtime.  The user can use the "help" variable place
 43:                  additional help messages in this printout.
 44:   */
 45:   PetscFunctionBeginUser;
 46:   PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
 47:   RCP<const Comm<int>> comm(new MpiComm<int>(PETSC_COMM_WORLD));
 48:   // Get my process' rank, and the total number of processes.
 49:   // Equivalent to MPI_Comm_rank resp. MPI_Comm_size.
 50:   const int myRank = comm->getRank();
 51:   const int size   = comm->getSize();
 52:   if (myRank == 0) cout << "Total number of processes: " << size << endl;
 53:   // Do something with the new communicator.
 54:   exampleRoutine(comm);
 55:   // This tells the Trilinos test framework that the test passed.
 56:   if (myRank == 0) cout << "End Result: TEST PASSED" << endl;

 58:   PetscCall(PetscFinalize());
 59:   return 0;
 60: }

 62: /*TEST

 64:    build:
 65:      requires: trilinos

 67:    test:
 68:       nsize: 3
 69:       filter: grep -v "Tpetra in Trilinos"

 71: TEST*/