Actual source code: ex45.cxx

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

  3: /*
  4:    Example obtained from: http://trilinos.org/docs/dev/packages/tpetra/doc/html/Tpetra_Lesson01.html
  5: */

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

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

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

 35:   /*
 36:     Every PETSc routine should begin with the PetscInitialize() routine.
 37:     argc, argv - These command line arguments are taken to extract the options
 38:                  supplied to PETSc and options supplied to MPI.
 39:     help       - When PETSc executable is invoked with the option -help,
 40:                  it prints the various options that can be applied at
 41:                  runtime.  The user can use the "help" variable place
 42:                  additional help messages in this printout.
 43:   */
 44:   PetscFunctionBeginUser;
 45:   PetscCall(PetscInitialize(&argc, &argv, nullptr, help));
 46:   RCP<const Comm<int>> comm(new MpiComm<int>(PETSC_COMM_WORLD));
 47:   // Get my process' rank, and the total number of processes.
 48:   // Equivalent to MPI_Comm_rank resp. MPI_Comm_size.
 49:   const int myRank = comm->getRank();
 50:   const int size   = comm->getSize();
 51:   if (myRank == 0) cout << "Total number of processes: " << size << endl;
 52:   // Do something with the new communicator.
 53:   exampleRoutine(comm);
 54:   // This tells the Trilinos test framework that the test passed.
 55:   if (myRank == 0) cout << "End Result: TEST PASSED" << endl;

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

 61: /*TEST

 63:    build:
 64:      requires: trilinos

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

 70: TEST*/