NAME

       XMPI_Buoy -  LAM/MPI-specific function to drop a buoy in the XMPI trace stream.

SYNOPSIS

       #include <mpi.h>
       int
       XMPI_Buoy(const char* name)

INPUT PARAMETER

       name   - buoy name (string)

NOTES

       The  LAM  implementation  of  MPI  is  integrated  with the XMPI run/debug viewer.  It can
       generate tracefiles and on-the-fly trace streams suitable for display in XMPI.

       A new functionality in XMPI is the ability to view "buoys" in the trace stream that can be
       helpful in marking particular sections of code.  LAM/MPI allows the dropping of buoys with
       the XMPI_Buoy function.  Calling XMPI_Buoy with a string will drop a bouy of that name (if
       tracing is enabled) in the trace stream.  Dropping a buoy is a local action; the call will
       return immediately.  The buoy is dropped in the trace stream of the local rank,  and  will
       appear on the corresponding rank timeline in XMPI.

       The name can be a maximum of 32 characters long; if it is longer, it will be truncated.

       If this function is invoked and tracing is not active, the buoy is ignored.

       There is no profiling version of this function.

       This  is  a  LAM/MPI-specific  function and is intended mainly for use with XMPI.  If this
       function is used, it should be used in conjunction with the LAM_MPI C preprocessor macro

       #if LAM_MPI
       XMPI_Buoy("my function begins");
       // ... message passing code
       XMPI_Buoy("my function ends");
       #endif

NOTES FOR FORTRAN

       All MPI routines in Fortran (except for MPI_WTIME  and  MPI_WTICK  )  have  an  additional
       argument  ierr  at  the  end  of  the  argument list.  ierr is an integer and has the same
       meaning as the  return  value  of  the  routine  in  C.   In  Fortran,  MPI  routines  are
       subroutines, and are invoked with the call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in Fortran.

ERRORS

       If  an  error occurs in an MPI function, the current MPI error handler is called to handle
       it.  By default, this error handler aborts the MPI job.  The error handler may be  changed
       with  MPI_Errhandler_set  ;  the predefined error handler MPI_ERRORS_RETURN may be used to
       cause error values to be returned (in C and Fortran; this error handler is less useful  in
       with  the  C++  MPI  bindings.   The predefined error handler MPI::ERRORS_THROW_EXCEPTIONS
       should be used in C++ if the error value needs to be recovered).  Note that MPI  does  not
       guarantee that an MPI program can continue past an error.

       All  MPI  routines  (except MPI_Wtime and MPI_Wtick ) return an error value; C routines as
       the value of the function and Fortran routines in the last argument.  The C++ bindings for
       MPI  do  not  return  error  values;  instead,  error  values are communicated by throwing
       exceptions of type MPI::Exception (but not by default).  Exceptions are only thrown if the
       error value is not MPI::SUCCESS .

       Note that if the MPI::ERRORS_RETURN handler is set in C++, while MPI functions will return
       upon an error, there will be no way to recover what the actual error value was.
       MPI_SUCCESS
              - No error; MPI routine completed successfully.
       MPI_ERR_ARG
              - Invalid argument.  Some argument is invalid and is not identified by  a  specific
              error class.  This is typically a NULL pointer or other such error.
       MPI_ERR_INTERN
              - An internal error has been detected.  This is fatal.  Please send a bug report to
              the LAM mailing list (see http://www.lam-mpi.org/contact.php ).

SEE ALSO

       XMPI_Coloron, XMPI_Coloroff

LOCATION

       xbuoy.c