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