MPI_Lookup_name(3) Lookup a previously published name


#include <mpi.h>
MPI_Unpublish_name(char *service_name, MPI_Info info, char *port_name)


- a service name
- implementation-specific information
- a port name from MPI_Open_port


Currently, LAM/MPI ignores any info keys that are passed to this function. As such, info keys specific to a different implementation can safely be passed to this function. Additionally, the MPI constant MPI_INFO_NULL can also be used.

The scope of the published name is the LAM universe -- MPI processes running on any node included from the initial lamboot are capable of retrieving a name published by MPI_Publish_name . Service names stay in existence until they are either manually removed with MPI_Unpublish_name or cleaned with the lamclean command. It is a common mistake to forget to MPI_Unpublish_name at the end of a run, and therefore leave published names in the LAM runtime environment.


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.


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.

- No error; MPI routine completed successfully.
- 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.
- This error class is associated with an error code that indicates that there was a problem with the service name that was used. Depending on the context, this can indicate that the service name was already published or that the service name was not yet published.


For more information, please see the official MPI Forum web site, which contains the text of both the MPI-1 and MPI-2 standards. These documents contain detailed information about each MPI function (most of which is not duplicated in these man pages).