MPI_Comm_get_name(3)               Open MPI               MPI_Comm_get_name(3)



NAME
       MPI_Comm_get_name - Returns the name that was most recently associated
       with a communicator.


SYNTAX
C Syntax
       #include <mpi.h>
       int MPI_Comm_get_name(MPI_Comm comm, char *comm_name, int *resultlen)


Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_COMM_GET_NAME(COMM, COMM_NAME, RESULTLEN, IERROR)
            INTEGER   COMM, RESULTLEN, IERROR
            CHARACTER*(*) COMM_NAME


C++ Syntax
       #include <mpi.h>
       void MPI::Comm::Get_name(char* comm_name, int& resultlen) const


INPUT PARAMETER
       comm      Communicator the name of which is to be returned (handle).



       OUTPUT PARAMETER

       comm_name Name previously stored on the communicator, or an empty
                 string if no such name exists (string).

       resultlen Length of returned name (integer).

       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       MPI_Comm_get_name returns the last name that was previously associated
       with the given communicator. The name may be set and retrieved from any
       language. The same name will be returned independent of the language
       used. comm_name should be allocated so that it can hold a resulting
       string of length MPI_MAX_OBJECT_NAME characters. MPI_Comm_get_name
       returns a copy of the set name in comm_name.

       If the user has not associated a name with a communicator, or an error
       occurs, MPI_Comm_get_name will return an empty string (all spaces in
       Fortran, "" in C and C++). The three predefined communicators will have
       predefined names associated with them. Thus, the names of
       MPI_COMM_WORLD, MPI_COMM_SELF, and MPI_COMM_PARENT will have the
       default of MPI_COMM_WORLD, MPI_COMM_SELF, and MPI_COMM_PARENT. The fact
       that the system may have chosen to give a default name to a
       communicator does not prevent the user from setting a name on the same
       communicator; doing this removes the old name and assigns the new one.


NOTES
       It is safe simply to print the string returned by MPI_Comm_get_name, as
       it is always a valid string even if there was no name.

       Note that associating a name with a communicator has no effect on the
       semantics of an MPI program, and will (necessarily) increase the store
       requirement of the program, since the names must be saved. Therefore,
       there is no requirement that users use these functions to associate
       names with communicators. However debugging and profiling MPI
       applications may be made easier if names are associated with
       communicators, since the debugger or profiler should then be able to
       present information in a less cryptic manner.


ERRORS
       Almost all MPI routines return an error value; C routines as the value
       of the function and Fortran routines in the last argument. C++
       functions do not return errors. If the default error handler is set to
       MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
       will be used to throw an MPI:Exception object.

       Before the error value is returned, the current MPI error handler is
       called. By default, this error handler aborts the MPI job, except for
       I/O function errors. The error handler may be changed with
       MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN
       may be used to cause error values to be returned. Note that MPI does
       not guarantee that an MPI program can continue past an error.




1.4.1                            Jan 14, 2010             MPI_Comm_get_name(3)
