MPI_Comm_get_name(3OpenMPI) MPI_Comm_get_name(3OpenMPI)
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 communica-
tor does not prevent the user from setting a name on the same communi-
cator; 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 applica-
tions may be made easier if names are associated with communicators,
since the debugger or profiler should then be able to present informa-
tion 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++ func-
tions 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.
Open MPI 1.2 September 2006 MPI_Comm_get_name(3OpenMPI)
Mac OS X 10.6 - Generated Thu Sep 17 20:12:54 CDT 2009