MPI_Comm_set_name(3) Open MPI MPI_Comm_set_name(3)NAMEMPI_Comm_set_name - Associates a name with a communicator.
SYNTAXC Syntax
#include <mpi.h>
int MPI_Comm_set_name(MPI_Comm comm, const char *comm_name)
Fortran Syntax
INCLUDE 'mpif.h'
MPI_COMM_SET_NAME(COMM, COMM_NAME, IERROR)
INTEGER COMM, IERROR
CHARACTER*(*) COMM_NAME
C++ Syntax
#include <mpi.h>
void MPI::Comm::Set_name(const char* comm_name)
INPUT/OUTPUT PARAMETER
comm Communicator whose identifier is to be set (handle).
INPUT PARAMETER
comm_name Character string to be used as the identifier for the commu‐
nicator (string).
OUTPUT PARAMETER
IERROR Fortran only: Error status (integer).
DESCRIPTIONMPI_Comm_set_name allows a user to associate a name string with a com‐
municator. The character string that is passed to MPI_Comm_set_name is
saved inside the MPI library (so it can be freed by the caller immedi‐
ately after the call, or allocated on the stack). Leading spaces in
name are significant, but trailing ones are not.
MPI_Comm_set_name is a local (noncollective) operation, which affects
only the name of the communicator as seen in the process that made the
MPI_Comm_set_name call. There is no requirement that the same (or any)
name be assigned to a communicator in every process where it exists.
The length of the name that can be stored is limited to the value of
MPI_MAX_OBJECT_NAME in Fortran and MPI_MAX_OBJECT_NAME-1 in C and C++
(to allow for the null terminator). Attempts to set names longer than
this will result in truncation of the name. MPI_MAX_OBJECT_NAME must
have a value of at least 64.
NOTES
Since MPI_Comm_set_name is provided to help debug code, it is sensible
to give the same name to a communicator in all of the processes where
it exists, to avoid confusion.
Regarding name length, under circumstances of store exhaustion, an
attempt to set a name of any length could fail; therefore, the value of
MPI_MAX_OBJECT_NAME should be viewed only as a strict upper bound on
the name length, not a guarantee that setting names of less than this
length will always succeed.
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.
SEE ALSO
MPI_Comm_get_name
1.7.4 Feb 04, 2014 MPI_Comm_set_name(3)
