NAME

       MPI_Comm_set_attr -  Stores attribute value associated with a key

SYNOPSIS

       int MPI_Comm_set_attr(MPI_Comm comm, int comm_keyval, void *attribute_val)

INPUT PARAMETERS

       comm   - communicator to which attribute will be attached (handle)
       comm_keyval
              - key value, as returned by MPI_Comm_create_keyval (integer)
       attribute_val
              - attribute value

NOTES

       Values   of   the   permanent   attributes  MPI_TAG_UB  ,  MPI_HOST  ,  MPI_IO  ,  MPI_WTIME_IS_GLOBAL  ,
       MPI_UNIVERSE_SIZE , MPI_LASTUSEDCODE , and MPI_APPNUM may not be changed.

       The type of the attribute value depends on whether C, C++, or Fortran is being used.  In C  and  C++,  an
       attribute value is a pointer ( void * ); in Fortran, it is an address-sized integer.

       If  an  attribute  is  already  present, the delete function (specified when the corresponding keyval was
       created) will be called.

THREAD AND INTERRUPT SAFETY

       This routine is thread-safe.  This means that this routine may be safely used by multiple threads without
       the  need  for  any  user-provided thread locks.  However, the routine is not interrupt safe.  Typically,
       this is due to the use of memory allocation routines such as malloc or other non-MPICH  runtime  routines
       that are themselves not interrupt-safe.

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

       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.  Before the value is returned, the current MPI  error
       handler  is called.  By default, this error handler aborts the MPI job.  The error handler may be changed
       with   MPI_Comm_set_errhandler   (for   communicators),   MPI_File_set_errhandler   (for   files),    and
       MPI_Win_set_errhandler  (for  RMA windows).  The MPI-1 routine MPI_Errhandler_set may be used but its use
       is deprecated.  The predefined error handler MPI_ERRORS_RETURN may be used to cause error  values  to  be
       returned.   Note that MPI does not guarentee that an MPI program can continue past an error; however, MPI
       implementations will attempt to continue whenever possible.

       MPI_SUCCESS
              - No error; MPI routine completed successfully.
       MPI_ERR_COMM
              - Invalid communicator.  A common error is to use a null communicator in a call (not even  allowed
              in MPI_Comm_rank ).
       MPI_ERR_KEYVAL
              - Invalid keyval
       MPI_ERR_ARG
              -  This  error  class  is associated with an error code that indicates that an attempt was made to
              free one of the permanent keys.

SEE ALSO

       MPI_Comm_create_keyval, MPI_Comm_delete_attr

                                                   11/12/2016                               MPI_Comm_set_attr(3)