bionic (3) MPI_Comm_get_attr.3.gz

NAME

       MPI_Comm_get_attr -  Retrieves attribute value by key

SYNOPSIS

       int MPI_Comm_get_attr(MPI_Comm comm, int comm_keyval, void *attribute_val,
                            int *flag)

INPUT PARAMETERS

       comm   - communicator to which attribute is attached (handle)
       comm_keyval
              - key value (integer)

OUTPUT PARAMETERS

       attribute_val
              - attribute value, unless flag = false
       flag   - true if an attribute value was extracted;  false if no attribute is associated with the key

NOTES

       Attributes  must  be  extracted  from the same language as they were inserted in with MPI_Comm_set_attr .
       The notes for C and Fortran below explain why.

NOTES FOR C

       Even though the attr_value argument is declared as void * , it is really the address of a  void  pointer.
       See the rationale in the standard for more details.

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

                                                   11/12/2016                               MPI_Comm_get_attr(3)