|
« Return to documentation listing
Table of Contents
MPI_Type_ub - Returns the upper bound of a datatype -- use of this
routine is deprecated.
#include <mpi.h>
int MPI_Type_ub(MPI_Datatype datatype, MPI_Aint *displacement)
INCLUDE ’mpif.h’
MPI_TYPE_UB(DATATYPE, DISPLACEMENT, IERROR)
INTEGER DATATYPE, DISPLACEMENT, IERROR
- datatype
- Datatype (handle).
- displacement
- Displacement of upper bound from origin, in bytes (integer).
- IERROR
- Fortran only: Error status (integer).
Note that use of this
routine is deprecated as of MPI-2. Please use MPI_Type_get_extent instead.
This deprecated routine is not available in C++.
MPI_Type_ub returns the
upper bound of a data type. This will differ from zero if the type was constructed
using MPI_UB. The upper bound will take into account any alignment considerations.
The "pseudo-datatypes," MPI_LB and MPI_UB, can be used, respectively, to
mark the upper bound (or the lower bound) of a datatype. These pseudo-datatypes
occupy no space (extent (MPI_LB) = extent (MPI_UB) =0. They do not affect
the size or count of a datatype, and do not affect the context of a message
created with this datatype. However, they do affect the definition of the
extent of a datatype and, therefore, affect the outcome of a replication
of this datatype by a datatype constructor.
In general, if
Typemap = {(type(0), disp(0)), ..., (type(n-1), disp(n-1))}
then the lower bound of Typemap is defined to be
(min(j) disp(j) if no entry
has
lb(Typemap) = ( basic type lb
(min(j) {disp(j) such that type(j) = lb} otherwise
Similarly, the upper bound of Typemap is defined to be
(max(j) disp(j) + sizeof(type(j) = lb} if no entry
has
ub(Typemap) = ( basic type ub
(max(j) {disp(j) such that type(j) = ub} otherwise
Then
extent(Typemap) = ub(Typemap) - lb(Typemap)
If type(i) requires alignment to a byte address that is a multiple of k(i),
then e is the least nonnegative increment needed to round extent(Typemap)
to the next multiple of max(i) k(i).
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.
MPI_Type_get_extent
Table of Contents
« Return to documentation listing
|
