Manpages - MPI_Type_extent.3
Table of Contents
NAME
MPI_Type_extent - Returns the extent of a data type, the difference between the upper and lower bounds of the data type – use of this routine is deprecated.
SYNTAX
C Syntax
#include <mpi.h> int MPI_Type_extent(MPI_Datatype datatype, MPI_Aint *extent)
Fortran Syntax
INCLUDE 'mpif.h' MPI_TYPE_EXTENT(DATATYPE, EXTENT, IERROR) INTEGER DATATYPE, EXTENT, IERROR
INPUT PARAMETER
- datatype
- Datatype (handle).
OUTPUT PARAMETERS
- extent
- Datatype extent (integer).
- IERROR
- Fortran only: Error status (integer).
DESCRIPTION
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_extent returns the extent of a data type, the difference between the upper and lower bounds of the data type.
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)) + e 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).
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++ 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.
SEE ALSO
MPI_Type_get_extent