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MPI_Type_extent(3) man page (version 1.8.1)

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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


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