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MPI_Type_get_contents - Returns information about arguments used
in creation of a data type.
#include <mpi.h>
int MPI_Type_get_contents(MPI_Datatype datatype, int max_integers,
int max_addresses, int max_datatypes, int array_of_integers[], MPI_Aint
array_of_addresses[], MPI_Datatype array_of_datatypes[])
INCLUDE ’mpif.h’
MPI_TYPE_GET_CONTENTS(DATATYPE, MAX_INTEGERS, MAX_ADDRESSES,
MAX_DATATYPES, ARRAY_OF_INTEGERS, ARRAY_OF_ADDRESSES,
ARRAY_OF_DATATYPES, IERROR)
INTEGER DATATYPE, MAX_INTEGERS, MAX_ADDRESSES, MAX_DATATYPES
INTEGER ARRAY_OF_INTEGERS(*), ARRAY_OF_DATATYPES(*), IERROR
INTEGER(KIND=MPI_ADDRESS_KIND) ARRAY_OF_ADDRESSES(*)
#include <mpi.h>
void MPI::Datatype::Get_contents(int max_integers, int max_addresses,
int max_datatypes, int array_of_integers[],
MPI::Aint array_of_addresses[],
MPI::Datatype array_of_datatypes[]) const
- datatype
- Data type to access (handle).
- max_integers
- Number
of elements in array_of_integers (nonnegative integer).
- max_addresses
- Number
of elements in array_of_addresses (nonnegative integer).
- max_datatypes
- Number
of elements in array_of_datatypes (nonnegative integer).
- array_of_integers
- Contains integer arguments used in constructing datatype (array of integers).
- array_of_addresses
- Contains address arguments used in constructing datatype
(array of integers).
- array_of_datatypes
- Contains data-type arguments used
in constructing datatype (array of integers).
- IERROR
- Fortran only: Error
status (integer).
For the given data type, MPI_Type_get_envelope
returns information on the number and type of input arguments used in the
call that created the data type. The number-of-arguments values returned can
be used to provide sufficiently large arrays in the decoding routine MPI_Type_get_contents.
This call and the meaning of the returned values is described below. The
combiner reflects the MPI data type constructor call that was used in creating
datatype.
The parameter datatype must be a predefined unnamed or a derived
data type. The call is erroneous if datatype is a predefined named data
type.
The values given for max_integers, max_addresses, and max_datatypes
must be at least as large as the value returned in num_integers, num_addresses,
and num_datatypes, respectively, in the call MPI_Type_get_envelope for
the same datatype argument.
The data types returned in array_of_datatypes
are handles to data-type objects that are equivalent to the data types used
in the original construction call. If these were derived data types, then
the returned data types are new data-type objects, and the user is responsible
for freeing these datatypes with MPI_Type_free. If these were predefined
data types, then the returned data type is equal to that (constant) predefined
data type and cannot be freed.
The committed state of returned derived
data types is undefined, that is, the data types may or may not be committed.
Furthermore, the content of attributes of returned data types is undefined.
Note that MPI_Type_get_contents can be invoked with a data-type argument
that was constructed using MPI_Type_create_f90_real, MPI_Type_create_f90_integer,
or MPI_Type_create_f90_complex (an unnamed predefined data type). In such
a case, an empty array_of_datatypes is returned.
In the MPI-1 data-type constructor
calls, the address arguments in Fortran are of type INTEGER. In the new
MPI-2 calls, the address arguments are of type INTEGER(KIND=MPI ADDRESS
KIND). The call MPI_Type_get_contents returns all addresses in an argument
of type INTEGER(KIND=MPI ADDRESS KIND). This is true even if the old MPI-1
calls were used. Thus, the location of values returned can be thought of
as being returned by the C bindings. It can also be determined by examining
the new MPI-2 calls for data-type constructors for the deprecated MPI-1 calls
that involve addresses.
The MPI standard prescribes portable
Fortran syntax for the ARRAY_OF_ADDRESSES argument only for Fortran 90.
FORTRAN 77 users may use the non-portable syntax
INTEGER*MPI_ADDRESS_KIND ARRAY_OF_ADDRESSES(*)
where MPI_ADDRESS_KIND is a constant defined in mpif.h and gives the length
of the declared integer in bytes.
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_envelope
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