MPI_Type_get_envelope(3) Open MPI MPI_Type_get_envelope(3)NAMEMPI_Type_get_envelope - Returns information about input arguments asso‐
ciated with a data type.
SYNTAXC Syntax
#include <mpi.h>
int MPI_Type_get_envelope(MPI_Datatype datatype, int *num_integers,
int *num_addresses, int *num_datatypes, int *combiner)
Fortran Syntax
INCLUDE 'mpif.h'
MPI_TYPE_GET_ENVELOPE(DATATYPE, NUM_INTEGERS, NUM_ADDRESSES,
NUM_DATATYPES, COMBINER, IERROR)
INTEGER DATATYPE, NUM_INTEGERS, NUM_ADDRESSES
INTEGER NUM_DATATYPES, COMBINER, IERROR
C++ Syntax
#include <mpi.h>
void MPI::Datatype::Get_envelope(int& num_integers,
int& num_addresses, int& num_datatypes,
int& combiner) const
INPUT PARAMETER
datatype Data type to access (handle).
OUTPUT PARAMETERS
num_integers
Number of input integers used in the call constructing com‐
biner (nonnegative integer).
num_addresses
Number of input addresses used in the call constructing com‐
biner (nonnegative integer).
num_datatypes
Number of input data types used in the call constructing com‐
biner (nonnegative integer).
combiner Combiner (state).
IERROR Fortran only: Error status (integer).
DESCRIPTION
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.
NOTES
These are the values that can be returned in combiner and their associ‐
ated calls:
Values Associated Calls
MPI_COMBINER_NAMED a named predefined data type
MPI_COMBINER_DUP MPI_Type_dup
MPI_COMBINER_CONTIGUOUS MPI_Type_contiguous
MPI_COMBINER_VECTOR MPI_Type_vector
MPI_COMBINER_HVECTOR_INTEGER MPI_Type_hvector from Fortran
MPI_COMBINER_HVECTOR MPI_Type_hvector from C or C++
and MPI_Type_create for
all languages
MPI_COMBINER_INDEXED MPI_Type_indexed
MPI_COMBINER_HINDEXED_INTEGER MPI_Type_hindexed from Fortran
MPI_COMBINER_HINDEXED MPI_Type_hindexed from C or C++
and MPI_Type_create_hindexed
for all languages
MPI_COMBINER_INDEXED_BLOCK MPI_Type_create_indexed_block
MPI_COMBINER_STRUCT_INTEGER MPI_Type_struct from Fortran
MPI_COMBINER_STRUCT MPI_Type_struct from C or C++
and MPI_Type_create_struct
for all languages
MPI_COMBINER_SUBARRAY MPI_Type_create_subarray
MPI_COMBINER_DARRAY MPI_Type_create_darray
MPI_COMBINER_F90_REAL MPI_Type_create_f90_real
MPI_COMBINER_F90_COMPLEX MPI_Type_create_f90_complex
MPI_COMBINER_F90_INTEGER MPI_Type_create_f90_integer
MPI_COMBINER_RESIZED MPI_Type_create_resized
If combiner is MPI_COMBINER_NAMED, then datatype is a named predefined
data type.
The actual arguments used in the creation call for a data type can be
obtained from the call MPI_Type_get_contents.
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++ func‐
tions 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_contents
1.7.4 Feb 04, 2014 MPI_Type_get_envelope(3)
