oracular (3) MPI_Type_get_envelope.openmpi.3.gz

NAME

       MPI_Type_get_envelope - Returns information about input arguments associated with a data type.

SYNTAX

C 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

       USE MPI
       ! or the older form: 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

Fortran 2008 Syntax

       USE mpi_f08
       MPI_Type_get_envelope(datatype, num_integers, num_addresses, num_datatypes,
                 combiner, ierror)
            TYPE(MPI_Datatype), INTENT(IN) :: datatype
            INTEGER, INTENT(OUT) :: num_integers, num_addresses, num_datatypes,
            combiner
            INTEGER, OPTIONAL, INTENT(OUT) :: 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 combiner (nonnegative integer).

       num_addresses
                 Number of input addresses used in the call constructing combiner (nonnegative integer).

       num_datatypes
                 Number of input data types used in the call constructing combiner (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 associated 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            MPI_Type_hvector
       MPI_COMBINER_INDEXED            MPI_Type_indexed
       MPI_COMBINER_HINDEXED           MPI_Type_hindexed
       MPI_COMBINER_INDEXED_BLOCK      MPI_Type_create_indexed_block
       MPI_COMBINER_STRUCT             MPI_Type_struct
       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++ 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_contents