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MPI_Type_struct(3OpenMPI)                                                          MPI_Type_struct(3OpenMPI)



NAME
       MPI_Type_struct - Creates a struct data type -- use of this routine is deprecated.


SYNTAX
C Syntax
       #include <mpi.h>
       int MPI_Type_struct(int count, int *array_of_blocklengths,
            MPI_Aint *array_of_displacements, MPI_Datatype *array_of_types,
            MPI_Datatype *newtype)


Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_TYPE_STRUCT(COUNT, ARRAY_OF_BLOCKLENGTHS,
                 ARRAY_OF_DISPLACEMENTS, ARRAY_OF_TYPES,
                 NEWTYPE, IERROR)
            INTEGER   COUNT, ARRAY_OF_BLOCKLENGTHS(*)
            INTEGER   ARRAY_OF_DISPLACEMENTS(*)
            INTEGER   ARRAY_OF_TYPES(*), NEWTYPE, IERROR



INPUT PARAMETERS
       count     Number of blocks (integer)  also number of entries in arrays array_of_types,  array_of_dis-placements, array_of_displacements,
                 placements, and array_of_blocklengths.

       array_of_blocklengths
                 Number of elements in each block (array).

       array_of_displacements
                 Byte displacement of each block (array).

       array_of_types
                 Type of elements in each block (array of handles to datatype objects).



OUTPUT PARAMETERS
       newtype   New datatype (handle).

       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       Note that use of this routine is deprecated as of MPI-2. Use MPI_Type_create_struct instead.

       This deprecated routine is not available in C++.

       MPI_Type_struct is the most general type constructor. It  further  generalizes  MPI_Type_hindexed  in
       that it allows each block to consist of replications of different datatypes.

       Example: Let type1 have type map

           {(double, 0), (char, 8)}

       with extent 16. Let B = (2, 1, 3), D = (0, 16, 26), and T = (MPI_FLOAT, type1, MPI_CHAR). Then a call
       to MPI_Type_struct(3, B, D, T, newtype) returns a datatype with type map

           {(float, 0), (float,4), (double, 16), (char, 24),
           (char, 26), (char, 27), (char, 28)}

       That is, two copies of MPI_FLOAT starting at 0, followed by one copy of type1 starting  at  16,  fol-lowed followed
       lowed by three copies of MPI_CHAR, starting at 26. (We assume that a float occupies 4 bytes.)

       For more information, see section 3.12.1 of the MPI-1.1 Standard.


NOTES
       If  an upperbound is set explicitly by using the MPI datatype MPI_UB, the corresponding index must be
       positive.

       The MPI-1 Standard originally made vague statements about padding and alignment; this was intended to
       allow the simple definition of structures that could be sent with a count greater than one. For exam-ple, example,
       ple,
           struct {int a; char b;} foo;
       may have
           sizeof(foo) = sizeof(int) + sizeof(char);
       defining the extent of a datatype as including an epsilon, which would have allowed an implementation
       to  make the extent an MPI datatype for this structure equal to 2*sizeof(int). However, since differ-ent different
       ent systems might define different paddings, a clarification to the standard made epsilon zero. Thus,
       if  you define a structure datatype and wish to send or receive multiple items, you should explicitly
       include an MPI_UB entry as the last member of the structure.  For example, the following code can  be
       used for the structure foo:

           blen[0] = 1; indices[0] = 0; oldtypes[0] = MPI_INT;
           blen[1] = 1; indices[1] = &foo.b - &foo; oldtypes[1] = MPI_CHAR;
           blen[2] = 1; indices[2] = sizeof(foo); oldtypes[2] = MPI_UB;
           MPI_Type_struct( 3, blen, indices, oldtypes, &newtype );



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_create_struct
       MPI_Type_create_hindexed




Open MPI 1.2                                   September 2006                      MPI_Type_struct(3OpenMPI)