MPITypestruct(3OpenMPI) MPITypestruct(3OpenMPI)

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


SSYYNNTTAAXX
CC SSyynnttaaxx
       #include 
       int MPITypestruct(int count, int *arrayofblocklengths,
            MPIAint *arrayofdisplacements, MPIDatatype *arrayoftypes,
            MPIDatatype *newtype)


FFoorrttrraann SSyynnttaaxx
       INCLUDE 'mpif.h'
       MPITYPESTRUCT(COUNT, ARRAYOFBLOCKLENGTHS,
                 ARRAYOFDISPLACEMENTS, ARRAYOFTYPES,
                 NEWTYPE, IERROR)
            INTEGER   COUNT, ARRAYOFBLOCKLENGTHS(*)
            INTEGER   ARRAYOFDISPLACEMENTS(*)
            INTEGER   ARRAYOFTYPES(*), NEWTYPE, IERROR



IINNPPUUTT PPAARRAAMMEETTEERRSS
       count     Number of blocks (integer)  also number of entries in  arrays
                 arrayoftypes,   arrayofdisplacements, and arrayofblock-
                 lengths.

       arrayofblocklengths
                 Number of elements in each block (array).

       arrayofdisplacements
                 Byte displacement of each block (array).

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



OOUUTTPPUUTT PPAARRAAMMEETTEERRSS
       newtype   New datatype (handle).

       IERROR    Fortran only: Error status (integer).


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

       This deprecated routine is not available in C++.

       MPITypestruct is the most general type constructor. It further gener-
       alizes  MPITypehindexed  in  that  it allows each block to consist of
       replications of different datatypes.

       EExxaammppllee:: Let type1 have type map

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

       with extent 16. Let B = (2, 1, 3), D = (0, 16, 26), and T = (MPIFLOAT,
       type1,  MPICHAR).  Then a call to MPITypestruct(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 MPIFLOAT starting at 0, followed by one copy of
       type1 starting at 16, followed by three copies of MPICHAR, 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.


NNOOTTEESS
       If an upperbound is set explicitly by using the  MPI  datatype  MPIUB,
       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  struc-
       tures that could be sent with a count greater than one. For example,
           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 different 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  MPIUB
       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] = MPIINT;
           blen[1] = 1; indices[1] = &foo.b - &foo; oldtypes[1] = MPICHAR;
           blen[2] = 1; indices[2] = sizeof(foo); oldtypes[2] = MPIUB;
           MPITypestruct( 3, blen, indices, oldtypes, &newtype );



EERRRROORRSS
       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::ERRORSTHROWEXCEPTIONS, 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
       MPICommseterrhandler; the predefined error handler MPIERRORSRETURN
       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
       MPITypecreatestruct
       MPITypecreatehindexed




Open MPI 1.2                    September 2006       MPITypestruct(3OpenMPI)