This document is a Mac OS X manual page. Manual pages are a command-line technology for providing documentation. You can view these manual pages locally using the man(1) command. These manual pages come from many different sources, and thus, have a variety of writing styles.

For more information about the manual page format, see the manual page for manpages(5).

MPI_Pack_external_size(3OpenMPI)                                            MPI_Pack_external_size(3OpenMPI)



NAME
       MPI_Pack_external_size - Calculates upper bound on space needed to write to a portable format


SYNTAX
C Syntax
       #include <mpi.h>
       int MPI_Pack_external_size(char *datarep, int incount,
            MPI_Datatype datatype, MPI_Aint *size)


Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_PACK_EXTERNAL_SIZE(DATAREP, INCOUNT, DATATYPE, SIZE, IERROR)

            INTEGER        INCOUNT, DATATYPE, IERROR
            INTEGER (KIND=MPI_ADDRESS_KIND) SIZE
            CHARACTER*(*)  DATAREP


C++ Syntax
       #include <mpi.h>
       MPI::Aint MPI::Datatype::Pack_external_size(const char* datarep,
            int incount) const


INPUT PARAMETERS
       datarep   Data representation (string).

       incount   Number of input data items (integer).

       datatype  Datatype of each input data item (handle).


OUTPUT PARAMETERS
       size      Upper bound on size of packed message, in bytes (integer).

       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       MPI_Pack_external_size  allows the application to find out how much space is needed to pack a message
       in the portable format defined by the MPI Forum. It returns in size an upper bound on  the  increment
       in  position  that  would  occur  in  a  call  to MPI_Pack_external with the same values for datarep,
       incount, and datatype.

       The call returns an upper bound, rather than an exact bound, as the exact amount of space  needed  to
       pack  the  message  may  depend on context and alignment (e.g., the first message packed in a packing
       unit may take more space).


NOTES
       The datarep argument specifies the data format. The only valid value in the current version of MPI is
       "external32". The argument is provided for future extensibility.


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 the MPI man page for a full list of MPI error codes.


SEE ALSO
       MPI_Pack_external
       MPI_Unpack_external




Open MPI 1.2                                   September 2006               MPI_Pack_external_size(3OpenMPI)