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mpi_pack_external_size(3openmpi) [osx man page]

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  pro-
       vided 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++ 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 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)

Check Out this Related Man Page

MPI_Pack_external_size(3)						MPI						 MPI_Pack_external_size(3)

NAME

       MPI_Pack_external_size -  Returns the upper bound on the amount of space needed to pack a message using MPI_Pack_external.

SYNOPSIS

       int MPI_Pack_external_size(char *datarep,
				int incount,
				MPI_Datatype datatype,
				MPI_Aint *size)

INPUT PARAMETERS

       datarep
	      - data representation (string)
       incount
	      - number of input data items (integer)
       datatype
	      - datatype of each input data item (handle)

OUTPUT PARAMETERS

       size   - output buffer size, in bytes (address integer)

THREAD AND INTERRUPT SAFETY

       This  routine  is  thread-safe.	This means that this routine may be safely used by multiple threads without the need for any user-provided
       thread locks.  However, the routine is not interrupt safe.  Typically, this is due to the use of memory allocation routines such as  malloc
       or other non-MPICH runtime routines that are themselves not interrupt-safe.

NOTES FOR FORTRAN

       All  MPI  routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have an additional argument ierr at the end of the argument list.  ierr
       is an integer and has the same meaning as the return value of the routine in C.	In Fortran, MPI routines are subroutines, and are  invoked
       with the call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in Fortran.

ERRORS

       All  MPI  routines (except MPI_Wtime and MPI_Wtick ) return an error value; C routines as the value of the function and Fortran routines in
       the last argument.  Before the value is returned, the current MPI error handler is called.  By default, this error handler aborts  the  MPI
       job.   The  error  handler  may	be  changed  with  MPI_Comm_set_errhandler  (for  communicators), MPI_File_set_errhandler (for files), and
       MPI_Win_set_errhandler (for RMA windows).  The MPI-1 routine MPI_Errhandler_set may be used but its  use  is  deprecated.   The	predefined
       error handler MPI_ERRORS_RETURN may be used to cause error values to be returned.  Note that MPI does not guarentee that an MPI program can
       continue past an error; however, MPI implementations will attempt to continue whenever possible.

       MPI_SUCCESS
	      - No error; MPI routine completed successfully.
       MPI_ERR_TYPE
	      - Invalid datatype argument.  May be an uncommitted MPI_Datatype (see MPI_Type_commit ).
       MPI_ERR_ARG
	      - Invalid argument.  Some argument is invalid and is not identified by a specific error class (e.g., MPI_ERR_RANK ).

LOCATION

       pack_external_size.c

								     8/2/2008						 MPI_Pack_external_size(3)
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