mpi_pack_size(3openmpi) [osx man page]

MPI_Pack_size(3OpenMPI) 												   MPI_Pack_size(3OpenMPI)

NAME

       MPI_Pack_size - Returns the upper bound on the amount of space needed to pack a message.

SYNTAX

C Syntax
       #include <mpi.h>
       int MPI_Pack_size(int incount, MPI_Datatype datatype, MPI_Comm comm,
	    int *size)

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_PACK_SIZE(INCOUNT, DATATYPE, COMM, SIZE, IERROR)
	    INTEGER   INCOUNT, DATATYPE, COMM, SIZE, IERROR

C++ Syntax
       #include <mpi.h>
       int Datatype::Pack_size(int incount, const Comm& comm) const

INPUT PARAMETERS

       incount	 Count argument to packing call (integer).

       datatype  Datatype argument to packing call (handle).

       comm	 Communicator argument to packing call (handle).

OUTPUT PARAMETERS

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

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       MPI_Pack_size  allows  the  application	to find out how much space is needed to pack a message. A call to MPI_Pack_size(incount, datatype,
       comm, size) returns in size an upper bound on the increment in position that would occur in a call to MPI_Pack, with the  same  values  for
       incount, datatype, and comm.

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

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 ALSO

       MPI_Pack
       MPI_Unpack

Open MPI 1.2							  September 2006					   MPI_Pack_size(3OpenMPI)

MPI_Pack_size(3)							MPI							  MPI_Pack_size(3)

NAME

       MPI_Pack_size -	Returns the upper bound on the amount of space needed to pack a message

SYNOPSIS

       int MPI_Pack_size(int incount,
			MPI_Datatype datatype,
			MPI_Comm comm,
			int *size)

INPUT PARAMETERS

       incount
	      - count argument to packing call (integer)
       datatype
	      - datatype argument to packing call (handle)
       comm   - communicator argument to packing call (handle)

OUTPUT PARAMETER

       size   - upper bound on size of packed message, in bytes (integer)

NOTES

       The  MPI  standard document describes this in terms of MPI_Pack , but it applies to both MPI_Pack and MPI_Unpack .  That is, the value size
       is the maximum that is needed by either MPI_Pack or MPI_Unpack .

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_COMM
	      - Invalid communicator.  A common error is to use a null communicator in a call (not even allowed in MPI_Comm_rank ).
       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_size.c

								     8/9/2010							  MPI_Pack_size(3)