NAME

       MPI_Pack -  Packs a datatype into contiguous memory

SYNOPSIS

       #ifdef ENABLE_QMPI
       #ifndef MPICH_MPI_FROM_PMPI
       int QMPI_Pack(QMPI_Context context, int tool_id, const void *inbuf, int incount,
       MPI_Datatype datatype, void *outbuf, int outsize, int *position,
       MPI_Comm comm) MPICH_API_PUBLIC

INPUT PARAMETERS

       inbuf  - input buffer start (choice)
       incount
              - number of input data items (non-negative integer)
       datatype
              - datatype of each input data item (handle)
       outsize
              - output buffer size, in bytes (non-negative integer)
       comm   - communicator for packed message (handle)

INPUT/OUTPUT PARAMETERS

       position
              - current position in buffer, in bytes (integer)

OUTPUT PARAMETERS

       outbuf - output buffer start (choice)

NOTES (FROM THE SPECIFICATIONS)

       The  input value of position is the first location in the output buffer to be used for packing.  position
       is incremented by the size of the packed message, and the output value of position is the first  location
       in  the  output  buffer following the locations occupied by the packed message.  The comm argument is the
       communicator that will be subsequently used for sending the packed message.

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 guarantee 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_ARG
              - Invalid argument.  Some argument is invalid and is not identified  by  a  specific  error  class
              (e.g., MPI_ERR_RANK ).
       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_COUNT
              - Invalid count argument.  Count arguments must be non-negative; a count of zero is often valid.
       MPI_ERR_TYPE
              - Invalid datatype argument.  Additionally, this error can occur if  an  uncommitted  MPI_Datatype
              (see MPI_Type_commit ) is used in a communication call.
       MPI_ERR_OTHER
              - Other error; use MPI_Error_string to get more information about this error code.

                                                    1/21/2022                                        MPI_Pack(3)