GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages


Manual Reference Pages  -  MPI_PACK (3)

NAME

MPI_Pack - Packs data of a given datatype into contiguous memory.

CONTENTS

Syntax
C Syntax
Fortran Syntax
C++ Syntax
Input Parameters
Input/output Parameter
Output Parameters
Description
Errors
See Also

SYNTAX

C Syntax

#include <mpi.h>
int MPI_Pack(const void *inbuf, int incount, MPI_Datatype datatype,
        void *outbuf, int outsize, int *position, MPI_Comm comm)

Fortran Syntax

INCLUDE ’mpif.h’
MPI_PACK(INBUF, INCOUNT, DATATYPE, OUTBUF,OUTSIZE, POSITION,
                COMM, IERROR)
        <type>  INBUF(*), OUTBUF(*)
        INTEGER INCOUNT, DATATYPE, OUTSIZE, POSITION, COMM, IERROR

C++ Syntax

#include <mpi.h>
void Datatype::Pack(const void* inbuf, int incount, void *outbuf,
        int outsize, int& position, const Comm &comm) const

INPUT PARAMETERS

inbuf Input buffer start (choice).
incount Number of input data items (integer).
datatype Datatype of each input data item (handle).
outsize Output buffer size, in bytes (integer).
comm Communicator for packed message (handle).

INPUT/OUTPUT PARAMETER

position Current position in buffer, in bytes (integer).

OUTPUT PARAMETERS

outbuf Output buffer start (choice).
IERROR Fortran only: Error status (integer).

DESCRIPTION

Packs the message in the send buffer specified by inbuf, incount, datatype into the buffer space specified by outbuf and outsize. The input buffer can be any communication buffer allowed in MPI_Send. The output buffer is a contiguous storage area containing outsize bytes, starting at the address outbuf (length is counted in bytes, not elements, as if it were a communication buffer for a message of type MPI_Packed).

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.

Example: An example using MPI_Pack:

    int position, i, j, a[2];
    char buff[1000];
    
    ....
    
    MPI_Comm_rank(MPI_COMM_WORLD, &myrank);
    if (myrank == 0)
    {
       / * SENDER CODE */
    
    position = 0;
      MPI_Pack(&i, 1, MPI_INT, buff, 1000, &position, MPI_COMM_WORLD);
      MPI_Pack(&j, 1, MPI_INT, buff, 1000, &position, MPI_COMM_WORLD);
      MPI_Send( buff, position, MPI_PACKED, 1, 0, MPI_COMM_WORLD);
    }
    else  /* RECEIVER CODE */
      MPI_Recv( a, 2, MPI_INT, 0, 0, MPI_COMM_WORLD)
    
    }

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 ALSO

MPI_Unpack
MPI_Pack_size

Search for    or go to Top of page |  Section 3 |  Main Index


1.10.2 MPI_PACK (3) Jan 21, 2016

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with manServer 1.07.