87 строки
2.7 KiB
Plaintext
87 строки
2.7 KiB
Plaintext
.\" Copyright 2010 Cisco Systems, Inc. All rights reserved.
|
|
.\" Copyright 2006-2008 Sun Microsystems, Inc.
|
|
.\" Copyright (c) 1996 Thinking Machines
|
|
.TH MPI_Buffer_attach 3 "#OMPI_DATE#" "#PACKAGE_VERSION#" "#PACKAGE_NAME#"
|
|
.SH NAME
|
|
\fBMPI_Buffer_attach\fP \- Attaches a user-defined buffer for sending.
|
|
|
|
.SH SYNTAX
|
|
.ft R
|
|
.SH C Syntax
|
|
.nf
|
|
#include <mpi.h>
|
|
int MPI_Buffer_attach(void \fI*buf\fP, int\fI size\fP)
|
|
|
|
.fi
|
|
.SH Fortran Syntax
|
|
.nf
|
|
INCLUDE 'mpif.h'
|
|
MPI_BUFFER_ATTACH(\fIBUF\fP,\fI SIZE\fP, \fIIERROR\fP)
|
|
<type> \fIBUF\fP(\fI*\fP)
|
|
INTEGER \fISIZE\fP,\fI IERROR \fP
|
|
|
|
.fi
|
|
.SH C++ Syntax
|
|
.nf
|
|
#include <mpi.h>
|
|
void Attach_buffer(void* \fIbuffer\fP, int \fIsize\fP)
|
|
|
|
.fi
|
|
.SH Java Syntax
|
|
.nf
|
|
import mpi.*;
|
|
void MPI.Buffer_attach(byte[] \fIbuffer\fP)
|
|
|
|
.fi
|
|
.SH INPUT PARAMETERS
|
|
.ft R
|
|
.TP 1i
|
|
buf
|
|
Initial buffer address (choice).
|
|
.TP 1i
|
|
size
|
|
Buffer size, in bytes (integer).
|
|
|
|
.SH OUTPUT PARAMETER
|
|
.ft R
|
|
.TP 1i
|
|
IERROR
|
|
Fortran only: Error status (integer).
|
|
|
|
.SH DESCRIPTION
|
|
.ft R
|
|
Provides to MPI a buffer in the user's memory to be used for buffering outgoing messages. The buffer is used only by messages sent in buffered mode. Only one buffer can be attached to a process at a time.
|
|
|
|
.SH NOTES
|
|
.ft R
|
|
The size given should be the sum of the sizes of all outstanding Bsends that you intend to have, plus MPI_BSEND_OVERHEAD bytes for each Bsend that you do. For the purposes of calculating size, you should use MPI_Pack_size. In other words, in the code
|
|
.sp
|
|
.nf
|
|
MPI_Buffer_attach( buf, size );
|
|
MPI_Bsend( \&..., count=20, datatype=type1, \&... );
|
|
\&...
|
|
MPI_Bsend( \&..., count=40, datatype=type2, \&... );
|
|
.fi
|
|
.sp
|
|
the value of size in the MPI_Buffer_attach call should be greater than the value computed by
|
|
.sp
|
|
.nf
|
|
MPI_Pack_size( 20, type1, comm, &s1 );
|
|
MPI_Pack_size( 40, type2, comm, &s2 );
|
|
size = s1 + s2 + 2 * MPI_BSEND_OVERHEAD;
|
|
.fi
|
|
.sp
|
|
MPI_BSEND_OVERHEAD gives the maximum amount of buffer space that may be used by the Bsend routines. This value is in mpi.h for C and mpif.h for Fortran.
|
|
|
|
.SH 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.
|
|
.sp
|
|
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.
|
|
|
|
.SH SEE ALSO
|
|
.ft R
|
|
.sp
|
|
MPI_Buffer_detach
|
|
|