65 строки
2.1 KiB
Groff
65 строки
2.1 KiB
Groff
.\"Copyright 2006, Sun Microsystems, Inc.
|
|
.\" Copyright (c) 1996 Thinking Machines Corporation
|
|
.TH MPI_File_set_atomicity 3OpenMPI "September 2006" "Open MPI 1.2" " "
|
|
.SH NAME
|
|
\fBMPI_File_set_atomicity\fP \- Sets consistency semantics for data-access operations (collective).
|
|
|
|
.SH SYNTAX
|
|
.ft R
|
|
.nf
|
|
C Syntax
|
|
#include <mpi.h>
|
|
int MPI_File_set_atomicity(MPI_File \fIfh\fP, int \fIflag\fP)
|
|
|
|
Fortran Syntax
|
|
INCLUDE 'mpif.h'
|
|
MPI_FILE_SET_ATOMICITY(\fIFH\fP,\fI FLAG\fP,\fI IERROR\fP)
|
|
INTEGER FH, FLAG, IERROR
|
|
|
|
.SH C++ Syntax
|
|
.nf
|
|
#include <mpi.h>
|
|
void MPI::File::Set_atomicity(bool \fIflag\fP)
|
|
|
|
.SH INPUT PARAMETERS
|
|
.ft R
|
|
.TP 1i
|
|
fh
|
|
File handle (handle).
|
|
.TP 1i
|
|
flag
|
|
\fBtrue\fP to enable atomic mode, \fBfalse\fP to enable nonatomic mode (boolean).
|
|
|
|
.SH OUTPUT PARAMETER
|
|
.ft R
|
|
.TP 1i
|
|
IERROR
|
|
Fortran only: Error status (integer).
|
|
|
|
.SH DESCRIPTION
|
|
.ft R
|
|
The consistency semantics for data-access operations using the set of
|
|
file handles created by one collective MPI_File_open is set by collectively
|
|
calling MPI_File_set_atomicity. All processes in the group must pass identical values for
|
|
.I fh
|
|
and
|
|
.I flag.
|
|
If
|
|
.I flag
|
|
is
|
|
.I true,
|
|
atomic mode is set; if
|
|
.I flag
|
|
is
|
|
.I false,
|
|
nonatomic mode is set.
|
|
.sp
|
|
The default value on a call to MPI_File_open in Open MPI is \fItrue\fP for jobs running on more than one node, \fIfalse\fP for jobs running on a single SMP. For more information, see the MPI-2 standard.
|
|
|
|
.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. For MPI I/O function errors, the default error handler is set to MPI_ERRORS_RETURN. The error handler may be changed with MPI_File_set_errhandler; the predefined error handler MPI_ERRORS_ARE_FATAL may be used to make I/O errors fatal. Note that MPI does not guarantee that an MPI program can continue past an error.
|
|
|