59cc09fd1a
This commit was SVN r13456. The following Trac tickets were found above: Ticket 850 --> https://svn.open-mpi.org/trac/ompi/ticket/850
107 строки
3.1 KiB
Groff
107 строки
3.1 KiB
Groff
.\"Copyright 2006, Sun Microsystems, Inc.
|
|
.\" Copyright (c) 1996 Thinking Machines Corporation
|
|
.TH MPI_File_iread_at 3OpenMPI "September 2006" "Open MPI 1.2" " "
|
|
.SH NAME
|
|
\fBMPI_File_iread_at\fP \- Reads a file at an explicitly specified offset (nonblocking, noncollective).
|
|
|
|
.SH SYNTAX
|
|
.ft R
|
|
.nf
|
|
C Syntax
|
|
#include <mpi.h>
|
|
int MPI_File_iread_at(MPI_File \fIfh\fP, MPI_Offset \fIoffset\fP,
|
|
void \fI*buf\fP, int \fIcount\fP, MPI_Datatype \fIdatatype\fP,
|
|
MPI_Request \fI*request\fP)
|
|
|
|
Fortran Syntax (see FORTRAN 77 NOTES)
|
|
INCLUDE 'mpif.h'
|
|
MPI_FILE_IREAD_AT(\fIFH\fP, \fIOFFSET\fP, \fIBUF\fP, \fICOUNT\fP, \fIDATATYPE\fP, \fIREQUEST\fP, \fIIERROR\fP)
|
|
<type> \fIBUF\fP(*)
|
|
INTEGER \fIFH, COUNT, DATATYPE, REQUEST, IERROR\fP
|
|
INTEGER(KIND=MPI_OFFSET_KIND) \fIOFFSET\fP
|
|
|
|
.SH C++ Syntax
|
|
.nf
|
|
#include <mpi.h>
|
|
MPI::Request MPI::File::Iread_at(MPI::Offset \fIoffset\fP, void* \fIbuf\fP,
|
|
int \fIcount\fP, const MPI::Datatype& \fIdatatype\fP)
|
|
|
|
.SH INPUT PARAMETERS
|
|
.ft R
|
|
.TP 1i
|
|
fh
|
|
File handle (handle).
|
|
.ft R
|
|
.TP 1i
|
|
offset
|
|
File offset (integer).
|
|
.ft R
|
|
.TP 1i
|
|
count
|
|
Number of elements in the buffer (integer).
|
|
.ft R
|
|
.TP 1i
|
|
datatype
|
|
Data type of each buffer element (handle).
|
|
|
|
.SH OUTPUT PARAMETERS
|
|
.ft R
|
|
.TP 1i
|
|
buf
|
|
Initial address of the buffer (choice).
|
|
.ft R
|
|
.TP 1i
|
|
request
|
|
Request object (handle).
|
|
.TP 1i
|
|
IERROR
|
|
Fortran only: Error status (integer).
|
|
|
|
.SH DESCRIPTION
|
|
.ft R
|
|
MPI_File_iread_at is the nonblocking version of MPI_File_read_at.
|
|
|
|
MPI_File_iread_at is a nonblocking routine that attempts to read from the file associated with
|
|
.I fh
|
|
at the
|
|
.I offset
|
|
position a total number of
|
|
.I count
|
|
data items having
|
|
.I datatype
|
|
type into the user's buffer
|
|
.I buf.
|
|
The
|
|
.I offset
|
|
is in etype units relative to the current view. That is, holes are not counted
|
|
when locating an offset. The data is taken out of those parts of the
|
|
file specified by the current view. MPI_File_iread_at stores the
|
|
number of
|
|
.I datatype
|
|
elements actually read in
|
|
.I status.
|
|
All other fields of
|
|
.I status
|
|
are undefined.
|
|
|
|
.SH FORTRAN 77 NOTES
|
|
.ft R
|
|
The MPI standard prescribes portable Fortran syntax for
|
|
the \fIOFFSET\fP argument only for Fortran 90. Sun FORTRAN 77
|
|
users may use the non-portable syntax
|
|
.sp
|
|
.nf
|
|
INTEGER*MPI_OFFSET_KIND \fIOFFSET\fP
|
|
.fi
|
|
.sp
|
|
where MPI_OFFSET_KIND is a constant defined in mpif.h
|
|
and gives the length of the declared integer in bytes.
|
|
|
|
.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.
|
|
|
|
' @(#)MPI_File_iread_at.3 1.22 06/03/09
|