mirror of https://github.com/mkerrisk/man-pages
107 lines
2.6 KiB
Groff
107 lines
2.6 KiB
Groff
.\" Copyright (C) 2003 Free Software Foundation, Inc.
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.\" This file is distributed according to the GNU General Public License.
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.\" See the file COPYING in the top level source directory for details.
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.\"
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.\" .de Sh \" Subsection
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.\" ..
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.TH IO_SETUP 2 2008-06-18 "Linux" "Linux Programmer's Manual"
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.SH NAME
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io_setup \- create an asynchronous I/O context
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.SH "SYNOPSIS"
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.nf
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.\" .ad l
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.\" .hy 0
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.B #include <libaio.h>
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.\" #include <linux/aio.h>
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.sp
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.\" .HP 15
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.BI "int io_setup(unsigned " nr_events ", aio_context_t *" ctxp );
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.\" .ad
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.\" .hy
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.sp
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Link with \fI\-laio\fP.
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.fi
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.SH "DESCRIPTION"
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.PP
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.BR io_setup ()
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creates an asynchronous I/O context capable of receiving
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at least \fInr_events\fP.
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\fIctxp\fP must not point to an AIO context that already exists, and must
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be initialized to 0 prior to the call.
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On successful creation of the AIO context, \fI*ctxp\fP is filled in
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with the resulting handle.
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.SH "RETURN VALUE"
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On success,
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.BR io_setup ()
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returns 0.
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For the failure return, see NOTES.
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.SH "ERRORS"
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.TP
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.B EAGAIN
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The specified \fInr_events\fP exceeds the user's limit of available events.
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.TP
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.B EFAULT
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An invalid pointer is passed for \fIctxp\fP.
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.TP
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.B EINVAL
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\fIctxp\fP is not initialized, or the specified \fInr_events\fP
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exceeds internal limits.
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\fInr_events\fP should be greater than 0.
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.TP
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.B ENOMEM
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Insufficient kernel resources are available.
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.TP
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.B ENOSYS
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.BR io_setup ()
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is not implemented on this architecture.
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.SH "VERSIONS"
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.PP
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The asynchronous I/O system calls first appeared in Linux 2.5, August 2002.
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.SH "CONFORMING TO"
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.PP
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.BR io_setup ()
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is Linux-specific and should not be used in programs
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that are intended to be portable.
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.SH NOTES
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Glibc does not provide a wrapper function for this system call.
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The wrapper provided in
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.I libaio
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for
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.BR io_setup ()
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does not follow the usual C library conventions for indicating error:
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on error it returns a negated error number
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(the negative of one of the values listed in ERRORS).
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If the system call is invoked via
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.BR syscall (2),
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then the return value follows the usual conventions for
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indicating an error: \-1, with
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.I errno
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set to a (positive) value that indicates the error.
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.SH "SEE ALSO"
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.BR io_cancel (2),
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.BR io_destroy (2),
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.BR io_getevents (2),
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.BR io_submit (2)
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.\" .SH "NOTES"
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.\" .PP
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.\" The asynchronous I/O system calls were written by Benjamin LaHaise.
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.\" .SH AUTHOR
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.\" Kent Yoder.
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