mirror of https://github.com/mkerrisk/man-pages
95 lines
3.4 KiB
Plaintext
95 lines
3.4 KiB
Plaintext
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "AIO_CANCEL" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" aio_cancel
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.SH NAME
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aio_cancel \- cancel an asynchronous I/O request (\fBREALTIME\fP)
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.SH SYNOPSIS
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.LP
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\fB#include <aio.h>
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.br
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.sp
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int aio_cancel(int\fP \fIfildes\fP\fB, struct aiocb *\fP\fIaiocbp\fP\fB);
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\fP
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\fB
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.br
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\fP
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.SH DESCRIPTION
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.LP
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The \fIaio_cancel\fP() function shall attempt to cancel one or more
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asynchronous I/O requests currently outstanding against
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file descriptor \fIfildes\fP. The \fIaiocbp\fP argument points to
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the asynchronous I/O control block for a particular request to
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be canceled. If \fIaiocbp\fP is NULL, then all outstanding cancelable
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asynchronous I/O requests against \fIfildes\fP shall be
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canceled.
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.LP
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Normal asynchronous notification shall occur for asynchronous I/O
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operations that are successfully canceled. If there are
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requests that cannot be canceled, then the normal asynchronous completion
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process shall take place for those requests when they are
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completed.
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.LP
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For requested operations that are successfully canceled, the associated
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error status shall be set to [ECANCELED] and the return
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status shall be -1. For requested operations that are not successfully
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canceled, the \fIaiocbp\fP shall not be modified by
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\fIaio_cancel\fP().
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.LP
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If \fIaiocbp\fP is not NULL, then if \fIfildes\fP does not have the
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same value as the file descriptor with which the
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asynchronous operation was initiated, unspecified results occur.
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.LP
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Which operations are cancelable is implementation-defined.
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.SH RETURN VALUE
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.LP
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The \fIaio_cancel\fP() function shall return the value AIO_CANCELED
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to the calling process if the requested operation(s) were
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canceled. The value AIO_NOTCANCELED shall be returned if at least
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one of the requested operation(s) cannot be canceled because it
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is in progress. In this case, the state of the other operations, if
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any, referenced in the call to \fIaio_cancel\fP() is not
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indicated by the return value of \fIaio_cancel\fP(). The application
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may determine the state of affairs for these operations by
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using \fIaio_error\fP(). The value AIO_ALLDONE is returned if all
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of the operations have
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already completed. Otherwise, the function shall return -1 and set
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\fIerrno\fP to indicate the error.
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.SH ERRORS
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.LP
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The \fIaio_cancel\fP() function shall fail if:
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.TP 7
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.B EBADF
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The \fIfildes\fP argument is not a valid file descriptor.
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.sp
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.LP
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\fIThe following sections are informative.\fP
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.SH EXAMPLES
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.LP
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None.
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.SH APPLICATION USAGE
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.LP
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The \fIaio_cancel\fP() function is part of the Asynchronous Input
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and Output option and need not be available on all
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implementations.
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.SH RATIONALE
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.LP
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None.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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\fIaio_read\fP() , \fIaio_write\fP() , the Base Definitions volume
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of
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IEEE\ Std\ 1003.1-2001, \fI<aio.h>\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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