| .\" Copyright (c) 2003 Andries Brouwer (aeb@cwi.nl) |
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| .TH AIO_CANCEL 3 2015-03-02 "" "Linux Programmer's Manual" |
| .SH NAME |
| aio_cancel \- cancel an outstanding asynchronous I/O request |
| .SH SYNOPSIS |
| .B "#include <aio.h>" |
| .sp |
| .BI "int aio_cancel(int " fd ", struct aiocb *" aiocbp ); |
| .sp |
| Link with \fI\-lrt\fP. |
| .SH DESCRIPTION |
| The |
| .BR aio_cancel () |
| function attempts to cancel outstanding asynchronous I/O requests |
| for the file descriptor |
| .IR fd . |
| If |
| .I aiocbp |
| is NULL, all such requests are canceled. |
| Otherwise, only the request |
| described by the control block pointed to by |
| .I aiocbp |
| is canceled. |
| (See |
| .BR aio (7) |
| for a description of the |
| .I aiocb |
| structure.) |
| .LP |
| Normal asynchronous notification occurs for canceled requests (see |
| .BR aio (7) |
| and |
| .BR sigevent (7)). |
| The request return status |
| .RB ( aio_return (3)) |
| is set to \-1, and the request error status |
| .RB ( aio_error (3)) |
| is set to |
| .BR ECANCELED . |
| The control block of requests that cannot be canceled is not changed. |
| .LP |
| If the request could not be canceled, |
| then it will terminate in the usual way after performing the I/O operation. |
| (In this case, |
| .BR aio_error (3) |
| will return the status |
| .BR EINPROGRESSS .) |
| .LP |
| If |
| .I aiocbp |
| is not NULL, and |
| .I fd |
| differs from the file descriptor with which the asynchronous operation |
| was initiated, unspecified results occur. |
| .LP |
| Which operations are cancelable is implementation-defined. |
| .\" FreeBSD: not those on raw disk devices. |
| .SH RETURN VALUE |
| The |
| .BR aio_cancel () |
| function returns one of the following values: |
| .TP |
| .B AIO_CANCELED |
| All requests were successfully canceled. |
| .TP |
| .B AIO_NOTCANCELED |
| At least one of the |
| requests specified was not canceled because it was in progress. |
| In this case, one may check the status of individual requests using |
| .BR aio_error (3). |
| .TP |
| .B AIO_ALLDONE |
| All requests had already been completed before the call. |
| .TP |
| \-1 |
| An error occurred. |
| The cause of the error can be found by inspecting |
| .IR errno . |
| .SH ERRORS |
| .TP |
| .B EBADF |
| .I fd |
| is not a valid file descriptor. |
| .TP |
| .B ENOSYS |
| .BR aio_cancel () |
| is not implemented. |
| .SH VERSIONS |
| The |
| .BR aio_cancel () |
| function is available since glibc 2.1. |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .TS |
| allbox; |
| lb lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR aio_cancel () |
| T} Thread safety MT-Safe |
| .TE |
| .SH CONFORMING TO |
| POSIX.1-2001, POSIX.1-2008. |
| .SH EXAMPLE |
| See |
| .BR aio (7). |
| .SH SEE ALSO |
| .BR aio_error (3), |
| .BR aio_fsync (3), |
| .BR aio_read (3), |
| .BR aio_return (3), |
| .BR aio_suspend (3), |
| .BR aio_write (3), |
| .BR lio_listio (3), |
| .BR aio (7) |