debuggers.hg

view tools/libaio/man/io_cancel.3 @ 0:7d21f7218375

Exact replica of unstable on 051908 + README-this
author Mukesh Rathor
date Mon May 19 15:34:57 2008 -0700 (2008-05-19)
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1 .TH io_cancel 2 2002-09-03 "Linux 2.4" "Linux AIO"
2 .SH NAME
3 io_cancel \- Cancel io requests
4 .SH SYNOPSIS
5 .nf
6 .B #include <errno.h>
7 .sp
8 .br
9 .B #include <libaio.h>
10 .sp
11 .br
12 .BI "int io_cancel(io_context_t ctx, struct iocb *iocb)"
13 .br
14 .sp
15 struct iocb {
16 void *data; /* Return in the io completion event */
17 unsigned key; /* For use in identifying io requests */
18 short aio_lio_opcode;
19 short aio_reqprio; /* Not used */
20 int aio_fildes;
21 };
22 .fi
23 .SH DESCRIPTION
24 Attempts to cancel an iocb previously passed to io_submit. If
25 the operation is successfully cancelled, the resulting event is
26 copied into the memory pointed to by result without being placed
27 into the completion queue.
28 .PP
29 When one or more requests are asynchronously processed, it might be
30 useful in some situations to cancel a selected operation, e.g., if it
31 becomes obvious that the written data is no longer accurate and would
32 have to be overwritten soon. As an example, assume an application, which
33 writes data in files in a situation where new incoming data would have
34 to be written in a file which will be updated by an enqueued request.
35 .SH "RETURN VALUES"
36 0 is returned on success , otherwise returns Errno.
37 .SH ERRORS
38 .TP
39 .B EFAULT
40 If any of the data structures pointed to are invalid.
41 .TP
42 .B EINVAL
43 If aio_context specified by ctx_id is
44 invalid.
45 .TP
46 .B EAGAIN
47 If the iocb specified was not
48 cancelled.
49 .TP
50 .B ENOSYS
51 if not implemented.
52 .SH "SEE ALSO"
53 .BR io(3),
54 .BR io_fsync(3),
55 .BR io_getevents(3),
56 .BR io_prep_fsync(3),
57 .BR io_prep_pread(3),
58 .BR io_prep_pwrite(3),
59 .BR io_queue_init(3),
60 .BR io_queue_release(3),
61 .BR io_queue_run(3),
62 .BR io_queue_wait(3),
63 .BR io_set_callback(3),
64 .BR io_submit(3),
65 .BR errno(3)