debuggers.hg

view tools/blktap2/drivers/io-optimize.h @ 22848:6341fe0f4e5a

Added tag 4.1.0-rc2 for changeset 9dca60d88c63
author Keir Fraser <keir@xen.org>
date Tue Jan 25 14:06:55 2011 +0000 (2011-01-25)
parents 1c627434605e
children
line source
1 /*
2 * Copyright (c) 2008, XenSource Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 * * Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * * Neither the name of XenSource Inc. nor the names of its contributors
13 * may be used to endorse or promote products derived from this software
14 * without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
20 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
21 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
23 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
24 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
25 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
26 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
29 #ifndef __IO_OPTIMIZE_H__
30 #define __IO_OPTIMIZE_H__
32 #include <libaio.h>
34 struct opio;
36 struct opio_list {
37 struct opio *head;
38 struct opio *tail;
39 };
41 struct opio {
42 char *buf;
43 unsigned long nbytes;
44 long long offset;
45 void *data;
46 struct iocb *iocb;
47 struct io_event event;
48 struct opio *head;
49 struct opio *next;
50 struct opio_list list;
51 };
53 struct opioctx {
54 int num_opios;
55 int free_opio_cnt;
56 struct opio *opios;
57 struct opio **free_opios;
58 struct iocb **iocb_queue;
59 struct io_event *event_queue;
60 };
62 int opio_init(struct opioctx *ctx, int num_iocbs);
63 void opio_free(struct opioctx *ctx);
64 int io_merge(struct opioctx *ctx, struct iocb **queue, int num);
65 int io_split(struct opioctx *ctx, struct io_event *events, int num);
66 int io_expand_iocbs(struct opioctx *ctx, struct iocb **queue, int idx, int num);
68 #endif