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a76bab49 AL |
1 | /* |
2 | * QEMU aio implementation | |
3 | * | |
4 | * Copyright IBM, Corp. 2008 | |
5 | * | |
6 | * Authors: | |
7 | * Anthony Liguori <[email protected]> | |
8 | * | |
9 | * This work is licensed under the terms of the GNU GPL, version 2. See | |
10 | * the COPYING file in the top-level directory. | |
11 | * | |
12 | */ | |
13 | ||
14 | #ifndef QEMU_AIO_H | |
15 | #define QEMU_AIO_H | |
16 | ||
17 | #include "qemu-common.h" | |
18 | #include "qemu-char.h" | |
19 | ||
85e8dab1 PB |
20 | typedef struct BlockDriverAIOCB BlockDriverAIOCB; |
21 | typedef void BlockDriverCompletionFunc(void *opaque, int ret); | |
22 | ||
23 | typedef struct AIOPool { | |
24 | void (*cancel)(BlockDriverAIOCB *acb); | |
25 | int aiocb_size; | |
26 | BlockDriverAIOCB *free_aiocb; | |
27 | } AIOPool; | |
28 | ||
29 | struct BlockDriverAIOCB { | |
30 | AIOPool *pool; | |
31 | BlockDriverState *bs; | |
32 | BlockDriverCompletionFunc *cb; | |
33 | void *opaque; | |
34 | BlockDriverAIOCB *next; | |
35 | }; | |
36 | ||
37 | void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs, | |
38 | BlockDriverCompletionFunc *cb, void *opaque); | |
39 | void qemu_aio_release(void *p); | |
40 | ||
a76bab49 AL |
41 | /* Returns 1 if there are still outstanding AIO requests; 0 otherwise */ |
42 | typedef int (AioFlushHandler)(void *opaque); | |
43 | ||
8febfa26 KW |
44 | /* Runs all currently allowed AIO callbacks of completed requests in the |
45 | * respective AIO backend. Returns 0 if no requests was handled, non-zero | |
46 | * if at least one queued request was handled. */ | |
47 | typedef int (AioProcessQueue)(void *opaque); | |
48 | ||
a76bab49 AL |
49 | /* Flush any pending AIO operation. This function will block until all |
50 | * outstanding AIO operations have been completed or cancelled. */ | |
51 | void qemu_aio_flush(void); | |
52 | ||
986c28d6 AA |
53 | /* Wait for a single AIO completion to occur. This function will wait |
54 | * until a single AIO event has completed and it will ensure something | |
55 | * has moved before returning. This can issue new pending aio as | |
56 | * result of executing I/O completion or bh callbacks. */ | |
a76bab49 AL |
57 | void qemu_aio_wait(void); |
58 | ||
8febfa26 KW |
59 | /* |
60 | * Runs all currently allowed AIO callbacks of completed requests. Returns 0 | |
61 | * if no requests were handled, non-zero if at least one request was | |
62 | * processed. | |
63 | */ | |
64 | int qemu_aio_process_queue(void); | |
65 | ||
a76bab49 AL |
66 | /* Register a file descriptor and associated callbacks. Behaves very similarly |
67 | * to qemu_set_fd_handler2. Unlike qemu_set_fd_handler2, these callbacks will | |
68 | * be invoked when using either qemu_aio_wait() or qemu_aio_flush(). | |
69 | * | |
70 | * Code that invokes AIO completion functions should rely on this function | |
71 | * instead of qemu_set_fd_handler[2]. | |
72 | */ | |
73 | int qemu_aio_set_fd_handler(int fd, | |
74 | IOHandler *io_read, | |
75 | IOHandler *io_write, | |
76 | AioFlushHandler *io_flush, | |
8febfa26 | 77 | AioProcessQueue *io_process_queue, |
a76bab49 AL |
78 | void *opaque); |
79 | ||
80 | #endif |