Mercurial > hg > nginx
annotate src/os/unix/ngx_linux_aio_read.c @ 3351:b759cf8f6000
add comment from r2716 commit message
author | Igor Sysoev <igor@sysoev.ru> |
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date | Tue, 17 Nov 2009 10:31:39 +0000 |
parents | 04cfc09b8b8d |
children | cd04f652478c |
rev | line source |
---|---|
3052 | 1 |
2 /* | |
3 * Copyright (C) Igor Sysoev | |
4 */ | |
5 | |
6 | |
7 #include <ngx_config.h> | |
8 #include <ngx_core.h> | |
9 #include <ngx_event.h> | |
10 | |
11 | |
12 extern int ngx_eventfd; | |
13 extern aio_context_t ngx_aio_ctx; | |
14 | |
15 | |
16 static void ngx_file_aio_event_handler(ngx_event_t *ev); | |
17 | |
18 | |
19 static long | |
20 io_submit(aio_context_t ctx, long n, struct iocb **paiocb) | |
21 { | |
22 return syscall(SYS_io_submit, ctx, n, paiocb); | |
23 } | |
24 | |
25 | |
26 ssize_t | |
27 ngx_file_aio_read(ngx_file_t *file, u_char *buf, size_t size, off_t offset, | |
28 ngx_pool_t *pool) | |
29 { | |
3294
04cfc09b8b8d
export aio presence knowledge to prevent using "aio sendfile",
Igor Sysoev <igor@sysoev.ru>
parents:
3052
diff
changeset
|
30 long n; |
04cfc09b8b8d
export aio presence knowledge to prevent using "aio sendfile",
Igor Sysoev <igor@sysoev.ru>
parents:
3052
diff
changeset
|
31 struct iocb *piocb[1]; |
04cfc09b8b8d
export aio presence knowledge to prevent using "aio sendfile",
Igor Sysoev <igor@sysoev.ru>
parents:
3052
diff
changeset
|
32 ngx_event_t *ev; |
04cfc09b8b8d
export aio presence knowledge to prevent using "aio sendfile",
Igor Sysoev <igor@sysoev.ru>
parents:
3052
diff
changeset
|
33 ngx_event_aio_t *aio; |
3052 | 34 |
3294
04cfc09b8b8d
export aio presence knowledge to prevent using "aio sendfile",
Igor Sysoev <igor@sysoev.ru>
parents:
3052
diff
changeset
|
35 if (!ngx_file_aio) { |
3052 | 36 return ngx_read_file(file, buf, size, offset); |
37 } | |
38 | |
39 aio = file->aio; | |
40 | |
41 if (aio == NULL) { | |
42 aio = ngx_pcalloc(pool, sizeof(ngx_event_aio_t)); | |
43 if (aio == NULL) { | |
44 return NGX_ERROR; | |
45 } | |
46 | |
47 aio->file = file; | |
48 aio->fd = file->fd; | |
49 aio->event.data = aio; | |
50 aio->event.ready = 1; | |
51 aio->event.log = file->log; | |
52 file->aio = aio; | |
53 } | |
54 | |
55 ev = &aio->event; | |
56 | |
57 if (!ev->ready) { | |
58 ngx_log_error(NGX_LOG_ALERT, file->log, 0, | |
59 "second aio post for \"%V\"", &file->name); | |
60 return NGX_AGAIN; | |
61 } | |
62 | |
63 ngx_log_debug4(NGX_LOG_DEBUG_CORE, file->log, 0, | |
64 "aio complete:%d @%O:%z %V", | |
65 ev->complete, offset, size, &file->name); | |
66 | |
67 if (ev->complete) { | |
68 ev->active = 0; | |
69 ev->complete = 0; | |
70 | |
71 if (aio->res >= 0) { | |
72 ngx_set_errno(0); | |
73 return aio->res; | |
74 } | |
75 | |
76 ngx_set_errno(-aio->res); | |
77 return NGX_ERROR; | |
78 } | |
79 | |
80 ngx_memzero(&aio->aiocb, sizeof(struct iocb)); | |
81 | |
82 aio->aiocb.aio_data = (uint64_t) (uintptr_t) ev; | |
83 aio->aiocb.aio_lio_opcode = IOCB_CMD_PREAD; | |
84 aio->aiocb.aio_fildes = file->fd; | |
85 aio->aiocb.aio_buf = (uint64_t) (uintptr_t) buf; | |
86 aio->aiocb.aio_nbytes = size; | |
87 aio->aiocb.aio_offset = offset; | |
88 aio->aiocb.aio_flags = IOCB_FLAG_RESFD; | |
89 aio->aiocb.aio_resfd = ngx_eventfd; | |
90 | |
91 ev->handler = ngx_file_aio_event_handler; | |
92 | |
93 piocb[0] = &aio->aiocb; | |
94 | |
95 n = io_submit(ngx_aio_ctx, 1, piocb); | |
96 | |
97 if (n == 1) { | |
98 return NGX_AGAIN; | |
99 } | |
100 | |
101 n = -n; | |
102 | |
103 if (n == NGX_EAGAIN) { | |
104 return ngx_read_file(file, buf, size, offset); | |
105 } | |
106 | |
107 ngx_log_error(NGX_LOG_CRIT, file->log, n, | |
108 "io_submit(\"%V\") failed", &file->name); | |
109 | |
110 if (n == NGX_ENOSYS) { | |
3294
04cfc09b8b8d
export aio presence knowledge to prevent using "aio sendfile",
Igor Sysoev <igor@sysoev.ru>
parents:
3052
diff
changeset
|
111 ngx_file_aio = 0; |
3052 | 112 return ngx_read_file(file, buf, size, offset); |
113 } | |
114 | |
115 return NGX_ERROR; | |
116 } | |
117 | |
118 | |
119 static void | |
120 ngx_file_aio_event_handler(ngx_event_t *ev) | |
121 { | |
122 ngx_event_aio_t *aio; | |
123 | |
124 aio = ev->data; | |
125 | |
126 ngx_log_debug2(NGX_LOG_DEBUG_CORE, ev->log, 0, | |
127 "aio event handler fd:%d %V", aio->fd, &aio->file->name); | |
128 | |
129 aio->handler(ev); | |
130 } |