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 {
30 long n;
31 struct iocb *piocb[1];
32 ngx_event_t *ev;
33 ngx_event_aio_t *aio;
34 static ngx_uint_t enosys = 0;
35
36 if (enosys) {
37 return ngx_read_file(file, buf, size, offset);
38 }
39
40 aio = file->aio;
41
42 if (aio == NULL) {
43 aio = ngx_pcalloc(pool, sizeof(ngx_event_aio_t));
44 if (aio == NULL) {
45 return NGX_ERROR;
46 }
47
48 aio->file = file;
49 aio->fd = file->fd;
50 aio->event.data = aio;
51 aio->event.ready = 1;
52 aio->event.log = file->log;
53 file->aio = aio;
54 }
55
56 ev = &aio->event;
57
58 if (!ev->ready) {
59 ngx_log_error(NGX_LOG_ALERT, file->log, 0,
60 "second aio post for \"%V\"", &file->name);
61 return NGX_AGAIN;
62 }
63
64 ngx_log_debug4(NGX_LOG_DEBUG_CORE, file->log, 0,
65 "aio complete:%d @%O:%z %V",
66 ev->complete, offset, size, &file->name);
67
68 if (ev->complete) {
69 ev->active = 0;
70 ev->complete = 0;
71
72 if (aio->res >= 0) {
73 ngx_set_errno(0);
74 return aio->res;
75 }
76
77 ngx_set_errno(-aio->res);
78 return NGX_ERROR;
79 }
80
81 ngx_memzero(&aio->aiocb, sizeof(struct iocb));
82
83 aio->aiocb.aio_data = (uint64_t) (uintptr_t) ev;
84 aio->aiocb.aio_lio_opcode = IOCB_CMD_PREAD;
85 aio->aiocb.aio_fildes = file->fd;
86 aio->aiocb.aio_buf = (uint64_t) (uintptr_t) buf;
87 aio->aiocb.aio_nbytes = size;
88 aio->aiocb.aio_offset = offset;
89 aio->aiocb.aio_flags = IOCB_FLAG_RESFD;
90 aio->aiocb.aio_resfd = ngx_eventfd;
91
92 ev->handler = ngx_file_aio_event_handler;
93
94 piocb[0] = &aio->aiocb;
95
96 n = io_submit(ngx_aio_ctx, 1, piocb);
97
98 if (n == 1) {
99 return NGX_AGAIN;
100 }
101
102 n = -n;
103
104 if (n == NGX_EAGAIN) {
105 return ngx_read_file(file, buf, size, offset);
106 }
107
108 ngx_log_error(NGX_LOG_CRIT, file->log, n,
109 "io_submit(\"%V\") failed", &file->name);
110
111 if (n == NGX_ENOSYS) {
112 enosys = 1;
113 return ngx_read_file(file, buf, size, offset);
114 }
115
116 return NGX_ERROR;
117 }
118
119
120 static void
121 ngx_file_aio_event_handler(ngx_event_t *ev)
122 {
123 ngx_event_aio_t *aio;
124
125 aio = ev->data;
126
127 ngx_log_debug2(NGX_LOG_DEBUG_CORE, ev->log, 0,
128 "aio event handler fd:%d %V", aio->fd, &aio->file->name);
129
130 aio->handler(ev);
131 }
132
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