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comparison src/os/unix/ngx_file_aio_read.c @ 518:86dad910eeb6 NGINX_0_8_11

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nginx 0.8.11 *) Change: directive "gzip_disable msie6" enables gzipping for MSIE 6.0 SV1. *) Feature: file AIO support on FreeBSD and Linux. *) Feature: the "directio_alignment" directive.
author Igor Sysoev <http://sysoev.ru>
date Fri, 28 Aug 2009 00:00:00 +0400
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children d41628eb4d0a
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517:15b5cddc5190 518:86dad910eeb6
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 /*
13 * FreeBSD file AIO features and quirks:
14 *
15 * if an asked data are already in VM cache, then aio_error() returns 0,
16 * and the data are already copied in buffer;
17 *
18 * aio_read() preread in VM cache as minimum 32K;
19 *
20 * aio_read/aio_error() may return EINPROGRESS for just written data;
21 *
22 * kqueue EVFILT_AIO filter is level triggered only: an event repeats
23 * until aio_return() will be called;
24 *
25 * aio_cancel() can not cancel file AIO: it returns AIO_NOTCANCELED always.
26 */
27
28
29 extern int ngx_kqueue;
30
31
32 static ssize_t ngx_file_aio_result(ngx_file_t *file, ngx_event_aio_t *aio,
33 ngx_event_t *ev);
34 static void ngx_file_aio_event_handler(ngx_event_t *ev);
35
36
37 ssize_t
38 ngx_file_aio_read(ngx_file_t *file, u_char *buf, size_t size, off_t offset,
39 ngx_pool_t *pool)
40 {
41 int n;
42 ngx_event_t *ev;
43 ngx_event_aio_t *aio;
44 static ngx_uint_t enosys = 0;
45
46 if (enosys) {
47 return ngx_read_file(file, buf, size, offset);
48 }
49
50 aio = file->aio;
51
52 if (aio == NULL) {
53 aio = ngx_pcalloc(pool, sizeof(ngx_event_aio_t));
54 if (aio == NULL) {
55 return NGX_ERROR;
56 }
57
58 aio->file = file;
59 aio->fd = file->fd;
60 aio->event.data = aio;
61 aio->event.ready = 1;
62 aio->event.log = file->log;
63 file->aio = aio;
64 }
65
66 ev = &aio->event;
67
68 if (!ev->ready) {
69 ngx_log_error(NGX_LOG_ALERT, file->log, 0,
70 "second aio post for \"%V\"", &file->name);
71 return NGX_AGAIN;
72 }
73
74 ngx_log_debug4(NGX_LOG_DEBUG_CORE, file->log, 0,
75 "aio complete:%d @%O:%z %V",
76 ev->complete, offset, size, &file->name);
77
78 if (ev->complete) {
79 ev->complete = 0;
80 ngx_set_errno(aio->err);
81
82 if (aio->err == 0) {
83 return aio->nbytes;
84 }
85
86 return NGX_ERROR;
87 }
88
89 ngx_memzero(&aio->aiocb, sizeof(struct aiocb));
90
91 aio->aiocb.aio_fildes = file->fd;
92 aio->aiocb.aio_offset = offset;
93 aio->aiocb.aio_buf = buf;
94 aio->aiocb.aio_nbytes = size;
95 #if (NGX_HAVE_KQUEUE)
96 aio->aiocb.aio_sigevent.sigev_notify_kqueue = ngx_kqueue;
97 aio->aiocb.aio_sigevent.sigev_notify = SIGEV_KEVENT;
98 aio->aiocb.aio_sigevent.sigev_value.sigval_ptr = ev;
99 #endif
100 ev->handler = ngx_file_aio_event_handler;
101
102 n = aio_read(&aio->aiocb);
103
104 if (n == -1) {
105 n = ngx_errno;
106
107 if (n == NGX_EAGAIN) {
108 return ngx_read_file(file, buf, size, offset);
109 }
110
111 ngx_log_error(NGX_LOG_CRIT, file->log, n,
112 "aio_read(\"%V\") failed", &file->name);
113
114 if (n == NGX_ENOSYS) {
115 enosys = 1;
116 return ngx_read_file(file, buf, size, offset);
117 }
118
119 return NGX_ERROR;
120 }
121
122 ngx_log_debug2(NGX_LOG_DEBUG_CORE, file->log, 0,
123 "aio_read: fd:%d %d", file->fd, n);
124
125 ev->active = 1;
126 ev->ready = 0;
127 ev->complete = 0;
128
129 return ngx_file_aio_result(aio->file, aio, ev);
130 }
131
132
133 static ssize_t
134 ngx_file_aio_result(ngx_file_t *file, ngx_event_aio_t *aio, ngx_event_t *ev)
135 {
136 int n;
137 ngx_err_t err;
138
139 n = aio_error(&aio->aiocb);
140
141 ngx_log_debug2(NGX_LOG_DEBUG_CORE, file->log, 0,
142 "aio_error: fd:%d %d", file->fd, n);
143
144 if (n == -1) {
145 err = ngx_errno;
146 aio->err = err;
147
148 ngx_log_error(NGX_LOG_ALERT, file->log, err,
149 "aio_error(\"%V\") failed", &file->name);
150 return NGX_ERROR;
151 }
152
153 if (n != 0) {
154 if (n == NGX_EINPROGRESS) {
155 if (ev->ready) {
156 ev->ready = 0;
157 ngx_log_error(NGX_LOG_ALERT, file->log, n,
158 "aio_read(\"%V\") still in progress",
159 &file->name);
160 }
161
162 return NGX_AGAIN;
163 }
164
165 aio->err = n;
166 ev->ready = 0;
167
168 ngx_log_error(NGX_LOG_CRIT, file->log, n,
169 "aio_read(\"%V\") failed", &file->name);
170 return NGX_ERROR;
171 }
172
173 n = aio_return(&aio->aiocb);
174
175 if (n == -1) {
176 err = ngx_errno;
177 aio->err = err;
178 ev->ready = 0;
179
180 ngx_log_error(NGX_LOG_ALERT, file->log, err,
181 "aio_return(\"%V\") failed", &file->name);
182 return NGX_ERROR;
183 }
184
185 aio->err = 0;
186 aio->nbytes = n;
187 ev->ready = 1;
188 ev->active = 0;
189
190 ngx_log_debug2(NGX_LOG_DEBUG_CORE, file->log, 0,
191 "aio_return: fd:%d %d", file->fd, n);
192
193 return n;
194 }
195
196
197 static void
198 ngx_file_aio_event_handler(ngx_event_t *ev)
199 {
200 ngx_event_aio_t *aio;
201
202 aio = ev->data;
203
204 ngx_log_debug2(NGX_LOG_DEBUG_CORE, ev->log, 0,
205 "aio event handler fd:%d %V", aio->fd, &aio->file->name);
206
207 if (ngx_file_aio_result(aio->file, aio, ev) != NGX_AGAIN) {
208 aio->handler(ev);
209 }
210 }