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 static ngx_int_t ngx_select_init(ngx_cycle_t *cycle, ngx_msec_t timer);
13 static void ngx_select_done(ngx_cycle_t *cycle);
14 static ngx_int_t ngx_select_add_event(ngx_event_t *ev, ngx_int_t event,
15 ngx_uint_t flags);
16 static ngx_int_t ngx_select_del_event(ngx_event_t *ev, ngx_int_t event,
17 ngx_uint_t flags);
18 static ngx_int_t ngx_select_process_events(ngx_cycle_t *cycle, ngx_msec_t timer,
19 ngx_uint_t flags);
20 static void ngx_select_repair_fd_sets(ngx_cycle_t *cycle);
21 static char *ngx_select_init_conf(ngx_cycle_t *cycle, void *conf);
22
23
24 static fd_set master_read_fd_set;
25 static fd_set master_write_fd_set;
26 static fd_set work_read_fd_set;
27 static fd_set work_write_fd_set;
28
29 static ngx_uint_t max_read;
30 static ngx_uint_t max_write;
31 static ngx_uint_t nevents;
32
33 static ngx_event_t **event_index;
34
35
36 static ngx_str_t select_name = ngx_string("select");
37
38 ngx_event_module_t ngx_select_module_ctx = {
39 &select_name,
40 NULL, /* create configuration */
41 ngx_select_init_conf, /* init configuration */
42
43 {
44 ngx_select_add_event, /* add an event */
45 ngx_select_del_event, /* delete an event */
46 ngx_select_add_event, /* enable an event */
47 ngx_select_del_event, /* disable an event */
48 NULL, /* add an connection */
49 NULL, /* delete an connection */
50 NULL, /* process the changes */
51 ngx_select_process_events, /* process the events */
52 ngx_select_init, /* init the events */
53 ngx_select_done /* done the events */
54 }
55
56 };
57
58 ngx_module_t ngx_select_module = {
59 NGX_MODULE_V1,
60 &ngx_select_module_ctx, /* module context */
61 NULL, /* module directives */
62 NGX_EVENT_MODULE, /* module type */
63 NULL, /* init master */
64 NULL, /* init module */
65 NULL, /* init process */
66 NULL, /* init thread */
67 NULL, /* exit thread */
68 NULL, /* exit process */
69 NULL, /* exit master */
70 NGX_MODULE_V1_PADDING
71 };
72
73
74 static ngx_int_t
75 ngx_select_init(ngx_cycle_t *cycle, ngx_msec_t timer)
76 {
77 ngx_event_t **index;
78
79 if (event_index == NULL) {
80 FD_ZERO(&master_read_fd_set);
81 FD_ZERO(&master_write_fd_set);
82 nevents = 0;
83 }
84
85 if (ngx_process == NGX_PROCESS_WORKER
86 || cycle->old_cycle == NULL
87 || cycle->old_cycle->connection_n < cycle->connection_n)
88 {
89 index = ngx_alloc(sizeof(ngx_event_t *) * 2 * cycle->connection_n,
90 cycle->log);
91 if (index == NULL) {
92 return NGX_ERROR;
93 }
94
95 if (event_index) {
96 ngx_memcpy(index, event_index, sizeof(ngx_event_t *) * nevents);
97 ngx_free(event_index);
98 }
99
100 event_index = index;
101 }
102
103 ngx_io = ngx_os_io;
104
105 ngx_event_actions = ngx_select_module_ctx.actions;
106
107 ngx_event_flags = NGX_USE_LEVEL_EVENT;
108
109 max_read = 0;
110 max_write = 0;
111
112 return NGX_OK;
113 }
114
115
116 static void
117 ngx_select_done(ngx_cycle_t *cycle)
118 {
119 ngx_free(event_index);
120
121 event_index = NULL;
122 }
123
124
125 static ngx_int_t
126 ngx_select_add_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags)
127 {
128 ngx_connection_t *c;
129
130 c = ev->data;
131
132 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
133 "select add event fd:%d ev:%i", c->fd, event);
134
135 if (ev->index != NGX_INVALID_INDEX) {
136 ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
137 "select event fd:%d ev:%i is already set", c->fd, event);
138 return NGX_OK;
139 }
140
141 if ((event == NGX_READ_EVENT && ev->write)
142 || (event == NGX_WRITE_EVENT && !ev->write))
143 {
144 ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
145 "invalid select %s event fd:%d ev:%i",
146 ev->write ? "write" : "read", c->fd, event);
147 return NGX_ERROR;
148 }
149
150 if ((event == NGX_READ_EVENT) && (max_read >= FD_SETSIZE)
151 || (event == NGX_WRITE_EVENT) && (max_write >= FD_SETSIZE))
152 {
153 ngx_log_error(NGX_LOG_ERR, ev->log, 0,
154 "maximum number of descriptors "
155 "supported by select() is %d", FD_SETSIZE);
156 return NGX_ERROR;
157 }
158
159 if (event == NGX_READ_EVENT) {
160 FD_SET(c->fd, &master_read_fd_set);
161 max_read++;
162
163 } else if (event == NGX_WRITE_EVENT) {
164 FD_SET(c->fd, &master_write_fd_set);
165 max_write++;
166 }
167
168 ev->active = 1;
169
170 event_index[nevents] = ev;
171 ev->index = nevents;
172 nevents++;
173
174 return NGX_OK;
175 }
176
177
178 static ngx_int_t
179 ngx_select_del_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags)
180 {
181 ngx_event_t *e;
182 ngx_connection_t *c;
183
184 c = ev->data;
185
186 ev->active = 0;
187
188 if (ev->index == NGX_INVALID_INDEX) {
189 return NGX_OK;
190 }
191
192 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
193 "select del event fd:%d ev:%i", c->fd, event);
194
195 if (event == NGX_READ_EVENT) {
196 FD_CLR(c->fd, &master_read_fd_set);
197 max_read--;
198
199 } else if (event == NGX_WRITE_EVENT) {
200 FD_CLR(c->fd, &master_write_fd_set);
201 max_write--;
202 }
203
204 if (ev->index < --nevents) {
205 e = event_index[nevents];
206 event_index[ev->index] = e;
207 e->index = ev->index;
208 }
209
210 ev->index = NGX_INVALID_INDEX;
211
212 return NGX_OK;
213 }
214
215
216 static ngx_int_t
217 ngx_select_process_events(ngx_cycle_t *cycle, ngx_msec_t timer,
218 ngx_uint_t flags)
219 {
220 int ready, nready;
221 ngx_err_t err;
222 ngx_uint_t i, found;
223 ngx_event_t *ev, **queue;
224 struct timeval tv, *tp;
225 ngx_connection_t *c;
226
227 #if (NGX_DEBUG)
228 if (cycle->log->log_level & NGX_LOG_DEBUG_ALL) {
229 for (i = 0; i < nevents; i++) {
230 ev = event_index[i];
231 c = ev->data;
232 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
233 "select event: fd:%d wr:%d", c->fd, ev->write);
234 }
235 }
236 #endif
237
238 if (timer == NGX_TIMER_INFINITE) {
239 tp = NULL;
240
241 } else {
242 tv.tv_sec = (long) (timer / 1000);
243 tv.tv_usec = (long) ((timer % 1000) * 1000);
244 tp = &tv;
245 }
246
247 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
248 "select timer: %M", timer);
249
250 work_read_fd_set = master_read_fd_set;
251 work_write_fd_set = master_write_fd_set;
252
253 if (max_read || max_write) {
254 ready = select(0, &work_read_fd_set, &work_write_fd_set, NULL, tp);
255
256 } else {
257
258 /*
259 * Winsock select() requires that at least one descriptor set must be
260 * be non-null, and any non-null descriptor set must contain at least
261 * one handle to a socket. Otherwise select() returns WSAEINVAL.
262 */
263
264 ngx_msleep(timer);
265
266 ready = 0;
267 }
268
269 err = (ready == -1) ? ngx_socket_errno : 0;
270
271 if (flags & NGX_UPDATE_TIME) {
272 ngx_time_update(0, 0);
273 }
274
275 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
276 "select ready %d", ready);
277
278 if (err) {
279 ngx_log_error(NGX_LOG_ALERT, cycle->log, err, "select() failed");
280
281 if (err == WSAENOTSOCK) {
282 ngx_select_repair_fd_sets(cycle);
283 }
284
285 return NGX_ERROR;
286 }
287
288 if (ready == 0) {
289 if (timer != NGX_TIMER_INFINITE) {
290 return NGX_OK;
291 }
292
293 ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
294 "select() returned no events without timeout");
295 return NGX_ERROR;
296 }
297
298 ngx_mutex_lock(ngx_posted_events_mutex);
299
300 nready = 0;
301
302 for (i = 0; i < nevents; i++) {
303 ev = event_index[i];
304 c = ev->data;
305 found = 0;
306
307 if (ev->write) {
308 if (FD_ISSET(c->fd, &work_write_fd_set)) {
309 found = 1;
310 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
311 "select write %d", c->fd);
312 }
313
314 } else {
315 if (FD_ISSET(c->fd, &work_read_fd_set)) {
316 found = 1;
317 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
318 "select read %d", c->fd);
319 }
320 }
321
322 if (found) {
323 ev->ready = 1;
324
325 queue = (ngx_event_t **) (ev->accept ? &ngx_posted_accept_events:
326 &ngx_posted_events);
327 ngx_locked_post_event(ev, queue);
328
329 nready++;
330 }
331 }
332
333 ngx_mutex_unlock(ngx_posted_events_mutex);
334
335 if (ready != nready) {
336 ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
337 "select ready != events: %d:%d", ready, nready);
338
339 ngx_select_repair_fd_sets(cycle);
340 }
341
342 return NGX_OK;
343 }
344
345
346 static void
347 ngx_select_repair_fd_sets(ngx_cycle_t *cycle)
348 {
349 int n;
350 u_int i;
351 socklen_t len;
352 ngx_err_t err;
353 ngx_socket_t s;
354
355 for (i = 0; i < master_read_fd_set.fd_count; i++) {
356
357 s = master_read_fd_set.fd_array[i];
358 len = sizeof(int);
359
360 if (getsockopt(s, SOL_SOCKET, SO_TYPE, (char *) &n, &len) == -1) {
361 err = ngx_socket_errno;
362
363 ngx_log_error(NGX_LOG_ALERT, cycle->log, err,
364 "invalid descriptor #%d in read fd_set", s);
365
366 FD_CLR(s, &master_read_fd_set);
367 }
368 }
369
370 for (i = 0; i < master_write_fd_set.fd_count; i++) {
371
372 s = master_write_fd_set.fd_array[i];
373 len = sizeof(int);
374
375 if (getsockopt(s, SOL_SOCKET, SO_TYPE, (char *) &n, &len) == -1) {
376 err = ngx_socket_errno;
377
378 ngx_log_error(NGX_LOG_ALERT, cycle->log, err,
379 "invalid descriptor #%d in write fd_set", s);
380
381 FD_CLR(s, &master_write_fd_set);
382 }
383 }
384 }
385
386
387 static char *
388 ngx_select_init_conf(ngx_cycle_t *cycle, void *conf)
389 {
390 ngx_event_conf_t *ecf;
391
392 ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);
393
394 if (ecf->use != ngx_select_module.ctx_index) {
395 return NGX_CONF_OK;
396 }
397
398 return NGX_CONF_OK;
399 }
400
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