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_int_t max_fd;
30 static ngx_uint_t nevents;
31
32 static ngx_event_t **event_index;
33
34
35 static ngx_str_t select_name = ngx_string("select");
36
37 ngx_event_module_t ngx_select_module_ctx = {
38 &select_name,
39 NULL, /* create configuration */
40 ngx_select_init_conf, /* init configuration */
41
42 {
43 ngx_select_add_event, /* add an event */
44 ngx_select_del_event, /* delete an event */
45 ngx_select_add_event, /* enable an event */
46 ngx_select_del_event, /* disable an event */
47 NULL, /* add an connection */
48 NULL, /* delete an connection */
49 NULL, /* process the changes */
50 ngx_select_process_events, /* process the events */
51 ngx_select_init, /* init the events */
52 ngx_select_done /* done the events */
53 }
54
55 };
56
57 ngx_module_t ngx_select_module = {
58 NGX_MODULE_V1,
59 &ngx_select_module_ctx, /* module context */
60 NULL, /* module directives */
61 NGX_EVENT_MODULE, /* module type */
62 NULL, /* init master */
63 NULL, /* init module */
64 NULL, /* init process */
65 NULL, /* init thread */
66 NULL, /* exit thread */
67 NULL, /* exit process */
68 NULL, /* exit master */
69 NGX_MODULE_V1_PADDING
70 };
71
72
73 static ngx_int_t
74 ngx_select_init(ngx_cycle_t *cycle, ngx_msec_t timer)
75 {
76 ngx_event_t **index;
77
78 if (event_index == NULL) {
79 FD_ZERO(&master_read_fd_set);
80 FD_ZERO(&master_write_fd_set);
81 nevents = 0;
82 }
83
84 if (ngx_process == NGX_PROCESS_WORKER
85 || cycle->old_cycle == NULL
86 || cycle->old_cycle->connection_n < cycle->connection_n)
87 {
88 index = ngx_alloc(sizeof(ngx_event_t *) * 2 * cycle->connection_n,
89 cycle->log);
90 if (index == NULL) {
91 return NGX_ERROR;
92 }
93
94 if (event_index) {
95 ngx_memcpy(index, event_index, sizeof(ngx_event_t *) * nevents);
96 ngx_free(event_index);
97 }
98
99 event_index = index;
100 }
101
102 ngx_io = ngx_os_io;
103
104 ngx_event_actions = ngx_select_module_ctx.actions;
105
106 ngx_event_flags = NGX_USE_LEVEL_EVENT;
107
108 max_fd = -1;
109
110 return NGX_OK;
111 }
112
113
114 static void
115 ngx_select_done(ngx_cycle_t *cycle)
116 {
117 ngx_free(event_index);
118
119 event_index = NULL;
120 }
121
122
123 static ngx_int_t
124 ngx_select_add_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags)
125 {
126 ngx_connection_t *c;
127
128 c = ev->data;
129
130 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
131 "select add event fd:%d ev:%i", c->fd, event);
132
133 if (ev->index != NGX_INVALID_INDEX) {
134 ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
135 "select event fd:%d ev:%i is already set", c->fd, event);
136 return NGX_OK;
137 }
138
139 if ((event == NGX_READ_EVENT && ev->write)
140 || (event == NGX_WRITE_EVENT && !ev->write))
141 {
142 ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
143 "invalid select %s event fd:%d ev:%i",
144 ev->write ? "write" : "read", c->fd, event);
145 return NGX_ERROR;
146 }
147
148 if (event == NGX_READ_EVENT) {
149 FD_SET(c->fd, &master_read_fd_set);
150
151 } else if (event == NGX_WRITE_EVENT) {
152 FD_SET(c->fd, &master_write_fd_set);
153 }
154
155 if (max_fd != -1 && max_fd < c->fd) {
156 max_fd = c->fd;
157 }
158
159 ev->active = 1;
160
161 event_index[nevents] = ev;
162 ev->index = nevents;
163 nevents++;
164
165 return NGX_OK;
166 }
167
168
169 static ngx_int_t
170 ngx_select_del_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags)
171 {
172 ngx_event_t *e;
173 ngx_connection_t *c;
174
175 c = ev->data;
176
177 ev->active = 0;
178
179 if (ev->index == NGX_INVALID_INDEX) {
180 return NGX_OK;
181 }
182
183 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
184 "select del event fd:%d ev:%i", c->fd, event);
185
186 if (event == NGX_READ_EVENT) {
187 FD_CLR(c->fd, &master_read_fd_set);
188
189 } else if (event == NGX_WRITE_EVENT) {
190 FD_CLR(c->fd, &master_write_fd_set);
191 }
192
193 if (max_fd == c->fd) {
194 max_fd = -1;
195 }
196
197 if (ev->index < --nevents) {
198 e = event_index[nevents];
199 event_index[ev->index] = e;
200 e->index = ev->index;
201 }
202
203 ev->index = NGX_INVALID_INDEX;
204
205 return NGX_OK;
206 }
207
208
209 static ngx_int_t
210 ngx_select_process_events(ngx_cycle_t *cycle, ngx_msec_t timer,
211 ngx_uint_t flags)
212 {
213 int ready, nready;
214 ngx_err_t err;
215 ngx_uint_t i, found;
216 ngx_event_t *ev, **queue;
217 struct timeval tv, *tp;
218 ngx_connection_t *c;
219
220 if (max_fd == -1) {
221 for (i = 0; i < nevents; i++) {
222 c = event_index[i]->data;
223 if (max_fd < c->fd) {
224 max_fd = c->fd;
225 }
226 }
227
228 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
229 "change max_fd: %d", max_fd);
230 }
231
232 #if (NGX_DEBUG)
233 if (cycle->log->log_level & NGX_LOG_DEBUG_ALL) {
234 for (i = 0; i < nevents; i++) {
235 ev = event_index[i];
236 c = ev->data;
237 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
238 "select event: fd:%d wr:%d", c->fd, ev->write);
239 }
240
241 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
242 "max_fd: %d", max_fd);
243 }
244 #endif
245
246 if (timer == NGX_TIMER_INFINITE) {
247 tp = NULL;
248
249 } else {
250 tv.tv_sec = (long) (timer / 1000);
251 tv.tv_usec = (long) ((timer % 1000) * 1000);
252 tp = &tv;
253 }
254
255 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
256 "select timer: %M", timer);
257
258 work_read_fd_set = master_read_fd_set;
259 work_write_fd_set = master_write_fd_set;
260
261 ready = select(max_fd + 1, &work_read_fd_set, &work_write_fd_set, NULL, tp);
262
263 err = (ready == -1) ? ngx_errno : 0;
264
265 if (flags & NGX_UPDATE_TIME) {
266 ngx_time_update(0, 0);
267 }
268
269 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
270 "select ready %d", ready);
271
272 if (err) {
273 ngx_uint_t level;
274
275 if (err == NGX_EINTR) {
276
277 if (ngx_event_timer_alarm) {
278 ngx_event_timer_alarm = 0;
279 return NGX_OK;
280 }
281
282 level = NGX_LOG_INFO;
283
284 } else {
285 level = NGX_LOG_ALERT;
286 }
287
288 ngx_log_error(level, cycle->log, err, "select() failed");
289
290 if (err == EBADF) {
291 ngx_select_repair_fd_sets(cycle);
292 }
293
294 return NGX_ERROR;
295 }
296
297 if (ready == 0) {
298 if (timer != NGX_TIMER_INFINITE) {
299 return NGX_OK;
300 }
301
302 ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
303 "select() returned no events without timeout");
304 return NGX_ERROR;
305 }
306
307 ngx_mutex_lock(ngx_posted_events_mutex);
308
309 nready = 0;
310
311 for (i = 0; i < nevents; i++) {
312 ev = event_index[i];
313 c = ev->data;
314 found = 0;
315
316 if (ev->write) {
317 if (FD_ISSET(c->fd, &work_write_fd_set)) {
318 found = 1;
319 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
320 "select write %d", c->fd);
321 }
322
323 } else {
324 if (FD_ISSET(c->fd, &work_read_fd_set)) {
325 found = 1;
326 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
327 "select read %d", c->fd);
328 }
329 }
330
331 if (found) {
332 ev->ready = 1;
333
334 queue = (ngx_event_t **) (ev->accept ? &ngx_posted_accept_events:
335 &ngx_posted_events);
336 ngx_locked_post_event(ev, queue);
337
338 nready++;
339 }
340 }
341
342 ngx_mutex_unlock(ngx_posted_events_mutex);
343
344 if (ready != nready) {
345 ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
346 "select ready != events: %d:%d", ready, nready);
347
348 ngx_select_repair_fd_sets(cycle);
349 }
350
351 return NGX_OK;
352 }
353
354
355 static void
356 ngx_select_repair_fd_sets(ngx_cycle_t *cycle)
357 {
358 int n;
359 socklen_t len;
360 ngx_err_t err;
361 ngx_socket_t s;
362
363 for (s = 0; s <= max_fd; s++) {
364
365 if (FD_ISSET(s, &master_read_fd_set) == 0) {
366 continue;
367 }
368
369 len = sizeof(int);
370
371 if (getsockopt(s, SOL_SOCKET, SO_TYPE, &n, &len) == -1) {
372 err = ngx_socket_errno;
373
374 ngx_log_error(NGX_LOG_ALERT, cycle->log, err,
375 "invalid descriptor #%d in read fd_set", s);
376
377 FD_CLR(s, &master_read_fd_set);
378 }
379 }
380
381 for (s = 0; s <= max_fd; s++) {
382
383 if (FD_ISSET(s, &master_write_fd_set) == 0) {
384 continue;
385 }
386
387 len = sizeof(int);
388
389 if (getsockopt(s, SOL_SOCKET, SO_TYPE, &n, &len) == -1) {
390 err = ngx_socket_errno;
391
392 ngx_log_error(NGX_LOG_ALERT, cycle->log, err,
393 "invalid descriptor #%d in write fd_set", s);
394
395 FD_CLR(s, &master_write_fd_set);
396 }
397 }
398
399 max_fd = -1;
400 }
401
402
403 static char *
404 ngx_select_init_conf(ngx_cycle_t *cycle, void *conf)
405 {
406 ngx_event_conf_t *ecf;
407
408 ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);
409
410 if (ecf->use != ngx_select_module.ctx_index) {
411 return NGX_CONF_OK;
412 }
413
414 /* disable warning: the default FD_SETSIZE is 1024U in FreeBSD 5.x */
415
416 if (cycle->connection_n > FD_SETSIZE) {
417 ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
418 "the maximum number of files "
419 "supported by select() is %ud", FD_SETSIZE);
420 return NGX_CONF_ERROR;
421 }
422
423 #if (NGX_THREADS)
424
425 ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
426 "select() is not supported in the threaded mode");
427 return NGX_CONF_ERROR;
428
429 #else
430
431 return NGX_CONF_OK;
432
433 #endif
434 }
435
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