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comparison src/event/modules/ngx_select_module.c @ 0:f0b350454894 NGINX_0_1_0

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nginx 0.1.0 *) The first public version.
author Igor Sysoev <http://sysoev.ru>
date Mon, 04 Oct 2004 00:00:00 +0400
parents
children 46833bd150cb
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-1:000000000000 0:f0b350454894
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 static ngx_int_t ngx_select_init(ngx_cycle_t *cycle);
14 static void ngx_select_done(ngx_cycle_t *cycle);
15 static ngx_int_t ngx_select_add_event(ngx_event_t *ev, int event, u_int flags);
16 static ngx_int_t ngx_select_del_event(ngx_event_t *ev, int event, u_int flags);
17 static ngx_int_t ngx_select_process_events(ngx_cycle_t *cycle);
18 static char *ngx_select_init_conf(ngx_cycle_t *cycle, void *conf);
19
20
21 static fd_set master_read_fd_set;
22 static fd_set master_write_fd_set;
23 static fd_set work_read_fd_set;
24 static fd_set work_write_fd_set;
25
26 #if (WIN32)
27 static int max_read;
28 static int max_write;
29 #else
30 static int max_fd;
31 #endif
32
33 static ngx_uint_t nevents;
34
35 static ngx_event_t **event_index;
36 #if 0
37 static ngx_event_t **ready_index;
38 #endif
39
40 static ngx_event_t *accept_events;
41
42
43 static ngx_str_t select_name = ngx_string("select");
44
45 ngx_event_module_t ngx_select_module_ctx = {
46 &select_name,
47 NULL, /* create configuration */
48 ngx_select_init_conf, /* init configuration */
49
50 {
51 ngx_select_add_event, /* add an event */
52 ngx_select_del_event, /* delete an event */
53 ngx_select_add_event, /* enable an event */
54 ngx_select_del_event, /* disable an event */
55 NULL, /* add an connection */
56 NULL, /* delete an connection */
57 NULL, /* process the changes */
58 ngx_select_process_events, /* process the events */
59 ngx_select_init, /* init the events */
60 ngx_select_done /* done the events */
61 }
62
63 };
64
65 ngx_module_t ngx_select_module = {
66 NGX_MODULE,
67 &ngx_select_module_ctx, /* module context */
68 NULL, /* module directives */
69 NGX_EVENT_MODULE, /* module type */
70 NULL, /* init module */
71 NULL /* init process */
72 };
73
74
75 static ngx_int_t ngx_select_init(ngx_cycle_t *cycle)
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 ngx_test_null(index,
90 ngx_alloc(sizeof(ngx_event_t *) * 2 * cycle->connection_n,
91 cycle->log),
92 NGX_ERROR);
93
94 if (event_index) {
95 ngx_memcpy(index, event_index, sizeof(ngx_event_t *) * nevents);
96 ngx_free(event_index);
97 }
98 event_index = index;
99
100 #if 0
101 if (ready_index) {
102 ngx_free(ready_index);
103 }
104 ngx_test_null(ready_index,
105 ngx_alloc(sizeof(ngx_event_t *) * 2 * cycle->connection_n,
106 cycle->log),
107 NGX_ERROR);
108 #endif
109 }
110
111 ngx_io = ngx_os_io;
112
113 ngx_event_actions = ngx_select_module_ctx.actions;
114
115 ngx_event_flags = NGX_USE_LEVEL_EVENT|NGX_USE_ONESHOT_EVENT;
116
117 #if (WIN32)
118 max_read = max_write = 0;
119 #else
120 max_fd = -1;
121 #endif
122
123 return NGX_OK;
124 }
125
126
127 static void ngx_select_done(ngx_cycle_t *cycle)
128 {
129 ngx_free(event_index);
130 #if 0
131 ngx_free(ready_index);
132 #endif
133
134 event_index = NULL;
135 }
136
137
138 static ngx_int_t ngx_select_add_event(ngx_event_t *ev, int event, u_int flags)
139 {
140 ngx_connection_t *c;
141
142 c = ev->data;
143
144 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
145 "select add event fd:%d ev:%d", c->fd, event);
146
147 if (ev->index != NGX_INVALID_INDEX) {
148 ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
149 "select event fd:%d ev:%d is already set", c->fd, event);
150 return NGX_OK;
151 }
152
153 #if (WIN32)
154
155 if ((event == NGX_READ_EVENT) && (max_read >= FD_SETSIZE)
156 || (event == NGX_WRITE_EVENT) && (max_write >= FD_SETSIZE))
157 {
158 ngx_log_error(NGX_LOG_ERR, ev->log, 0,
159 "maximum number of descriptors "
160 "supported by select() is %d", FD_SETSIZE);
161 return NGX_ERROR;
162 }
163
164 if (event == NGX_READ_EVENT) {
165 FD_SET(c->fd, &master_read_fd_set);
166 max_read++;
167
168 } else if (event == NGX_WRITE_EVENT) {
169 FD_SET(c->fd, &master_write_fd_set);
170 max_write++;
171 }
172
173 #else
174
175 if (event == NGX_READ_EVENT) {
176 FD_SET(c->fd, &master_read_fd_set);
177
178 } else if (event == NGX_WRITE_EVENT) {
179 FD_SET(c->fd, &master_write_fd_set);
180 }
181
182 if (max_fd != -1 && max_fd < c->fd) {
183 max_fd = c->fd;
184 }
185
186 #endif
187
188 ev->active = 1;
189 ev->oneshot = (u_char) ((flags & NGX_ONESHOT_EVENT) ? 1 : 0);
190
191 event_index[nevents] = ev;
192 ev->index = nevents;
193 nevents++;
194
195 return NGX_OK;
196 }
197
198
199 static ngx_int_t ngx_select_del_event(ngx_event_t *ev, int event, u_int flags)
200 {
201 ngx_connection_t *c;
202
203 c = ev->data;
204
205 ev->active = 0;
206
207 if (ev->index == NGX_INVALID_INDEX) {
208 return NGX_OK;
209 }
210
211 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
212 "select del event fd:%d ev:%d", c->fd, event);
213
214 #if (WIN32)
215
216 if (event == NGX_READ_EVENT) {
217 FD_CLR(c->fd, &master_read_fd_set);
218 max_read--;
219
220 } else if (event == NGX_WRITE_EVENT) {
221 FD_CLR(c->fd, &master_write_fd_set);
222 max_write--;
223 }
224
225 #else
226
227 if (event == NGX_READ_EVENT) {
228 FD_CLR(c->fd, &master_read_fd_set);
229
230 } else if (event == NGX_WRITE_EVENT) {
231 FD_CLR(c->fd, &master_write_fd_set);
232 }
233
234 if (max_fd == c->fd) {
235 max_fd = -1;
236 }
237
238 #endif
239
240 if (ev->index < (u_int) --nevents) {
241 event_index[ev->index] = event_index[nevents];
242 event_index[ev->index]->index = ev->index;
243 }
244
245 ev->index = NGX_INVALID_INDEX;
246
247 return NGX_OK;
248 }
249
250
251 static ngx_int_t ngx_select_process_events(ngx_cycle_t *cycle)
252 {
253 int ready, nready;
254 ngx_uint_t i, found, lock, expire;
255 ngx_err_t err;
256 ngx_msec_t timer;
257 ngx_event_t *ev;
258 ngx_connection_t *c;
259 ngx_epoch_msec_t delta;
260 struct timeval tv, *tp;
261 #if (HAVE_SELECT_CHANGE_TIMEOUT)
262 static ngx_epoch_msec_t deltas = 0;
263 #endif
264
265 for ( ;; ) {
266 timer = ngx_event_find_timer();
267
268 if (timer != 0) {
269 break;
270 }
271
272 ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
273 "select expired timer");
274
275 ngx_event_expire_timers((ngx_msec_t)
276 (ngx_elapsed_msec - ngx_old_elapsed_msec));
277 }
278
279 ngx_old_elapsed_msec = ngx_elapsed_msec;
280
281 expire = 1;
282
283 #if !(WIN32)
284
285 if (ngx_accept_mutex) {
286 if (ngx_accept_disabled > 0) {
287 ngx_accept_disabled--;
288
289 } else {
290 if (ngx_trylock_accept_mutex(cycle) == NGX_ERROR) {
291 return NGX_ERROR;
292 }
293
294 if (ngx_accept_mutex_held == 0
295 && (timer == NGX_TIMER_INFINITE
296 || timer > ngx_accept_mutex_delay))
297 {
298 timer = ngx_accept_mutex_delay;
299 expire = 0;
300 }
301 }
302 }
303
304 if (max_fd == -1) {
305 for (i = 0; i < nevents; i++) {
306 c = event_index[i]->data;
307 if (max_fd < c->fd) {
308 max_fd = c->fd;
309 }
310 }
311
312 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
313 "change max_fd: %d", max_fd);
314 }
315
316 #endif
317
318 #if (NGX_DEBUG)
319 if (cycle->log->log_level & NGX_LOG_DEBUG_ALL) {
320 for (i = 0; i < nevents; i++) {
321 ev = event_index[i];
322 c = ev->data;
323 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
324 "select event: fd:%d wr:%d", c->fd, ev->write);
325 }
326
327 #if !(WIN32)
328 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
329 "max_fd: %d", max_fd);
330 #endif
331 }
332 #endif
333
334 if (timer == NGX_TIMER_INFINITE) {
335 tp = NULL;
336 expire = 0;
337
338 } else {
339 tv.tv_sec = timer / 1000;
340 tv.tv_usec = (timer % 1000) * 1000;
341 tp = &tv;
342 }
343
344 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
345 "select timer: %d", timer);
346
347 work_read_fd_set = master_read_fd_set;
348 work_write_fd_set = master_write_fd_set;
349
350 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
351 "select read fd_set: %08X", *(int *) &work_read_fd_set);
352
353 #if (WIN32)
354 ready = select(0, &work_read_fd_set, &work_write_fd_set, NULL, tp);
355 #else
356 ready = select(max_fd + 1, &work_read_fd_set, &work_write_fd_set, NULL, tp);
357 #endif
358
359 if (ready == -1) {
360 err = ngx_socket_errno;
361 } else {
362 err = 0;
363 }
364
365 #if (HAVE_SELECT_CHANGE_TIMEOUT)
366
367 if (timer != NGX_TIMER_INFINITE) {
368 delta = timer - (tv.tv_sec * 1000 + tv.tv_usec / 1000);
369
370 /*
371 * learn the real time and update the cached time
372 * if the sum of the last deltas overcomes 1 second
373 */
374
375 deltas += delta;
376 if (deltas > 1000) {
377 ngx_gettimeofday(&tv);
378 ngx_time_update(tv.tv_sec);
379 deltas = tv.tv_usec / 1000;
380
381 ngx_elapsed_msec = (ngx_epoch_msec_t) tv.tv_sec * 1000
382 + tv.tv_usec / 1000 - ngx_start_msec;
383 } else {
384 ngx_elapsed_msec += delta;
385 }
386
387 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
388 "select timer: %d, delta: %d", timer, (int) delta);
389
390 } else {
391 delta = 0;
392 ngx_gettimeofday(&tv);
393 ngx_time_update(tv.tv_sec);
394
395 ngx_elapsed_msec = (ngx_epoch_msec_t) tv.tv_sec * 1000
396 + tv.tv_usec / 1000 - ngx_start_msec;
397
398 if (ready == 0) {
399 ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
400 "select() returned no events without timeout");
401 ngx_accept_mutex_unlock();
402 return NGX_ERROR;
403 }
404 }
405
406 #else /* !(HAVE_SELECT_CHANGE_TIMEOUT) */
407
408 ngx_gettimeofday(&tv);
409 ngx_time_update(tv.tv_sec);
410
411 delta = ngx_elapsed_msec;
412 ngx_elapsed_msec = (ngx_epoch_msec_t) tv.tv_sec * 1000
413 + tv.tv_usec / 1000 - ngx_start_msec;
414
415 if (timer != NGX_TIMER_INFINITE) {
416 delta = ngx_elapsed_msec - delta;
417
418 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
419 "select timer: %d, delta: %d", timer, (int) delta);
420
421 } else {
422 if (ready == 0) {
423 ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
424 "select() returned no events without timeout");
425 ngx_accept_mutex_unlock();
426 return NGX_ERROR;
427 }
428 }
429
430 #endif /* HAVE_SELECT_CHANGE_TIMEOUT */
431
432 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
433 "select ready %d", ready);
434
435 if (err) {
436 #if (WIN32)
437 ngx_log_error(NGX_LOG_ALERT, cycle->log, err, "select() failed");
438 #else
439 ngx_log_error((err == NGX_EINTR) ? NGX_LOG_INFO : NGX_LOG_ALERT,
440 cycle->log, err, "select() failed");
441 #endif
442 ngx_accept_mutex_unlock();
443 return NGX_ERROR;
444 }
445
446
447 if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_ERROR) {
448 ngx_accept_mutex_unlock();
449 return NGX_ERROR;
450 }
451
452 lock = 1;
453 nready = 0;
454
455 for (i = 0; i < nevents; i++) {
456 ev = event_index[i];
457 c = ev->data;
458 found = 0;
459
460 if (ev->write) {
461 if (FD_ISSET(c->fd, &work_write_fd_set)) {
462 found = 1;
463 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
464 "select write %d", c->fd);
465 }
466
467 } else {
468 if (FD_ISSET(c->fd, &work_read_fd_set)) {
469 found = 1;
470 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
471 "select read %d", c->fd);
472 }
473 }
474
475 if (found) {
476 ev->ready = 1;
477
478 if (ev->oneshot) {
479 if (ev->timer_set) {
480 ngx_del_timer(ev);
481 }
482
483 if (ev->write) {
484 ngx_select_del_event(ev, NGX_WRITE_EVENT, 0);
485 } else {
486 ngx_select_del_event(ev, NGX_READ_EVENT, 0);
487 }
488 }
489
490 if (ev->accept) {
491 ev->next = accept_events;
492 accept_events = ev;
493 } else {
494 ngx_post_event(ev);
495 }
496
497 nready++;
498
499 #if 0
500 ready_index[nready++] = ev;
501 #endif
502 }
503 }
504
505 #if 0
506 for (i = 0; i < nready; i++) {
507 ev = ready_index[i];
508 ready--;
509
510 if (!ev->active) {
511 continue;
512 }
513
514 ev->ready = 1;
515
516 if (ev->oneshot) {
517 if (ev->timer_set) {
518 ngx_del_timer(ev);
519 }
520
521 if (ev->write) {
522 ngx_select_del_event(ev, NGX_WRITE_EVENT, 0);
523 } else {
524 ngx_select_del_event(ev, NGX_READ_EVENT, 0);
525 }
526 }
527
528 ev->event_handler(ev);
529 }
530 #endif
531
532 ev = accept_events;
533
534 for ( ;; ) {
535
536 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
537 "accept event " PTR_FMT, ev);
538
539 if (ev == NULL) {
540 break;
541 }
542
543 ngx_mutex_unlock(ngx_posted_events_mutex);
544
545 ev->event_handler(ev);
546
547 if (ngx_accept_disabled > 0) {
548 lock = 0;
549 break;
550 }
551
552 ev = ev->next;
553
554 if (ev == NULL) {
555 lock = 0;
556 break;
557 }
558
559 if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_ERROR) {
560 ngx_accept_mutex_unlock();
561 return NGX_ERROR;
562 }
563 }
564
565 ngx_accept_mutex_unlock();
566 accept_events = NULL;
567
568 if (lock) {
569 ngx_mutex_unlock(ngx_posted_events_mutex);
570 }
571
572 if (ready != nready) {
573 ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "select ready != events");
574 }
575
576 if (expire && delta) {
577 ngx_event_expire_timers((ngx_msec_t) delta);
578 }
579
580 if (!ngx_threaded) {
581 ngx_event_process_posted(cycle);
582 }
583
584 return NGX_OK;
585 }
586
587
588 static char *ngx_select_init_conf(ngx_cycle_t *cycle, void *conf)
589 {
590 ngx_event_conf_t *ecf;
591
592 ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);
593
594 if (ecf->use != ngx_select_module.ctx_index) {
595 return NGX_CONF_OK;
596 }
597
598 /* disable warning: the default FD_SETSIZE is 1024U in FreeBSD 5.x */
599
600 #if !(WIN32)
601 if ((unsigned) ecf->connections > FD_SETSIZE) {
602 ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
603 "the maximum number of files "
604 "supported by select() is " ngx_value(FD_SETSIZE));
605 return NGX_CONF_ERROR;
606 }
607 #endif
608
609 #if (NGX_THREADS)
610 ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
611 "select() is not supported in the threaded mode");
612 return NGX_CONF_ERROR;
613 #else
614 return NGX_CONF_OK;
615 #endif
616 }