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_poll_init(ngx_cycle_t *cycle, ngx_msec_t timer);
13 static void ngx_poll_done(ngx_cycle_t *cycle);
14 static ngx_int_t ngx_poll_add_event(ngx_event_t *ev, ngx_int_t event,
15 ngx_uint_t flags);
16 static ngx_int_t ngx_poll_del_event(ngx_event_t *ev, ngx_int_t event,
17 ngx_uint_t flags);
18 static ngx_int_t ngx_poll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer,
19 ngx_uint_t flags);
20 static char *ngx_poll_init_conf(ngx_cycle_t *cycle, void *conf);
21
22
23 static struct pollfd *event_list;
24 static ngx_int_t nevents;
25
26
27 static ngx_str_t poll_name = ngx_string("poll");
28
29 ngx_event_module_t ngx_poll_module_ctx = {
30 &poll_name,
31 NULL, /* create configuration */
32 ngx_poll_init_conf, /* init configuration */
33
34 {
35 ngx_poll_add_event, /* add an event */
36 ngx_poll_del_event, /* delete an event */
37 ngx_poll_add_event, /* enable an event */
38 ngx_poll_del_event, /* disable an event */
39 NULL, /* add an connection */
40 NULL, /* delete an connection */
41 NULL, /* process the changes */
42 ngx_poll_process_events, /* process the events */
43 ngx_poll_init, /* init the events */
44 ngx_poll_done /* done the events */
45 }
46
47 };
48
49 ngx_module_t ngx_poll_module = {
50 NGX_MODULE_V1,
51 &ngx_poll_module_ctx, /* module context */
52 NULL, /* module directives */
53 NGX_EVENT_MODULE, /* module type */
54 NULL, /* init master */
55 NULL, /* init module */
56 NULL, /* init process */
57 NULL, /* init thread */
58 NULL, /* exit thread */
59 NULL, /* exit process */
60 NULL, /* exit master */
61 NGX_MODULE_V1_PADDING
62 };
63
64
65
66 static ngx_int_t
67 ngx_poll_init(ngx_cycle_t *cycle, ngx_msec_t timer)
68 {
69 struct pollfd *list;
70
71 if (event_list == NULL) {
72 nevents = 0;
73 }
74
75 if (ngx_process == NGX_PROCESS_WORKER
76 || cycle->old_cycle == NULL
77 || cycle->old_cycle->connection_n < cycle->connection_n)
78 {
79 list = ngx_alloc(sizeof(struct pollfd) * cycle->connection_n,
80 cycle->log);
81 if (list == NULL) {
82 return NGX_ERROR;
83 }
84
85 if (event_list) {
86 ngx_memcpy(list, event_list, sizeof(ngx_event_t *) * nevents);
87 ngx_free(event_list);
88 }
89
90 event_list = list;
91 }
92
93 ngx_io = ngx_os_io;
94
95 ngx_event_actions = ngx_poll_module_ctx.actions;
96
97 ngx_event_flags = NGX_USE_LEVEL_EVENT|NGX_USE_FD_EVENT;
98
99 return NGX_OK;
100 }
101
102
103 static void
104 ngx_poll_done(ngx_cycle_t *cycle)
105 {
106 ngx_free(event_list);
107
108 event_list = NULL;
109 }
110
111
112 static ngx_int_t
113 ngx_poll_add_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags)
114 {
115 ngx_event_t *e;
116 ngx_connection_t *c;
117
118 c = ev->data;
119
120 ev->active = 1;
121
122 if (ev->index != NGX_INVALID_INDEX) {
123 ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
124 "poll event fd:%d ev:%i is already set", c->fd, event);
125 return NGX_OK;
126 }
127
128 if (event == NGX_READ_EVENT) {
129 e = c->write;
130 #if (NGX_READ_EVENT != POLLIN)
131 event = POLLIN;
132 #endif
133
134 } else {
135 e = c->read;
136 #if (NGX_WRITE_EVENT != POLLOUT)
137 event = POLLOUT;
138 #endif
139 }
140
141 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
142 "poll add event: fd:%d ev:%i", c->fd, event);
143
144 if (e == NULL || e->index == NGX_INVALID_INDEX) {
145 event_list[nevents].fd = c->fd;
146 event_list[nevents].events = (short) event;
147 event_list[nevents].revents = 0;
148
149 ev->index = nevents;
150 nevents++;
151
152 } else {
153 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ev->log, 0,
154 "poll add index: %i", e->index);
155
156 event_list[e->index].events |= (short) event;
157 ev->index = e->index;
158 }
159
160 return NGX_OK;
161 }
162
163
164 static ngx_int_t
165 ngx_poll_del_event(ngx_event_t *ev, ngx_int_t event, ngx_uint_t flags)
166 {
167 ngx_event_t *e;
168 ngx_connection_t *c;
169
170 c = ev->data;
171
172 ev->active = 0;
173
174 if (ev->index == NGX_INVALID_INDEX) {
175 ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
176 "poll event fd:%d ev:%i is already deleted",
177 c->fd, event);
178 return NGX_OK;
179 }
180
181 if (event == NGX_READ_EVENT) {
182 e = c->write;
183 #if (NGX_READ_EVENT != POLLIN)
184 event = POLLIN;
185 #endif
186
187 } else {
188 e = c->read;
189 #if (NGX_WRITE_EVENT != POLLOUT)
190 event = POLLOUT;
191 #endif
192 }
193
194 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
195 "poll del event: fd:%d ev:%i", c->fd, event);
196
197 if (e == NULL || e->index == NGX_INVALID_INDEX) {
198 nevents--;
199
200 if (ev->index < (ngx_uint_t) nevents) {
201
202 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
203 "index: copy event %ui to %i", nevents, ev->index);
204
205 event_list[ev->index] = event_list[nevents];
206
207 c = ngx_cycle->files[event_list[nevents].fd];
208
209 if (c->fd == -1) {
210 ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
211 "unexpected last event");
212
213 } else {
214 if (c->read->index == (ngx_uint_t) nevents) {
215 c->read->index = ev->index;
216 }
217
218 if (c->write->index == (ngx_uint_t) nevents) {
219 c->write->index = ev->index;
220 }
221 }
222 }
223
224 } else {
225 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ev->log, 0,
226 "poll del index: %i", e->index);
227
228 event_list[e->index].events &= (short) ~event;
229 }
230
231 ev->index = NGX_INVALID_INDEX;
232
233 return NGX_OK;
234 }
235
236
237 static ngx_int_t
238 ngx_poll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags)
239 {
240 int ready, revents;
241 ngx_err_t err;
242 ngx_int_t i, nready;
243 ngx_uint_t found, level;
244 ngx_event_t *ev, **queue;
245 ngx_connection_t *c;
246
247 /* NGX_TIMER_INFINITE == INFTIM */
248
249 #if (NGX_DEBUG0)
250 if (cycle->log->log_level & NGX_LOG_DEBUG_ALL) {
251 for (i = 0; i < nevents; i++) {
252 ngx_log_debug3(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
253 "poll: %d: fd:%d ev:%04Xd",
254 i, event_list[i].fd, event_list[i].events);
255 }
256 }
257 #endif
258
259 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "poll timer: %M", timer);
260
261 ready = poll(event_list, (u_int) nevents, (int) timer);
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_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
270 "poll ready %d of %d", ready, nevents);
271
272 if (err) {
273 if (err == NGX_EINTR) {
274
275 if (ngx_event_timer_alarm) {
276 ngx_event_timer_alarm = 0;
277 return NGX_OK;
278 }
279
280 level = NGX_LOG_INFO;
281
282 } else {
283 level = NGX_LOG_ALERT;
284 }
285
286 ngx_log_error(level, cycle->log, err, "poll() failed");
287 return NGX_ERROR;
288 }
289
290 if (ready == 0) {
291 if (timer != NGX_TIMER_INFINITE) {
292 return NGX_OK;
293 }
294
295 ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
296 "poll() returned no events without timeout");
297 return NGX_ERROR;
298 }
299
300 ngx_mutex_lock(ngx_posted_events_mutex);
301
302 nready = 0;
303
304 for (i = 0; i < nevents && ready; i++) {
305
306 revents = event_list[i].revents;
307
308 #if 1
309 ngx_log_debug4(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
310 "poll: %d: fd:%d ev:%04Xd rev:%04Xd",
311 i, event_list[i].fd, event_list[i].events, revents);
312 #else
313 if (revents) {
314 ngx_log_debug4(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
315 "poll: %d: fd:%d ev:%04Xd rev:%04Xd",
316 i, event_list[i].fd, event_list[i].events, revents);
317 }
318 #endif
319
320 if (revents & POLLNVAL) {
321 ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
322 "poll() error fd:%d ev:%04Xd rev:%04Xd",
323 event_list[i].fd, event_list[i].events, revents);
324 }
325
326 if (revents & ~(POLLIN|POLLOUT|POLLERR|POLLHUP|POLLNVAL)) {
327 ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
328 "strange poll() events fd:%d ev:%04Xd rev:%04Xd",
329 event_list[i].fd, event_list[i].events, revents);
330 }
331
332 if (event_list[i].fd == -1) {
333 /*
334 * the disabled event, a workaround for our possible bug,
335 * see the comment below
336 */
337 continue;
338 }
339
340 c = ngx_cycle->files[event_list[i].fd];
341
342 if (c->fd == -1) {
343 ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "unexpected event");
344
345 /*
346 * it is certainly our fault and it should be investigated,
347 * in the meantime we disable this event to avoid a CPU spinning
348 */
349
350 if (i == nevents - 1) {
351 nevents--;
352 } else {
353 event_list[i].fd = -1;
354 }
355
356 continue;
357 }
358
359 if ((revents & (POLLERR|POLLHUP|POLLNVAL))
360 && (revents & (POLLIN|POLLOUT)) == 0)
361 {
362 /*
363 * if the error events were returned without POLLIN or POLLOUT,
364 * then add these flags to handle the events at least in one
365 * active handler
366 */
367
368 revents |= POLLIN|POLLOUT;
369 }
370
371 found = 0;
372
373 if (revents & POLLIN) {
374 found = 1;
375
376 ev = c->read;
377
378 if ((flags & NGX_POST_THREAD_EVENTS) && !ev->accept) {
379 ev->posted_ready = 1;
380
381 } else {
382 ev->ready = 1;
383 }
384
385 queue = (ngx_event_t **) (ev->accept ? &ngx_posted_accept_events:
386 &ngx_posted_events);
387 ngx_locked_post_event(ev, queue);
388 }
389
390 if (revents & POLLOUT) {
391 found = 1;
392 ev = c->write;
393
394 if (flags & NGX_POST_THREAD_EVENTS) {
395 ev->posted_ready = 1;
396
397 } else {
398 ev->ready = 1;
399 }
400
401 ngx_locked_post_event(ev, &ngx_posted_events);
402 }
403
404 if (found) {
405 ready--;
406 continue;
407 }
408 }
409
410 ngx_mutex_unlock(ngx_posted_events_mutex);
411
412 if (ready != 0) {
413 ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "poll ready != events");
414 }
415
416 return nready;
417 }
418
419
420 static char *
421 ngx_poll_init_conf(ngx_cycle_t *cycle, void *conf)
422 {
423 ngx_event_conf_t *ecf;
424
425 ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);
426
427 if (ecf->use != ngx_poll_module.ctx_index) {
428 return NGX_CONF_OK;
429 }
430
431 #if (NGX_THREADS)
432
433 ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
434 "poll() is not supported in the threaded mode");
435 return NGX_CONF_ERROR;
436
437 #else
438
439 return NGX_CONF_OK;
440
441 #endif
442 }
443
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