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comparison src/event/ngx_event_busy_lock.c @ 0:f0b350454894 NGINX_0_1_0
nginx 0.1.0
*) The first public version.
author | Igor Sysoev <http://sysoev.ru> |
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date | Mon, 04 Oct 2004 00:00:00 +0400 |
parents | |
children | b55cbf18157e |
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-1:000000000000 | 0:f0b350454894 |
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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 int ngx_event_busy_lock_look_cachable(ngx_event_busy_lock_t *bl, | |
13 ngx_event_busy_lock_ctx_t *ctx); | |
14 static void ngx_event_busy_lock_handler(ngx_event_t *ev); | |
15 static void ngx_event_busy_lock_posted_handler(ngx_event_t *ev); | |
16 | |
17 | |
18 /* | |
19 * NGX_OK: the busy lock is held | |
20 * NGX_AGAIN: the all busy locks are held but we will wait the specified time | |
21 * NGX_BUSY: ctx->timer == 0: there are many the busy locks | |
22 * ctx->timer != 0: there are many the waiting locks | |
23 * NGX_ERROR: an error occured while the mutex locking | |
24 */ | |
25 | |
26 ngx_int_t ngx_event_busy_lock(ngx_event_busy_lock_t *bl, | |
27 ngx_event_busy_lock_ctx_t *ctx) | |
28 { | |
29 ngx_int_t rc; | |
30 | |
31 if (ngx_mutex_lock(bl->mutex) == NGX_ERROR) { | |
32 return NGX_ERROR; | |
33 } | |
34 | |
35 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ctx->event->log, 0, | |
36 "event busy lock: b:%d mb:%d", | |
37 bl->busy, bl->max_busy); | |
38 | |
39 if (bl->busy < bl->max_busy) { | |
40 bl->busy++; | |
41 rc = NGX_OK; | |
42 | |
43 } else if (ctx->timer && bl->waiting < bl->max_waiting) { | |
44 bl->waiting++; | |
45 ngx_add_timer(ctx->event, ctx->timer); | |
46 ctx->event->event_handler = ngx_event_busy_lock_handler; | |
47 | |
48 if (bl->events) { | |
49 bl->last->next = ctx; | |
50 | |
51 } else { | |
52 bl->events = ctx; | |
53 } | |
54 | |
55 bl->last = ctx; | |
56 | |
57 rc = NGX_AGAIN; | |
58 | |
59 } else { | |
60 rc = NGX_BUSY; | |
61 } | |
62 | |
63 ngx_mutex_unlock(bl->mutex); | |
64 | |
65 return rc; | |
66 } | |
67 | |
68 | |
69 ngx_int_t ngx_event_busy_lock_cachable(ngx_event_busy_lock_t *bl, | |
70 ngx_event_busy_lock_ctx_t *ctx) | |
71 { | |
72 ngx_int_t rc; | |
73 | |
74 if (ngx_mutex_lock(bl->mutex) == NGX_ERROR) { | |
75 return NGX_ERROR; | |
76 } | |
77 | |
78 rc = ngx_event_busy_lock_look_cachable(bl, ctx); | |
79 | |
80 ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ctx->event->log, 0, | |
81 "event busy lock: %d w:%d mw:%d", | |
82 rc, bl->waiting, bl->max_waiting); | |
83 | |
84 /* | |
85 * NGX_OK: no the same request, there is free slot and we locked it | |
86 * NGX_BUSY: no the same request and there is no free slot | |
87 * NGX_AGAIN: the same request is processing | |
88 */ | |
89 | |
90 if (rc == NGX_AGAIN) { | |
91 | |
92 if (ctx->timer && bl->waiting < bl->max_waiting) { | |
93 bl->waiting++; | |
94 ngx_add_timer(ctx->event, ctx->timer); | |
95 ctx->event->event_handler = ngx_event_busy_lock_handler; | |
96 | |
97 if (bl->events == NULL) { | |
98 bl->events = ctx; | |
99 } else { | |
100 bl->last->next = ctx; | |
101 } | |
102 bl->last = ctx; | |
103 | |
104 } else { | |
105 rc = NGX_BUSY; | |
106 } | |
107 } | |
108 | |
109 ngx_mutex_unlock(bl->mutex); | |
110 | |
111 return rc; | |
112 } | |
113 | |
114 | |
115 ngx_int_t ngx_event_busy_unlock(ngx_event_busy_lock_t *bl, | |
116 ngx_event_busy_lock_ctx_t *ctx) | |
117 { | |
118 ngx_event_t *ev; | |
119 ngx_event_busy_lock_ctx_t *wakeup; | |
120 | |
121 if (ngx_mutex_lock(bl->mutex) == NGX_ERROR) { | |
122 return NGX_ERROR; | |
123 } | |
124 | |
125 if (bl->events) { | |
126 wakeup = bl->events; | |
127 bl->events = bl->events->next; | |
128 | |
129 } else { | |
130 wakeup = NULL; | |
131 bl->busy--; | |
132 } | |
133 | |
134 /* | |
135 * MP: all ctx's and their queue must be in shared memory, | |
136 * each ctx has pid to wake up | |
137 */ | |
138 | |
139 if (wakeup == NULL) { | |
140 ngx_mutex_unlock(bl->mutex); | |
141 return NGX_OK; | |
142 } | |
143 | |
144 if (ctx->md5) { | |
145 for (wakeup = bl->events; wakeup; wakeup = wakeup->next) { | |
146 if (wakeup->md5 == NULL || wakeup->slot != ctx->slot) { | |
147 continue; | |
148 } | |
149 | |
150 wakeup->handler = ngx_event_busy_lock_posted_handler; | |
151 wakeup->cache_updated = 1; | |
152 | |
153 ev = wakeup->event; | |
154 | |
155 if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_ERROR) { | |
156 return NGX_ERROR; | |
157 } | |
158 | |
159 ngx_post_event(ev); | |
160 | |
161 ngx_mutex_unlock(ngx_posted_events_mutex); | |
162 } | |
163 | |
164 ngx_mutex_unlock(bl->mutex); | |
165 | |
166 } else { | |
167 bl->waiting--; | |
168 | |
169 ngx_mutex_unlock(bl->mutex); | |
170 | |
171 wakeup->handler = ngx_event_busy_lock_posted_handler; | |
172 wakeup->locked = 1; | |
173 | |
174 ev = wakeup->event; | |
175 | |
176 if (ev->timer_set) { | |
177 ngx_del_timer(ev); | |
178 } | |
179 | |
180 if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_ERROR) { | |
181 return NGX_ERROR; | |
182 } | |
183 | |
184 ngx_post_event(ev); | |
185 | |
186 ngx_mutex_unlock(ngx_posted_events_mutex); | |
187 } | |
188 | |
189 return NGX_OK; | |
190 } | |
191 | |
192 | |
193 ngx_int_t ngx_event_busy_lock_cancel(ngx_event_busy_lock_t *bl, | |
194 ngx_event_busy_lock_ctx_t *ctx) | |
195 { | |
196 ngx_event_busy_lock_ctx_t *c, *p; | |
197 | |
198 if (ngx_mutex_lock(bl->mutex) == NGX_ERROR) { | |
199 return NGX_ERROR; | |
200 } | |
201 | |
202 bl->waiting--; | |
203 | |
204 if (ctx == bl->events) { | |
205 bl->events = ctx->next; | |
206 | |
207 } else { | |
208 p = bl->events; | |
209 for (c = bl->events->next; c; c = c->next) { | |
210 if (c == ctx) { | |
211 p->next = ctx->next; | |
212 break; | |
213 } | |
214 p = c; | |
215 } | |
216 } | |
217 | |
218 ngx_mutex_unlock(bl->mutex); | |
219 | |
220 return NGX_OK; | |
221 } | |
222 | |
223 | |
224 static int ngx_event_busy_lock_look_cachable(ngx_event_busy_lock_t *bl, | |
225 ngx_event_busy_lock_ctx_t *ctx) | |
226 { | |
227 ngx_int_t free; | |
228 ngx_uint_t i, bit, cachable, mask; | |
229 | |
230 bit = 0; | |
231 cachable = 0; | |
232 free = -1; | |
233 | |
234 #if (NGX_SUPPRESS_WARN) | |
235 mask = 0; | |
236 #endif | |
237 | |
238 for (i = 0; i < bl->max_busy; i++) { | |
239 | |
240 if ((bit & 7) == 0) { | |
241 mask = bl->md5_mask[i / 8]; | |
242 } | |
243 | |
244 if (mask & 1) { | |
245 if (ngx_memcmp(&bl->md5[i * 16], ctx->md5, 16) == 0) { | |
246 ctx->waiting = 1; | |
247 ctx->slot = i; | |
248 return NGX_AGAIN; | |
249 } | |
250 cachable++; | |
251 | |
252 } else if (free == -1) { | |
253 free = i; | |
254 } | |
255 | |
256 if (cachable == bl->cachable) { | |
257 if (free == -1 && cachable < bl->max_busy) { | |
258 free = i + 1; | |
259 } | |
260 | |
261 break; | |
262 } | |
263 | |
264 mask >>= 1; | |
265 bit++; | |
266 } | |
267 | |
268 if (free == -1) { | |
269 return NGX_BUSY; | |
270 } | |
271 | |
272 #if 0 | |
273 if (bl->busy == bl->max_busy) { | |
274 return NGX_BUSY; | |
275 } | |
276 #endif | |
277 | |
278 ngx_memcpy(&bl->md5[free * 16], ctx->md5, 16); | |
279 bl->md5_mask[free / 8] |= 1 << (free & 7); | |
280 ctx->slot = free; | |
281 | |
282 bl->cachable++; | |
283 bl->busy++; | |
284 | |
285 return NGX_OK; | |
286 } | |
287 | |
288 | |
289 static void ngx_event_busy_lock_handler(ngx_event_t *ev) | |
290 { | |
291 if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_ERROR) { | |
292 return; | |
293 } | |
294 | |
295 ngx_post_event(ev); | |
296 | |
297 ngx_mutex_unlock(ngx_posted_events_mutex); | |
298 | |
299 ev->event_handler = ngx_event_busy_lock_posted_handler; | |
300 } | |
301 | |
302 | |
303 static void ngx_event_busy_lock_posted_handler(ngx_event_t *ev) | |
304 { | |
305 ngx_event_busy_lock_ctx_t *ctx; | |
306 | |
307 ctx = ev->data; | |
308 ctx->handler(ev); | |
309 } |