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ed9b544e | 1 | /* A simple event-driven programming library. Originally I wrote this code |
2 | * for the Jim's event-loop (Jim is a Tcl interpreter) but later translated | |
3 | * it in form of a library for easy reuse. | |
4 | * | |
5 | * Copyright (c) 2006-2009, Salvatore Sanfilippo <antirez at gmail dot com> | |
6 | * All rights reserved. | |
7 | * | |
8 | * Redistribution and use in source and binary forms, with or without | |
9 | * modification, are permitted provided that the following conditions are met: | |
10 | * | |
11 | * * Redistributions of source code must retain the above copyright notice, | |
12 | * this list of conditions and the following disclaimer. | |
13 | * * Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in the | |
15 | * documentation and/or other materials provided with the distribution. | |
16 | * * Neither the name of Redis nor the names of its contributors may be used | |
17 | * to endorse or promote products derived from this software without | |
18 | * specific prior written permission. | |
19 | * | |
20 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
21 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
22 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
23 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | |
24 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
25 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
26 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
27 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
28 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
29 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
30 | * POSSIBILITY OF SUCH DAMAGE. | |
31 | */ | |
32 | ||
33 | #include <stdio.h> | |
34 | #include <sys/time.h> | |
35 | #include <sys/types.h> | |
36 | #include <unistd.h> | |
37 | #include <stdlib.h> | |
38 | ||
39 | #include "ae.h" | |
40 | #include "zmalloc.h" | |
41 | ||
42 | aeEventLoop *aeCreateEventLoop(void) { | |
43 | aeEventLoop *eventLoop; | |
44 | ||
45 | eventLoop = zmalloc(sizeof(*eventLoop)); | |
46 | if (!eventLoop) return NULL; | |
47 | eventLoop->fileEventHead = NULL; | |
48 | eventLoop->timeEventHead = NULL; | |
49 | eventLoop->timeEventNextId = 0; | |
50 | eventLoop->stop = 0; | |
51 | return eventLoop; | |
52 | } | |
53 | ||
54 | void aeDeleteEventLoop(aeEventLoop *eventLoop) { | |
55 | zfree(eventLoop); | |
56 | } | |
57 | ||
58 | void aeStop(aeEventLoop *eventLoop) { | |
59 | eventLoop->stop = 1; | |
60 | } | |
61 | ||
62 | int aeCreateFileEvent(aeEventLoop *eventLoop, int fd, int mask, | |
63 | aeFileProc *proc, void *clientData, | |
64 | aeEventFinalizerProc *finalizerProc) | |
65 | { | |
66 | aeFileEvent *fe; | |
67 | ||
68 | fe = zmalloc(sizeof(*fe)); | |
69 | if (fe == NULL) return AE_ERR; | |
70 | fe->fd = fd; | |
71 | fe->mask = mask; | |
72 | fe->fileProc = proc; | |
73 | fe->finalizerProc = finalizerProc; | |
74 | fe->clientData = clientData; | |
75 | fe->next = eventLoop->fileEventHead; | |
76 | eventLoop->fileEventHead = fe; | |
77 | return AE_OK; | |
78 | } | |
79 | ||
80 | void aeDeleteFileEvent(aeEventLoop *eventLoop, int fd, int mask) | |
81 | { | |
82 | aeFileEvent *fe, *prev = NULL; | |
83 | ||
84 | fe = eventLoop->fileEventHead; | |
85 | while(fe) { | |
86 | if (fe->fd == fd && fe->mask == mask) { | |
87 | if (prev == NULL) | |
88 | eventLoop->fileEventHead = fe->next; | |
89 | else | |
90 | prev->next = fe->next; | |
91 | if (fe->finalizerProc) | |
92 | fe->finalizerProc(eventLoop, fe->clientData); | |
93 | zfree(fe); | |
94 | return; | |
95 | } | |
96 | prev = fe; | |
97 | fe = fe->next; | |
98 | } | |
99 | } | |
100 | ||
101 | static void aeGetTime(long *seconds, long *milliseconds) | |
102 | { | |
103 | struct timeval tv; | |
104 | ||
105 | gettimeofday(&tv, NULL); | |
106 | *seconds = tv.tv_sec; | |
107 | *milliseconds = tv.tv_usec/1000; | |
108 | } | |
109 | ||
110 | static void aeAddMillisecondsToNow(long long milliseconds, long *sec, long *ms) { | |
111 | long cur_sec, cur_ms, when_sec, when_ms; | |
112 | ||
113 | aeGetTime(&cur_sec, &cur_ms); | |
114 | when_sec = cur_sec + milliseconds/1000; | |
115 | when_ms = cur_ms + milliseconds%1000; | |
116 | if (when_ms >= 1000) { | |
117 | when_sec ++; | |
118 | when_ms -= 1000; | |
119 | } | |
120 | *sec = when_sec; | |
121 | *ms = when_ms; | |
122 | } | |
123 | ||
124 | long long aeCreateTimeEvent(aeEventLoop *eventLoop, long long milliseconds, | |
125 | aeTimeProc *proc, void *clientData, | |
126 | aeEventFinalizerProc *finalizerProc) | |
127 | { | |
128 | long long id = eventLoop->timeEventNextId++; | |
129 | aeTimeEvent *te; | |
130 | ||
131 | te = zmalloc(sizeof(*te)); | |
132 | if (te == NULL) return AE_ERR; | |
133 | te->id = id; | |
134 | aeAddMillisecondsToNow(milliseconds,&te->when_sec,&te->when_ms); | |
135 | te->timeProc = proc; | |
136 | te->finalizerProc = finalizerProc; | |
137 | te->clientData = clientData; | |
138 | te->next = eventLoop->timeEventHead; | |
139 | eventLoop->timeEventHead = te; | |
140 | return id; | |
141 | } | |
142 | ||
143 | int aeDeleteTimeEvent(aeEventLoop *eventLoop, long long id) | |
144 | { | |
145 | aeTimeEvent *te, *prev = NULL; | |
146 | ||
147 | te = eventLoop->timeEventHead; | |
148 | while(te) { | |
149 | if (te->id == id) { | |
150 | if (prev == NULL) | |
151 | eventLoop->timeEventHead = te->next; | |
152 | else | |
153 | prev->next = te->next; | |
154 | if (te->finalizerProc) | |
155 | te->finalizerProc(eventLoop, te->clientData); | |
156 | zfree(te); | |
157 | return AE_OK; | |
158 | } | |
159 | prev = te; | |
160 | te = te->next; | |
161 | } | |
162 | return AE_ERR; /* NO event with the specified ID found */ | |
163 | } | |
164 | ||
165 | /* Search the first timer to fire. | |
166 | * This operation is useful to know how many time the select can be | |
167 | * put in sleep without to delay any event. | |
168 | * If there are no timers NULL is returned. | |
169 | * | |
170 | * Note that's O(N) since time events are unsorted. */ | |
171 | static aeTimeEvent *aeSearchNearestTimer(aeEventLoop *eventLoop) | |
172 | { | |
173 | aeTimeEvent *te = eventLoop->timeEventHead; | |
174 | aeTimeEvent *nearest = NULL; | |
175 | ||
176 | while(te) { | |
177 | if (!nearest || te->when_sec < nearest->when_sec || | |
178 | (te->when_sec == nearest->when_sec && | |
179 | te->when_ms < nearest->when_ms)) | |
180 | nearest = te; | |
181 | te = te->next; | |
182 | } | |
183 | return nearest; | |
184 | } | |
185 | ||
186 | /* Process every pending time event, then every pending file event | |
187 | * (that may be registered by time event callbacks just processed). | |
188 | * Without special flags the function sleeps until some file event | |
189 | * fires, or when the next time event occurrs (if any). | |
190 | * | |
191 | * If flags is 0, the function does nothing and returns. | |
192 | * if flags has AE_ALL_EVENTS set, all the kind of events are processed. | |
193 | * if flags has AE_FILE_EVENTS set, file events are processed. | |
194 | * if flags has AE_TIME_EVENTS set, time events are processed. | |
195 | * if flags has AE_DONT_WAIT set the function returns ASAP until all | |
196 | * the events that's possible to process without to wait are processed. | |
197 | * | |
198 | * The function returns the number of events processed. */ | |
199 | int aeProcessEvents(aeEventLoop *eventLoop, int flags) | |
200 | { | |
201 | int maxfd = 0, numfd = 0, processed = 0; | |
202 | fd_set rfds, wfds, efds; | |
203 | aeFileEvent *fe = eventLoop->fileEventHead; | |
204 | aeTimeEvent *te; | |
205 | long long maxId; | |
206 | AE_NOTUSED(flags); | |
207 | ||
208 | /* Nothing to do? return ASAP */ | |
209 | if (!(flags & AE_TIME_EVENTS) && !(flags & AE_FILE_EVENTS)) return 0; | |
210 | ||
211 | FD_ZERO(&rfds); | |
212 | FD_ZERO(&wfds); | |
213 | FD_ZERO(&efds); | |
214 | ||
215 | /* Check file events */ | |
216 | if (flags & AE_FILE_EVENTS) { | |
217 | while (fe != NULL) { | |
218 | if (fe->mask & AE_READABLE) FD_SET(fe->fd, &rfds); | |
219 | if (fe->mask & AE_WRITABLE) FD_SET(fe->fd, &wfds); | |
220 | if (fe->mask & AE_EXCEPTION) FD_SET(fe->fd, &efds); | |
221 | if (maxfd < fe->fd) maxfd = fe->fd; | |
222 | numfd++; | |
223 | fe = fe->next; | |
224 | } | |
225 | } | |
226 | /* Note that we want call select() even if there are no | |
227 | * file events to process as long as we want to process time | |
228 | * events, in order to sleep until the next time event is ready | |
229 | * to fire. */ | |
230 | if (numfd || ((flags & AE_TIME_EVENTS) && !(flags & AE_DONT_WAIT))) { | |
231 | int retval; | |
232 | aeTimeEvent *shortest = NULL; | |
233 | struct timeval tv, *tvp; | |
234 | ||
235 | if (flags & AE_TIME_EVENTS && !(flags & AE_DONT_WAIT)) | |
236 | shortest = aeSearchNearestTimer(eventLoop); | |
237 | if (shortest) { | |
238 | long now_sec, now_ms; | |
239 | ||
240 | /* Calculate the time missing for the nearest | |
241 | * timer to fire. */ | |
242 | aeGetTime(&now_sec, &now_ms); | |
243 | tvp = &tv; | |
244 | tvp->tv_sec = shortest->when_sec - now_sec; | |
245 | if (shortest->when_ms < now_ms) { | |
246 | tvp->tv_usec = ((shortest->when_ms+1000) - now_ms)*1000; | |
247 | tvp->tv_sec --; | |
248 | } else { | |
249 | tvp->tv_usec = (shortest->when_ms - now_ms)*1000; | |
250 | } | |
251 | } else { | |
252 | /* If we have to check for events but need to return | |
253 | * ASAP because of AE_DONT_WAIT we need to se the timeout | |
254 | * to zero */ | |
255 | if (flags & AE_DONT_WAIT) { | |
256 | tv.tv_sec = tv.tv_usec = 0; | |
257 | tvp = &tv; | |
258 | } else { | |
259 | /* Otherwise we can block */ | |
260 | tvp = NULL; /* wait forever */ | |
261 | } | |
262 | } | |
263 | ||
264 | retval = select(maxfd+1, &rfds, &wfds, &efds, tvp); | |
265 | if (retval > 0) { | |
266 | fe = eventLoop->fileEventHead; | |
267 | while(fe != NULL) { | |
268 | int fd = (int) fe->fd; | |
269 | ||
270 | if ((fe->mask & AE_READABLE && FD_ISSET(fd, &rfds)) || | |
271 | (fe->mask & AE_WRITABLE && FD_ISSET(fd, &wfds)) || | |
272 | (fe->mask & AE_EXCEPTION && FD_ISSET(fd, &efds))) | |
273 | { | |
274 | int mask = 0; | |
275 | ||
276 | if (fe->mask & AE_READABLE && FD_ISSET(fd, &rfds)) | |
277 | mask |= AE_READABLE; | |
278 | if (fe->mask & AE_WRITABLE && FD_ISSET(fd, &wfds)) | |
279 | mask |= AE_WRITABLE; | |
280 | if (fe->mask & AE_EXCEPTION && FD_ISSET(fd, &efds)) | |
281 | mask |= AE_EXCEPTION; | |
282 | fe->fileProc(eventLoop, fe->fd, fe->clientData, mask); | |
283 | processed++; | |
284 | /* After an event is processed our file event list | |
285 | * may no longer be the same, so what we do | |
286 | * is to clear the bit for this file descriptor and | |
287 | * restart again from the head. */ | |
288 | fe = eventLoop->fileEventHead; | |
289 | FD_CLR(fd, &rfds); | |
290 | FD_CLR(fd, &wfds); | |
291 | FD_CLR(fd, &efds); | |
292 | } else { | |
293 | fe = fe->next; | |
294 | } | |
295 | } | |
296 | } | |
297 | } | |
298 | /* Check time events */ | |
299 | if (flags & AE_TIME_EVENTS) { | |
300 | te = eventLoop->timeEventHead; | |
301 | maxId = eventLoop->timeEventNextId-1; | |
302 | while(te) { | |
303 | long now_sec, now_ms; | |
304 | long long id; | |
305 | ||
306 | if (te->id > maxId) { | |
307 | te = te->next; | |
308 | continue; | |
309 | } | |
310 | aeGetTime(&now_sec, &now_ms); | |
311 | if (now_sec > te->when_sec || | |
312 | (now_sec == te->when_sec && now_ms >= te->when_ms)) | |
313 | { | |
314 | int retval; | |
315 | ||
316 | id = te->id; | |
317 | retval = te->timeProc(eventLoop, id, te->clientData); | |
318 | /* After an event is processed our time event list may | |
319 | * no longer be the same, so we restart from head. | |
320 | * Still we make sure to don't process events registered | |
321 | * by event handlers itself in order to don't loop forever. | |
322 | * To do so we saved the max ID we want to handle. */ | |
323 | if (retval != AE_NOMORE) { | |
324 | aeAddMillisecondsToNow(retval,&te->when_sec,&te->when_ms); | |
325 | } else { | |
326 | aeDeleteTimeEvent(eventLoop, id); | |
327 | } | |
328 | te = eventLoop->timeEventHead; | |
329 | } else { | |
330 | te = te->next; | |
331 | } | |
332 | } | |
333 | } | |
334 | return processed; /* return the number of processed file/time events */ | |
335 | } | |
336 | ||
337 | /* Wait for millseconds until the given file descriptor becomes | |
338 | * writable/readable/exception */ | |
339 | int aeWait(int fd, int mask, long long milliseconds) { | |
340 | struct timeval tv; | |
341 | fd_set rfds, wfds, efds; | |
342 | int retmask = 0, retval; | |
343 | ||
344 | tv.tv_sec = milliseconds/1000; | |
345 | tv.tv_usec = (milliseconds%1000)*1000; | |
346 | FD_ZERO(&rfds); | |
347 | FD_ZERO(&wfds); | |
348 | FD_ZERO(&efds); | |
349 | ||
350 | if (mask & AE_READABLE) FD_SET(fd,&rfds); | |
351 | if (mask & AE_WRITABLE) FD_SET(fd,&wfds); | |
352 | if (mask & AE_EXCEPTION) FD_SET(fd,&efds); | |
353 | if ((retval = select(fd+1, &rfds, &wfds, &efds, &tv)) > 0) { | |
354 | if (FD_ISSET(fd,&rfds)) retmask |= AE_READABLE; | |
355 | if (FD_ISSET(fd,&wfds)) retmask |= AE_WRITABLE; | |
356 | if (FD_ISSET(fd,&efds)) retmask |= AE_EXCEPTION; | |
357 | return retmask; | |
358 | } else { | |
359 | return retval; | |
360 | } | |
361 | } | |
362 | ||
363 | void aeMain(aeEventLoop *eventLoop) | |
364 | { | |
365 | eventLoop->stop = 0; | |
366 | while (!eventLoop->stop) | |
367 | aeProcessEvents(eventLoop, AE_ALL_EVENTS); | |
368 | } |