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460b9539 | 1 | /* |
2 | * This file is part of DisOrder. | |
e8c92ba7 | 3 | * Copyright (C) 2004, 2005, 2007 Richard Kettlewell |
460b9539 | 4 | * |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | |
18 | * USA | |
19 | */ | |
768d7355 RK |
20 | /** @file lib/event.c |
21 | * @brief DisOrder event loop | |
22 | */ | |
460b9539 | 23 | |
24 | #include <config.h> | |
25 | ||
26 | #include <unistd.h> | |
27 | #include <fcntl.h> | |
28 | #include <sys/time.h> | |
29 | #include <sys/types.h> | |
30 | #include <sys/resource.h> | |
31 | #include <sys/wait.h> | |
32 | #include <unistd.h> | |
33 | #include <assert.h> | |
34 | #include <signal.h> | |
35 | #include <errno.h> | |
36 | #include <string.h> | |
37 | #include <limits.h> | |
38 | #include <sys/socket.h> | |
39 | #include <netinet/in.h> | |
40 | #include <sys/un.h> | |
41 | #include <stdio.h> | |
42 | #include "event.h" | |
43 | #include "mem.h" | |
44 | #include "log.h" | |
45 | #include "syscalls.h" | |
46 | #include "printf.h" | |
47 | #include "sink.h" | |
768d7355 | 48 | #include "vector.h" |
460b9539 | 49 | |
768d7355 | 50 | /** @brief A timeout */ |
460b9539 | 51 | struct timeout { |
52 | struct timeout *next; | |
53 | struct timeval when; | |
54 | ev_timeout_callback *callback; | |
55 | void *u; | |
56 | int resolve; | |
57 | }; | |
58 | ||
768d7355 | 59 | /** @brief A file descriptor in one mode */ |
460b9539 | 60 | struct fd { |
61 | int fd; | |
62 | ev_fd_callback *callback; | |
63 | void *u; | |
e8c92ba7 | 64 | const char *what; |
460b9539 | 65 | }; |
66 | ||
768d7355 | 67 | /** @brief All the file descriptors in a given mode */ |
460b9539 | 68 | struct fdmode { |
768d7355 | 69 | /** @brief Mask of active file descriptors passed to @c select() */ |
460b9539 | 70 | fd_set enabled; |
768d7355 RK |
71 | |
72 | /** @brief File descriptor mask returned from @c select() */ | |
460b9539 | 73 | fd_set tripped; |
768d7355 RK |
74 | |
75 | /** @brief Number of file descriptors in @p fds */ | |
76 | int nfds; | |
77 | ||
78 | /** @brief Number of slots in @p fds */ | |
79 | int fdslots; | |
80 | ||
81 | /** @brief Array of all active file descriptors */ | |
460b9539 | 82 | struct fd *fds; |
768d7355 RK |
83 | |
84 | /** @brief Highest-numbered file descriptor or 0 */ | |
460b9539 | 85 | int maxfd; |
86 | }; | |
87 | ||
768d7355 | 88 | /** @brief A signal handler */ |
460b9539 | 89 | struct signal { |
90 | struct sigaction oldsa; | |
91 | ev_signal_callback *callback; | |
92 | void *u; | |
93 | }; | |
94 | ||
768d7355 | 95 | /** @brief A child process */ |
460b9539 | 96 | struct child { |
97 | pid_t pid; | |
98 | int options; | |
99 | ev_child_callback *callback; | |
100 | void *u; | |
101 | }; | |
102 | ||
768d7355 | 103 | /** @brief An event loop */ |
460b9539 | 104 | struct ev_source { |
768d7355 | 105 | /** @brief File descriptors, per mode */ |
460b9539 | 106 | struct fdmode mode[ev_nmodes]; |
768d7355 RK |
107 | |
108 | /** @brief Sorted linked list of timeouts | |
109 | * | |
110 | * We could use @ref HEAP_TYPE now, but there aren't many timeouts. | |
111 | */ | |
460b9539 | 112 | struct timeout *timeouts; |
768d7355 RK |
113 | |
114 | /** @brief Array of handled signals */ | |
460b9539 | 115 | struct signal signals[NSIG]; |
768d7355 RK |
116 | |
117 | /** @brief Mask of handled signals */ | |
460b9539 | 118 | sigset_t sigmask; |
768d7355 RK |
119 | |
120 | /** @brief Escape early from handling of @c select() results | |
121 | * | |
122 | * This is set if any of the file descriptor arrays are invalidated, since | |
123 | * it's then not safe for processing of them to continue. | |
124 | */ | |
460b9539 | 125 | int escape; |
768d7355 RK |
126 | |
127 | /** @brief Signal handling pipe | |
128 | * | |
129 | * The signal handle writes signal numbers down this pipe. | |
130 | */ | |
460b9539 | 131 | int sigpipe[2]; |
768d7355 RK |
132 | |
133 | /** @brief Number of child processes in @p children */ | |
134 | int nchildren; | |
135 | ||
136 | /** @brief Number of slots in @p children */ | |
137 | int nchildslots; | |
138 | ||
139 | /** @brief Array of child processes */ | |
460b9539 | 140 | struct child *children; |
141 | }; | |
142 | ||
768d7355 | 143 | /** @brief Names of file descriptor modes */ |
460b9539 | 144 | static const char *modenames[] = { "read", "write", "except" }; |
145 | ||
146 | /* utilities ******************************************************************/ | |
147 | ||
768d7355 RK |
148 | /** @brief Great-than comparison for timevals |
149 | * | |
150 | * Ought to be in @file lib/timeval.h | |
151 | */ | |
460b9539 | 152 | static inline int gt(const struct timeval *a, const struct timeval *b) { |
153 | if(a->tv_sec > b->tv_sec) | |
154 | return 1; | |
155 | if(a->tv_sec == b->tv_sec | |
156 | && a->tv_usec > b->tv_usec) | |
157 | return 1; | |
158 | return 0; | |
159 | } | |
160 | ||
768d7355 RK |
161 | /** @brief Greater-than-or-equal comparison for timevals |
162 | * | |
163 | * Ought to be in @file lib/timeval.h | |
164 | */ | |
460b9539 | 165 | static inline int ge(const struct timeval *a, const struct timeval *b) { |
166 | return !gt(b, a); | |
167 | } | |
168 | ||
169 | /* creation *******************************************************************/ | |
170 | ||
768d7355 | 171 | /** @brief Create a new event loop */ |
460b9539 | 172 | ev_source *ev_new(void) { |
173 | ev_source *ev = xmalloc(sizeof *ev); | |
174 | int n; | |
175 | ||
176 | memset(ev, 0, sizeof *ev); | |
177 | for(n = 0; n < ev_nmodes; ++n) | |
178 | FD_ZERO(&ev->mode[n].enabled); | |
179 | ev->sigpipe[0] = ev->sigpipe[1] = -1; | |
180 | sigemptyset(&ev->sigmask); | |
181 | return ev; | |
182 | } | |
183 | ||
184 | /* event loop *****************************************************************/ | |
185 | ||
768d7355 RK |
186 | /** @brief Run the event loop |
187 | * @return -1 on error, non-0 if any callback returned non-0 | |
188 | */ | |
460b9539 | 189 | int ev_run(ev_source *ev) { |
190 | for(;;) { | |
191 | struct timeval now; | |
192 | struct timeval delta; | |
193 | int n, mode; | |
194 | int ret; | |
195 | int maxfd; | |
196 | struct timeout *t, **tt; | |
e8c92ba7 | 197 | struct stat sb; |
460b9539 | 198 | |
199 | xgettimeofday(&now, 0); | |
200 | /* Handle timeouts. We don't want to handle any timeouts that are added | |
201 | * while we're handling them (otherwise we'd have to break out of infinite | |
202 | * loops, preferrably without starving better-behaved subsystems). Hence | |
203 | * the slightly complicated two-phase approach here. */ | |
204 | for(t = ev->timeouts; | |
205 | t && ge(&now, &t->when); | |
206 | t = t->next) { | |
207 | t->resolve = 1; | |
208 | D(("calling timeout for %ld.%ld callback %p %p", | |
209 | (long)t->when.tv_sec, (long)t->when.tv_usec, | |
210 | (void *)t->callback, t->u)); | |
211 | ret = t->callback(ev, &now, t->u); | |
212 | if(ret) | |
213 | return ret; | |
214 | } | |
215 | tt = &ev->timeouts; | |
216 | while((t = *tt)) { | |
217 | if(t->resolve) | |
218 | *tt = t->next; | |
219 | else | |
220 | tt = &t->next; | |
221 | } | |
222 | maxfd = 0; | |
223 | for(mode = 0; mode < ev_nmodes; ++mode) { | |
224 | ev->mode[mode].tripped = ev->mode[mode].enabled; | |
225 | if(ev->mode[mode].maxfd > maxfd) | |
226 | maxfd = ev->mode[mode].maxfd; | |
227 | } | |
228 | xsigprocmask(SIG_UNBLOCK, &ev->sigmask, 0); | |
229 | do { | |
230 | if(ev->timeouts) { | |
231 | xgettimeofday(&now, 0); | |
232 | delta.tv_sec = ev->timeouts->when.tv_sec - now.tv_sec; | |
233 | delta.tv_usec = ev->timeouts->when.tv_usec - now.tv_usec; | |
234 | if(delta.tv_usec < 0) { | |
235 | delta.tv_usec += 1000000; | |
236 | --delta.tv_sec; | |
237 | } | |
238 | if(delta.tv_sec < 0) | |
239 | delta.tv_sec = delta.tv_usec = 0; | |
240 | n = select(maxfd + 1, | |
241 | &ev->mode[ev_read].tripped, | |
242 | &ev->mode[ev_write].tripped, | |
243 | &ev->mode[ev_except].tripped, | |
244 | &delta); | |
245 | } else { | |
246 | n = select(maxfd + 1, | |
247 | &ev->mode[ev_read].tripped, | |
248 | &ev->mode[ev_write].tripped, | |
249 | &ev->mode[ev_except].tripped, | |
250 | 0); | |
251 | } | |
252 | } while(n < 0 && errno == EINTR); | |
253 | xsigprocmask(SIG_BLOCK, &ev->sigmask, 0); | |
254 | if(n < 0) { | |
255 | error(errno, "error calling select"); | |
e8c92ba7 RK |
256 | if(errno == EBADF) { |
257 | /* If there's a bad FD in the mix then check them all and log what we | |
258 | * find, to ease debugging */ | |
259 | for(mode = 0; mode < ev_nmodes; ++mode) { | |
260 | for(n = 0; n < ev->mode[mode].nfds; ++n) { | |
261 | const int fd = ev->mode[mode].fds[n].fd; | |
262 | ||
263 | if(FD_ISSET(fd, &ev->mode[mode].enabled) | |
264 | && fstat(fd, &sb) < 0) | |
34a3e246 RK |
265 | error(errno, "mode %s fstat %d (%s)", |
266 | modenames[mode], fd, ev->mode[mode].fds[n].what); | |
e8c92ba7 | 267 | } |
34a3e246 RK |
268 | for(n = 0; n < maxfd; ++n) |
269 | if(FD_ISSET(n, &ev->mode[mode].enabled) | |
270 | && fstat(n, &sb) < 0) | |
271 | error(errno, "mode %s fstat %d", modenames[mode], n); | |
e8c92ba7 RK |
272 | } |
273 | } | |
460b9539 | 274 | return -1; |
275 | } | |
276 | if(n > 0) { | |
277 | /* if anything deranges the meaning of an fd, or re-orders the | |
278 | * fds[] tables, we'd better give up; such operations will | |
279 | * therefore set @escape@. */ | |
280 | ev->escape = 0; | |
281 | for(mode = 0; mode < ev_nmodes && !ev->escape; ++mode) | |
282 | for(n = 0; n < ev->mode[mode].nfds && !ev->escape; ++n) { | |
283 | int fd = ev->mode[mode].fds[n].fd; | |
284 | if(FD_ISSET(fd, &ev->mode[mode].tripped)) { | |
285 | D(("calling %s fd %d callback %p %p", modenames[mode], fd, | |
286 | (void *)ev->mode[mode].fds[n].callback, | |
287 | ev->mode[mode].fds[n].u)); | |
288 | ret = ev->mode[mode].fds[n].callback(ev, fd, | |
289 | ev->mode[mode].fds[n].u); | |
290 | if(ret) | |
291 | return ret; | |
292 | } | |
293 | } | |
294 | } | |
295 | /* we'll pick up timeouts back round the loop */ | |
296 | } | |
297 | } | |
298 | ||
299 | /* file descriptors ***********************************************************/ | |
300 | ||
768d7355 RK |
301 | /** @brief Register a file descriptor |
302 | * @param ev Event loop | |
303 | * @param mode @c ev_read or @c ev_write | |
304 | * @param fd File descriptor | |
305 | * @param callback Called when @p is readable/writable | |
306 | * @param u Passed to @p callback | |
307 | * @param what Text description | |
308 | * @return 0 on success, non-0 on error | |
309 | * | |
310 | * Sets @ref ev_source::escape, so no further processing of file descriptors | |
311 | * will occur this time round the event loop. | |
312 | */ | |
460b9539 | 313 | int ev_fd(ev_source *ev, |
314 | ev_fdmode mode, | |
315 | int fd, | |
316 | ev_fd_callback *callback, | |
e8c92ba7 RK |
317 | void *u, |
318 | const char *what) { | |
460b9539 | 319 | int n; |
320 | ||
321 | D(("registering %s fd %d callback %p %p", modenames[mode], fd, | |
322 | (void *)callback, u)); | |
323 | assert(mode < ev_nmodes); | |
324 | if(ev->mode[mode].nfds >= ev->mode[mode].fdslots) { | |
325 | ev->mode[mode].fdslots = (ev->mode[mode].fdslots | |
326 | ? 2 * ev->mode[mode].fdslots : 16); | |
327 | D(("expanding %s fd table to %d entries", modenames[mode], | |
328 | ev->mode[mode].fdslots)); | |
329 | ev->mode[mode].fds = xrealloc(ev->mode[mode].fds, | |
330 | ev->mode[mode].fdslots * sizeof (struct fd)); | |
331 | } | |
332 | n = ev->mode[mode].nfds++; | |
333 | FD_SET(fd, &ev->mode[mode].enabled); | |
334 | ev->mode[mode].fds[n].fd = fd; | |
335 | ev->mode[mode].fds[n].callback = callback; | |
336 | ev->mode[mode].fds[n].u = u; | |
e8c92ba7 | 337 | ev->mode[mode].fds[n].what = what; |
460b9539 | 338 | if(fd > ev->mode[mode].maxfd) |
339 | ev->mode[mode].maxfd = fd; | |
340 | ev->escape = 1; | |
341 | return 0; | |
342 | } | |
343 | ||
768d7355 RK |
344 | /** @brief Cancel a file descriptor |
345 | * @param ev Event loop | |
346 | * @param mode @c ev_read or @c ev_write | |
347 | * @param fd File descriptor | |
348 | * @return 0 on success, non-0 on error | |
349 | * | |
350 | * Sets @ref ev_source::escape, so no further processing of file descriptors | |
351 | * will occur this time round the event loop. | |
352 | */ | |
460b9539 | 353 | int ev_fd_cancel(ev_source *ev, ev_fdmode mode, int fd) { |
354 | int n; | |
355 | int maxfd; | |
356 | ||
357 | D(("cancelling mode %s fd %d", modenames[mode], fd)); | |
358 | /* find the right struct fd */ | |
359 | for(n = 0; n < ev->mode[mode].nfds && fd != ev->mode[mode].fds[n].fd; ++n) | |
360 | ; | |
361 | assert(n < ev->mode[mode].nfds); | |
362 | /* swap in the last fd and reduce the count */ | |
363 | if(n != ev->mode[mode].nfds - 1) | |
364 | ev->mode[mode].fds[n] = ev->mode[mode].fds[ev->mode[mode].nfds - 1]; | |
365 | --ev->mode[mode].nfds; | |
366 | /* if that was the biggest fd, find the new biggest one */ | |
367 | if(fd == ev->mode[mode].maxfd) { | |
368 | maxfd = 0; | |
369 | for(n = 0; n < ev->mode[mode].nfds; ++n) | |
370 | if(ev->mode[mode].fds[n].fd > maxfd) | |
371 | maxfd = ev->mode[mode].fds[n].fd; | |
372 | ev->mode[mode].maxfd = maxfd; | |
373 | } | |
374 | /* don't tell select about this fd any more */ | |
375 | FD_CLR(fd, &ev->mode[mode].enabled); | |
376 | ev->escape = 1; | |
377 | return 0; | |
378 | } | |
379 | ||
768d7355 RK |
380 | /** @brief Re-enable a file descriptor |
381 | * @param ev Event loop | |
382 | * @param mode @c ev_read or @c ev_write | |
383 | * @param fd File descriptor | |
384 | * @return 0 on success, non-0 on error | |
385 | * | |
386 | * It is harmless if @p fd is currently disabled, but it must not have been | |
387 | * cancelled. | |
388 | */ | |
460b9539 | 389 | int ev_fd_enable(ev_source *ev, ev_fdmode mode, int fd) { |
390 | D(("enabling mode %s fd %d", modenames[mode], fd)); | |
391 | FD_SET(fd, &ev->mode[mode].enabled); | |
392 | return 0; | |
393 | } | |
394 | ||
768d7355 RK |
395 | /** @brief Temporarily disable a file descriptor |
396 | * @param ev Event loop | |
397 | * @param mode @c ev_read or @c ev_write | |
398 | * @param fd File descriptor | |
399 | * @return 0 on success, non-0 on error | |
400 | * | |
401 | * Re-enable with ev_fd_enable(). It is harmless if @p fd is already disabled, | |
402 | * but it must not have been cancelled. | |
403 | */ | |
460b9539 | 404 | int ev_fd_disable(ev_source *ev, ev_fdmode mode, int fd) { |
405 | D(("disabling mode %s fd %d", modenames[mode], fd)); | |
406 | FD_CLR(fd, &ev->mode[mode].enabled); | |
407 | FD_CLR(fd, &ev->mode[mode].tripped); | |
408 | return 0; | |
409 | } | |
410 | ||
768d7355 RK |
411 | /** @brief Log a report of file descriptor state */ |
412 | void ev_report(ev_source *ev) { | |
413 | int n, fd; | |
414 | ev_fdmode mode; | |
415 | struct dynstr d[1]; | |
416 | char b[4096]; | |
417 | ||
418 | dynstr_init(d); | |
419 | for(mode = 0; mode < ev_nmodes; ++mode) { | |
420 | info("mode %s maxfd %d", modenames[mode], ev->mode[mode].maxfd); | |
421 | for(n = 0; n < ev->mode[mode].nfds; ++n) { | |
422 | fd = ev->mode[mode].fds[n].fd; | |
423 | info("fd %s %d%s%s (%s)", modenames[mode], fd, | |
424 | FD_ISSET(fd, &ev->mode[mode].enabled) ? " enabled" : "", | |
425 | FD_ISSET(fd, &ev->mode[mode].tripped) ? " tripped" : "", | |
426 | ev->mode[mode].fds[n].what); | |
427 | } | |
428 | d->nvec = 0; | |
429 | for(fd = 0; fd <= ev->mode[mode].maxfd; ++fd) { | |
430 | if(!FD_ISSET(fd, &ev->mode[mode].enabled)) | |
431 | continue; | |
432 | for(n = 0; n < ev->mode[mode].nfds; ++n) { | |
433 | if(ev->mode[mode].fds[n].fd == fd) | |
434 | break; | |
435 | } | |
436 | if(n < ev->mode[mode].nfds) | |
34a3e246 | 437 | snprintf(b, sizeof b, "%d(%s)", fd, ev->mode[mode].fds[n].what); |
768d7355 | 438 | else |
34a3e246 | 439 | snprintf(b, sizeof b, "%d", fd); |
768d7355 RK |
440 | dynstr_append(d, ' '); |
441 | dynstr_append_string(d, b); | |
442 | } | |
443 | dynstr_terminate(d); | |
444 | info("%s enabled:%s", modenames[mode], d->vec); | |
445 | } | |
446 | } | |
447 | ||
460b9539 | 448 | /* timeouts *******************************************************************/ |
449 | ||
768d7355 RK |
450 | /** @brief Register a timeout |
451 | * @param ev Event source | |
452 | * @param handle Where to store timeout handle, or @c NULL | |
453 | * @param when Earliest time to call @p callback, or @c NULL | |
454 | * @param callback Function to call at or after @p when | |
455 | * @param u Passed to @p callback | |
456 | * @return 0 on success, non-0 on error | |
457 | * | |
458 | * If @p when is a null pointer then a time of 0 is assumed. The effect is to | |
459 | * call the timeout handler from ev_run() next time around the event loop. | |
460 | * This is used internally to schedule various operations if it is not | |
461 | * convenient to call them from the current place in the call stack, or | |
462 | * externally to ensure that other clients of the event loop get a look in when | |
463 | * performing some lengthy operation. | |
464 | */ | |
460b9539 | 465 | int ev_timeout(ev_source *ev, |
466 | ev_timeout_handle *handlep, | |
467 | const struct timeval *when, | |
468 | ev_timeout_callback *callback, | |
469 | void *u) { | |
470 | struct timeout *t, *p, **pp; | |
471 | ||
472 | D(("registering timeout at %ld.%ld callback %p %p", | |
473 | when ? (long)when->tv_sec : 0, when ? (long)when->tv_usec : 0, | |
474 | (void *)callback, u)); | |
475 | t = xmalloc(sizeof *t); | |
476 | if(when) | |
477 | t->when = *when; | |
478 | t->callback = callback; | |
479 | t->u = u; | |
480 | pp = &ev->timeouts; | |
481 | while((p = *pp) && gt(&t->when, &p->when)) | |
482 | pp = &p->next; | |
483 | t->next = p; | |
484 | *pp = t; | |
485 | if(handlep) | |
486 | *handlep = t; | |
487 | return 0; | |
488 | } | |
489 | ||
768d7355 RK |
490 | /** @brief Cancel a timeout |
491 | * @param ev Event loop | |
492 | * @param handle Handle returned from ev_timeout() | |
493 | * @return 0 on success, non-0 on error | |
494 | */ | |
460b9539 | 495 | int ev_timeout_cancel(ev_source *ev, |
496 | ev_timeout_handle handle) { | |
497 | struct timeout *t = handle, *p, **pp; | |
498 | ||
499 | for(pp = &ev->timeouts; (p = *pp) && p != t; pp = &p->next) | |
500 | ; | |
501 | if(p) { | |
502 | *pp = p->next; | |
503 | return 0; | |
504 | } else | |
505 | return -1; | |
506 | } | |
507 | ||
508 | /* signals ********************************************************************/ | |
509 | ||
768d7355 RK |
510 | /** @brief Mapping of signals to pipe write ends |
511 | * | |
512 | * The pipes are per-event loop, it's possible in theory for there to be | |
513 | * multiple event loops (e.g. in different threads), although in fact DisOrder | |
514 | * does not do this. | |
515 | */ | |
460b9539 | 516 | static int sigfd[NSIG]; |
517 | ||
768d7355 RK |
518 | /** @brief The signal handler |
519 | * @param s Signal number | |
520 | * | |
521 | * Writes to @c sigfd[s]. | |
522 | */ | |
460b9539 | 523 | static void sighandler(int s) { |
524 | unsigned char sc = s; | |
525 | static const char errmsg[] = "error writing to signal pipe"; | |
526 | ||
527 | /* probably the reader has stopped listening for some reason */ | |
528 | if(write(sigfd[s], &sc, 1) < 0) { | |
529 | write(2, errmsg, sizeof errmsg - 1); | |
530 | abort(); | |
531 | } | |
532 | } | |
533 | ||
768d7355 | 534 | /** @brief Read callback for signals */ |
460b9539 | 535 | static int signal_read(ev_source *ev, |
536 | int attribute((unused)) fd, | |
537 | void attribute((unused)) *u) { | |
538 | unsigned char s; | |
539 | int n; | |
540 | int ret; | |
541 | ||
542 | if((n = read(ev->sigpipe[0], &s, 1)) == 1) | |
543 | if((ret = ev->signals[s].callback(ev, s, ev->signals[s].u))) | |
544 | return ret; | |
545 | assert(n != 0); | |
546 | if(n < 0 && (errno != EINTR && errno != EAGAIN)) { | |
547 | error(errno, "error reading from signal pipe %d", ev->sigpipe[0]); | |
548 | return -1; | |
549 | } | |
550 | return 0; | |
551 | } | |
552 | ||
768d7355 | 553 | /** @brief Close the signal pipe */ |
460b9539 | 554 | static void close_sigpipe(ev_source *ev) { |
555 | int save_errno = errno; | |
556 | ||
557 | xclose(ev->sigpipe[0]); | |
558 | xclose(ev->sigpipe[1]); | |
559 | ev->sigpipe[0] = ev->sigpipe[1] = -1; | |
560 | errno = save_errno; | |
561 | } | |
562 | ||
768d7355 RK |
563 | /** @brief Register a signal handler |
564 | * @param ev Event loop | |
565 | * @param sig Signal to handle | |
566 | * @param callback Called when signal is delivered | |
567 | * @param u Passed to @p callback | |
568 | * @return 0 on success, non-0 on error | |
569 | * | |
570 | * Note that @p callback is called from inside ev_run(), not from inside the | |
571 | * signal handler, so the usual restrictions on signal handlers do not apply. | |
572 | */ | |
460b9539 | 573 | int ev_signal(ev_source *ev, |
574 | int sig, | |
575 | ev_signal_callback *callback, | |
576 | void *u) { | |
577 | int n; | |
578 | struct sigaction sa; | |
579 | ||
580 | D(("registering signal %d handler callback %p %p", sig, (void *)callback, u)); | |
581 | assert(sig > 0); | |
582 | assert(sig < NSIG); | |
583 | assert(sig <= UCHAR_MAX); | |
584 | if(ev->sigpipe[0] == -1) { | |
585 | D(("creating signal pipe")); | |
586 | xpipe(ev->sigpipe); | |
587 | D(("signal pipe is %d, %d", ev->sigpipe[0], ev->sigpipe[1])); | |
588 | for(n = 0; n < 2; ++n) { | |
589 | nonblock(ev->sigpipe[n]); | |
590 | cloexec(ev->sigpipe[n]); | |
591 | } | |
e8c92ba7 | 592 | if(ev_fd(ev, ev_read, ev->sigpipe[0], signal_read, 0, "sigpipe read")) { |
460b9539 | 593 | close_sigpipe(ev); |
594 | return -1; | |
595 | } | |
596 | } | |
597 | sigaddset(&ev->sigmask, sig); | |
598 | xsigprocmask(SIG_BLOCK, &ev->sigmask, 0); | |
599 | sigfd[sig] = ev->sigpipe[1]; | |
600 | ev->signals[sig].callback = callback; | |
601 | ev->signals[sig].u = u; | |
602 | sa.sa_handler = sighandler; | |
603 | sigfillset(&sa.sa_mask); | |
604 | sa.sa_flags = SA_RESTART; | |
605 | xsigaction(sig, &sa, &ev->signals[sig].oldsa); | |
606 | ev->escape = 1; | |
607 | return 0; | |
608 | } | |
609 | ||
768d7355 RK |
610 | /** @brief Cancel a signal handler |
611 | * @param ev Event loop | |
612 | * @param sig Signal to cancel | |
613 | * @return 0 on success, non-0 on error | |
614 | */ | |
460b9539 | 615 | int ev_signal_cancel(ev_source *ev, |
616 | int sig) { | |
617 | sigset_t ss; | |
618 | ||
619 | xsigaction(sig, &ev->signals[sig].oldsa, 0); | |
620 | ev->signals[sig].callback = 0; | |
621 | ev->escape = 1; | |
622 | sigdelset(&ev->sigmask, sig); | |
623 | sigemptyset(&ss); | |
624 | sigaddset(&ss, sig); | |
625 | xsigprocmask(SIG_UNBLOCK, &ss, 0); | |
626 | return 0; | |
627 | } | |
628 | ||
768d7355 RK |
629 | /** @brief Clean up signal handling |
630 | * @param ev Event loop | |
631 | * | |
632 | * This function can be called from inside a fork. It restores signal | |
633 | * handlers, unblocks the signals, and closes the signal pipe for @p ev. | |
634 | */ | |
460b9539 | 635 | void ev_signal_atfork(ev_source *ev) { |
636 | int sig; | |
637 | ||
638 | if(ev->sigpipe[0] != -1) { | |
639 | /* revert any handled signals to their original state */ | |
640 | for(sig = 1; sig < NSIG; ++sig) { | |
641 | if(ev->signals[sig].callback != 0) | |
642 | xsigaction(sig, &ev->signals[sig].oldsa, 0); | |
643 | } | |
644 | /* and then unblock them */ | |
645 | xsigprocmask(SIG_UNBLOCK, &ev->sigmask, 0); | |
646 | /* don't want a copy of the signal pipe open inside the fork */ | |
647 | xclose(ev->sigpipe[0]); | |
648 | xclose(ev->sigpipe[1]); | |
649 | } | |
650 | } | |
651 | ||
652 | /* child processes ************************************************************/ | |
653 | ||
768d7355 | 654 | /** @brief Called on SIGCHLD */ |
460b9539 | 655 | static int sigchld_callback(ev_source *ev, |
656 | int attribute((unused)) sig, | |
657 | void attribute((unused)) *u) { | |
658 | struct rusage ru; | |
659 | pid_t r; | |
660 | int status, n, ret, revisit; | |
661 | ||
662 | do { | |
663 | revisit = 0; | |
664 | for(n = 0; n < ev->nchildren; ++n) { | |
665 | r = wait4(ev->children[n].pid, | |
666 | &status, | |
667 | ev->children[n].options | WNOHANG, | |
668 | &ru); | |
669 | if(r > 0) { | |
670 | ev_child_callback *c = ev->children[n].callback; | |
671 | void *cu = ev->children[n].u; | |
672 | ||
673 | if(WIFEXITED(status) || WIFSIGNALED(status)) | |
674 | ev_child_cancel(ev, r); | |
675 | revisit = 1; | |
676 | if((ret = c(ev, r, status, &ru, cu))) | |
677 | return ret; | |
678 | } else if(r < 0) { | |
679 | /* We should "never" get an ECHILD but it can in fact happen. For | |
680 | * instance on Linux 2.4.31, and probably other versions, if someone | |
681 | * straces a child process and then a different child process | |
682 | * terminates, when we wait4() the trace process we will get ECHILD | |
683 | * because it has been reparented to strace. Obviously this is a | |
684 | * hopeless design flaw in the tracing infrastructure, but we don't | |
685 | * want the disorder server to bomb out because of it. So we just log | |
686 | * the problem and ignore it. | |
687 | */ | |
688 | error(errno, "error calling wait4 for PID %lu (broken ptrace?)", | |
689 | (unsigned long)ev->children[n].pid); | |
690 | if(errno != ECHILD) | |
691 | return -1; | |
692 | } | |
693 | } | |
694 | } while(revisit); | |
695 | return 0; | |
696 | } | |
697 | ||
768d7355 RK |
698 | /** @brief Configure event loop for child process handling |
699 | * @return 0 on success, non-0 on error | |
700 | * | |
701 | * Currently at most one event loop can handle child processes and it must be | |
702 | * distinguished from others by calling this function on it. This could be | |
703 | * fixed but since no process ever makes use of more than one event loop there | |
704 | * is no need. | |
705 | */ | |
460b9539 | 706 | int ev_child_setup(ev_source *ev) { |
707 | D(("installing SIGCHLD handler")); | |
708 | return ev_signal(ev, SIGCHLD, sigchld_callback, 0); | |
709 | } | |
710 | ||
768d7355 RK |
711 | /** @brief Wait for a child process to terminate |
712 | * @param ev Event loop | |
713 | * @param pid Process ID of child | |
714 | * @param options Options to pass to @c wait4() | |
715 | * @param callback Called when child terminates (or possibly when it stops) | |
716 | * @param u Passed to @p callback | |
717 | * @return 0 on success, non-0 on error | |
718 | * | |
719 | * You must have called ev_child_setup() on @p ev once first. | |
720 | */ | |
460b9539 | 721 | int ev_child(ev_source *ev, |
722 | pid_t pid, | |
723 | int options, | |
724 | ev_child_callback *callback, | |
725 | void *u) { | |
726 | int n; | |
727 | ||
728 | D(("registering child handling %ld options %d callback %p %p", | |
729 | (long)pid, options, (void *)callback, u)); | |
730 | assert(ev->signals[SIGCHLD].callback == sigchld_callback); | |
731 | if(ev->nchildren >= ev->nchildslots) { | |
732 | ev->nchildslots = ev->nchildslots ? 2 * ev->nchildslots : 16; | |
733 | ev->children = xrealloc(ev->children, | |
734 | ev->nchildslots * sizeof (struct child)); | |
735 | } | |
736 | n = ev->nchildren++; | |
737 | ev->children[n].pid = pid; | |
738 | ev->children[n].options = options; | |
739 | ev->children[n].callback = callback; | |
740 | ev->children[n].u = u; | |
741 | return 0; | |
742 | } | |
743 | ||
768d7355 RK |
744 | /** @brief Stop waiting for a child process |
745 | * @param ev Event loop | |
746 | * @param pid Child process ID | |
747 | * @return 0 on success, non-0 on error | |
748 | */ | |
460b9539 | 749 | int ev_child_cancel(ev_source *ev, |
750 | pid_t pid) { | |
751 | int n; | |
752 | ||
753 | for(n = 0; n < ev->nchildren && ev->children[n].pid != pid; ++n) | |
754 | ; | |
755 | assert(n < ev->nchildren); | |
756 | if(n != ev->nchildren - 1) | |
757 | ev->children[n] = ev->children[ev->nchildren - 1]; | |
758 | --ev->nchildren; | |
759 | return 0; | |
760 | } | |
761 | ||
762 | /* socket listeners ***********************************************************/ | |
763 | ||
768d7355 | 764 | /** @brief State for a socket listener */ |
460b9539 | 765 | struct listen_state { |
766 | ev_listen_callback *callback; | |
767 | void *u; | |
768 | }; | |
769 | ||
768d7355 | 770 | /** @brief Called when a listenign socket is readable */ |
460b9539 | 771 | static int listen_callback(ev_source *ev, int fd, void *u) { |
772 | const struct listen_state *l = u; | |
773 | int newfd; | |
774 | union { | |
775 | struct sockaddr_in in; | |
776 | #if HAVE_STRUCT_SOCKADDR_IN6 | |
777 | struct sockaddr_in6 in6; | |
778 | #endif | |
779 | struct sockaddr_un un; | |
780 | struct sockaddr sa; | |
781 | } addr; | |
782 | socklen_t addrlen; | |
783 | int ret; | |
784 | ||
785 | D(("callback for listener fd %d", fd)); | |
786 | while((addrlen = sizeof addr), | |
787 | (newfd = accept(fd, &addr.sa, &addrlen)) >= 0) { | |
788 | if((ret = l->callback(ev, newfd, &addr.sa, addrlen, l->u))) | |
789 | return ret; | |
790 | } | |
791 | switch(errno) { | |
792 | case EINTR: | |
793 | case EAGAIN: | |
794 | break; | |
795 | #ifdef ECONNABORTED | |
796 | case ECONNABORTED: | |
797 | error(errno, "error calling accept"); | |
798 | break; | |
799 | #endif | |
800 | #ifdef EPROTO | |
801 | case EPROTO: | |
802 | /* XXX on some systems EPROTO should be fatal, but we don't know if | |
803 | * we're running on one of them */ | |
804 | error(errno, "error calling accept"); | |
805 | break; | |
806 | #endif | |
807 | default: | |
808 | fatal(errno, "error calling accept"); | |
809 | break; | |
810 | } | |
811 | if(errno != EINTR && errno != EAGAIN) | |
812 | error(errno, "error calling accept"); | |
813 | return 0; | |
814 | } | |
815 | ||
768d7355 RK |
816 | /** @brief Listen on a socket for inbound stream connections |
817 | * @param ev Event source | |
818 | * @param fd File descriptor of socket | |
819 | * @param callback Called when a new connection arrives | |
820 | * @param u Passed to @p callback | |
821 | * @param what Text description of socket | |
822 | * @return 0 on success, non-0 on error | |
823 | */ | |
460b9539 | 824 | int ev_listen(ev_source *ev, |
825 | int fd, | |
826 | ev_listen_callback *callback, | |
e8c92ba7 RK |
827 | void *u, |
828 | const char *what) { | |
460b9539 | 829 | struct listen_state *l = xmalloc(sizeof *l); |
830 | ||
831 | D(("registering listener fd %d callback %p %p", fd, (void *)callback, u)); | |
832 | l->callback = callback; | |
833 | l->u = u; | |
e8c92ba7 | 834 | return ev_fd(ev, ev_read, fd, listen_callback, l, what); |
460b9539 | 835 | } |
836 | ||
768d7355 RK |
837 | /** @brief Stop listening on a socket |
838 | * @param ev Event loop | |
839 | * @param fd File descriptor of socket | |
840 | * @return 0 on success, non-0 on error | |
841 | */ | |
460b9539 | 842 | int ev_listen_cancel(ev_source *ev, int fd) { |
843 | D(("cancelling listener fd %d", fd)); | |
844 | return ev_fd_cancel(ev, ev_read, fd); | |
845 | } | |
846 | ||
847 | /* buffer *********************************************************************/ | |
848 | ||
768d7355 | 849 | /** @brief Buffer structure */ |
460b9539 | 850 | struct buffer { |
851 | char *base, *start, *end, *top; | |
852 | }; | |
853 | ||
768d7355 | 854 | /* @brief Make sure there is @p bytes available at @c b->end */ |
460b9539 | 855 | static void buffer_space(struct buffer *b, size_t bytes) { |
856 | D(("buffer_space %p %p %p %p want %lu", | |
857 | (void *)b->base, (void *)b->start, (void *)b->end, (void *)b->top, | |
858 | (unsigned long)bytes)); | |
859 | if(b->start == b->end) | |
860 | b->start = b->end = b->base; | |
861 | if((size_t)(b->top - b->end) < bytes) { | |
862 | if((size_t)((b->top - b->end) + (b->start - b->base)) < bytes) { | |
863 | size_t newspace = b->end - b->start + bytes, n; | |
864 | char *newbase; | |
865 | ||
866 | for(n = 16; n < newspace; n *= 2) | |
867 | ; | |
868 | newbase = xmalloc_noptr(n); | |
869 | memcpy(newbase, b->start, b->end - b->start); | |
870 | b->base = newbase; | |
871 | b->end = newbase + (b->end - b->start); | |
872 | b->top = newbase + n; | |
873 | b->start = newbase; /* must be last */ | |
874 | } else { | |
875 | memmove(b->base, b->start, b->end - b->start); | |
876 | b->end = b->base + (b->end - b->start); | |
877 | b->start = b->base; | |
878 | } | |
879 | } | |
880 | D(("result %p %p %p %p", | |
881 | (void *)b->base, (void *)b->start, (void *)b->end, (void *)b->top)); | |
882 | } | |
883 | ||
884 | /* buffered writer ************************************************************/ | |
885 | ||
768d7355 | 886 | /** @brief State structure for a buffered writer */ |
460b9539 | 887 | struct ev_writer { |
888 | struct sink s; | |
889 | struct buffer b; | |
890 | int fd; | |
891 | int eof; | |
892 | ev_error_callback *callback; | |
893 | void *u; | |
894 | ev_source *ev; | |
895 | }; | |
896 | ||
768d7355 | 897 | /** @brief Called when a writer's file descriptor is writable */ |
460b9539 | 898 | static int writer_callback(ev_source *ev, int fd, void *u) { |
899 | ev_writer *w = u; | |
900 | int n; | |
901 | ||
902 | n = write(fd, w->b.start, w->b.end - w->b.start); | |
903 | D(("callback for writer fd %d, %ld bytes, n=%d, errno=%d", | |
904 | fd, (long)(w->b.end - w->b.start), n, errno)); | |
905 | if(n >= 0) { | |
906 | w->b.start += n; | |
907 | if(w->b.start == w->b.end) { | |
908 | if(w->eof) { | |
909 | ev_fd_cancel(ev, ev_write, fd); | |
910 | return w->callback(ev, fd, 0, w->u); | |
911 | } else | |
912 | ev_fd_disable(ev, ev_write, fd); | |
913 | } | |
914 | } else { | |
915 | switch(errno) { | |
916 | case EINTR: | |
917 | case EAGAIN: | |
918 | break; | |
919 | default: | |
920 | ev_fd_cancel(ev, ev_write, fd); | |
921 | return w->callback(ev, fd, errno, w->u); | |
922 | } | |
923 | } | |
924 | return 0; | |
925 | } | |
926 | ||
768d7355 RK |
927 | /** @brief Write bytes to a writer's buffer |
928 | * | |
929 | * This is the sink write callback. | |
930 | * | |
931 | * Calls ev_fd_enable() if necessary (i.e. if the buffer was empty but | |
932 | * now is not). | |
933 | */ | |
460b9539 | 934 | static int ev_writer_write(struct sink *sk, const void *s, int n) { |
935 | ev_writer *w = (ev_writer *)sk; | |
936 | ||
937 | buffer_space(&w->b, n); | |
938 | if(w->b.start == w->b.end) | |
939 | ev_fd_enable(w->ev, ev_write, w->fd); | |
940 | memcpy(w->b.end, s, n); | |
941 | w->b.end += n; | |
942 | return 0; | |
943 | } | |
944 | ||
768d7355 RK |
945 | /** @brief Create a new buffered writer |
946 | * @param ev Event loop | |
947 | * @param fd File descriptor to write to | |
948 | * @param callback Called if an error occurs and when finished | |
949 | * @param u Passed to @p callback | |
950 | * @param what Text description | |
951 | * @return New writer or @c NULL | |
952 | */ | |
460b9539 | 953 | ev_writer *ev_writer_new(ev_source *ev, |
954 | int fd, | |
955 | ev_error_callback *callback, | |
e8c92ba7 RK |
956 | void *u, |
957 | const char *what) { | |
460b9539 | 958 | ev_writer *w = xmalloc(sizeof *w); |
959 | ||
960 | D(("registering writer fd %d callback %p %p", fd, (void *)callback, u)); | |
961 | w->s.write = ev_writer_write; | |
962 | w->fd = fd; | |
963 | w->callback = callback; | |
964 | w->u = u; | |
965 | w->ev = ev; | |
e8c92ba7 | 966 | if(ev_fd(ev, ev_write, fd, writer_callback, w, what)) |
460b9539 | 967 | return 0; |
968 | ev_fd_disable(ev, ev_write, fd); | |
969 | return w; | |
970 | } | |
971 | ||
768d7355 RK |
972 | /** @brief Return the sink associated with a writer |
973 | * @param w Writer | |
974 | * @return Pointer to sink | |
975 | * | |
976 | * Writing to the sink will arrange for those bytes to be written to the file | |
977 | * descriptor as and when it is writable. | |
978 | */ | |
460b9539 | 979 | struct sink *ev_writer_sink(ev_writer *w) { |
980 | return &w->s; | |
981 | } | |
982 | ||
768d7355 RK |
983 | /** @brief Shutdown callback |
984 | * | |
985 | * See ev_writer_close(). | |
986 | */ | |
460b9539 | 987 | static int writer_shutdown(ev_source *ev, |
988 | const attribute((unused)) struct timeval *now, | |
989 | void *u) { | |
990 | ev_writer *w = u; | |
991 | ||
992 | return w->callback(ev, w->fd, 0, w->u); | |
993 | } | |
994 | ||
768d7355 RK |
995 | /** @brief Close a writer |
996 | * @param w Writer to close | |
997 | * @return 0 on success, non-0 on error | |
998 | * | |
999 | * Close a writer. No more bytes should be written to its sink. | |
1000 | * | |
1001 | * When the last byte has been written the callback will be called with an | |
1002 | * error code of 0. It is guaranteed that this will NOT happen before | |
1003 | * ev_writer_close() returns (although the file descriptor for the writer might | |
1004 | * be cancelled by the time it returns). | |
1005 | */ | |
460b9539 | 1006 | int ev_writer_close(ev_writer *w) { |
1007 | D(("close writer fd %d", w->fd)); | |
1008 | w->eof = 1; | |
1009 | if(w->b.start == w->b.end) { | |
1010 | /* we're already finished */ | |
1011 | ev_fd_cancel(w->ev, ev_write, w->fd); | |
1012 | return ev_timeout(w->ev, 0, 0, writer_shutdown, w); | |
1013 | } | |
1014 | return 0; | |
1015 | } | |
1016 | ||
768d7355 RK |
1017 | /** @brief Cancel a writer discarding any buffered data |
1018 | * @param w Writer to close | |
1019 | * @return 0 on success, non-0 on error | |
1020 | * | |
1021 | * This cancels a writer immediately. Any unwritten buffered data is discarded | |
1022 | * and the error callback is never called. This is appropriate to call if (for | |
1023 | * instance) the read half of a TCP connection is known to have failed and the | |
1024 | * writer is therefore obsolete. | |
1025 | */ | |
460b9539 | 1026 | int ev_writer_cancel(ev_writer *w) { |
1027 | D(("cancel writer fd %d", w->fd)); | |
1028 | return ev_fd_cancel(w->ev, ev_write, w->fd); | |
1029 | } | |
1030 | ||
768d7355 RK |
1031 | /** @brief Attempt to flush a writer |
1032 | * @param w Writer to flush | |
1033 | * @return 0 on success, non-0 on error | |
1034 | * | |
1035 | * Does a speculative write of any buffered data. Does not block if it cannot | |
1036 | * be written. | |
1037 | */ | |
460b9539 | 1038 | int ev_writer_flush(ev_writer *w) { |
1039 | return writer_callback(w->ev, w->fd, w); | |
1040 | } | |
1041 | ||
1042 | /* buffered reader ************************************************************/ | |
1043 | ||
768d7355 | 1044 | /** @brief State structure for a buffered reader */ |
460b9539 | 1045 | struct ev_reader { |
1046 | struct buffer b; | |
1047 | int fd; | |
1048 | ev_reader_callback *callback; | |
1049 | ev_error_callback *error_callback; | |
1050 | void *u; | |
1051 | ev_source *ev; | |
1052 | int eof; | |
1053 | }; | |
1054 | ||
768d7355 | 1055 | /** @brief Called when a reader's @p fd is readable */ |
460b9539 | 1056 | static int reader_callback(ev_source *ev, int fd, void *u) { |
1057 | ev_reader *r = u; | |
1058 | int n; | |
1059 | ||
1060 | buffer_space(&r->b, 1); | |
1061 | n = read(fd, r->b.end, r->b.top - r->b.end); | |
1062 | D(("read fd %d buffer %d returned %d errno %d", | |
1063 | fd, (int)(r->b.top - r->b.end), n, errno)); | |
1064 | if(n > 0) { | |
1065 | r->b.end += n; | |
1066 | return r->callback(ev, r, fd, r->b.start, r->b.end - r->b.start, 0, r->u); | |
1067 | } else if(n == 0) { | |
1068 | r->eof = 1; | |
1069 | ev_fd_cancel(ev, ev_read, fd); | |
1070 | return r->callback(ev, r, fd, r->b.start, r->b.end - r->b.start, 1, r->u); | |
1071 | } else { | |
1072 | switch(errno) { | |
1073 | case EINTR: | |
1074 | case EAGAIN: | |
1075 | break; | |
1076 | default: | |
1077 | ev_fd_cancel(ev, ev_read, fd); | |
1078 | return r->error_callback(ev, fd, errno, r->u); | |
1079 | } | |
1080 | } | |
1081 | return 0; | |
1082 | } | |
1083 | ||
768d7355 RK |
1084 | /** @brief Create a new buffered reader |
1085 | * @param ev Event loop | |
1086 | * @param fd File descriptor to read from | |
1087 | * @param callback Called when new data is available | |
1088 | * @param error_callback Called if an error occurs | |
1089 | * @param u Passed to callbacks | |
1090 | * @param what Text description | |
1091 | * @return New reader or @c NULL | |
1092 | */ | |
460b9539 | 1093 | ev_reader *ev_reader_new(ev_source *ev, |
1094 | int fd, | |
1095 | ev_reader_callback *callback, | |
1096 | ev_error_callback *error_callback, | |
e8c92ba7 RK |
1097 | void *u, |
1098 | const char *what) { | |
460b9539 | 1099 | ev_reader *r = xmalloc(sizeof *r); |
1100 | ||
1101 | D(("registering reader fd %d callback %p %p %p", | |
1102 | fd, (void *)callback, (void *)error_callback, u)); | |
1103 | r->fd = fd; | |
1104 | r->callback = callback; | |
1105 | r->error_callback = error_callback; | |
1106 | r->u = u; | |
1107 | r->ev = ev; | |
e8c92ba7 | 1108 | if(ev_fd(ev, ev_read, fd, reader_callback, r, what)) |
460b9539 | 1109 | return 0; |
1110 | return r; | |
1111 | } | |
1112 | ||
1113 | void ev_reader_buffer(ev_reader *r, size_t nbytes) { | |
1114 | buffer_space(&r->b, nbytes - (r->b.end - r->b.start)); | |
1115 | } | |
1116 | ||
768d7355 RK |
1117 | /** @brief Consume @p n bytes from the reader's buffer |
1118 | * @param r Reader | |
1119 | * @param n Number of bytes to consume | |
1120 | * | |
1121 | * Tells the reader than the next @p n bytes have been dealt with and can now | |
1122 | * be discarded. | |
1123 | */ | |
460b9539 | 1124 | void ev_reader_consume(ev_reader *r, size_t n) { |
1125 | r->b.start += n; | |
1126 | } | |
1127 | ||
768d7355 RK |
1128 | /** @brief Cancel a reader |
1129 | * @param r Reader | |
1130 | * @return 0 on success, non-0 on error | |
1131 | */ | |
460b9539 | 1132 | int ev_reader_cancel(ev_reader *r) { |
1133 | D(("cancel reader fd %d", r->fd)); | |
1134 | return ev_fd_cancel(r->ev, ev_read, r->fd); | |
1135 | } | |
1136 | ||
768d7355 RK |
1137 | /** @brief Temporarily disable a reader |
1138 | * @param r Reader | |
1139 | * @return 0 on success, non-0 on error | |
1140 | * | |
1141 | * No further callbacks for this reader will be made. Re-enable with | |
1142 | * ev_reader_enable(). | |
1143 | */ | |
460b9539 | 1144 | int ev_reader_disable(ev_reader *r) { |
1145 | D(("disable reader fd %d", r->fd)); | |
1146 | return r->eof ? 0 : ev_fd_disable(r->ev, ev_read, r->fd); | |
1147 | } | |
1148 | ||
768d7355 | 1149 | /** @brief Called from ev_run() for ev_reader_incomplete() */ |
460b9539 | 1150 | static int reader_continuation(ev_source attribute((unused)) *ev, |
1151 | const attribute((unused)) struct timeval *now, | |
1152 | void *u) { | |
1153 | ev_reader *r = u; | |
1154 | ||
1155 | D(("reader continuation callback fd %d", r->fd)); | |
1156 | if(ev_fd_enable(r->ev, ev_read, r->fd)) return -1; | |
1157 | return r->callback(ev, r, r->fd, r->b.start, r->b.end - r->b.start, r->eof, r->u); | |
1158 | } | |
1159 | ||
768d7355 RK |
1160 | /** @brief Arrange another callback |
1161 | * @param r reader | |
1162 | * @return 0 on success, non-0 on error | |
1163 | * | |
1164 | * Indicates that the reader can process more input but would like to yield to | |
1165 | * other clients of the event loop. Input will be disabled but it will be | |
1166 | * re-enabled on the next iteration of the event loop and the read callback | |
1167 | * will be called again (even if no further bytes are available). | |
1168 | */ | |
460b9539 | 1169 | int ev_reader_incomplete(ev_reader *r) { |
1170 | if(ev_fd_disable(r->ev, ev_read, r->fd)) return -1; | |
1171 | return ev_timeout(r->ev, 0, 0, reader_continuation, r); | |
1172 | } | |
1173 | ||
1174 | static int reader_enabled(ev_source *ev, | |
1175 | const attribute((unused)) struct timeval *now, | |
1176 | void *u) { | |
1177 | ev_reader *r = u; | |
1178 | ||
1179 | D(("reader enabled callback fd %d", r->fd)); | |
1180 | return r->callback(ev, r, r->fd, r->b.start, r->b.end - r->b.start, r->eof, r->u); | |
1181 | } | |
1182 | ||
768d7355 RK |
1183 | /** @brief Re-enable reading |
1184 | * @param r reader | |
1185 | * @return 0 on success, non-0 on error | |
1186 | * | |
1187 | * If there is unconsumed data then you get a callback next time round the | |
1188 | * event loop even if nothing new has been read. | |
1189 | * | |
1190 | * The idea is in your read callback you come across a line (or whatever) that | |
1191 | * can't be processed immediately. So you set up processing and disable | |
1192 | * reading with ev_reader_disable(). Later when you finish processing you | |
1193 | * re-enable. You'll automatically get another callback directly from the | |
1194 | * event loop (i.e. not from inside ev_reader_enable()) so you can handle the | |
1195 | * next line (or whatever) if the whole thing has in fact already arrived. | |
1196 | */ | |
460b9539 | 1197 | int ev_reader_enable(ev_reader *r) { |
1198 | D(("enable reader fd %d", r->fd)); | |
1199 | return ((r->eof ? 0 : ev_fd_enable(r->ev, ev_read, r->fd)) | |
1200 | || ev_timeout(r->ev, 0, 0, reader_enabled, r)) ? -1 : 0; | |
1201 | } | |
1202 | ||
1203 | /* | |
1204 | Local Variables: | |
1205 | c-basic-offset:2 | |
1206 | comment-column:40 | |
1207 | fill-column:79 | |
1208 | End: | |
1209 | */ |