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f7deaa1a | 1 | /* |
61515785 | 2 | * "$Id: select.c 11142 2013-07-17 01:07:00Z msweet $" |
f7deaa1a | 3 | * |
10d09e33 | 4 | * Select abstraction functions for the CUPS scheduler. |
f7deaa1a | 5 | * |
990c79d2 | 6 | * Copyright 2007-2013 by Apple Inc. |
f899b121 | 7 | * Copyright 2006-2007 by Easy Software Products. |
f7deaa1a | 8 | * |
9 | * These coded instructions, statements, and computer programs are the | |
bc44d920 | 10 | * property of Apple Inc. and are protected by Federal copyright |
11 | * law. Distribution and use rights are outlined in the file "LICENSE.txt" | |
12 | * which should have been included with this file. If this file is | |
13 | * file is missing or damaged, see the license at "http://www.cups.org/". | |
f7deaa1a | 14 | * |
15 | * Contents: | |
16 | * | |
17 | * cupsdAddSelect() - Add a file descriptor to the list. | |
18 | * cupsdDoSelect() - Do a select-like operation. | |
19 | * cupsdIsSelecting() - Determine whether we are monitoring a file | |
20 | * descriptor. | |
21 | * cupsdRemoveSelect() - Remove a file descriptor from the list. | |
22 | * cupsdStartSelect() - Initialize the file polling engine. | |
23 | * cupsdStopSelect() - Shutdown the file polling engine. | |
24 | * compare_fds() - Compare file descriptors. | |
25 | * find_fd() - Find an existing file descriptor record. | |
26 | */ | |
27 | ||
28 | /* | |
29 | * Include necessary headers... | |
30 | */ | |
31 | ||
32 | #include "cupsd.h" | |
33 | ||
34 | #ifdef HAVE_EPOLL | |
35 | # include <sys/epoll.h> | |
dcb445bc | 36 | # include <poll.h> |
f7deaa1a | 37 | #elif defined(HAVE_KQUEUE) |
38 | # include <sys/event.h> | |
39 | # include <sys/time.h> | |
40 | #elif defined(HAVE_POLL) | |
dcb445bc | 41 | # include <poll.h> |
f7deaa1a | 42 | #elif defined(__hpux) |
43 | # include <sys/time.h> | |
44 | #else | |
45 | # include <sys/select.h> | |
46 | #endif /* HAVE_EPOLL */ | |
47 | ||
48 | ||
49 | /* | |
50 | * Design Notes for Poll/Select API in CUPSD | |
51 | * ----------------------------------------- | |
3dd9c340 | 52 | * |
f7deaa1a | 53 | * SUPPORTED APIS |
3dd9c340 | 54 | * |
f7deaa1a | 55 | * OS select poll epoll kqueue /dev/poll |
56 | * -------------- ------ ------ ------ ------ --------- | |
57 | * AIX YES YES NO NO NO | |
58 | * FreeBSD YES YES NO YES NO | |
59 | * HP-UX YES YES NO NO NO | |
f7deaa1a | 60 | * Linux YES YES YES NO NO |
61 | * MacOS X YES YES NO YES NO | |
62 | * NetBSD YES YES NO YES NO | |
63 | * OpenBSD YES YES NO YES NO | |
64 | * Solaris YES YES NO NO YES | |
65 | * Tru64 YES YES NO NO NO | |
66 | * Windows YES NO NO NO NO | |
3dd9c340 MS |
67 | * |
68 | * | |
f7deaa1a | 69 | * HIGH-LEVEL API |
3dd9c340 | 70 | * |
f7deaa1a | 71 | * typedef void (*cupsd_selfunc_t)(void *data); |
3dd9c340 | 72 | * |
f7deaa1a | 73 | * void cupsdStartSelect(void); |
74 | * void cupsdStopSelect(void); | |
75 | * void cupsdAddSelect(int fd, cupsd_selfunc_t read_cb, | |
76 | * cupsd_selfunc_t write_cb, void *data); | |
77 | * void cupsdRemoveSelect(int fd); | |
78 | * int cupsdDoSelect(int timeout); | |
3dd9c340 MS |
79 | * |
80 | * | |
f7deaa1a | 81 | * IMPLEMENTATION STRATEGY |
3dd9c340 | 82 | * |
f7deaa1a | 83 | * 0. Common Stuff |
84 | * a. CUPS array of file descriptor to callback functions | |
c0e1af83 | 85 | * and data + temporary array of removed fd's. |
86 | * b. cupsdStartSelect() creates the arrays | |
87 | * c. cupsdStopSelect() destroys the arrays and all elements. | |
f7deaa1a | 88 | * d. cupsdAddSelect() adds to the array and allocates a |
89 | * new callback element. | |
c0e1af83 | 90 | * e. cupsdRemoveSelect() removes from the active array and |
91 | * adds to the inactive array. | |
f7deaa1a | 92 | * f. _cupsd_fd_t provides a reference-counted structure for |
93 | * tracking file descriptors that are monitored. | |
c0e1af83 | 94 | * g. cupsdDoSelect() frees all inactive FDs. |
95 | * | |
f7deaa1a | 96 | * 1. select() O(n) |
97 | * a. Input/Output fd_set variables, copied to working | |
98 | * copies and then used with select(). | |
99 | * b. Loop through CUPS array, using FD_ISSET and calling | |
100 | * the read/write callbacks as needed. | |
101 | * c. cupsdRemoveSelect() clears fd_set bit from main and | |
102 | * working sets. | |
103 | * d. cupsdStopSelect() frees all of the memory used by the | |
104 | * CUPS array and fd_set's. | |
3dd9c340 | 105 | * |
f7deaa1a | 106 | * 2. poll() - O(n log n) |
107 | * a. Regular array of pollfd, sorted the same as the CUPS | |
108 | * array. | |
109 | * b. Loop through pollfd array, call the corresponding | |
110 | * read/write callbacks as needed. | |
111 | * c. cupsdAddSelect() adds first to CUPS array and flags the | |
112 | * pollfd array as invalid. | |
113 | * d. cupsdDoSelect() rebuilds pollfd array as needed, calls | |
114 | * poll(), then loops through the pollfd array looking up | |
115 | * as needed. | |
116 | * e. cupsdRemoveSelect() flags the pollfd array as invalid. | |
117 | * f. cupsdStopSelect() frees all of the memory used by the | |
118 | * CUPS array and pollfd array. | |
3dd9c340 | 119 | * |
f7deaa1a | 120 | * 3. epoll() - O(n) |
121 | * a. cupsdStartSelect() creates epoll file descriptor using | |
122 | * epoll_create() with the maximum fd count, and | |
123 | * allocates an events buffer for the maximum fd count. | |
124 | * b. cupsdAdd/RemoveSelect() uses epoll_ctl() to add | |
125 | * (EPOLL_CTL_ADD) or remove (EPOLL_CTL_DEL) a single | |
126 | * event using the level-triggered semantics. The event | |
127 | * user data field is a pointer to the new callback array | |
128 | * element. | |
129 | * c. cupsdDoSelect() uses epoll_wait() with the global event | |
130 | * buffer allocated in cupsdStartSelect() and then loops | |
131 | * through the events, using the user data field to find | |
132 | * the callback record. | |
133 | * d. cupsdStopSelect() closes the epoll file descriptor and | |
134 | * frees all of the memory used by the event buffer. | |
3dd9c340 | 135 | * |
f7deaa1a | 136 | * 4. kqueue() - O(n) |
137 | * b. cupsdStartSelect() creates kqueue file descriptor | |
41681883 | 138 | * using kqueue() function and allocates a global event |
f7deaa1a | 139 | * buffer. |
140 | * c. cupsdAdd/RemoveSelect() uses EV_SET and kevent() to | |
141 | * register the changes. The event user data field is a | |
142 | * pointer to the new callback array element. | |
143 | * d. cupsdDoSelect() uses kevent() to poll for events and | |
144 | * loops through the events, using the user data field to | |
145 | * find the callback record. | |
41681883 | 146 | * e. cupsdStopSelect() closes the kqueue() file descriptor |
f7deaa1a | 147 | * and frees all of the memory used by the event buffer. |
3dd9c340 | 148 | * |
f7deaa1a | 149 | * 5. /dev/poll - O(n log n) - NOT YET IMPLEMENTED |
150 | * a. cupsdStartSelect() opens /dev/poll and allocates an | |
151 | * array of pollfd structs; on failure to open /dev/poll, | |
152 | * revert to poll() system call. | |
153 | * b. cupsdAddSelect() writes a single pollfd struct to | |
154 | * /dev/poll with the new file descriptor and the | |
155 | * POLLIN/POLLOUT flags. | |
156 | * c. cupsdRemoveSelect() writes a single pollfd struct to | |
157 | * /dev/poll with the file descriptor and the POLLREMOVE | |
158 | * flag. | |
159 | * d. cupsdDoSelect() uses the DP_POLL ioctl to retrieve | |
160 | * events from /dev/poll and then loops through the | |
161 | * returned pollfd array, looking up the file descriptors | |
162 | * as needed. | |
163 | * e. cupsdStopSelect() closes /dev/poll and frees the | |
164 | * pollfd array. | |
165 | * | |
166 | * PERFORMANCE | |
167 | * | |
168 | * In tests using the "make test" target with option 0 (keep cupsd | |
169 | * running) and the "testspeed" program with "-c 50 -r 1000", epoll() | |
0a682745 MS |
170 | * performed 5.5% slower than select(), followed by kqueue() at 16% |
171 | * slower than select() and poll() at 18% slower than select(). Similar | |
f7deaa1a | 172 | * results were seen with twice the number of client connections. |
173 | * | |
174 | * The epoll() and kqueue() performance is likely limited by the | |
175 | * number of system calls used to add/modify/remove file | |
176 | * descriptors dynamically. Further optimizations may be possible | |
177 | * in the area of limiting use of cupsdAddSelect() and | |
178 | * cupsdRemoveSelect(), however extreme care will be needed to avoid | |
179 | * excess CPU usage and deadlock conditions. | |
180 | * | |
181 | * We may be able to improve the poll() implementation simply by | |
182 | * keeping the pollfd array sync'd with the _cupsd_fd_t array, as that | |
183 | * will eliminate the rebuilding of the array whenever there is a | |
184 | * change and eliminate the fd array lookups in the inner loop of | |
185 | * cupsdDoSelect(). | |
186 | * | |
187 | * Since /dev/poll will never be able to use a shadow array, it may | |
188 | * not make sense to implement support for it. ioctl() overhead will | |
189 | * impact performance as well, so my guess would be that, for CUPS, | |
190 | * /dev/poll will yield a net performance loss. | |
191 | */ | |
192 | ||
193 | /* | |
194 | * Local structures... | |
195 | */ | |
196 | ||
197 | typedef struct _cupsd_fd_s | |
198 | { | |
199 | int fd, /* File descriptor */ | |
200 | use; /* Use count */ | |
201 | cupsd_selfunc_t read_cb, /* Read callback */ | |
202 | write_cb; /* Write callback */ | |
203 | void *data; /* Data pointer for callbacks */ | |
204 | } _cupsd_fd_t; | |
205 | ||
206 | ||
207 | /* | |
208 | * Local globals... | |
209 | */ | |
210 | ||
211 | static cups_array_t *cupsd_fds = NULL; | |
c0e1af83 | 212 | #if defined(HAVE_EPOLL) || defined(HAVE_KQUEUE) |
213 | static cups_array_t *cupsd_inactive_fds = NULL; | |
214 | static int cupsd_in_select = 0; | |
215 | #endif /* HAVE_EPOLL || HAVE_KQUEUE */ | |
f7deaa1a | 216 | |
0a682745 | 217 | #ifdef HAVE_KQUEUE |
f7deaa1a | 218 | static int cupsd_kqueue_fd = -1, |
219 | cupsd_kqueue_changes = 0; | |
220 | static struct kevent *cupsd_kqueue_events = NULL; | |
221 | #elif defined(HAVE_POLL) | |
222 | static int cupsd_alloc_pollfds = 0, | |
223 | cupsd_update_pollfds = 0; | |
224 | static struct pollfd *cupsd_pollfds = NULL; | |
0a682745 MS |
225 | # ifdef HAVE_EPOLL |
226 | static int cupsd_epoll_fd = -1; | |
227 | static struct epoll_event *cupsd_epoll_events = NULL; | |
228 | # endif /* HAVE_EPOLL */ | |
f7deaa1a | 229 | #else /* select() */ |
230 | static fd_set cupsd_global_input, | |
231 | cupsd_global_output, | |
232 | cupsd_current_input, | |
233 | cupsd_current_output; | |
0a682745 | 234 | #endif /* HAVE_KQUEUE */ |
f7deaa1a | 235 | |
236 | ||
237 | /* | |
238 | * Local functions... | |
239 | */ | |
240 | ||
241 | static int compare_fds(_cupsd_fd_t *a, _cupsd_fd_t *b); | |
242 | static _cupsd_fd_t *find_fd(int fd); | |
c7017ecc | 243 | #define release_fd(f) { \ |
f7deaa1a | 244 | (f)->use --; \ |
245 | if (!(f)->use) free((f));\ | |
246 | } | |
c7017ecc | 247 | #define retain_fd(f) (f)->use++ |
f7deaa1a | 248 | |
249 | ||
250 | /* | |
251 | * 'cupsdAddSelect()' - Add a file descriptor to the list. | |
252 | */ | |
253 | ||
254 | int /* O - 1 on success, 0 on error */ | |
255 | cupsdAddSelect(int fd, /* I - File descriptor */ | |
256 | cupsd_selfunc_t read_cb, /* I - Read callback */ | |
257 | cupsd_selfunc_t write_cb,/* I - Write callback */ | |
258 | void *data) /* I - Data to pass to callback */ | |
259 | { | |
260 | _cupsd_fd_t *fdptr; /* File descriptor record */ | |
1f0275e3 | 261 | #ifdef HAVE_EPOLL |
f7deaa1a | 262 | int added; /* 1 if added, 0 if modified */ |
1f0275e3 | 263 | #endif /* HAVE_EPOLL */ |
f7deaa1a | 264 | |
265 | ||
266 | /* | |
267 | * Range check input... | |
268 | */ | |
269 | ||
1bc82dd9 | 270 | cupsdLogMessage(CUPSD_LOG_DEBUG2, |
b9faaae1 | 271 | "cupsdAddSelect(fd=%d, read_cb=%p, write_cb=%p, data=%p)", |
f7deaa1a | 272 | fd, read_cb, write_cb, data); |
273 | ||
274 | if (fd < 0) | |
275 | return (0); | |
276 | ||
277 | /* | |
278 | * See if this FD has already been added... | |
279 | */ | |
280 | ||
281 | if ((fdptr = find_fd(fd)) == NULL) | |
282 | { | |
283 | /* | |
284 | * No, add a new entry... | |
285 | */ | |
286 | ||
287 | if ((fdptr = calloc(1, sizeof(_cupsd_fd_t))) == NULL) | |
288 | return (0); | |
289 | ||
290 | fdptr->fd = fd; | |
291 | fdptr->use = 1; | |
292 | ||
293 | if (!cupsArrayAdd(cupsd_fds, fdptr)) | |
294 | { | |
295 | cupsdLogMessage(CUPSD_LOG_EMERG, "Unable to add fd %d to array!", fd); | |
296 | free(fdptr); | |
297 | return (0); | |
298 | } | |
299 | ||
1f0275e3 | 300 | #ifdef HAVE_EPOLL |
f7deaa1a | 301 | added = 1; |
302 | } | |
303 | else | |
304 | added = 0; | |
1f0275e3 MS |
305 | #else |
306 | } | |
307 | #endif /* HAVE_EPOLL */ | |
f7deaa1a | 308 | |
0a682745 | 309 | #ifdef HAVE_KQUEUE |
f7deaa1a | 310 | { |
311 | struct kevent event; /* Event data */ | |
312 | struct timespec timeout; /* Timeout value */ | |
313 | ||
314 | ||
315 | timeout.tv_sec = 0; | |
316 | timeout.tv_nsec = 0; | |
317 | ||
318 | if (fdptr->read_cb != read_cb) | |
319 | { | |
320 | if (read_cb) | |
321 | EV_SET(&event, fd, EVFILT_READ, EV_ADD, 0, 0, fdptr); | |
322 | else | |
323 | EV_SET(&event, fd, EVFILT_READ, EV_DELETE, 0, 0, fdptr); | |
324 | ||
325 | if (kevent(cupsd_kqueue_fd, &event, 1, NULL, 0, &timeout)) | |
326 | { | |
b9faaae1 | 327 | cupsdLogMessage(CUPSD_LOG_EMERG, "kevent() returned %s", |
f7deaa1a | 328 | strerror(errno)); |
329 | return (0); | |
330 | } | |
331 | } | |
332 | ||
333 | if (fdptr->write_cb != write_cb) | |
334 | { | |
335 | if (write_cb) | |
336 | EV_SET(&event, fd, EVFILT_WRITE, EV_ADD, 0, 0, fdptr); | |
337 | else | |
338 | EV_SET(&event, fd, EVFILT_WRITE, EV_DELETE, 0, 0, fdptr); | |
339 | ||
340 | if (kevent(cupsd_kqueue_fd, &event, 1, NULL, 0, &timeout)) | |
341 | { | |
b9faaae1 | 342 | cupsdLogMessage(CUPSD_LOG_EMERG, "kevent() returned %s", |
f7deaa1a | 343 | strerror(errno)); |
344 | return (0); | |
345 | } | |
346 | } | |
347 | } | |
348 | ||
349 | #elif defined(HAVE_POLL) | |
0a682745 MS |
350 | # ifdef HAVE_EPOLL |
351 | if (cupsd_epoll_fd >= 0) | |
352 | { | |
353 | struct epoll_event event; /* Event data */ | |
354 | ||
355 | ||
356 | event.events = 0; | |
357 | ||
358 | if (read_cb) | |
359 | event.events |= EPOLLIN; | |
360 | ||
361 | if (write_cb) | |
362 | event.events |= EPOLLOUT; | |
363 | ||
364 | event.data.ptr = fdptr; | |
365 | ||
366 | if (epoll_ctl(cupsd_epoll_fd, added ? EPOLL_CTL_ADD : EPOLL_CTL_MOD, fd, | |
367 | &event)) | |
368 | { | |
369 | close(cupsd_epoll_fd); | |
370 | cupsd_epoll_fd = -1; | |
371 | cupsd_update_pollfds = 1; | |
372 | } | |
373 | } | |
374 | else | |
375 | # endif /* HAVE_EPOLL */ | |
376 | ||
f7deaa1a | 377 | cupsd_update_pollfds = 1; |
378 | ||
379 | #else /* select() */ | |
380 | /* | |
381 | * Add or remove the file descriptor in the input and output sets | |
382 | * for select()... | |
383 | */ | |
384 | ||
385 | if (read_cb) | |
f7deaa1a | 386 | FD_SET(fd, &cupsd_global_input); |
f7deaa1a | 387 | else |
388 | { | |
f7deaa1a | 389 | FD_CLR(fd, &cupsd_global_input); |
390 | FD_CLR(fd, &cupsd_current_input); | |
391 | } | |
392 | ||
393 | if (write_cb) | |
f7deaa1a | 394 | FD_SET(fd, &cupsd_global_output); |
f7deaa1a | 395 | else |
396 | { | |
f7deaa1a | 397 | FD_CLR(fd, &cupsd_global_output); |
398 | FD_CLR(fd, &cupsd_current_output); | |
399 | } | |
0a682745 | 400 | #endif /* HAVE_KQUEUE */ |
f7deaa1a | 401 | |
402 | /* | |
403 | * Save the (new) read and write callbacks... | |
404 | */ | |
405 | ||
406 | fdptr->read_cb = read_cb; | |
407 | fdptr->write_cb = write_cb; | |
408 | fdptr->data = data; | |
409 | ||
410 | return (1); | |
411 | } | |
412 | ||
413 | ||
414 | /* | |
415 | * 'cupsdDoSelect()' - Do a select-like operation. | |
416 | */ | |
417 | ||
418 | int /* O - Number of files or -1 on error */ | |
419 | cupsdDoSelect(long timeout) /* I - Timeout in seconds */ | |
420 | { | |
421 | int nfds; /* Number of file descriptors */ | |
422 | _cupsd_fd_t *fdptr; /* Current file descriptor */ | |
0a682745 | 423 | #ifdef HAVE_KQUEUE |
f7deaa1a | 424 | int i; /* Looping var */ |
425 | struct kevent *event; /* Current event */ | |
426 | struct timespec ktimeout; /* kevent() timeout */ | |
427 | ||
428 | ||
c0e1af83 | 429 | cupsd_in_select = 1; |
430 | ||
f7deaa1a | 431 | if (timeout >= 0 && timeout < 86400) |
432 | { | |
433 | ktimeout.tv_sec = timeout; | |
434 | ktimeout.tv_nsec = 0; | |
435 | ||
436 | nfds = kevent(cupsd_kqueue_fd, NULL, 0, cupsd_kqueue_events, MaxFDs, | |
437 | &ktimeout); | |
438 | } | |
439 | else | |
440 | nfds = kevent(cupsd_kqueue_fd, NULL, 0, cupsd_kqueue_events, MaxFDs, NULL); | |
441 | ||
f7deaa1a | 442 | cupsd_kqueue_changes = 0; |
443 | ||
444 | for (i = nfds, event = cupsd_kqueue_events; i > 0; i --, event ++) | |
445 | { | |
446 | fdptr = (_cupsd_fd_t *)event->udata; | |
447 | ||
c0e1af83 | 448 | if (cupsArrayFind(cupsd_inactive_fds, fdptr)) |
449 | continue; | |
450 | ||
f7deaa1a | 451 | retain_fd(fdptr); |
452 | ||
453 | if (fdptr->read_cb && event->filter == EVFILT_READ) | |
f7deaa1a | 454 | (*(fdptr->read_cb))(fdptr->data); |
f7deaa1a | 455 | |
c7017ecc MS |
456 | if (fdptr->use > 1 && fdptr->write_cb && event->filter == EVFILT_WRITE && |
457 | !cupsArrayFind(cupsd_inactive_fds, fdptr)) | |
f7deaa1a | 458 | (*(fdptr->write_cb))(fdptr->data); |
f7deaa1a | 459 | |
460 | release_fd(fdptr); | |
461 | } | |
462 | ||
463 | #elif defined(HAVE_POLL) | |
464 | struct pollfd *pfd; /* Current pollfd structure */ | |
465 | int count; /* Number of file descriptors */ | |
466 | ||
467 | ||
0a682745 MS |
468 | # ifdef HAVE_EPOLL |
469 | cupsd_in_select = 1; | |
470 | ||
471 | if (cupsd_epoll_fd >= 0) | |
472 | { | |
473 | int i; /* Looping var */ | |
474 | struct epoll_event *event; /* Current event */ | |
475 | ||
476 | ||
477 | if (timeout >= 0 && timeout < 86400) | |
478 | nfds = epoll_wait(cupsd_epoll_fd, cupsd_epoll_events, MaxFDs, | |
479 | timeout * 1000); | |
480 | else | |
481 | nfds = epoll_wait(cupsd_epoll_fd, cupsd_epoll_events, MaxFDs, -1); | |
482 | ||
0a682745 MS |
483 | if (nfds < 0 && errno != EINTR) |
484 | { | |
485 | close(cupsd_epoll_fd); | |
486 | cupsd_epoll_fd = -1; | |
487 | } | |
488 | else | |
489 | { | |
490 | for (i = nfds, event = cupsd_epoll_events; i > 0; i --, event ++) | |
491 | { | |
492 | fdptr = (_cupsd_fd_t *)event->data.ptr; | |
493 | ||
494 | if (cupsArrayFind(cupsd_inactive_fds, fdptr)) | |
495 | continue; | |
496 | ||
497 | retain_fd(fdptr); | |
498 | ||
499 | if (fdptr->read_cb && (event->events & (EPOLLIN | EPOLLERR | EPOLLHUP))) | |
0a682745 | 500 | (*(fdptr->read_cb))(fdptr->data); |
0a682745 | 501 | |
ef55b745 | 502 | if (fdptr->use > 1 && fdptr->write_cb && |
c7017ecc MS |
503 | (event->events & (EPOLLOUT | EPOLLERR | EPOLLHUP)) && |
504 | !cupsArrayFind(cupsd_inactive_fds, fdptr)) | |
0a682745 | 505 | (*(fdptr->write_cb))(fdptr->data); |
0a682745 MS |
506 | |
507 | release_fd(fdptr); | |
508 | } | |
509 | ||
510 | goto release_inactive; | |
511 | } | |
512 | } | |
513 | # endif /* HAVE_EPOLL */ | |
514 | ||
f7deaa1a | 515 | count = cupsArrayCount(cupsd_fds); |
516 | ||
517 | if (cupsd_update_pollfds) | |
518 | { | |
519 | /* | |
520 | * Update the cupsd_pollfds array to match the current FD array... | |
521 | */ | |
522 | ||
523 | cupsd_update_pollfds = 0; | |
524 | ||
f7deaa1a | 525 | /* |
526 | * (Re)allocate memory as needed... | |
527 | */ | |
528 | ||
529 | if (count > cupsd_alloc_pollfds) | |
530 | { | |
531 | int allocfds = count + 16; | |
532 | ||
533 | ||
534 | if (cupsd_pollfds) | |
535 | pfd = realloc(cupsd_pollfds, allocfds * sizeof(struct pollfd)); | |
536 | else | |
537 | pfd = malloc(allocfds * sizeof(struct pollfd)); | |
538 | ||
539 | if (!pfd) | |
540 | { | |
541 | cupsdLogMessage(CUPSD_LOG_EMERG, | |
542 | "Unable to allocate %d bytes for polling!", | |
543 | (int)(allocfds * sizeof(struct pollfd))); | |
544 | ||
545 | return (-1); | |
546 | } | |
547 | ||
548 | cupsd_pollfds = pfd; | |
549 | cupsd_alloc_pollfds = allocfds; | |
550 | } | |
551 | ||
552 | /* | |
553 | * Rebuild the array... | |
554 | */ | |
555 | ||
556 | for (fdptr = (_cupsd_fd_t *)cupsArrayFirst(cupsd_fds), pfd = cupsd_pollfds; | |
557 | fdptr; | |
558 | fdptr = (_cupsd_fd_t *)cupsArrayNext(cupsd_fds), pfd ++) | |
559 | { | |
560 | pfd->fd = fdptr->fd; | |
561 | pfd->events = 0; | |
562 | ||
563 | if (fdptr->read_cb) | |
564 | pfd->events |= POLLIN; | |
565 | ||
566 | if (fdptr->write_cb) | |
567 | pfd->events |= POLLOUT; | |
568 | } | |
569 | } | |
570 | ||
f7deaa1a | 571 | if (timeout >= 0 && timeout < 86400) |
572 | nfds = poll(cupsd_pollfds, count, timeout * 1000); | |
573 | else | |
574 | nfds = poll(cupsd_pollfds, count, -1); | |
575 | ||
f7deaa1a | 576 | if (nfds > 0) |
577 | { | |
578 | /* | |
579 | * Do callbacks for each file descriptor... | |
580 | */ | |
581 | ||
582 | for (pfd = cupsd_pollfds; count > 0; pfd ++, count --) | |
583 | { | |
f7deaa1a | 584 | if (!pfd->revents) |
585 | continue; | |
586 | ||
587 | if ((fdptr = find_fd(pfd->fd)) == NULL) | |
588 | continue; | |
589 | ||
590 | retain_fd(fdptr); | |
591 | ||
592 | if (fdptr->read_cb && (pfd->revents & (POLLIN | POLLERR | POLLHUP))) | |
f7deaa1a | 593 | (*(fdptr->read_cb))(fdptr->data); |
f7deaa1a | 594 | |
ef55b745 MS |
595 | if (fdptr->use > 1 && fdptr->write_cb && |
596 | (pfd->revents & (POLLOUT | POLLERR | POLLHUP))) | |
f7deaa1a | 597 | (*(fdptr->write_cb))(fdptr->data); |
f7deaa1a | 598 | |
599 | release_fd(fdptr); | |
600 | } | |
601 | } | |
602 | ||
603 | #else /* select() */ | |
604 | struct timeval stimeout; /* Timeout for select() */ | |
605 | int maxfd; /* Maximum file descriptor */ | |
606 | ||
607 | ||
608 | /* | |
609 | * Figure out the highest file descriptor number... | |
610 | */ | |
611 | ||
612 | if ((fdptr = (_cupsd_fd_t *)cupsArrayLast(cupsd_fds)) == NULL) | |
613 | maxfd = 1; | |
614 | else | |
615 | maxfd = fdptr->fd + 1; | |
616 | ||
617 | /* | |
618 | * Do the select()... | |
619 | */ | |
620 | ||
621 | cupsd_current_input = cupsd_global_input; | |
622 | cupsd_current_output = cupsd_global_output; | |
623 | ||
f7deaa1a | 624 | if (timeout >= 0 && timeout < 86400) |
625 | { | |
626 | stimeout.tv_sec = timeout; | |
627 | stimeout.tv_usec = 0; | |
628 | ||
629 | nfds = select(maxfd, &cupsd_current_input, &cupsd_current_output, NULL, | |
630 | &stimeout); | |
631 | } | |
632 | else | |
633 | nfds = select(maxfd, &cupsd_current_input, &cupsd_current_output, NULL, | |
634 | NULL); | |
635 | ||
f7deaa1a | 636 | if (nfds > 0) |
637 | { | |
638 | /* | |
639 | * Do callbacks for each file descriptor... | |
640 | */ | |
641 | ||
642 | for (fdptr = (_cupsd_fd_t *)cupsArrayFirst(cupsd_fds); | |
643 | fdptr; | |
644 | fdptr = (_cupsd_fd_t *)cupsArrayNext(cupsd_fds)) | |
645 | { | |
646 | retain_fd(fdptr); | |
647 | ||
648 | if (fdptr->read_cb && FD_ISSET(fdptr->fd, &cupsd_current_input)) | |
f7deaa1a | 649 | (*(fdptr->read_cb))(fdptr->data); |
f7deaa1a | 650 | |
ef55b745 MS |
651 | if (fdptr->use > 1 && fdptr->write_cb && |
652 | FD_ISSET(fdptr->fd, &cupsd_current_output)) | |
f7deaa1a | 653 | (*(fdptr->write_cb))(fdptr->data); |
f7deaa1a | 654 | |
655 | release_fd(fdptr); | |
656 | } | |
657 | } | |
658 | ||
0a682745 | 659 | #endif /* HAVE_KQUEUE */ |
f7deaa1a | 660 | |
c0e1af83 | 661 | #if defined(HAVE_EPOLL) || defined(HAVE_KQUEUE) |
662 | /* | |
663 | * Release all inactive file descriptors... | |
664 | */ | |
665 | ||
0a682745 MS |
666 | # ifndef HAVE_KQUEUE |
667 | release_inactive: | |
668 | # endif /* !HAVE_KQUEUE */ | |
669 | ||
c0e1af83 | 670 | cupsd_in_select = 0; |
671 | ||
672 | for (fdptr = (_cupsd_fd_t *)cupsArrayFirst(cupsd_inactive_fds); | |
673 | fdptr; | |
674 | fdptr = (_cupsd_fd_t *)cupsArrayNext(cupsd_inactive_fds)) | |
675 | { | |
676 | cupsArrayRemove(cupsd_inactive_fds, fdptr); | |
677 | release_fd(fdptr); | |
678 | } | |
679 | #endif /* HAVE_EPOLL || HAVE_KQUEUE */ | |
680 | ||
f7deaa1a | 681 | /* |
682 | * Return the number of file descriptors handled... | |
683 | */ | |
684 | ||
685 | return (nfds); | |
686 | } | |
687 | ||
688 | ||
f899b121 | 689 | #ifdef CUPSD_IS_SELECTING |
f7deaa1a | 690 | /* |
691 | * 'cupsdIsSelecting()' - Determine whether we are monitoring a file | |
692 | * descriptor. | |
693 | */ | |
694 | ||
695 | int /* O - 1 if selecting, 0 otherwise */ | |
696 | cupsdIsSelecting(int fd) /* I - File descriptor */ | |
697 | { | |
698 | return (find_fd(fd) != NULL); | |
699 | } | |
f899b121 | 700 | #endif /* CUPSD_IS_SELECTING */ |
f7deaa1a | 701 | |
702 | ||
703 | /* | |
704 | * 'cupsdRemoveSelect()' - Remove a file descriptor from the list. | |
705 | */ | |
706 | ||
707 | void | |
708 | cupsdRemoveSelect(int fd) /* I - File descriptor */ | |
709 | { | |
710 | _cupsd_fd_t *fdptr; /* File descriptor record */ | |
711 | #ifdef HAVE_EPOLL | |
712 | struct epoll_event event; /* Event data */ | |
713 | #elif defined(HAVE_KQUEUE) | |
714 | struct kevent event; /* Event data */ | |
715 | struct timespec timeout; /* Timeout value */ | |
716 | #elif defined(HAVE_POLL) | |
717 | /* No variables for poll() */ | |
718 | #endif /* HAVE_EPOLL */ | |
719 | ||
720 | ||
721 | /* | |
722 | * Range check input... | |
723 | */ | |
724 | ||
1bc82dd9 | 725 | cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdRemoveSelect(fd=%d)", fd); |
f7deaa1a | 726 | |
727 | if (fd < 0) | |
728 | return; | |
729 | ||
730 | /* | |
731 | * Find the file descriptor... | |
732 | */ | |
733 | ||
734 | if ((fdptr = find_fd(fd)) == NULL) | |
735 | return; | |
736 | ||
737 | #ifdef HAVE_EPOLL | |
0a682745 MS |
738 | if (epoll_ctl(cupsd_epoll_fd, EPOLL_CTL_DEL, fd, &event)) |
739 | { | |
740 | close(cupsd_epoll_fd); | |
741 | cupsd_epoll_fd = -1; | |
742 | cupsd_update_pollfds = 1; | |
743 | } | |
f7deaa1a | 744 | |
745 | #elif defined(HAVE_KQUEUE) | |
746 | timeout.tv_sec = 0; | |
747 | timeout.tv_nsec = 0; | |
748 | ||
749 | if (fdptr->read_cb) | |
750 | { | |
751 | EV_SET(&event, fd, EVFILT_READ, EV_DELETE, 0, 0, fdptr); | |
752 | ||
753 | if (kevent(cupsd_kqueue_fd, &event, 1, NULL, 0, &timeout)) | |
754 | { | |
b9faaae1 | 755 | cupsdLogMessage(CUPSD_LOG_EMERG, "kevent() returned %s", |
f7deaa1a | 756 | strerror(errno)); |
4a4b4f99 | 757 | goto cleanup; |
f7deaa1a | 758 | } |
759 | } | |
760 | ||
761 | if (fdptr->write_cb) | |
762 | { | |
763 | EV_SET(&event, fd, EVFILT_WRITE, EV_DELETE, 0, 0, fdptr); | |
764 | ||
765 | if (kevent(cupsd_kqueue_fd, &event, 1, NULL, 0, &timeout)) | |
766 | { | |
b9faaae1 | 767 | cupsdLogMessage(CUPSD_LOG_EMERG, "kevent() returned %s", |
f7deaa1a | 768 | strerror(errno)); |
4a4b4f99 | 769 | goto cleanup; |
f7deaa1a | 770 | } |
771 | } | |
772 | ||
f7deaa1a | 773 | #elif defined(HAVE_POLL) |
774 | /* | |
775 | * Update the pollfds array... | |
776 | */ | |
777 | ||
778 | cupsd_update_pollfds = 1; | |
779 | ||
780 | #else /* select() */ | |
f7deaa1a | 781 | FD_CLR(fd, &cupsd_global_input); |
782 | FD_CLR(fd, &cupsd_global_output); | |
783 | FD_CLR(fd, &cupsd_current_input); | |
784 | FD_CLR(fd, &cupsd_current_output); | |
785 | #endif /* HAVE_EPOLL */ | |
786 | ||
4a4b4f99 MS |
787 | #ifdef HAVE_KQUEUE |
788 | cleanup: | |
789 | #endif /* HAVE_KQUEUE */ | |
790 | ||
f7deaa1a | 791 | /* |
c0e1af83 | 792 | * Remove the file descriptor from the active array and add to the |
793 | * inactive array (or release, if we don't need the inactive array...) | |
f7deaa1a | 794 | */ |
795 | ||
796 | cupsArrayRemove(cupsd_fds, fdptr); | |
c0e1af83 | 797 | |
798 | #if defined(HAVE_EPOLL) || defined(HAVE_KQUEUE) | |
799 | if (cupsd_in_select) | |
800 | cupsArrayAdd(cupsd_inactive_fds, fdptr); | |
801 | else | |
802 | #endif /* HAVE_EPOLL || HAVE_KQUEUE */ | |
803 | ||
f7deaa1a | 804 | release_fd(fdptr); |
805 | } | |
806 | ||
807 | ||
808 | /* | |
809 | * 'cupsdStartSelect()' - Initialize the file polling engine. | |
810 | */ | |
811 | ||
812 | void | |
813 | cupsdStartSelect(void) | |
814 | { | |
f2d18633 | 815 | cupsdLogMessage(CUPSD_LOG_DEBUG, "cupsdStartSelect()"); |
b9faaae1 | 816 | |
f7deaa1a | 817 | cupsd_fds = cupsArrayNew((cups_array_func_t)compare_fds, NULL); |
818 | ||
c0e1af83 | 819 | #if defined(HAVE_EPOLL) || defined(HAVE_KQUEUE) |
820 | cupsd_inactive_fds = cupsArrayNew((cups_array_func_t)compare_fds, NULL); | |
821 | #endif /* HAVE_EPOLL || HAVE_KQUEUE */ | |
822 | ||
f7deaa1a | 823 | #ifdef HAVE_EPOLL |
0a682745 MS |
824 | cupsd_epoll_fd = epoll_create(MaxFDs); |
825 | cupsd_epoll_events = calloc(MaxFDs, sizeof(struct epoll_event)); | |
826 | cupsd_update_pollfds = 0; | |
f7deaa1a | 827 | |
828 | #elif defined(HAVE_KQUEUE) | |
829 | cupsd_kqueue_fd = kqueue(); | |
830 | cupsd_kqueue_changes = 0; | |
831 | cupsd_kqueue_events = calloc(MaxFDs, sizeof(struct kevent)); | |
832 | ||
833 | #elif defined(HAVE_POLL) | |
834 | cupsd_update_pollfds = 0; | |
835 | ||
836 | #else /* select() */ | |
837 | FD_ZERO(&cupsd_global_input); | |
838 | FD_ZERO(&cupsd_global_output); | |
839 | #endif /* HAVE_EPOLL */ | |
840 | } | |
841 | ||
842 | ||
843 | /* | |
844 | * 'cupsdStopSelect()' - Shutdown the file polling engine. | |
845 | */ | |
846 | ||
847 | void | |
848 | cupsdStopSelect(void) | |
849 | { | |
850 | _cupsd_fd_t *fdptr; /* Current file descriptor */ | |
851 | ||
852 | ||
f2d18633 | 853 | cupsdLogMessage(CUPSD_LOG_DEBUG, "cupsdStopSelect()"); |
b9faaae1 | 854 | |
f7deaa1a | 855 | for (fdptr = (_cupsd_fd_t *)cupsArrayFirst(cupsd_fds); |
856 | fdptr; | |
857 | fdptr = (_cupsd_fd_t *)cupsArrayNext(cupsd_fds)) | |
858 | free(fdptr); | |
859 | ||
860 | cupsArrayDelete(cupsd_fds); | |
861 | cupsd_fds = NULL; | |
862 | ||
c0e1af83 | 863 | #if defined(HAVE_EPOLL) || defined(HAVE_KQUEUE) |
864 | cupsArrayDelete(cupsd_inactive_fds); | |
865 | cupsd_inactive_fds = NULL; | |
866 | #endif /* HAVE_EPOLL || HAVE_KQUEUE */ | |
867 | ||
0a682745 | 868 | #ifdef HAVE_KQUEUE |
f7deaa1a | 869 | if (cupsd_kqueue_events) |
870 | { | |
871 | free(cupsd_kqueue_events); | |
872 | cupsd_kqueue_events = NULL; | |
873 | } | |
874 | ||
875 | if (cupsd_kqueue_fd >= 0) | |
876 | { | |
877 | close(cupsd_kqueue_fd); | |
878 | cupsd_kqueue_fd = -1; | |
879 | } | |
880 | ||
881 | cupsd_kqueue_changes = 0; | |
882 | ||
883 | #elif defined(HAVE_POLL) | |
0a682745 MS |
884 | # ifdef HAVE_EPOLL |
885 | if (cupsd_epoll_events) | |
886 | { | |
887 | free(cupsd_epoll_events); | |
888 | cupsd_epoll_events = NULL; | |
889 | } | |
890 | ||
891 | if (cupsd_epoll_fd >= 0) | |
892 | { | |
893 | close(cupsd_epoll_fd); | |
894 | cupsd_epoll_fd = -1; | |
895 | } | |
896 | # endif /* HAVE_EPOLL */ | |
897 | ||
f7deaa1a | 898 | if (cupsd_pollfds) |
899 | { | |
900 | free(cupsd_pollfds); | |
901 | cupsd_pollfds = NULL; | |
902 | cupsd_alloc_pollfds = 0; | |
903 | } | |
904 | ||
905 | cupsd_update_pollfds = 0; | |
906 | ||
907 | #else /* select() */ | |
908 | FD_ZERO(&cupsd_global_input); | |
909 | FD_ZERO(&cupsd_global_output); | |
910 | #endif /* HAVE_EPOLL */ | |
911 | } | |
912 | ||
913 | ||
914 | /* | |
915 | * 'compare_fds()' - Compare file descriptors. | |
916 | */ | |
917 | ||
918 | static int /* O - Result of comparison */ | |
919 | compare_fds(_cupsd_fd_t *a, /* I - First file descriptor */ | |
920 | _cupsd_fd_t *b) /* I - Second file descriptor */ | |
921 | { | |
922 | return (a->fd - b->fd); | |
923 | } | |
924 | ||
925 | ||
926 | /* | |
927 | * 'find_fd()' - Find an existing file descriptor record. | |
928 | */ | |
929 | ||
930 | static _cupsd_fd_t * /* O - FD record pointer or NULL */ | |
931 | find_fd(int fd) /* I - File descriptor */ | |
932 | { | |
933 | _cupsd_fd_t *fdptr, /* Matching record (if any) */ | |
934 | key; /* Search key */ | |
935 | ||
936 | ||
937 | cupsArraySave(cupsd_fds); | |
938 | ||
939 | key.fd = fd; | |
940 | fdptr = (_cupsd_fd_t *)cupsArrayFind(cupsd_fds, &key); | |
941 | ||
942 | cupsArrayRestore(cupsd_fds); | |
943 | ||
944 | return (fdptr); | |
945 | } | |
946 | ||
947 | ||
948 | /* | |
61515785 | 949 | * End of "$Id: select.c 11142 2013-07-17 01:07:00Z msweet $". |
f7deaa1a | 950 | */ |