2 * UCW Library -- Main Loop
4 * (c) 2004--2005 Martin Mares <mj@ucw.cz>
6 * This software may be freely distributed and used according to the terms
7 * of the GNU Lesser General Public License.
13 #include "lib/mainloop.h"
27 sh_time_t main_now_seconds;
30 clist main_timer_list, main_file_list, main_hook_list, main_process_list;
31 static uns main_file_cnt;
32 static uns main_poll_table_obsolete, main_poll_table_size;
33 static struct pollfd *main_poll_table;
34 static uns main_sigchld_set_up;
40 gettimeofday(&tv, NULL);
41 main_now_seconds = tv.tv_sec;
42 main_now = (timestamp_t)tv.tv_sec * 1000 + tv.tv_usec / 1000;
43 DBG("It's %Ld o'clock", (long long) main_now);
49 DBG("MAIN: Initializing");
50 clist_init(&main_timer_list);
51 clist_init(&main_file_list);
52 clist_init(&main_hook_list);
53 clist_init(&main_process_list);
58 timer_add(struct main_timer *tm, timestamp_t expires)
62 tm->expires = expires;
65 cnode *t = main_timer_list.head.next;
66 while (t != &main_timer_list.head && ((struct main_timer *) t)->expires < expires)
68 clist_insert_before(&tm->n, t);
73 timer_del(struct main_timer *tm)
79 file_timer_expired(struct main_timer *tm)
81 struct main_file *fi = tm->data;
82 timer_del(&fi->timer);
83 if (fi->error_handler)
84 fi->error_handler(fi, MFERR_TIMEOUT);
88 file_add(struct main_file *fi)
91 clist_add_tail(&main_file_list, &fi->n);
92 fi->timer.handler = file_timer_expired;
95 main_poll_table_obsolete = 1;
96 if (fcntl(fi->fd, F_SETFL, O_NONBLOCK) < 0)
97 log(L_ERROR, "Error setting fd %d to non-blocking mode: %m. Keep fingers crossed.", fi->fd);
101 file_chg(struct main_file *fi)
103 struct pollfd *p = fi->pollfd;
107 if (fi->read_handler)
108 p->events |= POLLIN | POLLHUP | POLLERR;
109 if (fi->write_handler)
110 p->events |= POLLOUT | POLLERR;
115 file_del(struct main_file *fi)
118 timer_del(&fi->timer);
119 clist_remove(&fi->n);
121 main_poll_table_obsolete = 1;
122 fi->n.next = fi->n.prev = NULL;
126 file_read_handler(struct main_file *fi)
128 while (fi->rpos < fi->rlen)
130 int l = read(fi->fd, fi->rbuf + fi->rpos, fi->rlen - fi->rpos);
131 DBG("MAIN: FD %d: read %d", fi->fd, l);
134 if (errno != EINTR && errno != EAGAIN && fi->error_handler)
135 fi->error_handler(fi, MFERR_READ);
142 DBG("MAIN: FD %d done read %d of %d", fi->fd, fi->rpos, fi->rlen);
143 fi->read_handler = NULL;
150 file_write_handler(struct main_file *fi)
152 while (fi->wpos < fi->wlen)
154 int l = write(fi->fd, fi->wbuf + fi->wpos, fi->wlen - fi->wpos);
155 DBG("MAIN: FD %d: write %d", fi->fd, l);
158 if (errno != EINTR && errno != EAGAIN && fi->error_handler)
159 fi->error_handler(fi, MFERR_WRITE);
164 DBG("MAIN: FD %d done write %d", fi->fd, fi->wpos);
165 fi->write_handler = NULL;
172 file_read(struct main_file *fi, void *buf, uns len)
177 fi->read_handler = file_read_handler;
184 fi->read_handler = NULL;
186 fi->rpos = fi->rlen = 0;
192 file_write(struct main_file *fi, void *buf, uns len)
197 fi->write_handler = file_write_handler;
204 fi->write_handler = NULL;
206 fi->wpos = fi->wlen = 0;
212 file_set_timeout(struct main_file *fi, timestamp_t expires)
215 timer_add(&fi->timer, expires);
221 CLIST_FOR_EACH(struct main_file *, f, main_file_list)
226 hook_add(struct main_hook *ho)
229 clist_add_tail(&main_hook_list, &ho->n);
233 hook_del(struct main_hook *ho)
236 clist_remove(&ho->n);
237 ho->n.next = ho->n.prev = NULL;
241 main_sigchld_handler(int x UNUSED)
243 DBG("SIGCHLD received");
247 process_add(struct main_process *mp)
251 clist_add_tail(&main_process_list, &mp->n);
252 if (!main_sigchld_set_up)
255 bzero(&sa, sizeof(sa));
256 sa.sa_handler = main_sigchld_handler;
257 sa.sa_flags = SA_NOCLDSTOP | SA_RESTART;
258 sigaction(SIGCHLD, &sa, NULL);
259 main_sigchld_set_up = 1;
264 process_del(struct main_process *mp)
267 clist_remove(&mp->n);
273 process_fork(struct main_process *mp)
279 DBG("MAIN: Fork failed");
281 format_exit_status(mp->status_msg, -1);
289 DBG("MAIN: Forked process %d", (int) pid);
300 log(L_DEBUG, "### Main loop status on %Ld", (long long)main_now);
301 log(L_DEBUG, "\tActive timers:");
302 struct main_timer *tm;
303 CLIST_WALK(tm, main_timer_list)
304 log(L_DEBUG, "\t\t%p (expires %Ld, data %p)", tm, (long long)(tm->expires ? tm->expires-main_now : 999999), tm->data);
305 struct main_file *fi;
306 log(L_DEBUG, "\tActive files:");
307 CLIST_WALK(fi, main_file_list)
308 log(L_DEBUG, "\t\t%p (fd %d, rh %p, wh %p, eh %p, expires %Ld, data %p)",
309 fi, fi->fd, fi->read_handler, fi->write_handler, fi->error_handler,
310 (long long)(fi->timer.expires ? fi->timer.expires-main_now : 999999), fi->data);
311 log(L_DEBUG, "\tActive hooks:");
312 struct main_hook *ho;
313 CLIST_WALK(ho, main_hook_list)
314 log(L_DEBUG, "\t\t%p (func %p, data %p)", ho, ho->handler, ho->data);
315 log(L_DEBUG, "\tActive processes:");
316 struct main_process *pr;
317 CLIST_WALK(pr, main_process_list)
318 log(L_DEBUG, "\t\t%p (pid %d, data %p)", pr, pr->pid, pr->data);
323 main_rebuild_poll_table(void)
325 struct main_file *fi;
326 if (main_poll_table_size < main_file_cnt)
329 xfree(main_poll_table);
331 main_poll_table_size = 1;
332 while (main_poll_table_size < main_file_cnt)
333 main_poll_table_size *= 2;
334 main_poll_table = xmalloc(sizeof(struct pollfd) * main_poll_table_size);
336 struct pollfd *p = main_poll_table;
337 DBG("MAIN: Rebuliding poll table: %d of %d entries set", main_file_cnt, main_poll_table_size);
338 CLIST_WALK(fi, main_file_list)
344 main_poll_table_obsolete = 0;
350 DBG("MAIN: Entering main_loop");
351 ASSERT(main_timer_list.head.next);
353 struct main_file *fi;
354 struct main_hook *ho;
355 struct main_timer *tm;
356 struct main_process *pr;
362 timestamp_t wake = main_now + 1000000000;
363 while ((tm = clist_head(&main_timer_list)) && tm->expires <= main_now)
365 DBG("MAIN: Timer %p expired at %Ld", tm, (long long) tm->expires);
368 int hook_min = HOOK_RETRY;
369 int hook_max = HOOK_SHUTDOWN;
370 CLIST_WALK_DELSAFE(ho, main_hook_list, tmp)
372 DBG("MAIN: Hook %p", ho);
373 int ret = ho->handler(ho);
374 hook_min = MIN(hook_min, ret);
375 hook_max = MAX(hook_max, ret);
377 if (hook_min == HOOK_SHUTDOWN ||
378 hook_min == HOOK_DONE && hook_max == HOOK_DONE ||
381 DBG("MAIN: Shut down by %s", main_shutdown ? "main_shutdown" : "a hook");
384 if (hook_max == HOOK_RETRY)
386 if (main_poll_table_obsolete)
387 main_rebuild_poll_table();
388 if (!clist_empty(&main_process_list))
392 wake = MIN(wake, main_now + 10000);
393 while ((pid = waitpid(-1, &stat, WNOHANG)) > 0)
395 DBG("MAIN: Child %d exited with status %x", pid, stat);
396 CLIST_WALK(pr, main_process_list)
401 format_exit_status(pr->status_msg, pr->status);
402 DBG("MAIN: Calling process exit handler");
409 /* FIXME: Here is a small race window where SIGCHLD can come unnoticed. */
410 if ((tm = clist_head(&main_timer_list)) && tm->expires < wake)
412 int timeout = (wake ? wake - main_now : 0);
413 DBG("MAIN: Poll for %d fds and timeout %d ms", main_file_cnt, timeout);
414 if (poll(main_poll_table, main_file_cnt, timeout))
416 struct pollfd *p = main_poll_table;
418 CLIST_WALK(fi, main_file_list)
420 if (p->revents & (POLLIN | POLLHUP | POLLERR))
423 DBG("MAIN: Read event on fd %d", p->fd);
424 while (fi->read_handler && fi->read_handler(fi) && !main_poll_table_obsolete);
425 if (main_poll_table_obsolete) /* File entries have been inserted or deleted => better not risk continuing to nowhere */
428 if (p->revents & (POLLOUT | POLLERR))
431 DBG("MAIN: Write event on fd %d", p->fd);
432 while (fi->write_handler && fi->write_handler(fi) && !main_poll_table_obsolete);
433 if (main_poll_table_obsolete)
444 static struct main_process mp;
445 static struct main_file fin, fout;
446 static struct main_hook hook;
447 static struct main_timer tm;
451 static void dread(struct main_file *fi)
453 if (fi->rpos < fi->rlen)
455 log(L_INFO, "Read EOF");
460 log(L_INFO, "Read done");
461 file_read(fi, rb, sizeof(rb));
465 static void derror(struct main_file *fi, int cause)
467 log(L_INFO, "Error: %m !!! (cause %d)", cause);
471 static void dwrite(struct main_file *fi UNUSED)
473 log(L_INFO, "Write done");
476 static int dhook(struct main_hook *ho UNUSED)
478 log(L_INFO, "Hook called");
482 static void dtimer(struct main_timer *tm)
484 log(L_INFO, "Timer tick");
485 timer_add(tm, main_now + 10000);
488 static void dentry(void)
490 log(L_INFO, "*** SUBPROCESS START ***");
492 log(L_INFO, "*** SUBPROCESS FINISH ***");
496 static void dexit(struct main_process *pr)
498 log(L_INFO, "Subprocess %d exited with status %x", pr->pid, pr->status);
508 fin.read_done = dread;
509 fin.error_handler = derror;
511 file_read(&fin, rb, sizeof(rb));
514 fout.write_done = dwrite;
515 fout.error_handler = derror;
517 file_write(&fout, "Hello, world!\n", 14);
519 hook.handler = dhook;
523 timer_add(&tm, main_now + 1000);
526 if (!process_fork(&mp))
532 log(L_INFO, "Finished.");