2 * UCW Library -- Main Loop
4 * (c) 2004--2010 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.
14 #include "ucw/mainloop.h"
15 #include "ucw/threads.h"
30 #ifdef CONFIG_UCW_THREADS
32 #define THREAD_SIGMASK pthread_sigmask
34 #define THREAD_SIGMASK sigprocmask
37 #define MAIN_TIMER_LESS(x,y) ((x)->expires < (y)->expires)
38 #define MAIN_TIMER_SWAP(heap,a,b,t) (t=heap[a], heap[a]=heap[b], heap[b]=t, heap[a]->index=(a), heap[b]->index=(b))
41 do_main_get_time(struct main_context *m)
44 gettimeofday(&tv, NULL);
45 m->now_seconds = tv.tv_sec;
46 m->now = (timestamp_t)tv.tv_sec * 1000 + tv.tv_usec / 1000;
52 struct main_context *m = xmalloc_zero(sizeof(*m));
54 DBG("MAIN: New context");
55 clist_init(&m->file_list);
56 clist_init(&m->hook_list);
57 clist_init(&m->hook_done_list);
58 clist_init(&m->process_list);
59 clist_init(&m->signal_list);
60 m->poll_table_obsolete = 1;
62 sigemptyset(&m->want_signals);
63 m->sig_pipe_recv = m->sig_pipe_send = -1;
69 main_delete(struct main_context *m)
71 if (m->sigchld_handler)
72 signal_del(m->sigchld_handler);
74 file_del(m->sig_pipe_file);
75 if (m->sig_pipe_recv >= 0)
77 close(m->sig_pipe_recv);
78 close(m->sig_pipe_send);
80 ASSERT(clist_empty(&m->file_list));
81 ASSERT(clist_empty(&m->hook_list));
82 ASSERT(clist_empty(&m->hook_done_list));
83 ASSERT(clist_empty(&m->process_list));
84 ASSERT(clist_empty(&m->signal_list));
86 GARY_FREE(m->timer_table);
89 // FIXME: Some mechanism for cleaning up after fork()
93 main_switch_context(struct main_context *m)
95 struct ucwlib_context *c = ucwlib_thread_context();
96 struct main_context *m0 = c->main_context;
99 * Not only we need to switch the signal sets of the two contexts,
100 * but it is also necessary to avoid invoking a signal handler
101 * in the middle of changing c->main_context.
103 if (m0 && !clist_empty(&m0->signal_list))
104 THREAD_SIGMASK(SIG_BLOCK, &m0->want_signals, NULL);
106 if (m && !clist_empty(&m->signal_list))
107 THREAD_SIGMASK(SIG_UNBLOCK, &m->want_signals, NULL);
112 struct main_context *
115 struct ucwlib_context *c = ucwlib_thread_context();
116 struct main_context *m = c->main_context;
124 struct main_context *m = main_switch_context(main_new());
131 struct main_context *m = main_switch_context(NULL);
138 do_main_get_time(main_current());
142 count_timers(struct main_context *m)
144 return GARY_SIZE(m->timer_table) - 1;
148 timer_add(struct main_timer *tm, timestamp_t expires)
150 struct main_context *m = main_current();
154 GARY_INIT(m->timer_table, 1);
155 m->timer_table[0] = NULL;
159 DBG("MAIN: Setting timer %p (expire at now+%lld)", tm, (long long)(expires - m->now));
161 DBG("MAIN: Clearing timer %p", tm);
162 uns num_timers = count_timers(m);
163 if (tm->expires < expires)
167 tm->expires = expires;
168 tm->index = num_timers + 1;
169 *GARY_PUSH(m->timer_table, 1) = tm;
170 HEAP_INSERT(struct main_timer *, m->timer_table, tm->index, MAIN_TIMER_LESS, MAIN_TIMER_SWAP);
174 tm->expires = expires;
175 HEAP_INCREASE(struct main_timer *, m->timer_table, num_timers, MAIN_TIMER_LESS, MAIN_TIMER_SWAP, tm->index);
178 else if (tm->expires > expires)
182 ASSERT(tm->index && tm->index <= num_timers);
183 HEAP_DELETE(struct main_timer *, m->timer_table, num_timers, MAIN_TIMER_LESS, MAIN_TIMER_SWAP, tm->index);
186 GARY_POP(m->timer_table, 1);
190 tm->expires = expires;
191 HEAP_DECREASE(struct main_timer *, m->timer_table, num_timers, MAIN_TIMER_LESS, MAIN_TIMER_SWAP, tm->index);
197 timer_add_rel(struct main_timer *tm, timestamp_t expires_delta)
199 struct main_context *m = main_current();
200 return timer_add(tm, m->now + expires_delta);
204 timer_del(struct main_timer *tm)
210 file_add(struct main_file *fi)
212 struct main_context *m = main_current();
214 DBG("MAIN: Adding file %p (fd=%d)", fi, fi->fd);
216 clist_add_tail(&m->file_list, &fi->n);
218 m->poll_table_obsolete = 1;
219 if (fcntl(fi->fd, F_SETFL, O_NONBLOCK) < 0)
220 msg(L_ERROR, "Error setting fd %d to non-blocking mode: %m. Keep fingers crossed.", fi->fd);
224 file_chg(struct main_file *fi)
226 struct pollfd *p = fi->pollfd;
230 if (fi->read_handler)
231 p->events |= POLLIN | POLLHUP | POLLERR;
232 if (fi->write_handler)
233 p->events |= POLLOUT | POLLERR;
238 file_del(struct main_file *fi)
240 struct main_context *m = main_current();
242 DBG("MAIN: Deleting file %p (fd=%d)", fi, fi->fd);
244 clist_remove(&fi->n);
246 m->poll_table_obsolete = 1;
247 fi->n.next = fi->n.prev = NULL;
253 struct main_context *m = main_current();
255 CLIST_FOR_EACH(struct main_file *, f, m->file_list)
260 hook_add(struct main_hook *ho)
262 struct main_context *m = main_current();
264 DBG("MAIN: Adding hook %p", ho);
266 clist_add_tail(&m->hook_list, &ho->n);
270 hook_del(struct main_hook *ho)
272 DBG("MAIN: Deleting hook %p", ho);
274 clist_remove(&ho->n);
275 ho->n.next = ho->n.prev = NULL;
279 sigchld_received(struct main_signal *sg UNUSED)
281 struct main_context *m = main_current();
285 while ((pid = waitpid(-1, &stat, WNOHANG)) > 0)
287 DBG("MAIN: Child %d exited with status %x", pid, stat);
288 CLIST_FOR_EACH(struct main_process *, pr, m->process_list)
293 format_exit_status(pr->status_msg, pr->status);
294 DBG("MAIN: Calling process exit handler");
302 process_add(struct main_process *mp)
304 struct main_context *m = main_current();
306 DBG("MAIN: Adding process %p (pid=%d)", mp, mp->pid);
309 clist_add_tail(&m->process_list, &mp->n);
310 if (!m->sigchld_handler)
312 struct main_signal *sg = xmalloc_zero(sizeof(*sg));
313 m->sigchld_handler = sg;
314 sg->signum = SIGCHLD;
315 sg->handler = sigchld_received;
321 process_del(struct main_process *mp)
323 DBG("MAIN: Deleting process %p (pid=%d)", mp, mp->pid);
325 clist_remove(&mp->n);
330 process_fork(struct main_process *mp)
335 DBG("MAIN: Fork failed");
337 format_exit_status(mp->status_msg, -1);
345 DBG("MAIN: Forked process %d", (int) pid);
353 pipe_read_handler(struct main_file *mf UNUSED)
355 struct main_context *m = main_current();
357 int n = read(m->sig_pipe_recv, &signum, sizeof(signum));
362 msg(L_ERROR, "Error reading signal pipe: %m");
365 ASSERT(n == sizeof(signum));
367 DBG("MAIN: Sigpipe: received signal %d", signum);
368 struct main_signal *tmp;
369 CLIST_FOR_EACH_DELSAFE(struct main_signal *, sg, m->signal_list, tmp)
370 if (sg->signum == signum)
372 DBG("MAIN: Sigpipe: invoking handler %p", sg);
373 // FIXME: Can the handler disappear from here?
381 pipe_configure(int fd)
384 if ((flags = fcntl(fd, F_GETFL)) < 0 || fcntl(fd, F_SETFL, flags|O_NONBLOCK) < 0)
385 die("Could not set file descriptor %d to non-blocking: %m", fd);
389 pipe_setup(struct main_context *m)
391 DBG("MAIN: Sigpipe: Setting up the pipe");
394 if (pipe(pipe_result) == -1)
395 die("Could not create signal pipe: %m");
396 pipe_configure(pipe_result[0]);
397 pipe_configure(pipe_result[1]);
398 m->sig_pipe_recv = pipe_result[0];
399 m->sig_pipe_send = pipe_result[1];
401 struct main_file *f = xmalloc_zero(sizeof(*f));
402 m->sig_pipe_file = f;
403 f->fd = m->sig_pipe_recv;
404 f->read_handler = pipe_read_handler;
409 signal_handler_pipe(int signum)
411 struct main_context *m = main_current();
413 msg(L_DEBUG | L_SIGHANDLER, "MAIN: Sigpipe: sending signal %d down the drain", signum);
415 write(m->sig_pipe_send, &signum, sizeof(signum));
419 signal_add(struct main_signal *ms)
421 struct main_context *m = main_current();
423 DBG("MAIN: Adding signal %p (sig=%d)", ms, ms->signum);
426 clist_add_tail(&m->signal_list, &ms->n);
427 if (m->sig_pipe_recv < 0)
430 struct sigaction sa = {
431 .sa_handler = signal_handler_pipe,
432 .sa_flags = SA_NOCLDSTOP | SA_RESTART,
434 sigaction(ms->signum, &sa, NULL);
438 sigaddset(&ss, ms->signum);
439 THREAD_SIGMASK(SIG_UNBLOCK, &ss, NULL);
440 sigaddset(&m->want_signals, ms->signum);
444 signal_del(struct main_signal *ms)
446 struct main_context *m = main_current();
448 DBG("MAIN: Deleting signal %p (sig=%d)", ms, ms->signum);
451 clist_remove(&ms->n);
452 ms->n.next = ms->n.prev = NULL;
455 CLIST_FOR_EACH(struct main_signal *, s, m->signal_list)
456 if (s->signum == ms->signum)
462 sigaddset(&ss, ms->signum);
463 THREAD_SIGMASK(SIG_BLOCK, &ss, NULL);
464 sigdelset(&m->want_signals, ms->signum);
469 main_debug_context(struct main_context *m UNUSED)
472 msg(L_DEBUG, "### Main loop status on %lld", (long long) m->now);
473 msg(L_DEBUG, "\tActive timers:");
474 uns num_timers = count_timers(m);
475 for (uns i = 1; i <= num_timers; i++)
477 struct main_timer *tm = m->timer_table[i];
478 msg(L_DEBUG, "\t\t%p (expires %lld, data %p)", tm, (long long)(tm->expires ? tm->expires - m->now : 999999), tm->data);
480 msg(L_DEBUG, "\tActive files:");
481 CLIST_FOR_EACH(struct main_file *, fi, m->file_list)
482 msg(L_DEBUG, "\t\t%p (fd %d, rh %p, wh %p, data %p)",
483 fi, fi->fd, fi->read_handler, fi->write_handler, fi->data);
484 // FIXME: Can we display status of block_io requests somehow?
485 msg(L_DEBUG, "\tActive hooks:");
486 CLIST_FOR_EACH(struct main_hook *, ho, m->hook_done_list)
487 msg(L_DEBUG, "\t\t%p (func %p, data %p)", ho, ho->handler, ho->data);
488 CLIST_FOR_EACH(struct main_hook *, ho, m->hook_list)
489 msg(L_DEBUG, "\t\t%p (func %p, data %p)", ho, ho->handler, ho->data);
490 msg(L_DEBUG, "\tActive processes:");
491 CLIST_FOR_EACH(struct main_process *, pr, m->process_list)
492 msg(L_DEBUG, "\t\t%p (pid %d, func %p, data %p)", pr, pr->pid, pr->handler, pr->data);
493 msg(L_DEBUG, "\tActive signal catchers:");
494 CLIST_FOR_EACH(struct main_signal *, sg, m->signal_list)
495 msg(L_DEBUG, "\t\t%p (sig %d, func %p, data %p)", sg, sg->signum, sg->handler, sg->data);
500 main_rebuild_poll_table(struct main_context *m)
502 struct main_file *fi;
503 if (m->poll_table_size < m->file_cnt)
506 xfree(m->poll_table);
508 m->poll_table_size = 1;
509 while (m->poll_table_size < m->file_cnt)
510 m->poll_table_size *= 2;
511 m->poll_table = xmalloc(sizeof(struct pollfd) * m->poll_table_size);
513 struct pollfd *p = m->poll_table;
514 DBG("MAIN: Rebuilding poll table: %d of %d entries set", m->file_cnt, m->poll_table_size);
515 CLIST_WALK(fi, m->file_list)
521 m->poll_table_obsolete = 0;
527 DBG("MAIN: Entering main_loop");
528 struct main_context *m = main_current();
530 struct main_file *fi;
531 struct main_hook *ho;
532 struct main_timer *tm;
537 timestamp_t wake = m->now + 1000000000;
538 while (GARY_SIZE(m->timer_table) > 1 && (tm = m->timer_table[1])->expires <= m->now)
540 DBG("MAIN: Timer %p expired at now-%lld", tm, (long long)(m->now - tm->expires));
543 int hook_min = HOOK_RETRY;
544 int hook_max = HOOK_SHUTDOWN;
545 while (ho = clist_remove_head(&m->hook_list))
547 clist_add_tail(&m->hook_done_list, &ho->n);
548 DBG("MAIN: Hook %p", ho);
549 int ret = ho->handler(ho);
550 hook_min = MIN(hook_min, ret);
551 hook_max = MAX(hook_max, ret);
553 clist_move(&m->hook_list, &m->hook_done_list);
554 if (hook_min == HOOK_SHUTDOWN ||
555 hook_min == HOOK_DONE && hook_max == HOOK_DONE ||
558 DBG("MAIN: Shut down by %s", m->shutdown ? "main_shutdown" : "a hook");
561 if (hook_max == HOOK_RETRY)
563 if (m->poll_table_obsolete)
564 main_rebuild_poll_table(m);
565 if (count_timers(m) && (tm = m->timer_table[1])->expires < wake)
568 int timeout = ((wake > m->now) ? wake - m->now : 0);
569 DBG("MAIN: Poll for %d fds and timeout %d ms", m->file_cnt, timeout);
570 int p = poll(m->poll_table, m->file_cnt, timeout);
571 timestamp_t old_now = m->now;
573 m->idle_time += m->now - old_now;
576 struct pollfd *p = m->poll_table;
577 CLIST_WALK(fi, m->file_list)
579 if (p->revents & (POLLIN | POLLHUP | POLLERR))
582 DBG("MAIN: Read event on fd %d", p->fd);
583 while (fi->read_handler && fi->read_handler(fi) && !m->poll_table_obsolete);
584 if (m->poll_table_obsolete) /* File entries have been inserted or deleted => better not risk continuing to nowhere */
587 if (p->revents & (POLLOUT | POLLERR))
590 DBG("MAIN: Write event on fd %d", p->fd);
591 while (fi->write_handler && fi->write_handler(fi) && !m->poll_table_obsolete);
592 if (m->poll_table_obsolete)
603 static struct main_process mp;
604 static struct main_block_io fin, fout;
605 static struct main_hook hook;
606 static struct main_timer tm;
607 static struct main_signal sg;
611 static void dread(struct main_block_io *bio)
613 if (bio->rpos < bio->rlen)
615 msg(L_INFO, "Read EOF");
620 msg(L_INFO, "Read done");
621 block_io_read(bio, rb, sizeof(rb));
625 static void derror(struct main_block_io *bio, int cause)
627 msg(L_INFO, "Error: %m !!! (cause %d)", cause);
631 static void dwrite(struct main_block_io *bio UNUSED)
633 msg(L_INFO, "Write done");
636 static int dhook(struct main_hook *ho UNUSED)
638 msg(L_INFO, "Hook called");
642 static void dtimer(struct main_timer *tm)
644 msg(L_INFO, "Timer tick");
645 timer_add_rel(tm, 11000);
646 timer_add_rel(tm, 10000);
649 static void dentry(void)
651 msg(L_INFO, "*** SUBPROCESS START ***");
653 msg(L_INFO, "*** SUBPROCESS FINISH ***");
657 static void dexit(struct main_process *pr)
659 msg(L_INFO, "Subprocess %d exited with status %x", pr->pid, pr->status);
662 static void dsignal(struct main_signal *sg UNUSED)
664 msg(L_INFO, "SIGINT received (use Ctrl-\\ to really quit)");
673 fin.read_done = dread;
674 fin.error_handler = derror;
675 block_io_add(&fin, 0);
676 block_io_read(&fin, rb, sizeof(rb));
678 fout.write_done = dwrite;
679 fout.error_handler = derror;
680 block_io_add(&fout, 1);
681 block_io_write(&fout, "Hello, world!\n", 14);
683 hook.handler = dhook;
687 timer_add_rel(&tm, 1000);
690 sg.handler = dsignal;
694 if (!process_fork(&mp))
700 msg(L_INFO, "Finished.");