2 * Copyright (c)1996-2002 by Hartmut Brandt
5 * Author: Hartmut Brandt
7 * Redistribution of this software and documentation and use in source and
8 * binary forms, with or without modification, are permitted provided that
9 * the following conditions are met:
11 * 1. Redistributions of source code or documentation must retain the above
12 * copyright notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE AND DOCUMENTATION IS PROVIDED BY THE AUTHOR
18 * AND ITS CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
19 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21 * THE AUTHOR OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
24 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
25 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
26 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
27 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 * These functions try to hide the poll/select/setitimer interface from the
31 * user. You associate callback functions with file descriptors and timers.
33 * $Begemot: libbegemot/rpoll.c,v 1.14 2004/09/21 15:59:00 brandt Exp $
45 # include <sys/time.h>
54 # ifdef NEED_POLL_XOPEN_TWIDDLE
58 # ifdef NEED_POLL_XOPEN_TWIDDLE
65 * the second define is for Linux, which sometimes fails to
68 # if defined(USE_SELECT) || !defined(INFTIM)
73 # define SIGNAL SIGPOLL
81 # define poll_in (POLLIN | POLLRDNORM | POLLRDBAND | POLLPRI)
82 # define poll_out (POLLOUT | POLLWRNORM | POLLWRBAND)
83 # define poll_except (POLLERR | POLLHUP)
86 # ifdef BROKEN_SELECT_PROTO
87 # define SELECT_CAST(P) (int *)P
89 # define SELECT_CAST(P) P
93 typedef int64_t tval_t;
95 static inline tval_t GETUSECS(void);
101 (void)gettimeofday(&tval, NULL);
102 return (tval_t)tval.tv_sec * 1000000 + tval.tv_usec;
109 _panic(const char *fmt, ...)
114 fprintf(stderr, "panic: ");
115 vfprintf(stderr, fmt, ap);
116 fprintf(stderr, "\n");
123 _xrealloc(void *p, size_t s)
128 if((ptr=malloc(s)) == NULL && (s!=0 || (ptr=malloc(1)) == NULL))
129 _panic("out of memory: xrealloc(%lx, %lu)",
130 (unsigned long)p, (unsigned long)s);
133 if((ptr=malloc(s)) == NULL && (ptr=malloc(1)) == NULL)
134 _panic("out of memory: xrealloc(%lx, %lu)",
135 (unsigned long)p, (unsigned long)s);
137 if((ptr = realloc(p, s)) == NULL)
138 _panic("out of memory: xrealloc(%lx, %lu)",
139 (unsigned long)p, (unsigned long)s);
146 * This structure holds one registration record for files
149 int fd; /* file descriptor (-1 if struct unused) */
150 int mask; /* event flags */
151 void * arg; /* client arg */
152 poll_f func; /* handler */
154 struct pollfd *pfd; /* pointer to corresponding poll() structure */
162 uint64_t usecs; /* microsecond value of the timer */
163 int repeat; /* one shot or repeat? */
164 void *arg; /* client arg */
165 timer_f func; /* handler, 0 means disfunct */
166 tval_t when; /* next time to trigger in usecs! */
169 /* how many records should our table grow at once? */
170 # define POLL_REG_GROW 100
173 static struct pollfd * pfd; /* fd list for poll() */
177 static fd_set rset, wset, xset; /* file descriptor sets for select() */
178 static int maxfd; /* maximum fd number */
181 static int in_dispatch;
183 static PollReg_t * regs; /* registration records */
184 static u_int regs_alloc; /* how many are allocated */
185 static u_int regs_used; /* upper used limit */
186 static sigset_t bset; /* blocked signals */
187 static int rebuild; /* rebuild table on next dispatch() */
189 static int * tfd; /* sorted entries */
190 static u_int tfd_alloc; /* number of entries allocated */
191 static u_int tfd_used; /* number of entries used */
192 static PollTim_t * tims; /* timer registration records */
193 static u_int tims_alloc; /* how many are allocated */
194 static u_int tims_used; /* how many are used */
195 static int resort; /* resort on next dispatch */
198 int rpoll_policy; /* if 0 start sched callbacks from 0 else try round robin */
200 static void poll_build(void);
201 static void poll_blocksig(void);
202 static void poll_unblocksig(void);
203 static void sort_timers(void);
207 * Private function to block SIGPOLL or SIGIO for a short time.
208 * Don't forget to call poll_unblock before return from the calling function.
209 * Don't change the mask between this calls (your changes will be lost).
217 sigaddset(&set, SIGNAL);
219 if(sigprocmask(SIG_BLOCK, &set, &bset))
220 _panic("sigprocmask(SIG_BLOCK): %s", strerror(errno));
224 * unblock the previously blocked signal
227 poll_unblocksig(void)
229 if(sigprocmask(SIG_SETMASK, &bset, NULL))
230 _panic("sigprocmask(SIG_SETMASK): %s", strerror(errno));
234 * Register the file descriptor fd. If the event corresponding to
235 * mask arrives func is called with arg.
236 * If fd is already registered with that func and arg, only the mask
238 * We block the IO-signal, so the dispatch function can be called from
239 * within the signal handler.
242 poll_register(int fd, poll_f func, void *arg, int mask)
248 /* already registered? */
249 for(p = regs; p < ®s[regs_alloc]; p++)
250 if(p->fd == fd && p->func == func && p->arg == arg) {
255 if(p == ®s[regs_alloc]) {
258 /* find a free slot */
259 for(p = regs; p < ®s[regs_alloc]; p++)
263 if(p == ®s[regs_alloc]) {
264 size_t newsize = regs_alloc + POLL_REG_GROW;
265 regs = _xrealloc(regs, sizeof(regs[0]) * newsize);
266 for(p = ®s[regs_alloc]; p < ®s[newsize]; p++) {
272 p = ®s[regs_alloc];
273 regs_alloc = newsize;
288 fprintf(stderr, "poll_register(%d, %p, %p, %#x)->%tu",
289 fd, (void *)func, (void *)arg, mask, p - regs);
294 * remove registration
297 poll_unregister(int handle)
300 fprintf(stderr, "poll_unregister(%d)", handle);
304 regs[handle].fd = -1;
306 regs[handle].pfd = NULL;
315 * Build the structures used by poll() or select()
325 f = pfd = _xrealloc(pfd, sizeof(pfd[0]) * regs_used);
327 for(p = regs; p < ®s[regs_alloc]; p++)
331 if(p->mask & RPOLL_IN)
332 f->events |= poll_in;
333 if(p->mask & RPOLL_OUT)
334 f->events |= poll_out;
335 if(p->mask & RPOLL_EXCEPT)
336 f->events |= poll_except;
340 assert(f == &pfd[regs_used]);
348 for(p = regs; p < ®s[regs_alloc]; p++)
352 if(p->mask & RPOLL_IN)
353 FD_SET(p->fd, &rset);
354 if(p->mask & RPOLL_OUT)
355 FD_SET(p->fd, &wset);
356 if(p->mask & RPOLL_EXCEPT)
357 FD_SET(p->fd, &xset);
363 poll_start_timer(u_int msecs, int repeat, timer_f func, void *arg)
365 return (poll_start_utimer((unsigned long long)msecs * 1000,
370 poll_start_utimer(unsigned long long usecs, int repeat, timer_f func, void *arg)
374 /* find unused entry */
375 for(p = tims; p < &tims[tims_alloc]; p++)
379 if(p == &tims[tims_alloc]) {
380 if(tims_alloc == tims_used) {
381 size_t newsize = tims_alloc + POLL_REG_GROW;
382 tims = _xrealloc(tims, sizeof(tims[0]) * newsize);
383 for(p = &tims[tims_alloc]; p < &tims[newsize]; p++)
385 p = &tims[tims_alloc];
386 tims_alloc = newsize;
395 p->when = GETUSECS() + usecs;
402 fprintf(stderr, "poll_start_utimer(%llu, %d, %p, %p)->%tu",
403 usecs, repeat, (void *)func, (void *)arg, p - tims);
409 * Here we have to look into the sorted table, whether any entry there points
410 * into the registration table for the deleted entry. This is needed,
411 * because a unregistration can occure while we are scanning through the
412 * table in dispatch(). Do this only, if we are really there - resorting
413 * will sort out things if we are called from outside the loop.
416 poll_stop_timer(int handle)
421 fprintf(stderr, "poll_stop_timer(%d)", handle);
423 tims[handle].func = NULL;
431 for(i = 0; i < tfd_used; i++)
432 if(tfd[i] == handle) {
439 * Squeeze and sort timer table.
440 * Should perhaps use a custom sort.
443 tim_cmp(const void *p1, const void *p2)
445 int t1 = *(const int *)p1;
446 int t2 = *(const int *)p2;
448 return tims[t1].when < tims[t2].when ? -1
449 : tims[t1].when > tims[t2].when ? +1
454 * Reconstruct the tfd-array. This will be an sorted array of indexes
455 * to the used entries in tims. The next timer to expire will be infront
456 * of the array. tfd_used is the number of used entries. The array is
457 * re-allocated if needed.
465 if(tims_used > tfd_alloc) {
466 tfd_alloc = tims_used;
467 tfd = _xrealloc(tfd, sizeof(int *) * tfd_alloc);
472 for(i = 0; i < tims_alloc; i++)
475 assert(pp - tfd == (ptrdiff_t)tims_used);
477 tfd_used = tims_used;
479 qsort(tfd, tfd_used, sizeof(int), tim_cmp);
483 * Poll the file descriptors and dispatch to the right function
484 * If wait is true the poll blocks until somewhat happens.
485 * Don't use a pointer here, because the called function may cause
486 * a reallocation! The check for pfd != NULL is required, because
487 * a sequence of unregister/register could make the wrong callback
488 * to be called. So we clear pfd in unregister and check here.
491 poll_dispatch(int wait)
497 static u_int last_index;
500 fd_set nrset, nwset, nxset;
515 /* in wait mode - compute the timeout */
521 fprintf(stderr, "now=%llu", now);
522 for(i = 0; i < tims_used; i++)
523 fprintf(stderr, "timers[%2d] = %lld",
524 i, tfd[i]->when - now);
527 if((tout = tims[tfd[0]].when - now) < 0)
535 fprintf(stderr, "rpoll -- selecting with tout=%u", tout);
539 ret = poll(pfd, regs_used, tout == INFTIM ? INFTIM : (tout / 1000));
547 tv.tv_sec = tout / 1000000;
548 tv.tv_usec = tout % 1000000;
550 ret = select(maxfd+1,
553 SELECT_CAST(&nxset), (tout==INFTIM) ? NULL : &tv);
559 _panic("poll/select: %s", strerror(errno));
564 for(i = 0; i < regs_alloc; i++) {
565 idx = rpoll_policy ? ((last_index+i) % regs_alloc) : i;
567 assert(idx < regs_alloc);
569 if(regs[idx].fd >= 0) {
574 if ((regs[idx].mask & RPOLL_IN) &&
575 (regs[idx].pfd->revents & poll_in))
577 if ((regs[idx].mask & RPOLL_OUT) &&
578 (regs[idx].pfd->revents & poll_out))
580 if((regs[idx].mask & RPOLL_EXCEPT) &&
581 (regs[idx].pfd->revents & poll_except))
582 mask |= RPOLL_EXCEPT;
586 if ((regs[idx].mask & RPOLL_IN) &&
587 FD_ISSET(regs[idx].fd, &nrset))
589 if ((regs[idx].mask & RPOLL_OUT) &&
590 FD_ISSET(regs[idx].fd, &nwset))
592 if ((regs[idx].mask & RPOLL_EXCEPT) &&
593 FD_ISSET(regs[idx].fd, &nxset))
594 mask |= RPOLL_EXCEPT;
596 assert(idx < regs_alloc);
600 fprintf(stderr, "poll_dispatch() -- "
602 regs[idx].fd, idx, mask);
603 (*regs[idx].func)(regs[idx].fd, mask, regs[idx].arg);
611 /* dispatch timeouts */
614 for(i = 0; i < tfd_used; i++) {
617 if(tims[tfd[i]].when > now)
620 fprintf(stderr, "rpoll_dispatch() -- timeout %d",tfd[i]);
621 (*tims[tfd[i]].func)(tfd[i], tims[tfd[i]].arg);
624 if(tims[tfd[i]].repeat)
625 tims[tfd[i]].when = now + tims[tfd[i]].usecs;
627 tims[tfd[i]].func = NULL;
639 struct timeval start, now;
643 void infunc(int fd, int mask, void *arg);
648 gettimeofday(&now, NULL);
650 return (double)(10 * now.tv_sec + now.tv_usec / 100000 -
651 10 * start.tv_sec - start.tv_usec / 100000) / 10;
655 infunc(int fd, int mask, void *arg)
662 if((ret = read(fd, buf, sizeof(buf))) < 0)
663 _panic("read: %s", strerror(errno));
664 write(1, "stdin:", 6);
668 void tfunc0(int tid, void *arg);
669 void tfunc1(int tid, void *arg);
672 tfunc0(int tid, void *arg)
674 printf("%4.1f -- %d: %s\n", elaps(), tid, (char *)arg);
677 tfunc1(int tid, void *arg)
679 printf("%4.1f -- %d: %s\n", elaps(), tid, (char *)arg);
682 tfunc2(int tid, void *arg)
684 static u_int count = 0;
686 if (++count % 10000 == 0)
687 printf("%4.1f -- %d\n", elaps(), tid);
690 void first(int tid, void *arg);
691 void second(int tid, void *arg);
694 second(int tid, void *arg)
696 printf("%4.1f -- %d: %s\n", elaps(), tid, (char *)arg);
697 poll_start_utimer(5500000, 0, first, "first");
699 t0 = poll_start_timer(1000, 1, tfunc0, "1 second");
702 first(int tid, void *arg)
704 printf("%4.1f -- %d: %s\n", elaps(), tid, (char *)arg);
705 poll_start_timer(3700, 0, second, "second");
707 t1 = poll_start_timer(250, 1, tfunc1, "1/4 second");
711 main(int argc, char *argv[])
714 gettimeofday(&start, NULL);
715 poll_register(0, infunc, NULL, RPOLL_IN);
718 t0 = poll_start_timer(1000, 1, tfunc0, "1 second");
719 poll_start_timer(2500, 0, first, "first");
721 t0 = poll_start_utimer(300, 1, tfunc2, NULL);