1 /* $OpenBSD: select.c,v 1.2 2002/06/25 15:50:15 mickey Exp $ */
4 * Copyright 2000-2002 Niels Provos <provos@citi.umich.edu>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 #include <sys/types.h>
34 #ifdef HAVE_SYS_TIME_H
37 #include <sys/_time.h>
39 #ifdef HAVE_SYS_SELECT_H
40 #include <sys/select.h>
42 #include <sys/queue.h>
50 #ifdef CHECK_INVARIANTS
55 #include "event-internal.h"
60 #define howmany(x, y) (((x)+((y)-1))/(y))
64 int event_fds; /* Highest fd in fd set */
66 fd_set *event_readset_in;
67 fd_set *event_writeset_in;
68 fd_set *event_readset_out;
69 fd_set *event_writeset_out;
70 struct event **event_r_by_fd;
71 struct event **event_w_by_fd;
74 void *select_init (struct event_base *);
75 int select_add (void *, struct event *);
76 int select_del (void *, struct event *);
77 int select_recalc (struct event_base *, void *, int);
78 int select_dispatch (struct event_base *, void *, struct timeval *);
79 void select_dealloc (struct event_base *, void *);
81 const struct eventop selectops = {
91 static int select_resize(struct selectop *sop, int fdsz);
94 select_init(struct event_base *base)
98 /* Disable select when this environment variable is set */
99 if (getenv("EVENT_NOSELECT"))
102 if (!(sop = calloc(1, sizeof(struct selectop))))
105 select_resize(sop, howmany(32 + 1, NFDBITS)*sizeof(fd_mask));
112 #ifdef CHECK_INVARIANTS
114 check_selectop(struct selectop *sop)
117 for (i = 0; i <= sop->event_fds; ++i) {
118 if (FD_ISSET(i, sop->event_readset_in)) {
119 assert(sop->event_r_by_fd[i]);
120 assert(sop->event_r_by_fd[i]->ev_events & EV_READ);
121 assert(sop->event_r_by_fd[i]->ev_fd == i);
123 assert(! sop->event_r_by_fd[i]);
125 if (FD_ISSET(i, sop->event_writeset_in)) {
126 assert(sop->event_w_by_fd[i]);
127 assert(sop->event_w_by_fd[i]->ev_events & EV_WRITE);
128 assert(sop->event_w_by_fd[i]->ev_fd == i);
130 assert(! sop->event_w_by_fd[i]);
136 #define check_selectop(sop) do { (void) sop; } while (0)
140 * Called with the highest fd that we know about. If it is 0, completely
141 * recalculate everything.
145 select_recalc(struct event_base *base, void *arg, int max)
147 struct selectop *sop = arg;
155 select_dispatch(struct event_base *base, void *arg, struct timeval *tv)
158 struct selectop *sop = arg;
162 memcpy(sop->event_readset_out, sop->event_readset_in,
164 memcpy(sop->event_writeset_out, sop->event_writeset_in,
167 res = select(sop->event_fds + 1, sop->event_readset_out,
168 sop->event_writeset_out, NULL, tv);
173 if (errno != EINTR) {
174 event_warn("select");
178 evsignal_process(base);
180 } else if (base->sig.evsignal_caught) {
181 evsignal_process(base);
184 event_debug(("%s: select reports %d", __func__, res));
187 for (i = 0; i <= sop->event_fds; ++i) {
188 struct event *r_ev = NULL, *w_ev = NULL;
190 if (FD_ISSET(i, sop->event_readset_out)) {
191 r_ev = sop->event_r_by_fd[i];
194 if (FD_ISSET(i, sop->event_writeset_out)) {
195 w_ev = sop->event_w_by_fd[i];
198 if (r_ev && (res & r_ev->ev_events)) {
199 if (!(r_ev->ev_events & EV_PERSIST))
201 event_active(r_ev, res & r_ev->ev_events, 1);
203 if (w_ev && w_ev != r_ev && (res & w_ev->ev_events)) {
204 if (!(w_ev->ev_events & EV_PERSIST))
206 event_active(w_ev, res & w_ev->ev_events, 1);
216 select_resize(struct selectop *sop, int fdsz)
218 int n_events, n_events_old;
220 fd_set *readset_in = NULL;
221 fd_set *writeset_in = NULL;
222 fd_set *readset_out = NULL;
223 fd_set *writeset_out = NULL;
224 struct event **r_by_fd = NULL;
225 struct event **w_by_fd = NULL;
227 n_events = (fdsz/sizeof(fd_mask)) * NFDBITS;
228 n_events_old = (sop->event_fdsz/sizeof(fd_mask)) * NFDBITS;
230 if (sop->event_readset_in)
233 if ((readset_in = realloc(sop->event_readset_in, fdsz)) == NULL)
235 sop->event_readset_in = readset_in;
236 if ((readset_out = realloc(sop->event_readset_out, fdsz)) == NULL)
238 sop->event_readset_out = readset_out;
239 if ((writeset_in = realloc(sop->event_writeset_in, fdsz)) == NULL)
241 sop->event_writeset_in = writeset_in;
242 if ((writeset_out = realloc(sop->event_writeset_out, fdsz)) == NULL)
244 sop->event_writeset_out = writeset_out;
245 if ((r_by_fd = realloc(sop->event_r_by_fd,
246 n_events*sizeof(struct event*))) == NULL)
248 sop->event_r_by_fd = r_by_fd;
249 if ((w_by_fd = realloc(sop->event_w_by_fd,
250 n_events * sizeof(struct event*))) == NULL)
252 sop->event_w_by_fd = w_by_fd;
254 memset((char *)sop->event_readset_in + sop->event_fdsz, 0,
255 fdsz - sop->event_fdsz);
256 memset((char *)sop->event_writeset_in + sop->event_fdsz, 0,
257 fdsz - sop->event_fdsz);
258 memset(sop->event_r_by_fd + n_events_old, 0,
259 (n_events-n_events_old) * sizeof(struct event*));
260 memset(sop->event_w_by_fd + n_events_old, 0,
261 (n_events-n_events_old) * sizeof(struct event*));
263 sop->event_fdsz = fdsz;
269 event_warn("malloc");
275 select_add(void *arg, struct event *ev)
277 struct selectop *sop = arg;
279 if (ev->ev_events & EV_SIGNAL)
280 return (evsignal_add(ev));
284 * Keep track of the highest fd, so that we can calculate the size
285 * of the fd_sets for select(2)
287 if (sop->event_fds < ev->ev_fd) {
288 int fdsz = sop->event_fdsz;
290 if (fdsz < sizeof(fd_mask))
291 fdsz = sizeof(fd_mask);
294 (howmany(ev->ev_fd + 1, NFDBITS) * sizeof(fd_mask)))
297 if (fdsz != sop->event_fdsz) {
298 if (select_resize(sop, fdsz)) {
304 sop->event_fds = ev->ev_fd;
307 if (ev->ev_events & EV_READ) {
308 FD_SET(ev->ev_fd, sop->event_readset_in);
309 sop->event_r_by_fd[ev->ev_fd] = ev;
311 if (ev->ev_events & EV_WRITE) {
312 FD_SET(ev->ev_fd, sop->event_writeset_in);
313 sop->event_w_by_fd[ev->ev_fd] = ev;
321 * Nothing to be done here.
325 select_del(void *arg, struct event *ev)
327 struct selectop *sop = arg;
330 if (ev->ev_events & EV_SIGNAL)
331 return (evsignal_del(ev));
333 if (sop->event_fds < ev->ev_fd) {
338 if (ev->ev_events & EV_READ) {
339 FD_CLR(ev->ev_fd, sop->event_readset_in);
340 sop->event_r_by_fd[ev->ev_fd] = NULL;
343 if (ev->ev_events & EV_WRITE) {
344 FD_CLR(ev->ev_fd, sop->event_writeset_in);
345 sop->event_w_by_fd[ev->ev_fd] = NULL;
353 select_dealloc(struct event_base *base, void *arg)
355 struct selectop *sop = arg;
357 evsignal_dealloc(base);
358 if (sop->event_readset_in)
359 free(sop->event_readset_in);
360 if (sop->event_writeset_in)
361 free(sop->event_writeset_in);
362 if (sop->event_readset_out)
363 free(sop->event_readset_out);
364 if (sop->event_writeset_out)
365 free(sop->event_writeset_out);
366 if (sop->event_r_by_fd)
367 free(sop->event_r_by_fd);
368 if (sop->event_w_by_fd)
369 free(sop->event_w_by_fd);
371 memset(sop, 0, sizeof(struct selectop));