1 /* $OpenBSD: poll.c,v 1.2 2002/06/25 15:50:15 mickey Exp $ */
4 * Copyright 2000-2003 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 #include <sys/queue.h>
48 #ifdef CHECK_INVARIANTS
53 #include "event-internal.h"
58 int event_count; /* Highest number alloc */
59 int nfds; /* Size of event_* */
60 int fd_count; /* Size of idxplus1_by_fd */
61 struct pollfd *event_set;
62 struct event **event_r_back;
63 struct event **event_w_back;
64 int *idxplus1_by_fd; /* Index into event_set by fd; we add 1 so
65 * that 0 (which is easy to memset) can mean
69 void *poll_init (struct event_base *);
70 int poll_add (void *, struct event *);
71 int poll_del (void *, struct event *);
72 int poll_recalc (struct event_base *, void *, int);
73 int poll_dispatch (struct event_base *, void *, struct timeval *);
74 void poll_dealloc (struct event_base *, void *);
76 const struct eventop pollops = {
87 poll_init(struct event_base *base)
89 struct pollop *pollop;
91 /* Disable poll when this environment variable is set */
92 if (getenv("EVENT_NOPOLL"))
95 if (!(pollop = calloc(1, sizeof(struct pollop))))
104 * Called with the highest fd that we know about. If it is 0, completely
105 * recalculate everything.
109 poll_recalc(struct event_base *base, void *arg, int max)
114 #ifdef CHECK_INVARIANTS
116 poll_check_ok(struct pollop *pop)
121 for (i = 0; i < pop->fd_count; ++i) {
122 idx = pop->idxplus1_by_fd[i]-1;
125 assert(pop->event_set[idx].fd == i);
126 if (pop->event_set[idx].events & POLLIN) {
127 ev = pop->event_r_back[idx];
129 assert(ev->ev_events & EV_READ);
130 assert(ev->ev_fd == i);
132 if (pop->event_set[idx].events & POLLOUT) {
133 ev = pop->event_w_back[idx];
135 assert(ev->ev_events & EV_WRITE);
136 assert(ev->ev_fd == i);
139 for (i = 0; i < pop->nfds; ++i) {
140 struct pollfd *pfd = &pop->event_set[i];
141 assert(pop->idxplus1_by_fd[pfd->fd] == i+1);
145 #define poll_check_ok(pop)
149 poll_dispatch(struct event_base *base, void *arg, struct timeval *tv)
151 int res, i, msec = -1, nfds;
152 struct pollop *pop = arg;
157 msec = tv->tv_sec * 1000 + (tv->tv_usec + 999) / 1000;
160 res = poll(pop->event_set, nfds, msec);
163 if (errno != EINTR) {
168 evsignal_process(base);
170 } else if (base->sig.evsignal_caught) {
171 evsignal_process(base);
174 event_debug(("%s: poll reports %d", __func__, res));
179 for (i = 0; i < nfds; i++) {
180 int what = pop->event_set[i].revents;
181 struct event *r_ev = NULL, *w_ev = NULL;
187 /* If the file gets closed notify */
188 if (what & (POLLHUP|POLLERR))
189 what |= POLLIN|POLLOUT;
192 r_ev = pop->event_r_back[i];
194 if (what & POLLOUT) {
196 w_ev = pop->event_w_back[i];
201 if (r_ev && (res & r_ev->ev_events)) {
202 if (!(r_ev->ev_events & EV_PERSIST))
204 event_active(r_ev, res & r_ev->ev_events, 1);
206 if (w_ev && w_ev != r_ev && (res & w_ev->ev_events)) {
207 if (!(w_ev->ev_events & EV_PERSIST))
209 event_active(w_ev, res & w_ev->ev_events, 1);
217 poll_add(void *arg, struct event *ev)
219 struct pollop *pop = arg;
220 struct pollfd *pfd = NULL;
223 if (ev->ev_events & EV_SIGNAL)
224 return (evsignal_add(ev));
225 if (!(ev->ev_events & (EV_READ|EV_WRITE)))
229 if (pop->nfds + 1 >= pop->event_count) {
230 struct pollfd *tmp_event_set;
231 struct event **tmp_event_r_back;
232 struct event **tmp_event_w_back;
235 if (pop->event_count < 32)
236 tmp_event_count = 32;
238 tmp_event_count = pop->event_count * 2;
240 /* We need more file descriptors */
241 tmp_event_set = realloc(pop->event_set,
242 tmp_event_count * sizeof(struct pollfd));
243 if (tmp_event_set == NULL) {
244 event_warn("realloc");
247 pop->event_set = tmp_event_set;
249 tmp_event_r_back = realloc(pop->event_r_back,
250 tmp_event_count * sizeof(struct event *));
251 if (tmp_event_r_back == NULL) {
252 /* event_set overallocated; that's okay. */
253 event_warn("realloc");
256 pop->event_r_back = tmp_event_r_back;
258 tmp_event_w_back = realloc(pop->event_w_back,
259 tmp_event_count * sizeof(struct event *));
260 if (tmp_event_w_back == NULL) {
261 /* event_set and event_r_back overallocated; that's
263 event_warn("realloc");
266 pop->event_w_back = tmp_event_w_back;
268 pop->event_count = tmp_event_count;
270 if (ev->ev_fd >= pop->fd_count) {
271 int *tmp_idxplus1_by_fd;
273 if (pop->fd_count < 32)
276 new_count = pop->fd_count * 2;
277 while (new_count <= ev->ev_fd)
280 realloc(pop->idxplus1_by_fd, new_count * sizeof(int));
281 if (tmp_idxplus1_by_fd == NULL) {
282 event_warn("realloc");
285 pop->idxplus1_by_fd = tmp_idxplus1_by_fd;
286 memset(pop->idxplus1_by_fd + pop->fd_count,
287 0, sizeof(int)*(new_count - pop->fd_count));
288 pop->fd_count = new_count;
291 i = pop->idxplus1_by_fd[ev->ev_fd] - 1;
293 pfd = &pop->event_set[i];
296 pfd = &pop->event_set[i];
299 pop->event_w_back[i] = pop->event_r_back[i] = NULL;
300 pop->idxplus1_by_fd[ev->ev_fd] = i + 1;
304 if (ev->ev_events & EV_WRITE) {
305 pfd->events |= POLLOUT;
306 pop->event_w_back[i] = ev;
308 if (ev->ev_events & EV_READ) {
309 pfd->events |= POLLIN;
310 pop->event_r_back[i] = ev;
318 * Nothing to be done here.
322 poll_del(void *arg, struct event *ev)
324 struct pollop *pop = arg;
325 struct pollfd *pfd = NULL;
328 if (ev->ev_events & EV_SIGNAL)
329 return (evsignal_del(ev));
331 if (!(ev->ev_events & (EV_READ|EV_WRITE)))
335 i = pop->idxplus1_by_fd[ev->ev_fd] - 1;
339 /* Do we still want to read or write? */
340 pfd = &pop->event_set[i];
341 if (ev->ev_events & EV_READ) {
342 pfd->events &= ~POLLIN;
343 pop->event_r_back[i] = NULL;
345 if (ev->ev_events & EV_WRITE) {
346 pfd->events &= ~POLLOUT;
347 pop->event_w_back[i] = NULL;
351 /* Another event cares about that fd. */
354 /* Okay, so we aren't interested in that fd anymore. */
355 pop->idxplus1_by_fd[ev->ev_fd] = 0;
358 if (i != pop->nfds) {
360 * Shift the last pollfd down into the now-unoccupied
363 memcpy(&pop->event_set[i], &pop->event_set[pop->nfds],
364 sizeof(struct pollfd));
365 pop->event_r_back[i] = pop->event_r_back[pop->nfds];
366 pop->event_w_back[i] = pop->event_w_back[pop->nfds];
367 pop->idxplus1_by_fd[pop->event_set[i].fd] = i + 1;
375 poll_dealloc(struct event_base *base, void *arg)
377 struct pollop *pop = arg;
379 evsignal_dealloc(base);
381 free(pop->event_set);
382 if (pop->event_r_back)
383 free(pop->event_r_back);
384 if (pop->event_w_back)
385 free(pop->event_w_back);
386 if (pop->idxplus1_by_fd)
387 free(pop->idxplus1_by_fd);
389 memset(pop, 0, sizeof(struct pollop));