2 * IRC - Internet Relay Chat, ircd/engine_devpoll.c
3 * Copyright (C) 2001 Kevin L. Mitchell <klmitch@mit.edu>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 1, or (at your option)
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 #include "ircd_events.h"
26 #include "ircd_alloc.h"
27 #include "ircd_features.h"
34 #include <sys/devpoll.h>
36 #include <sys/socket.h>
38 #include <sys/types.h>
41 #define DEVPOLL_ERROR_THRESHOLD 20 /* after 20 devpoll errors, restart */
42 #define ERROR_EXPIRE_TIME 3600 /* expire errors after an hour */
44 /* Figure out what bits to set for read */
45 #if defined(POLLMSG) && defined(POLLIN) && defined(POLLRDNORM)
46 # define POLLREADFLAGS (POLLMSG|POLLIN|POLLRDNORM)
47 #elif defined(POLLIN) && defined(POLLRDNORM)
48 # define POLLREADFLAGS (POLLIN|POLLRDNORM)
50 # define POLLREADFLAGS POLLIN
51 #elif defined(POLLRDNORM)
52 # define POLLREADFLAGS POLLRDNORM
55 /* Figure out what bits to set for write */
56 #if defined(POLLOUT) && defined(POLLWRNORM)
57 # define POLLWRITEFLAGS (POLLOUT|POLLWRNORM)
58 #elif defined(POLLOUT)
59 # define POLLWRITEFLAGS POLLOUT
60 #elif defined(POLLWRNORM)
61 # define POLLWRITEFLAGS POLLWRNORM
64 static struct Socket** sockList;
65 static int devpoll_max;
66 static int devpoll_fd;
68 static int errors = 0;
69 static struct Timer clear_error;
71 /* decrements the error count once per hour */
73 error_clear(struct Event* ev)
75 if (!--errors) /* remove timer when error count reaches 0 */
76 timer_del(ev_timer(ev));
79 /* initialize the devpoll engine */
81 engine_init(int max_sockets)
85 if ((devpoll_fd = open("/dev/poll", O_RDWR)) < 0) {
86 log_write(LS_SYSTEM, L_WARNING, 0,
87 "/dev/poll engine cannot open device: %m");
88 return 0; /* engine cannot be initialized; defer */
91 /* allocate necessary memory */
92 sockList = (struct Socket**) MyMalloc(sizeof(struct Socket*) * max_sockets);
94 /* initialize the data */
95 for (i = 0; i < max_sockets; i++)
98 devpoll_max = max_sockets; /* number of sockets allocated */
103 /* Figure out what events go with a given state */
105 state_to_events(enum SocketState state, unsigned int events)
108 case SS_CONNECTING: /* connecting socket */
109 return SOCK_EVENT_WRITABLE;
112 case SS_LISTENING: /* listening socket */
113 case SS_NOTSOCK: /* our signal socket */
114 return SOCK_EVENT_READABLE;
117 case SS_CONNECTED: case SS_DATAGRAM: case SS_CONNECTDG:
118 return events; /* ordinary socket */
126 /* Reset the desired events */
128 set_events(struct Socket* sock, unsigned int events)
134 if (s_ed_int(sock)) { /* is one in /dev/poll already? */
135 pfd.events = POLLREMOVE; /* First, remove old pollfd */
137 Debug((DEBUG_ENGINE, "devpoll: Removing old entry for socket %d [%p]",
140 if (write(devpoll_fd, &pfd, sizeof(pfd)) != sizeof(pfd)) {
141 event_generate(ET_ERROR, sock, errno); /* report error */
145 s_ed_int(sock) = 0; /* mark that it's gone */
148 if (!(events & SOCK_EVENT_MASK)) /* no events, so stop here */
151 pfd.events = 0; /* Now, set up new pollfd... */
152 if (events & SOCK_EVENT_READABLE)
153 pfd.events |= POLLREADFLAGS; /* look for readable conditions */
154 if (events & SOCK_EVENT_WRITABLE)
155 pfd.events |= POLLWRITEFLAGS; /* look for writable conditions */
157 Debug((DEBUG_ENGINE, "devpoll: Registering interest on %d [%p] (state %s, "
158 "mask [%s])", s_fd(sock), sock, state_to_name(s_state(sock)),
159 sock_flags(s_events(sock))));
161 if (write(devpoll_fd, &pfd, sizeof(pfd)) != sizeof(pfd)) {
162 event_generate(ET_ERROR, sock, errno); /* report error */
166 s_ed_int(sock) = 1; /* mark that we've added a pollfd */
169 /* add a socket to be listened on */
171 engine_add(struct Socket* sock)
174 assert(0 == sockList[s_fd(sock)]);
176 /* bounds-check... */
177 if (s_fd(sock) >= devpoll_max) {
178 log_write(LS_SYSTEM, L_ERROR, 0,
179 "Attempt to add socket %d (> %d) to event engine", s_fd(sock),
184 sockList[s_fd(sock)] = sock; /* add to list */
186 Debug((DEBUG_ENGINE, "devpoll: Adding socket %d [%p], state %s, to engine",
187 s_fd(sock), sock, state_to_name(s_state(sock))));
189 /* set the correct events */
190 set_events(sock, state_to_events(s_state(sock), s_events(sock)));
192 return 1; /* success */
195 /* socket switching to new state */
197 engine_state(struct Socket* sock, enum SocketState new_state)
200 assert(sock == sockList[s_fd(sock)]);
202 Debug((DEBUG_ENGINE, "devpoll: Changing state for socket %p to %s", sock,
203 state_to_name(new_state)));
205 /* set the correct events */
206 set_events(sock, state_to_events(new_state, s_events(sock)));
209 /* socket events changing */
211 engine_events(struct Socket* sock, unsigned int new_events)
214 assert(sock == sockList[s_fd(sock)]);
216 Debug((DEBUG_ENGINE, "devpoll: Changing event mask for socket %p to [%s]",
217 sock, sock_flags(new_events)));
219 /* set the correct events */
220 set_events(sock, state_to_events(s_state(sock), new_events));
223 /* socket going away */
225 engine_delete(struct Socket* sock)
228 assert(sock == sockList[s_fd(sock)]);
230 Debug((DEBUG_ENGINE, "devpoll: Deleting socket %d [%p], state %s",
231 s_fd(sock), sock, state_to_name(s_state(sock))));
233 set_events(sock, 0); /* get rid of the socket */
235 sockList[s_fd(sock)] = 0; /* zero the socket list entry */
238 /* engine event loop */
240 engine_loop(struct Generators* gen)
242 struct dvpoll dopoll;
243 struct pollfd *polls;
251 if ((polls_count = feature_int(FEAT_POLLS_PER_LOOP)) < 20)
253 polls = (struct pollfd *)MyMalloc(sizeof(struct pollfd) * polls_count);
256 if ((i = feature_int(FEAT_POLLS_PER_LOOP)) >= 20 && i != polls_count) {
257 polls = (struct pollfd *)MyRealloc(polls, sizeof(struct pollfd) * i);
261 dopoll.dp_fds = polls; /* set up the struct dvpoll */
262 dopoll.dp_nfds = polls_count;
264 /* calculate the proper timeout */
265 dopoll.dp_timeout = timer_next(gen) ?
266 (timer_next(gen) - CurrentTime) * 1000 : -1;
268 Debug((DEBUG_INFO, "devpoll: delay: %Tu (%Tu) %d", timer_next(gen),
269 CurrentTime, dopoll.dp_timeout));
271 /* check for active files */
272 nfds = ioctl(devpoll_fd, DP_POLL, &dopoll);
274 CurrentTime = time(0); /* set current time... */
277 if (errno != EINTR) { /* ignore interrupts */
278 /* Log the poll error */
279 log_write(LS_SOCKET, L_ERROR, 0, "ioctl(DP_POLL) error: %m");
281 timer_add(timer_init(&clear_error), error_clear, 0, TT_PERIODIC,
283 else if (errors > DEVPOLL_ERROR_THRESHOLD) /* too many errors... */
284 server_restart("too many /dev/poll errors");
286 /* old code did a sleep(1) here; with usage these days,
287 * that may be too expensive
292 for (i = 0; i < nfds; i++) {
293 assert(-1 < polls[i].fd);
295 sock = sockList[polls[i].fd];
296 if (!sock) /* slots may become empty while processing events */
299 assert(s_fd(sock) == polls[i].fd);
301 gen_ref_inc(sock); /* can't have it going away on us */
303 Debug((DEBUG_ENGINE, "devpoll: Checking socket %p (fd %d) state %s, "
304 "events %s", sock, s_fd(sock), state_to_name(s_state(sock)),
305 sock_flags(s_events(sock))));
307 if (s_state(sock) != SS_NOTSOCK) {
308 errcode = 0; /* check for errors on socket */
309 codesize = sizeof(errcode);
310 if (getsockopt(s_fd(sock), SOL_SOCKET, SO_ERROR, &errcode,
312 errcode = errno; /* work around Solaris implementation */
314 if (errcode) { /* an error occurred; generate an event */
315 Debug((DEBUG_ENGINE, "devpoll: Error %d on fd %d, socket %p",
316 errcode, s_fd(sock), sock));
317 event_generate(ET_ERROR, sock, errcode);
318 gen_ref_dec(sock); /* careful not to leak reference counts */
323 assert(!(polls[i].revents & POLLERR));
326 if (polls[i].revents & POLLHUP) { /* hang-up on socket */
327 Debug((DEBUG_ENGINE, "devpoll: EOF from client (POLLHUP)"));
328 event_generate(ET_EOF, sock, 0);
334 switch (s_state(sock)) {
336 if (polls[i].revents & POLLWRITEFLAGS) { /* connection completed */
337 Debug((DEBUG_ENGINE, "devpoll: Connection completed"));
338 event_generate(ET_CONNECT, sock, 0);
343 if (polls[i].revents & POLLREADFLAGS) { /* connect. to be accept. */
344 Debug((DEBUG_ENGINE, "devpoll: Ready for accept"));
345 event_generate(ET_ACCEPT, sock, 0);
350 if (polls[i].revents & POLLREADFLAGS) { /* data on socket */
351 /* can't peek; it's not a socket */
352 Debug((DEBUG_ENGINE, "devpoll: non-socket readable"));
353 event_generate(ET_READ, sock, 0);
358 if (polls[i].revents & POLLREADFLAGS) { /* data on socket */
361 switch (recv(s_fd(sock), &c, 1, MSG_PEEK)) { /* check EOF */
362 case -1: /* error occurred?!? */
363 if (errno == EAGAIN) {
364 Debug((DEBUG_ENGINE, "devpoll: Resource temporarily "
368 Debug((DEBUG_ENGINE, "devpoll: Uncaught error!"));
369 event_generate(ET_ERROR, sock, errno);
372 case 0: /* EOF from client */
373 Debug((DEBUG_ENGINE, "devpoll: EOF from client"));
374 event_generate(ET_EOF, sock, 0);
377 default: /* some data can be read */
378 Debug((DEBUG_ENGINE, "devpoll: Data to be read"));
379 event_generate(ET_READ, sock, 0);
383 if (polls[i].revents & POLLWRITEFLAGS) { /* socket writable */
384 Debug((DEBUG_ENGINE, "devpoll: Data can be written"));
385 event_generate(ET_WRITE, sock, 0);
389 case SS_DATAGRAM: case SS_CONNECTDG:
390 if (polls[i].revents & POLLREADFLAGS) { /* socket readable */
391 Debug((DEBUG_ENGINE, "devpoll: Datagram to be read"));
392 event_generate(ET_READ, sock, 0);
394 if (polls[i].revents & POLLWRITEFLAGS) { /* socket writable */
395 Debug((DEBUG_ENGINE, "devpoll: Datagram can be written"));
396 event_generate(ET_WRITE, sock, 0);
401 assert(s_fd(sock) == polls[i].fd);
403 gen_ref_dec(sock); /* we're done with it */
406 timer_run(); /* execute any pending timers */
410 struct Engine engine_devpoll = {
411 "/dev/poll", /* Engine name */
412 engine_init, /* Engine initialization function */
413 0, /* Engine signal registration function */
414 engine_add, /* Engine socket registration function */
415 engine_state, /* Engine socket state change function */
416 engine_events, /* Engine socket events mask function */
417 engine_delete, /* Engine socket deletion function */
418 engine_loop /* Core engine event loop */