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"
33 #include <sys/devpoll.h>
35 #include <sys/socket.h>
37 #include <sys/types.h>
40 #define DEVPOLL_ERROR_THRESHOLD 20 /* after 20 devpoll errors, restart */
41 #define ERROR_EXPIRE_TIME 3600 /* expire errors after an hour */
43 #define POLLS_PER_DEVPOLL 20 /* get 20 pollfd's per turn */
45 /* Figure out what bits to set for read */
46 #if defined(POLLMSG) && defined(POLLIN) && defined(POLLRDNORM)
47 # define POLLREADFLAGS (POLLMSG|POLLIN|POLLRDNORM)
48 #elif defined(POLLIN) && defined(POLLRDNORM)
49 # define POLLREADFLAGS (POLLIN|POLLRDNORM)
51 # define POLLREADFLAGS POLLIN
52 #elif defined(POLLRDNORM)
53 # define POLLREADFLAGS POLLRDNORM
56 /* Figure out what bits to set for write */
57 #if defined(POLLOUT) && defined(POLLWRNORM)
58 # define POLLWRITEFLAGS (POLLOUT|POLLWRNORM)
59 #elif defined(POLLOUT)
60 # define POLLWRITEFLAGS POLLOUT
61 #elif defined(POLLWRNORM)
62 # define POLLWRITEFLAGS POLLWRNORM
65 /* Figure out what bits indicate errors */
67 # define POLLERRORS (POLLHUP|POLLERR)
69 # define POLLERRORS POLLERR
72 static struct Socket** sockList;
73 static int devpoll_max;
74 static int devpoll_fd;
76 static int errors = 0;
77 static struct Timer clear_error;
79 /* decrements the error count once per hour */
81 error_clear(struct Event* ev)
83 if (!--errors) /* remove timer when error count reaches 0 */
84 timer_del(ev_timer(ev));
87 /* initialize the devpoll engine */
89 engine_init(int max_sockets)
93 if ((devpoll_fd = open("/dev/poll", O_RDWR)) < 0) {
94 log_write(LS_SYSTEM, L_WARNING, 0,
95 "/dev/poll engine cannot open device: %m");
96 return 0; /* engine cannot be initialized; defer */
99 /* allocate necessary memory */
100 sockList = (struct Socket**) MyMalloc(sizeof(struct Socket*) * max_sockets);
102 /* initialize the data */
103 for (i = 0; i < max_sockets; i++)
106 devpoll_max = max_sockets; /* number of sockets allocated */
111 /* Figure out what events go with a given state */
113 state_to_events(enum SocketState state, unsigned int events)
116 case SS_CONNECTING: /* connecting socket */
117 return SOCK_EVENT_WRITABLE;
120 case SS_LISTENING: /* listening socket */
121 case SS_NOTSOCK: /* our signal socket */
122 return SOCK_EVENT_READABLE;
125 case SS_CONNECTED: case SS_DATAGRAM: case SS_CONNECTDG:
126 return events; /* ordinary socket */
134 /* Reset the desired events */
136 set_events(struct Socket* sock, unsigned int events)
142 if (s_ed_int(sock)) { /* is one in /dev/poll already? */
143 pfd.events = POLLREMOVE; /* First, remove old pollfd */
145 Debug((DEBUG_ENGINE, "devpoll: Removing old entry for socket %d [%p]",
148 if (write(devpoll_fd, &pfd, sizeof(pfd)) != sizeof(pfd)) {
149 event_generate(ET_ERROR, sock, errno); /* report error */
153 s_ed_int(sock) = 0; /* mark that it's gone */
156 if (!(events & SOCK_EVENT_MASK)) /* no events, so stop here */
159 pfd.events = 0; /* Now, set up new pollfd... */
160 if (events & SOCK_EVENT_READABLE)
161 pfd.events |= POLLREADFLAGS; /* look for readable conditions */
162 if (events & SOCK_EVENT_WRITABLE)
163 pfd.events |= POLLWRITEFLAGS; /* look for writable conditions */
165 Debug((DEBUG_ENGINE, "devpoll: Registering interest on %d [%p] (state %s, "
166 "mask [%s])", s_fd(sock), sock, state_to_name(s_state(sock)),
167 sock_flags(s_events(sock))));
169 if (write(devpoll_fd, &pfd, sizeof(pfd)) != sizeof(pfd)) {
170 event_generate(ET_ERROR, sock, errno); /* report error */
174 s_ed_int(sock) = 1; /* mark that we've added a pollfd */
177 /* add a socket to be listened on */
179 engine_add(struct Socket* sock)
182 assert(0 == sockList[s_fd(sock)]);
184 /* bounds-check... */
185 if (s_fd(sock) >= devpoll_max) {
186 log_write(LS_SYSTEM, L_ERROR, 0,
187 "Attempt to add socket %d (> %d) to event engine", s_fd(sock),
192 sockList[s_fd(sock)] = sock; /* add to list */
194 Debug((DEBUG_ENGINE, "devpoll: Adding socket %d [%p], state %s, to engine",
195 s_fd(sock), sock, state_to_name(s_state(sock))));
197 /* set the correct events */
198 set_events(sock, state_to_events(s_state(sock), s_events(sock)));
200 return 1; /* success */
203 /* socket switching to new state */
205 engine_state(struct Socket* sock, enum SocketState new_state)
208 assert(sock == sockList[s_fd(sock)]);
210 Debug((DEBUG_ENGINE, "devpoll: Changing state for socket %p to %s", sock,
211 state_to_name(new_state)));
213 /* set the correct events */
214 set_events(sock, state_to_events(new_state, s_events(sock)));
217 /* socket events changing */
219 engine_events(struct Socket* sock, unsigned int new_events)
222 assert(sock == sockList[s_fd(sock)]);
224 Debug((DEBUG_ENGINE, "devpoll: Changing event mask for socket %p to [%s]",
225 sock, sock_flags(new_events)));
227 /* set the correct events */
228 set_events(sock, state_to_events(s_state(sock), new_events));
231 /* socket going away */
233 engine_delete(struct Socket* sock)
236 assert(sock == sockList[s_fd(sock)]);
238 Debug((DEBUG_ENGINE, "devpoll: Deleting socket %d [%p], state %s",
239 s_fd(sock), sock, state_to_name(s_state(sock))));
241 set_events(sock, 0); /* get rid of the socket */
243 sockList[s_fd(sock)] = 0; /* zero the socket list entry */
246 /* engine event loop */
248 engine_loop(struct Generators* gen)
250 struct dvpoll dopoll;
251 struct pollfd polls[POLLS_PER_DEVPOLL];
259 dopoll.dp_fds = polls; /* set up the struct dvpoll */
260 dopoll.dp_nfds = POLLS_PER_DEVPOLL;
262 /* calculate the proper timeout */
263 dopoll.dp_timeout = timer_next(gen) ?
264 (timer_next(gen) - CurrentTime) * 1000 : -1;
266 Debug((DEBUG_INFO, "devpoll: delay: %Tu (%Tu) %d", timer_next(gen),
267 CurrentTime, dopoll.dp_timeout));
269 /* check for active files */
270 nfds = ioctl(devpoll_fd, DP_POLL, &dopoll);
272 CurrentTime = time(0); /* set current time... */
275 if (errno != EINTR) { /* ignore interrupts */
276 /* Log the poll error */
277 log_write(LS_SOCKET, L_ERROR, 0, "ioctl(DP_POLL) error: %m");
279 timer_add(&clear_error, error_clear, 0, TT_PERIODIC,
281 else if (errors > DEVPOLL_ERROR_THRESHOLD) /* too many errors... */
282 server_restart("too many /dev/poll errors");
284 /* old code did a sleep(1) here; with usage these days,
285 * that may be too expensive
290 for (i = 0; i < nfds; i++) {
291 assert(-1 < polls[i].fd);
292 assert(0 != sockList[polls[i].fd]);
293 assert(s_fd(sockList[polls[i].fd]) == polls[i].fd);
295 sock = sockList[polls[i].fd];
296 if (!sock) /* slots may become empty while processing events */
299 gen_ref_inc(sock); /* can't have it going away on us */
301 Debug((DEBUG_ENGINE, "devpoll: Checking socket %p (fd %d) state %s, "
302 "events %s", sock, s_fd(sock), state_to_name(s_state(sock)),
303 sock_flags(s_events(sock))));
305 if (s_state(sock) != SS_NOTSOCK) {
306 errcode = 0; /* check for errors on socket */
307 codesize = sizeof(errcode);
308 if (getsockopt(s_fd(sock), SOL_SOCKET, SO_ERROR, &errcode,
310 errcode = errno; /* work around Solaris implementation */
312 if (errcode) { /* an error occurred; generate an event */
313 Debug((DEBUG_ENGINE, "devpoll: Error %d on fd %d, socket %p",
314 errcode, s_fd(sock), sock));
315 event_generate(ET_ERROR, sock, errcode);
316 gen_ref_dec(sock); /* careful not to leak reference counts */
321 switch (s_state(sock)) {
323 if (polls[i].revents & POLLWRITEFLAGS) { /* connection completed */
324 Debug((DEBUG_ENGINE, "devpoll: Connection completed"));
325 event_generate(ET_CONNECT, sock, 0);
330 if (polls[i].revents & POLLREADFLAGS) { /* connect. to be accept. */
331 Debug((DEBUG_ENGINE, "devpoll: Ready for accept"));
332 event_generate(ET_ACCEPT, sock, 0);
337 if (polls[i].revents & POLLREADFLAGS) { /* data on socket */
338 /* can't peek; it's not a socket */
339 Debug((DEBUG_ENGINE, "devpoll: non-socket readable"));
340 event_generate(ET_READ, sock, 0);
345 if (polls[i].revents & POLLREADFLAGS) { /* data on socket */
348 switch (recv(s_fd(sock), &c, 1, MSG_PEEK)) { /* check EOF */
349 case -1: /* error occurred?!? */
350 if (errno == EAGAIN) {
351 Debug((DEBUG_ENGINE, "devpoll: Resource temporarily "
355 Debug((DEBUG_ENGINE, "devpoll: Uncaught error!"));
356 event_generate(ET_ERROR, sock, errno);
359 case 0: /* EOF from client */
360 Debug((DEBUG_ENGINE, "devpoll: EOF from client"));
361 event_generate(ET_EOF, sock, 0);
364 default: /* some data can be read */
365 Debug((DEBUG_ENGINE, "devpoll: Data to be read"));
366 event_generate(ET_READ, sock, 0);
370 if (polls[i].revents & POLLWRITEFLAGS) { /* socket writable */
371 Debug((DEBUG_ENGINE, "devpoll: Data can be written"));
372 event_generate(ET_WRITE, sock, 0);
376 case SS_DATAGRAM: case SS_CONNECTDG:
377 if (polls[i].revents & POLLREADFLAGS) { /* socket readable */
378 Debug((DEBUG_ENGINE, "devpoll: Datagram to be read"));
379 event_generate(ET_READ, sock, 0);
381 if (polls[i].revents & POLLWRITEFLAGS) { /* socket writable */
382 Debug((DEBUG_ENGINE, "devpoll: Datagram can be written"));
383 event_generate(ET_WRITE, sock, 0);
388 assert(s_fd(sock) == polls[i].fd);
390 gen_ref_dec(sock); /* we're done with it */
393 timer_run(); /* execute any pending timers */
397 struct Engine engine_devpoll = {
398 "/dev/poll", /* Engine name */
399 engine_init, /* Engine initialization function */
400 0, /* Engine signal registration function */
401 engine_add, /* Engine socket registration function */
402 engine_state, /* Engine socket state change function */
403 engine_events, /* Engine socket events mask function */
404 engine_delete, /* Engine socket deletion function */
405 engine_loop /* Core engine event loop */