--- /dev/null
+/*
+ * IRC - Internet Relay Chat, ircd/engine_poll.c
+ * Copyright (C) 2001 Kevin L. Mitchell <klmitch@mit.edu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 1, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/** @file
+ * @brief POSIX poll() event engine.
+ * @version $Id$
+ */
+#include "config.h"
+
+#include "ircd_events.h"
+
+#include "ircd.h"
+#include "ircd_alloc.h"
+#include "ircd_log.h"
+#include "s_debug.h"
+
+/* #include <assert.h> -- Now using assert in ircd_log.h */
+#include <errno.h>
+#include <sys/poll.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#define POLL_ERROR_THRESHOLD 20 /**< after 20 poll errors, restart */
+#define ERROR_EXPIRE_TIME 3600 /**< expire errors after an hour */
+
+/* Figure out what bits to set for read */
+#if defined(POLLMSG) && defined(POLLIN) && defined(POLLRDNORM)
+# define POLLREADFLAGS (POLLMSG|POLLIN|POLLRDNORM)
+#elif defined(POLLIN) && defined(POLLRDNORM)
+# define POLLREADFLAGS (POLLIN|POLLRDNORM)
+#elif defined(POLLIN)
+# define POLLREADFLAGS POLLIN
+#elif defined(POLLRDNORM)
+# define POLLREADFLAGS POLLRDNORM
+#endif
+
+/* Figure out what bits to set for write */
+#if defined(POLLOUT) && defined(POLLWRNORM)
+# define POLLWRITEFLAGS (POLLOUT|POLLWRNORM)
+#elif defined(POLLOUT)
+# define POLLWRITEFLAGS POLLOUT
+#elif defined(POLLWRNORM)
+# define POLLWRITEFLAGS POLLWRNORM
+#endif
+
+/** Array of active Socket structures, indexed by file descriptor. */
+static struct Socket** sockList;
+/** Array of poll() active elements. */
+static struct pollfd* pollfdList;
+/** Number of pollfd elements currently used. */
+static unsigned int poll_count;
+/** Maximum file descriptor supported, plus one. */
+static unsigned int poll_max;
+
+/** Number of recent errors from poll(). */
+static int errors = 0;
+/** Periodic timer to forget errors. */
+static struct Timer clear_error;
+
+/** Decrement the error count (once per hour).
+ * @param[in] ev Expired timer event (ignored).
+ */
+static void
+error_clear(struct Event* ev)
+{
+ if (!--errors) /* remove timer when error count reaches 0 */
+ timer_del(ev_timer(ev));
+}
+
+/** Initialize the poll() engine.
+ * @param[in] max_sockets Maximum number of file descriptors to support.
+ * @return Non-zero on success, or zero on failure.
+ */
+static int
+engine_init(int max_sockets)
+{
+ int i;
+
+ /* allocate necessary memory */
+ sockList = (struct Socket**) MyMalloc(sizeof(struct Socket*) * max_sockets);
+ pollfdList = (struct pollfd*) MyMalloc(sizeof(struct pollfd) * max_sockets);
+
+ /* initialize the data */
+ for (i = 0; i < max_sockets; i++) {
+ sockList[i] = 0;
+ pollfdList[i].fd = -1;
+ pollfdList[i].events = 0;
+ pollfdList[i].revents = 0;
+ }
+
+ poll_count = 0; /* nothing in set */
+ poll_max = max_sockets; /* number of sockets allocated */
+
+ return 1;
+}
+
+/** Figure out what events go with a given state.
+ * @param[in] state %Socket state to consider.
+ * @param[in] events User-specified preferred event set.
+ * @return Actual set of preferred events.
+ */
+static unsigned int
+state_to_events(enum SocketState state, unsigned int events)
+{
+ switch (state) {
+ case SS_CONNECTING: /* connecting socket */
+ return SOCK_EVENT_WRITABLE;
+ break;
+
+ case SS_LISTENING: /* listening socket */
+ case SS_NOTSOCK: /* our signal socket */
+ return SOCK_EVENT_READABLE;
+ break;
+
+ case SS_CONNECTED: case SS_DATAGRAM: case SS_CONNECTDG:
+ return events; /* ordinary socket */
+ break;
+ }
+
+ /*NOTREACHED*/
+ return 0;
+}
+
+/** Set interest events in a pollfd as appropriate.
+ * @param[in] idx Index of pollfd to operate on.
+ * @param[in] clear Set of interest events to clear from socket.
+ * @param[in] set Set of interest events to set on socket.
+ */
+static void
+set_or_clear(int idx, unsigned int clear, unsigned int set)
+{
+ if ((clear ^ set) & SOCK_EVENT_READABLE) { /* readable has changed */
+ if (set & SOCK_EVENT_READABLE) /* it's set */
+ pollfdList[idx].events |= POLLREADFLAGS;
+ else /* clear it */
+ pollfdList[idx].events &= ~POLLREADFLAGS;
+ }
+
+ if ((clear ^ set) & SOCK_EVENT_WRITABLE) { /* writable has changed */
+ if (set & SOCK_EVENT_WRITABLE) /* it's set */
+ pollfdList[idx].events |= POLLWRITEFLAGS;
+ else /* clear it */
+ pollfdList[idx].events &= ~POLLWRITEFLAGS;
+ }
+}
+
+/** Add a socket to the event engine.
+ * @param[in] sock Socket to add to engine.
+ * @return Non-zero on success, or zero on error.
+ */
+static int
+engine_add(struct Socket* sock)
+{
+ int i;
+
+ assert(0 != sock);
+
+ for (i = 0; sockList[i] && i < poll_count; i++) /* Find an empty slot */
+ ;
+
+ Debug((DEBUG_ENGINE, "poll: Looking at slot %d, contents %p", i,
+ sockList[i]));
+
+ if (i >= poll_count) { /* ok, need to allocate another off the list */
+ if (poll_count >= poll_max) { /* bounds-check... */
+ log_write(LS_SYSTEM, L_ERROR, 0,
+ "Attempt to add socket %d (> %d) to event engine", sock->s_fd,
+ poll_max);
+ return 0;
+ }
+
+ i = poll_count++;
+ Debug((DEBUG_ENGINE, "poll: Allocating a new slot: %d", i));
+ }
+
+ s_ed_int(sock) = i; /* set engine data */
+ sockList[i] = sock; /* enter socket into data structures */
+ pollfdList[i].fd = s_fd(sock);
+
+ Debug((DEBUG_ENGINE, "poll: Adding socket %d to engine on %d [%p], state %s",
+ s_fd(sock), s_ed_int(sock), sock, state_to_name(s_state(sock))));
+
+ /* set the appropriate bits */
+ set_or_clear(i, 0, state_to_events(s_state(sock), s_events(sock)));
+
+ return 1; /* success */
+}
+
+/** Handle state transition for a socket.
+ * @param[in] sock Socket changing state.
+ * @param[in] new_state New state for socket.
+ */
+static void
+engine_state(struct Socket* sock, enum SocketState new_state)
+{
+ assert(0 != sock);
+ assert(sock == sockList[s_ed_int(sock)]);
+ assert(s_fd(sock) == pollfdList[s_ed_int(sock)].fd);
+
+ Debug((DEBUG_ENGINE, "poll: Changing state for socket %p to %s", sock,
+ state_to_name(new_state)));
+
+ /* set the correct events */
+ set_or_clear(s_ed_int(sock),
+ state_to_events(s_state(sock), s_events(sock)), /* old state */
+ state_to_events(new_state, s_events(sock))); /* new state */
+}
+
+/** Handle change to preferred socket events.
+ * @param[in] sock Socket getting new interest list.
+ * @param[in] new_events New set of interesting events for socket.
+ */
+static void
+engine_events(struct Socket* sock, unsigned int new_events)
+{
+ assert(0 != sock);
+ assert(sock == sockList[s_ed_int(sock)]);
+ assert(s_fd(sock) == pollfdList[s_ed_int(sock)].fd);
+
+ Debug((DEBUG_ENGINE, "poll: Changing event mask for socket %p to [%s]", sock,
+ sock_flags(new_events)));
+
+ /* set the correct events */
+ set_or_clear(s_ed_int(sock),
+ state_to_events(s_state(sock), s_events(sock)), /* old events */
+ state_to_events(s_state(sock), new_events)); /* new events */
+}
+
+/** Remove a socket from the event engine.
+ * @param[in] sock Socket being destroyed.
+ */
+static void
+engine_delete(struct Socket* sock)
+{
+ assert(0 != sock);
+ assert(sock == sockList[s_ed_int(sock)]);
+ assert(s_fd(sock) == pollfdList[s_ed_int(sock)].fd);
+
+ Debug((DEBUG_ENGINE, "poll: Deleting socket %d (%d) [%p], state %s",
+ s_fd(sock), s_ed_int(sock), sock, state_to_name(s_state(sock))));
+
+ /* clear the events */
+ pollfdList[s_ed_int(sock)].fd = -1;
+ pollfdList[s_ed_int(sock)].events = 0;
+
+ /* zero the socket list entry */
+ sockList[s_ed_int(sock)] = 0;
+
+ /* update poll_count */
+ while (poll_count > 0 && sockList[poll_count - 1] == 0)
+ poll_count--;
+}
+
+/** Run engine event loop.
+ * @param[in] gen Lists of generators of various types.
+ */
+static void
+engine_loop(struct Generators* gen)
+{
+ int wait;
+ int nfds;
+ int i;
+ int errcode;
+ socklen_t codesize;
+ struct Socket *sock;
+
+ while (running) {
+ wait = timer_next(gen) ? (timer_next(gen) - CurrentTime) * 1000 : -1;
+
+ Debug((DEBUG_INFO, "poll: delay: %Tu (%Tu) %d", timer_next(gen),
+ CurrentTime, wait));
+
+ /* check for active files */
+ nfds = poll(pollfdList, poll_count, wait);
+
+ CurrentTime = time(0); /* set current time... */
+
+ if (nfds < 0) {
+ if (errno != EINTR) { /* ignore poll interrupts */
+ /* Log the poll error */
+ log_write(LS_SOCKET, L_ERROR, 0, "poll() error: %m");
+ if (!errors++)
+ timer_add(timer_init(&clear_error), error_clear, 0, TT_PERIODIC,
+ ERROR_EXPIRE_TIME);
+ else if (errors > POLL_ERROR_THRESHOLD) /* too many errors... */
+ server_restart("too many poll errors");
+ }
+ /* old code did a sleep(1) here; with usage these days,
+ * that may be too expensive
+ */
+ continue;
+ }
+
+ for (i = 0; nfds && i < poll_count; i++) {
+ if (!(sock = sockList[i])) /* skip empty socket elements */
+ continue;
+
+ assert(s_fd(sock) == pollfdList[i].fd);
+
+ gen_ref_inc(sock); /* can't have it going away on us */
+
+ Debug((DEBUG_ENGINE, "poll: Checking socket %p (fd %d, index %d, "
+ "state %s, events %s", sock, s_fd(sock), i,
+ state_to_name(s_state(sock)), sock_flags(s_events(sock))));
+
+ if (s_state(sock) != SS_NOTSOCK) {
+ errcode = 0; /* check for errors on socket */
+ codesize = sizeof(errcode);
+ if (getsockopt(s_fd(sock), SOL_SOCKET, SO_ERROR, &errcode,
+ &codesize) < 0)
+ errcode = errno; /* work around Solaris implementation */
+
+ if (errcode) { /* an error occurred; generate an event */
+ Debug((DEBUG_ENGINE, "poll: Error %d on fd %d (index %d), socket %p",
+ errcode, s_fd(sock), i, sock));
+ event_generate(ET_ERROR, sock, errcode);
+ gen_ref_dec(sock); /* careful not to leak ref counts */
+ nfds--;
+ continue;
+ }
+ }
+
+#ifdef POLLHUP
+ if (pollfdList[i].revents & POLLHUP) { /* hang-up on socket */
+ Debug((DEBUG_ENGINE, "poll: EOF from client (POLLHUP)"));
+ event_generate(ET_EOF, sock, 0);
+ nfds--;
+ continue;
+ }
+#endif /* POLLHUP */
+
+ switch (s_state(sock)) {
+ case SS_CONNECTING:
+ if (pollfdList[i].revents & POLLWRITEFLAGS) { /* connect completed */
+ Debug((DEBUG_ENGINE, "poll: Connection completed"));
+ event_generate(ET_CONNECT, sock, 0);
+ nfds--;
+ }
+ break;
+
+ case SS_LISTENING:
+ if (pollfdList[i].revents & POLLREADFLAGS) { /* ready for accept */
+ Debug((DEBUG_ENGINE, "poll: Ready for accept"));
+ event_generate(ET_ACCEPT, sock, 0);
+ nfds--;
+ }
+ break;
+
+ case SS_NOTSOCK:
+ if (pollfdList[i].revents & POLLREADFLAGS) { /* data on socket */
+ /* can't peek; it's not a socket */
+ Debug((DEBUG_ENGINE, "poll: non-socket readable"));
+ event_generate(ET_READ, sock, 0);
+ nfds--;
+ }
+ break;
+
+ case SS_CONNECTED:
+ if (pollfdList[i].revents & POLLREADFLAGS) { /* data on socket */
+ char c;
+
+ switch (recv(s_fd(sock), &c, 1, MSG_PEEK)) { /* check EOF */
+ case -1: /* error occurred?!? */
+ if (errno == EAGAIN) {
+ Debug((DEBUG_ENGINE, "poll: Resource temporarily unavailable?"));
+ continue;
+ }
+ Debug((DEBUG_ENGINE, "poll: Uncaught error!"));
+ event_generate(ET_ERROR, sock, errno);
+ break;
+
+ case 0: /* EOF from client */
+ Debug((DEBUG_ENGINE, "poll: EOF from client"));
+ event_generate(ET_EOF, sock, 0);
+ break;
+
+ default: /* some data can be read */
+ Debug((DEBUG_ENGINE, "poll: Data to be read"));
+ event_generate(ET_READ, sock, 0);
+ break;
+ }
+ }
+ if (pollfdList[i].revents & POLLWRITEFLAGS) { /* socket writable */
+ Debug((DEBUG_ENGINE, "poll: Data can be written"));
+ event_generate(ET_WRITE, sock, 0);
+ }
+ if (pollfdList[i].revents & (POLLREADFLAGS | POLLWRITEFLAGS))
+ nfds--;
+ break;
+
+ case SS_DATAGRAM: case SS_CONNECTDG:
+ if (pollfdList[i].revents & POLLREADFLAGS) { /* socket readable */
+ Debug((DEBUG_ENGINE, "poll: Datagram to be read"));
+ event_generate(ET_READ, sock, 0);
+ }
+ if (pollfdList[i].revents & POLLWRITEFLAGS) { /* socket writable */
+ Debug((DEBUG_ENGINE, "poll: Datagram can be written"));
+ event_generate(ET_WRITE, sock, 0);
+ }
+ if (pollfdList[i].revents & (POLLREADFLAGS | POLLWRITEFLAGS))
+ nfds--;
+ break;
+ }
+
+ gen_ref_dec(sock); /* we're done with it */
+ }
+
+ timer_run(); /* execute any pending timers */
+ }
+}
+
+/** Descriptor for poll() event engine. */
+struct Engine engine_poll = {
+ "poll()", /* Engine name */
+ engine_init, /* Engine initialization function */
+ 0, /* Engine signal registration function */
+ engine_add, /* Engine socket registration function */
+ engine_state, /* Engine socket state change function */
+ engine_events, /* Engine socket events mask function */
+ engine_delete, /* Engine socket deletion function */
+ engine_loop /* Core engine event loop */
+};
projects / ircu2.10.12-pk.git / blobdiff