--- /dev/null
+/*
+ * IRC - Internet Relay Chat, ircd/engine_kqueue.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 FreeBSD kqueue()/kevent() event engine.
+ * @version $Id$
+ */
+#include "config.h"
+
+#include "ircd_events.h"
+
+#include "ircd.h"
+#include "ircd_alloc.h"
+#include "ircd_features.h"
+#include "ircd_log.h"
+#include "s_debug.h"
+
+/* #include <assert.h> -- Now using assert in ircd_log.h */
+#include <errno.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/event.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <time.h>
+#include <unistd.h>
+
+#define KQUEUE_ERROR_THRESHOLD 20 /**< after 20 kqueue errors, restart */
+#define ERROR_EXPIRE_TIME 3600 /**< expire errors after an hour */
+
+/** Array of active Socket structures, indexed by file descriptor. */
+static struct Socket** sockList;
+/** Maximum file descriptor supported, plus one. */
+static int kqueue_max;
+/** File descriptor for kqueue pseudo-file. */
+static int kqueue_id;
+/** Current array of event descriptors. */
+static struct kevent *events;
+/** Number of ::events elements that have been populated. */
+static int events_used;
+
+/** Number of recent errors from kqueue. */
+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 kqueue 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;
+
+ if ((kqueue_id = kqueue()) < 0) { /* initialize... */
+ log_write(LS_SYSTEM, L_WARNING, 0,
+ "kqueue() engine cannot initialize: %m");
+ return 0;
+ }
+
+ /* allocate necessary memory */
+ sockList = (struct Socket**) MyMalloc(sizeof(struct Socket*) * max_sockets);
+
+ /* initialize the data */
+ for (i = 0; i < max_sockets; i++)
+ sockList[i] = 0;
+
+ kqueue_max = max_sockets; /* number of sockets allocated */
+
+ return 1; /* success! */
+}
+
+/** Add a signal to the event engine.
+ * @param[in] sig Signal to add to engine.
+ */
+static void
+engine_signal(struct Signal* sig)
+{
+ struct kevent sigevent;
+ struct sigaction act;
+
+ assert(0 != sig);
+
+ Debug((DEBUG_ENGINE, "kqueue: Adding filter for signal %d [%p]",
+ sig_signal(sig), sig));
+
+ sigevent.ident = sig_signal(sig); /* set up the kqueue event */
+ sigevent.filter = EVFILT_SIGNAL; /* looking for signals... */
+ sigevent.flags = EV_ADD | EV_ENABLE; /* add and enable it */
+ sigevent.fflags = 0;
+ sigevent.data = 0;
+ sigevent.udata = sig; /* store our user data */
+
+ if (kevent(kqueue_id, &sigevent, 1, 0, 0, 0) < 0) { /* add event */
+ log_write(LS_SYSTEM, L_WARNING, 0, "Unable to trap signal %d",
+ sig_signal(sig));
+ return;
+ }
+
+ act.sa_handler = SIG_IGN; /* ignore the signal */
+ act.sa_flags = 0;
+ sigemptyset(&act.sa_mask);
+ sigaction(sig_signal(sig), &act, 0);
+}
+
+/** 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--just in case */
+ return SOCK_EVENT_READABLE;
+ break;
+
+ case SS_CONNECTED: case SS_DATAGRAM: case SS_CONNECTDG:
+ return events; /* ordinary socket */
+ break;
+ }
+
+ /*NOTREACHED*/
+ return 0;
+}
+
+/** Activate kqueue filters as appropriate.
+ * @param[in] sock Socket structure 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(struct Socket* sock, unsigned int clear, unsigned int set)
+{
+ int i = 0;
+ struct kevent chglist[2];
+
+ assert(0 != sock);
+ assert(-1 < s_fd(sock));
+
+ if ((clear ^ set) & SOCK_EVENT_READABLE) { /* readable has changed */
+ chglist[i].ident = s_fd(sock); /* set up the change list */
+ chglist[i].filter = EVFILT_READ; /* readable filter */
+ chglist[i].flags = EV_ADD; /* adding it */
+ chglist[i].fflags = 0;
+ chglist[i].data = 0;
+ chglist[i].udata = 0; /* I love udata, but it can't really be used here */
+
+ if (set & SOCK_EVENT_READABLE) /* it's set */
+ chglist[i].flags |= EV_ENABLE;
+ else /* clear it */
+ chglist[i].flags |= EV_DISABLE;
+
+ i++; /* advance to next element */
+ }
+
+ if ((clear ^ set) & SOCK_EVENT_WRITABLE) { /* writable has changed */
+ chglist[i].ident = s_fd(sock); /* set up the change list */
+ chglist[i].filter = EVFILT_WRITE; /* writable filter */
+ chglist[i].flags = EV_ADD; /* adding it */
+ chglist[i].fflags = 0;
+ chglist[i].data = 0;
+ chglist[i].udata = 0;
+
+ if (set & SOCK_EVENT_WRITABLE) /* it's set */
+ chglist[i].flags |= EV_ENABLE;
+ else /* clear it */
+ chglist[i].flags |= EV_DISABLE;
+
+ i++; /* advance count... */
+ }
+
+ if (kevent(kqueue_id, chglist, i, 0, 0, 0) < 0 && errno != EBADF)
+ event_generate(ET_ERROR, sock, errno); /* report error */
+}
+
+/** 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)
+{
+ assert(0 != sock);
+ assert(0 == sockList[s_fd(sock)]);
+
+ /* bounds-check... */
+ if (sock->s_fd >= kqueue_max) {
+ log_write(LS_SYSTEM, L_ERROR, 0,
+ "Attempt to add socket %d (> %d) to event engine", s_fd(sock),
+ kqueue_max);
+ return 0;
+ }
+
+ sockList[s_fd(sock)] = sock; /* add to list */
+
+ Debug((DEBUG_ENGINE, "kqueue: Adding socket %d [%p], state %s, to engine",
+ s_fd(sock), sock, state_to_name(s_state(sock))));
+
+ /* Add socket to queue */
+ set_or_clear(sock, 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_fd(sock)]);
+
+ Debug((DEBUG_ENGINE, "kqueue: Changing state for socket %p to %s", sock,
+ state_to_name(new_state)));
+
+ /* set the correct events */
+ set_or_clear(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_fd(sock)]);
+
+ Debug((DEBUG_ENGINE, "kqueue: Changing event mask for socket %p to [%s]",
+ sock, sock_flags(new_events)));
+
+ /* set the correct events */
+ set_or_clear(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)
+{
+ int ii;
+
+ assert(0 != sock);
+ assert(sock == sockList[s_fd(sock)]);
+
+ Debug((DEBUG_ENGINE, "kqueue: Deleting socket %d [%p], state %s",
+ s_fd(sock), sock, state_to_name(s_state(sock))));
+
+ sockList[s_fd(sock)] = 0;
+
+ /* Drop any unprocessed events citing this socket. */
+ for (ii = 0; ii < events_used; ii++) {
+ if (events[ii].ident == s_fd(sock)) {
+ events[ii] = events[--events_used];
+ }
+ }
+}
+
+/** Run engine event loop.
+ * @param[in] gen Lists of generators of various types.
+ */
+static void
+engine_loop(struct Generators* gen)
+{
+ int events_count;
+ struct kevent *evt;
+ struct Socket* sock;
+ struct timespec wait;
+ int i;
+ int errcode;
+ socklen_t codesize;
+
+ if ((events_count = feature_int(FEAT_POLLS_PER_LOOP)) < 20)
+ events_count = 20;
+ events = (struct kevent *)MyMalloc(sizeof(struct kevent) * events_count);
+
+ while (running) {
+ if ((i = feature_int(FEAT_POLLS_PER_LOOP)) >= 20 && i != events_count) {
+ events = (struct kevent *)MyRealloc(events, sizeof(struct kevent) * i);
+ events_count = i;
+ }
+
+ /* set up the sleep time */
+ wait.tv_sec = timer_next(gen) ? (timer_next(gen) - CurrentTime) : -1;
+ wait.tv_nsec = 0;
+
+ Debug((DEBUG_ENGINE, "kqueue: delay: %Tu (%Tu) %Tu", timer_next(gen),
+ CurrentTime, wait.tv_sec));
+
+ /* check for active events */
+ events_used = kevent(kqueue_id, 0, 0, events, events_count,
+ wait.tv_sec < 0 ? 0 : &wait);
+
+ CurrentTime = time(0); /* set current time... */
+
+ if (events_used < 0) {
+ if (errno != EINTR) { /* ignore kevent interrupts */
+ /* Log the kqueue error */
+ log_write(LS_SOCKET, L_ERROR, 0, "kevent() error: %m");
+ if (!errors++)
+ timer_add(timer_init(&clear_error), error_clear, 0, TT_PERIODIC,
+ ERROR_EXPIRE_TIME);
+ else if (errors > KQUEUE_ERROR_THRESHOLD) /* too many errors... */
+ server_restart("too many kevent errors");
+ }
+ /* old code did a sleep(1) here; with usage these days,
+ * that may be too expensive
+ */
+ continue;
+ }
+
+ while (events_used > 0) {
+ evt = &events[--events_used];
+
+ if (evt->filter == EVFILT_SIGNAL) {
+ /* it's a signal; deal appropriately */
+ event_generate(ET_SIGNAL, evt->udata, evt->ident);
+ continue; /* skip socket processing loop */
+ }
+
+ assert(evt->filter == EVFILT_READ || evt->filter == EVFILT_WRITE);
+
+ sock = sockList[evt->ident];
+ if (!sock) /* slots may become empty while processing events */
+ continue;
+
+ assert(s_fd(sock) == evt->ident);
+
+ gen_ref_inc(sock); /* can't have it going away on us */
+
+ Debug((DEBUG_ENGINE, "kqueue: Checking socket %p (fd %d) state %s, "
+ "events %s", sock, s_fd(sock), 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, "kqueue: Error %d on fd %d, socket %p", errcode,
+ s_fd(sock), sock));
+ event_generate(ET_ERROR, sock, errcode);
+ gen_ref_dec(sock); /* careful not to leak reference counts */
+ continue;
+ }
+ }
+
+ switch (s_state(sock)) {
+ case SS_CONNECTING:
+ if (evt->filter == EVFILT_WRITE) { /* connection completed */
+ Debug((DEBUG_ENGINE, "kqueue: Connection completed"));
+ event_generate(ET_CONNECT, sock, 0);
+ }
+ break;
+
+ case SS_LISTENING:
+ if (evt->filter == EVFILT_READ) { /* connect. to be accept. */
+ Debug((DEBUG_ENGINE, "kqueue: Ready for accept"));
+ event_generate(ET_ACCEPT, sock, 0);
+ }
+ break;
+
+ case SS_NOTSOCK: /* doing nothing socket-specific */
+ case SS_CONNECTED:
+ if (evt->filter == EVFILT_READ) { /* data on socket */
+ Debug((DEBUG_ENGINE, "kqueue: EOF or data to be read"));
+ event_generate(evt->flags & EV_EOF ? ET_EOF : ET_READ, sock, 0);
+ }
+ if (evt->filter == EVFILT_WRITE) { /* socket writable */
+ Debug((DEBUG_ENGINE, "kqueue: Data can be written"));
+ event_generate(ET_WRITE, sock, 0);
+ }
+ break;
+
+ case SS_DATAGRAM: case SS_CONNECTDG:
+ if (evt->filter == EVFILT_READ) { /* socket readable */
+ Debug((DEBUG_ENGINE, "kqueue: Datagram to be read"));
+ event_generate(ET_READ, sock, 0);
+ }
+ if (evt->filter == EVFILT_WRITE) { /* socket writable */
+ Debug((DEBUG_ENGINE, "kqueue: Datagram can be written"));
+ event_generate(ET_WRITE, sock, 0);
+ }
+ break;
+ }
+
+ gen_ref_dec(sock); /* we're done with it */
+ }
+
+ timer_run(); /* execute any pending timers */
+ }
+}
+
+/** Descriptor for kqueue() event engine. */
+struct Engine engine_kqueue = {
+ "kqueue()", /* Engine name */
+ engine_init, /* Engine initialization function */
+ engine_signal, /* 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