--- /dev/null
+/*
+ * IRC - Internet Relay Chat, ircd/engine_epoll.c
+ * Copyright (C) 2003 Michael Poole <mdpoole@troilus.org>
+ *
+ * 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 Linux epoll_*() event engine.
+ * @version $Id$
+ */
+#include "config.h"
+
+#include "ircd.h"
+#include "ircd_events.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 <sys/types.h>
+#ifdef HAVE_STDINT_H
+#include <stdint.h> /* bah */
+#endif
+#include <string.h>
+#include <sys/epoll.h>
+#include <sys/socket.h>
+#include <time.h>
+#include <linux/unistd.h>
+
+/* The GNU C library may have a valid header but stub implementations
+ * of the epoll system calls. If so, provide our own. */
+#if defined(__stub_epoll_create) || defined(__stub___epoll_create) || defined(EPOLL_NEED_BODY)
+
+/* Oh, did we mention that some glibc releases do not even define the
+ * syscall numbers? */
+#if !defined(__NR_epoll_create)
+#if defined(__ia64__)
+#define __NR_epoll_create 1243
+#define __NR_epoll_ctl 1244
+#define __NR_epoll_wait 1245
+#elif defined(__x86_64__)
+#define __NR_epoll_create 214
+#define __NR_epoll_ctl 233
+#define __NR_epoll_wait 232
+#elif defined(__sparc64__) || defined(__sparc__)
+#define __NR_epoll_create 193
+#define __NR_epoll_ctl 194
+#define __NR_epoll_wait 195
+#elif defined(__s390__) || defined(__m68k__)
+#define __NR_epoll_create 249
+#define __NR_epoll_ctl 250
+#define __NR_epoll_wait 251
+#elif defined(__ppc64__) || defined(__ppc__)
+#define __NR_epoll_create 236
+#define __NR_epoll_ctl 237
+#define __NR_epoll_wait 238
+#elif defined(__parisc__) || defined(__arm26__) || defined(__arm__)
+#define __NR_epoll_create 224
+#define __NR_epoll_ctl 225
+#define __NR_epoll_wait 226
+#elif defined(__alpha__)
+#define __NR_epoll_create 407
+#define __NR_epoll_ctl 408
+#define __NR_epoll_wait 409
+#elif defined(__sh64__)
+#define __NR_epoll_create 282
+#define __NR_epoll_ctl 283
+#define __NR_epoll_wait 284
+#elif defined(__i386__) || defined(__sh__) || defined(__m32r__) || defined(__h8300__) || defined(__frv__)
+#define __NR_epoll_create 254
+#define __NR_epoll_ctl 255
+#define __NR_epoll_wait 256
+#else /* cpu types */
+#error No system call numbers defined for epoll family.
+#endif /* cpu types */
+#endif /* !defined(__NR_epoll_create) */
+
+_syscall1(int, epoll_create, int, size)
+_syscall4(int, epoll_ctl, int, epfd, int, op, int, fd, struct epoll_event *, event)
+_syscall4(int, epoll_wait, int, epfd, struct epoll_event *, pevents, int, maxevents, int, timeout)
+
+#endif /* epoll_create defined as stub */
+
+#define EPOLL_ERROR_THRESHOLD 20 /**< after 20 epoll errors, restart */
+#define ERROR_EXPIRE_TIME 3600 /**< expire errors after an hour */
+
+/** File descriptor for epoll pseudo-file. */
+static int epoll_fd;
+/** Number of recent epoll errors. */
+static int errors;
+/** Periodic timer to forget errors. */
+static struct Timer clear_error;
+/** Current array of event descriptors. */
+static struct epoll_event *events;
+/** Number of ::events elements that have been populated. */
+static int events_used;
+
+/** Decrement the error count (once per hour).
+ * @param[in] ev Expired timer event (ignored).
+ */
+static void
+error_clear(struct Event *ev)
+{
+ if (!--errors)
+ timer_del(ev_timer(ev));
+}
+
+/** Initialize the epoll 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)
+{
+ if ((epoll_fd = epoll_create(max_sockets)) < 0) {
+ log_write(LS_SYSTEM, L_WARNING, 0,
+ "epoll() engine cannot initialize: %m");
+ return 0;
+ }
+ return 1;
+}
+
+/** Set events for a particular socket.
+ * @param[in] sock Socket to calculate events for.
+ * @param[in] state Current socket state.
+ * @param[in] events User-specified event interest list.
+ * @param[out] evt epoll event structure for socket.
+ */
+static void
+set_events(struct Socket *sock, enum SocketState state, unsigned int events, struct epoll_event *evt)
+{
+ assert(0 != sock);
+ assert(0 <= s_fd(sock));
+ memset(evt, 0, sizeof(*evt));
+
+ evt->data.ptr = sock;
+
+ switch (state) {
+ case SS_CONNECTING:
+ evt->events = EPOLLOUT;
+ break;
+
+ case SS_LISTENING:
+ case SS_NOTSOCK:
+ evt->events = EPOLLIN;
+ break;
+
+ case SS_CONNECTED:
+ case SS_DATAGRAM:
+ case SS_CONNECTDG:
+ switch (events & SOCK_EVENT_MASK) {
+ case 0:
+ evt->events = 0;
+ break;
+ case SOCK_EVENT_READABLE:
+ evt->events = EPOLLIN;
+ break;
+ case SOCK_EVENT_WRITABLE:
+ evt->events = EPOLLOUT;
+ break;
+ case SOCK_EVENT_READABLE|SOCK_EVENT_WRITABLE:
+ evt->events = EPOLLIN|EPOLLOUT;
+ break;
+ }
+ break;
+ }
+}
+
+/** 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)
+{
+ struct epoll_event evt;
+
+ assert(0 != sock);
+ Debug((DEBUG_ENGINE, "epoll: Adding socket %d [%p], state %s, to engine",
+ s_fd(sock), sock, state_to_name(s_state(sock))));
+ set_events(sock, s_state(sock), s_events(sock), &evt);
+ if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, s_fd(sock), &evt) < 0) {
+ event_generate(ET_ERROR, sock, errno);
+ return 0;
+ }
+ return 1;
+}
+
+/** Handle state transition for a socket.
+ * @param[in] sock Socket changing state.
+ * @param[in] new_state New state for socket.
+ */
+static void
+engine_set_state(struct Socket *sock, enum SocketState new_state)
+{
+ struct epoll_event evt;
+
+ assert(0 != sock);
+ Debug((DEBUG_ENGINE, "epoll: Changing state for socket %p to %s",
+ sock, state_to_name(new_state)));
+ set_events(sock, new_state, s_events(sock), &evt);
+ if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, s_fd(sock), &evt) < 0)
+ event_generate(ET_ERROR, sock, errno);
+}
+
+/** 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_set_events(struct Socket *sock, unsigned new_events)
+{
+ struct epoll_event evt;
+
+ assert(0 != sock);
+ Debug((DEBUG_ENGINE, "epoll: Changing event mask for socket %p to [%s]",
+ sock, sock_flags(new_events)));
+ set_events(sock, s_state(sock), new_events, &evt);
+ if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, s_fd(sock), &evt) < 0)
+ event_generate(ET_ERROR, sock, errno);
+}
+
+/** 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);
+ Debug((DEBUG_ENGINE, "epoll: Deleting socket %d [%p], state %s",
+ s_fd(sock), sock, state_to_name(s_state(sock))));
+ /* Drop any unprocessed events citing this socket. */
+ for (ii = 0; ii < events_used; ii++) {
+ if (events[ii].data.ptr == 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)
+{
+ struct epoll_event *evt;
+ struct Socket *sock;
+ socklen_t codesize;
+ int events_count, tmp, wait, errcode;
+
+ if ((events_count = feature_int(FEAT_POLLS_PER_LOOP)) < 20)
+ events_count = 20;
+ events = MyMalloc(sizeof(events[0]) * events_count);
+ while (running) {
+ if ((tmp = feature_int(FEAT_POLLS_PER_LOOP)) >= 20 && tmp != events_count) {
+ events = MyRealloc(events, sizeof(events[0]) * tmp);
+ events_count = tmp;
+ }
+
+ wait = timer_next(gen) ? (timer_next(gen) - CurrentTime) * 1000 : -1;
+ Debug((DEBUG_ENGINE, "epoll: delay: %d (%d) %d", timer_next(gen),
+ CurrentTime, wait));
+ events_used = epoll_wait(epoll_fd, events, events_count, wait);
+ CurrentTime = time(0);
+
+ if (events_used < 0) {
+ if (errno != EINTR) {
+ log_write(LS_SOCKET, L_ERROR, 0, "epoll() error: %m");
+ if (!errors++)
+ timer_add(timer_init(&clear_error), error_clear, 0, TT_PERIODIC,
+ ERROR_EXPIRE_TIME);
+ else if (errors > EPOLL_ERROR_THRESHOLD)
+ server_restart("too many epoll errors");
+ }
+ continue;
+ }
+
+ while (events_used > 0) {
+ evt = &events[--events_used];
+ if (!(sock = evt->data.ptr))
+ continue;
+ gen_ref_inc(sock);
+ Debug((DEBUG_ENGINE,
+ "epoll: 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 (evt->events & EPOLLERR) {
+ errcode = 0;
+ codesize = sizeof(errcode);
+ if (getsockopt(s_fd(sock), SOL_SOCKET, SO_ERROR, &errcode,
+ &codesize) < 0)
+ errcode = errno;
+ if (errcode) {
+ event_generate(ET_ERROR, sock, errcode);
+ gen_ref_dec(sock);
+ continue;
+ }
+ } else if (evt->events & EPOLLHUP) {
+ event_generate(ET_EOF, sock, 0);
+ } else switch (s_state(sock)) {
+ case SS_CONNECTING:
+ if (evt->events & EPOLLOUT) /* connection completed */
+ event_generate(ET_CONNECT, sock, 0);
+ break;
+
+ case SS_LISTENING:
+ if (evt->events & EPOLLIN) /* incoming connection */
+ event_generate(ET_ACCEPT, sock, 0);
+ break;
+
+ case SS_NOTSOCK:
+ case SS_CONNECTED:
+ case SS_DATAGRAM:
+ case SS_CONNECTDG:
+ if (evt->events & EPOLLIN)
+ event_generate(ET_READ, sock, 0);
+ if (evt->events & EPOLLOUT)
+ event_generate(ET_WRITE, sock, 0);
+ break;
+ }
+ gen_ref_dec(sock);
+ }
+ timer_run();
+ }
+ MyFree(events);
+}
+
+/** Descriptor for epoll event engine. */
+struct Engine engine_epoll = {
+ "epoll()",
+ engine_init,
+ 0,
+ engine_add,
+ engine_set_state,
+ engine_set_events,
+ engine_delete,
+ engine_loop
+};
projects / ircu2.10.12-pk.git / blobdiff