/*
- event.c -- event queue
- Copyright (C) 2002-2009 Guus Sliepen <guus@tinc-vpn.org>,
- 2002-2005 Ivo Timmermans
+ event.c -- I/O, timeout and signal event handling
+ Copyright (C) 2014-2017 Guus Sliepen <guus@meshlink.io>
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
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.
+ 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.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "system.h"
-#include "avl_tree.h"
+#include "dropin.h"
#include "event.h"
+#include "logger.h"
+#include "meshlink.h"
+#include "net.h"
+#include "splay_tree.h"
#include "utils.h"
#include "xalloc.h"
-avl_tree_t *event_tree;
-extern time_t now;
+#ifndef EVENT_CLOCK
+#if defined(CLOCK_MONOTONIC_RAW) && defined(__x86_64__)
+#define EVENT_CLOCK CLOCK_MONOTONIC_RAW
+#else
+#define EVENT_CLOCK CLOCK_MONOTONIC
+#endif
+#endif
-int id;
+static int io_compare(const io_t *a, const io_t *b) {
+ return a->fd - b->fd;
+}
-static int event_compare(const event_t *a, const event_t *b)
-{
- if(a->time > b->time)
+static int timeout_compare(const timeout_t *a, const timeout_t *b) {
+ if(a->tv.tv_sec < b->tv.tv_sec) {
+ return -1;
+ } else if(a->tv.tv_sec > b->tv.tv_sec) {
return 1;
-
- if(a->time < b->time)
+ } else if(a->tv.tv_nsec < b->tv.tv_nsec) {
+ return -1;
+ } else if(a->tv.tv_nsec > b->tv.tv_nsec) {
+ return 1;
+ } else if(a < b) {
return -1;
+ } else if(a > b) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
- return a->id - b->id;
+void io_add(event_loop_t *loop, io_t *io, io_cb_t cb, void *data, int fd, int flags) {
+ assert(!io->cb);
+
+ io->fd = fd;
+ io->cb = cb;
+ io->data = data;
+ io->node.data = io;
+
+ io_set(loop, io, flags);
+
+ splay_node_t *node = splay_insert_node(&loop->ios, &io->node);
+ assert(node);
+ (void)node;
}
-void init_events(void)
-{
- cp();
+void io_set(event_loop_t *loop, io_t *io, int flags) {
+ assert(io->cb);
+
+ io->flags = flags;
- event_tree = avl_alloc_tree((avl_compare_t) event_compare, (avl_action_t) free_event);
+ if(flags & IO_READ) {
+ FD_SET(io->fd, &loop->readfds);
+ } else {
+ FD_CLR(io->fd, &loop->readfds);
+ }
+
+ if(flags & IO_WRITE) {
+ FD_SET(io->fd, &loop->writefds);
+ } else {
+ FD_CLR(io->fd, &loop->writefds);
+ }
}
-void exit_events(void)
-{
- cp();
+void io_del(event_loop_t *loop, io_t *io) {
+ assert(io->cb);
+
+ loop->deletion = true;
- avl_delete_tree(event_tree);
+ io_set(loop, io, 0);
+
+ splay_unlink_node(&loop->ios, &io->node);
+ io->cb = NULL;
+}
+
+void timeout_add(event_loop_t *loop, timeout_t *timeout, timeout_cb_t cb, void *data, struct timespec *tv) {
+ timeout->cb = cb;
+ timeout->data = data;
+
+ timeout_set(loop, timeout, tv);
}
-void expire_events(void)
-{
- avl_node_t *node;
- event_t *event;
- time_t diff;
+void timeout_set(event_loop_t *loop, timeout_t *timeout, struct timespec *tv) {
+ assert(timeout->cb);
+
+ if(timeout->node.data) {
+ splay_unlink_node(&loop->timeouts, &timeout->node);
+ } else {
+ timeout->node.data = timeout;
+ }
+
+ if(!loop->now.tv_sec) {
+ clock_gettime(EVENT_CLOCK, &loop->now);
+ }
- /*
- * Make all events appear expired by substracting the difference between
- * the expiration time of the last event and the current time.
- */
+ timespec_add(&loop->now, tv, &timeout->tv);
- cp();
+ if(!splay_insert_node(&loop->timeouts, &timeout->node)) {
+ abort();
+ }
+
+ loop->deletion = true;
+}
+
+static void timeout_disable(event_loop_t *loop, timeout_t *timeout) {
+ if(timeout->node.data) {
+ splay_unlink_node(&loop->timeouts, &timeout->node);
+ timeout->node.data = NULL;
+ }
+
+ timespec_clear(&timeout->tv);
+}
- if(!event_tree->tail)
+void timeout_del(event_loop_t *loop, timeout_t *timeout) {
+ if(!timeout->cb) {
return;
+ }
+
+ if(timeout->node.data) {
+ timeout_disable(loop, timeout);
+ }
+
+ timeout->cb = NULL;
+ loop->deletion = true;
+}
+
+static int signal_compare(const signal_t *a, const signal_t *b) {
+ return (int)a->signum - (int)b->signum;
+}
+
+static void signalio_handler(event_loop_t *loop, void *data, int flags) {
+ (void)data;
+ (void)flags;
+ unsigned char signum;
- event = event_tree->tail->data;
- if(event->time < now)
+ if(read(loop->pipefd[0], &signum, 1) != 1) {
return;
+ }
+
+ signal_t *sig = splay_search(&loop->signals, &(signal_t) {
+ .signum = signum
+ });
- diff = 1 + event->time - now;
-
- for(node = event_tree->head; node; node = node->next) {
- event = node->data;
- event->time -= diff;
+ if(sig) {
+#ifdef HAVE_STDATOMIC_H
+ atomic_flag_clear(&sig->set);
+#endif
+ sig->cb(loop, sig->data);
}
}
-event_t *new_event(void)
-{
- cp();
+static void pipe_init(event_loop_t *loop) {
+ int result = pipe(loop->pipefd);
+ assert(result == 0);
+
+ if(result == 0) {
+#ifdef O_NONBLOCK
+ fcntl(loop->pipefd[0], F_SETFL, O_NONBLOCK);
+ fcntl(loop->pipefd[1], F_SETFL, O_NONBLOCK);
+#endif
+ io_add(loop, &loop->signalio, signalio_handler, NULL, loop->pipefd[0], IO_READ);
+ }
+}
+
+static void pipe_exit(event_loop_t *loop) {
+ io_del(loop, &loop->signalio);
+
+ close(loop->pipefd[0]);
+ close(loop->pipefd[1]);
- return xmalloc_and_zero(sizeof(event_t));
+ loop->pipefd[0] = -1;
+ loop->pipefd[1] = -1;
}
-void free_event(event_t *event)
-{
- cp();
+void signal_trigger(event_loop_t *loop, signal_t *sig) {
+#ifdef HAVE_STDATOMIC_H
- free(event);
+ if(atomic_flag_test_and_set(&sig->set)) {
+ return;
+ }
+
+#endif
+
+ uint8_t signum = sig->signum;
+ write(loop->pipefd[1], &signum, 1);
+ return;
}
-void event_add(event_t *event)
-{
- cp();
+void signal_add(event_loop_t *loop, signal_t *sig, signal_cb_t cb, void *data, uint8_t signum) {
+ assert(!sig->cb);
+
+ sig->cb = cb;
+ sig->data = data;
+ sig->signum = signum;
+ sig->node.data = sig;
+
+#ifdef HAVE_STDATOMIC_H
+ atomic_flag_clear(&sig->set);
+#endif
+
+ if(loop->pipefd[0] == -1) {
+ pipe_init(loop);
+ }
- event->id = ++id;
- avl_insert(event_tree, event);
+ if(!splay_insert_node(&loop->signals, &sig->node)) {
+ abort();
+ }
}
-void event_del(event_t *event)
-{
- cp();
+void signal_del(event_loop_t *loop, signal_t *sig) {
+ assert(sig->cb);
+
+ loop->deletion = true;
- avl_delete(event_tree, event);
+ splay_unlink_node(&loop->signals, &sig->node);
+ sig->cb = NULL;
+
+ if(!loop->signals.count && loop->pipefd[0] != -1) {
+ pipe_exit(loop);
+ }
}
-event_t *get_expired_event(void)
-{
- event_t *event;
+void idle_set(event_loop_t *loop, idle_cb_t cb, void *data) {
+ loop->idle_cb = cb;
+ loop->idle_data = data;
+}
+
+static void check_bad_fds(event_loop_t *loop, meshlink_handle_t *mesh) {
+ // Just call all registered callbacks and have them check their fds
+
+ do {
+ loop->deletion = false;
- cp();
+ for splay_each(io_t, io, &loop->ios) {
+ if(io->flags & IO_WRITE) {
+ io->cb(loop, io->data, IO_WRITE);
+ }
- if(event_tree->head) {
- event = event_tree->head->data;
+ if(loop->deletion) {
+ break;
+ }
- if(event->time < now) {
- avl_node_t *node = event_tree->head;
- avl_unlink_node(event_tree, node);
- free(node);
- return event;
+ if(io->flags & IO_READ) {
+ io->cb(loop, io->data, IO_READ);
+ }
+
+ if(loop->deletion) {
+ break;
+ }
+ }
+ } while(loop->deletion);
+
+ // Rebuild the fdsets
+
+ fd_set old_readfds;
+ fd_set old_writefds;
+ memcpy(&old_readfds, &loop->readfds, sizeof(old_readfds));
+ memcpy(&old_writefds, &loop->writefds, sizeof(old_writefds));
+
+ memset(&loop->readfds, 0, sizeof(loop->readfds));
+ memset(&loop->writefds, 0, sizeof(loop->writefds));
+
+ for splay_each(io_t, io, &loop->ios) {
+ if(io->flags & IO_READ) {
+ FD_SET(io->fd, &loop->readfds);
+ io->cb(loop, io->data, IO_READ);
+ }
+
+ if(io->flags & IO_WRITE) {
+ FD_SET(io->fd, &loop->writefds);
+ io->cb(loop, io->data, IO_WRITE);
+ }
+ }
+
+ if(memcmp(&old_readfds, &loop->readfds, sizeof(old_readfds))) {
+ logger(mesh, MESHLINK_WARNING, "Incorrect readfds fixed");
+ }
+
+ if(memcmp(&old_writefds, &loop->writefds, sizeof(old_writefds))) {
+ logger(mesh, MESHLINK_WARNING, "Incorrect writefds fixed");
+ }
+}
+
+bool event_loop_run(event_loop_t *loop, meshlink_handle_t *mesh) {
+ assert(mesh);
+
+ fd_set readable;
+ fd_set writable;
+ int errors = 0;
+
+ while(loop->running) {
+ clock_gettime(EVENT_CLOCK, &loop->now);
+ struct timespec it, ts = {3600, 0};
+
+ while(loop->timeouts.head) {
+ timeout_t *timeout = loop->timeouts.head->data;
+
+ if(timespec_lt(&timeout->tv, &loop->now)) {
+ timeout_disable(loop, timeout);
+ timeout->cb(loop, timeout->data);
+ } else {
+ timespec_sub(&timeout->tv, &loop->now, &ts);
+ break;
+ }
+ }
+
+ if(loop->idle_cb) {
+ it = loop->idle_cb(loop, loop->idle_data);
+
+ if(it.tv_sec >= 0 && timespec_lt(&it, &ts)) {
+ ts = it;
+ }
+ }
+
+ memcpy(&readable, &loop->readfds, sizeof(readable));
+ memcpy(&writable, &loop->writefds, sizeof(writable));
+
+ int fds = 0;
+
+ if(loop->ios.tail) {
+ io_t *last = loop->ios.tail->data;
+ fds = last->fd + 1;
+ }
+
+ // release mesh mutex during select
+ pthread_mutex_unlock(&mesh->mutex);
+
+#ifdef HAVE_PSELECT
+ int n = pselect(fds, &readable, &writable, NULL, &ts, NULL);
+#else
+ struct timeval tv = {ts.tv_sec, ts.tv_nsec / 1000};
+ int n = select(fds, &readable, &writable, NULL, (struct timeval *)&tv);
+#endif
+
+ if(pthread_mutex_lock(&mesh->mutex) != 0) {
+ abort();
+ }
+
+ clock_gettime(EVENT_CLOCK, &loop->now);
+
+ if(n < 0) {
+ if(sockwouldblock(errno)) {
+ continue;
+ } else {
+ errors++;
+
+ if(errors > 10) {
+ logger(mesh, MESHLINK_ERROR, "Unrecoverable error from select(): %s", strerror(errno));
+ return false;
+ }
+
+ logger(mesh, MESHLINK_WARNING, "Error from select(), checking for bad fds: %s", strerror(errno));
+ check_bad_fds(loop, mesh);
+ continue;
+ }
+ }
+
+ errors = 0;
+
+ if(!n) {
+ continue;
+ }
+
+ // Normally, splay_each allows the current node to be deleted. However,
+ // it can be that one io callback triggers the deletion of another io,
+ // so we have to detect this and break the loop.
+
+ loop->deletion = false;
+
+ for splay_each(io_t, io, &loop->ios) {
+ if(FD_ISSET(io->fd, &writable) && io->cb) {
+ io->cb(loop, io->data, IO_WRITE);
+ }
+
+ if(loop->deletion) {
+ break;
+ }
+
+ if(FD_ISSET(io->fd, &readable) && io->cb) {
+ io->cb(loop, io->data, IO_READ);
+ }
+
+ if(loop->deletion) {
+ break;
+ }
}
}
- return NULL;
+ return true;
+}
+
+void event_loop_start(event_loop_t *loop) {
+ loop->running = true;
+}
+
+void event_loop_stop(event_loop_t *loop) {
+ loop->running = false;
+}
+
+void event_loop_init(event_loop_t *loop) {
+ loop->ios.compare = (splay_compare_t)io_compare;
+ loop->timeouts.compare = (splay_compare_t)timeout_compare;
+ loop->signals.compare = (splay_compare_t)signal_compare;
+ loop->pipefd[0] = -1;
+ loop->pipefd[1] = -1;
+ clock_gettime(EVENT_CLOCK, &loop->now);
+}
+
+void event_loop_exit(event_loop_t *loop) {
+ assert(!loop->ios.count);
+ assert(!loop->timeouts.count);
+ assert(!loop->signals.count);
+
+ for splay_each(io_t, io, &loop->ios) {
+ splay_unlink_node(&loop->ios, splay_node);
+ }
+
+ for splay_each(timeout_t, timeout, &loop->timeouts) {
+ splay_unlink_node(&loop->timeouts, splay_node);
+ }
+
+ for splay_each(signal_t, signal, &loop->signals) {
+ splay_unlink_node(&loop->signals, splay_node);
+ }
}