/*
event.c -- I/O, timeout and signal event handling
- Copyright (C) 2012 Guus Sliepen <guus@tinc-vpn.org>
+ 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
#include "system.h"
+#include "dropin.h"
#include "event.h"
#include "net.h"
+#include "splay_tree.h"
#include "utils.h"
+#include "xalloc.h"
-struct timeval 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
-static fd_set readfds;
-static fd_set writefds;
-static volatile bool running;
+static void timespec_add(const struct timespec *a, const struct timespec *b, struct timespec *r) {
+ r->tv_sec = a->tv_sec + b->tv_sec;
+ r->tv_nsec = a->tv_nsec + b->tv_nsec;
-static int io_compare(const io_t *a, const io_t *b) {
- return a->fd - b->fd;
+ if(r->tv_nsec > 1000000000) {
+ r->tv_sec++, r->tv_nsec -= 1000000000;
+ }
}
-static int timeout_compare(const timeout_t *a, const timeout_t *b) {
- struct timeval diff;
- timersub(&a->tv, &b->tv, &diff);
- return diff.tv_sec ?: diff.tv_usec;
+static void timespec_sub(const struct timespec *a, const struct timespec *b, struct timespec *r) {
+ r->tv_sec = a->tv_sec - b->tv_sec;
+ r->tv_nsec = a->tv_nsec - b->tv_nsec;
+
+ if(r->tv_nsec < 0) {
+ r->tv_sec--, r->tv_nsec += 1000000000;
+ }
}
-static int signal_compare(const signal_t *a, const signal_t *b) {
- return a->signum - b->signum;
+static bool timespec_lt(const struct timespec *a, const struct timespec *b) {
+ if(a->tv_sec == b->tv_sec) {
+ return a->tv_nsec < b->tv_nsec;
+ } else {
+ return a->tv_sec < b->tv_sec;
+ }
}
-static splay_tree_t io_tree = {.compare = (splay_compare_t)io_compare};
-static splay_tree_t timeout_tree = {.compare = (splay_compare_t)timeout_compare};
-static splay_tree_t signal_tree = {.compare = (splay_compare_t)signal_compare};
+static void timespec_clear(struct timespec *a) {
+ a->tv_sec = 0;
+}
-void io_add(io_t *io, io_cb_t cb, void *data, int fd, int flags) {
- if(io->cb)
- return;
+static int io_compare(const io_t *a, const io_t *b) {
+ return a->fd - b->fd;
+}
+
+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;
+ } 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;
+ }
+}
+
+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(io, flags);
+ io_set(loop, io, flags);
- splay_insert_node(&io_tree, &io->node);
+ splay_node_t *node = splay_insert_node(&loop->ios, &io->node);
+ assert(node);
+ (void)node;
}
-void io_set(io_t *io, int flags) {
+void io_set(event_loop_t *loop, io_t *io, int flags) {
+ assert(io->cb);
+
io->flags = flags;
- if(flags & IO_READ)
- FD_SET(io->fd, &readfds);
- else
- FD_CLR(io->fd, &readfds);
+ 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, &writefds);
- else
- FD_CLR(io->fd, &writefds);
+ if(flags & IO_WRITE) {
+ FD_SET(io->fd, &loop->writefds);
+ } else {
+ FD_CLR(io->fd, &loop->writefds);
+ }
}
-void io_del(io_t *io) {
- if(!io->cb)
- return;
+void io_del(event_loop_t *loop, io_t *io) {
+ assert(io->cb);
+
+ loop->deletion = true;
- io_set(io, 0);
+ io_set(loop, io, 0);
- splay_unlink_node(&io_tree, &io->node);
+ splay_unlink_node(&loop->ios, &io->node);
io->cb = NULL;
}
-void timeout_add(timeout_t *timeout, timeout_cb_t cb, void *data, struct timeval *tv) {
- if(timeout->cb)
- return;
-
+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->node.data = timeout;
- timeout_set(timeout, tv);
+ timeout_set(loop, timeout, tv);
}
-void timeout_set(timeout_t *timeout, struct timeval *tv) {
- if(timeout->tv.tv_sec)
- splay_unlink_node(&timeout_tree, &timeout->node);
+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);
+ }
+
+ timespec_add(&loop->now, tv, &timeout->tv);
+
+ if(!splay_insert_node(&loop->timeouts, &timeout->node)) {
+ abort();
+ }
- if(!now.tv_sec)
- gettimeofday(&now, NULL);
+ loop->deletion = true;
+}
- timeradd(&now, tv, &timeout->tv);
+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;
+ }
- splay_insert_node(&timeout_tree, &timeout->node);
+ timespec_clear(&timeout->tv);
}
-void timeout_del(timeout_t *timeout) {
- if(!timeout->cb)
+void timeout_del(event_loop_t *loop, timeout_t *timeout) {
+ if(!timeout->cb) {
return;
+ }
+
+ if(timeout->node.data) {
+ timeout_disable(loop, timeout);
+ }
- splay_unlink_node(&timeout_tree, &timeout->node);
timeout->cb = NULL;
+ loop->deletion = true;
}
-#ifndef HAVE_MINGW
-static io_t signalio;
-static int pipefd[2] = {-1, -1};
-
-static void signal_handler(int signum) {
- unsigned char num = signum;
- write(pipefd[1], &num, 1);
+static int signal_compare(const signal_t *a, const signal_t *b) {
+ return (int)a->signum - (int)b->signum;
}
-static void signalio_handler(void *data, int flags) {
+static void signalio_handler(event_loop_t *loop, void *data, int flags) {
+ (void)data;
+ (void)flags;
unsigned char signum;
- if(read(pipefd[0], &signum, 1) != 1)
+
+ if(read(loop->pipefd[0], &signum, 1) != 1) {
return;
+ }
- signal_t *sig = splay_search(&signal_tree, &((signal_t){.signum = signum}));
- if(sig)
- sig->cb(sig->data);
+ signal_t *sig = splay_search(&loop->signals, &(signal_t) {
+ .signum = signum
+ });
+
+ if(sig) {
+ atomic_flag_clear(&sig->set);
+ sig->cb(loop, sig->data);
+ }
}
-static void pipe_init(void) {
- if(!pipe(pipefd))
- io_add(&signalio, signalio_handler, NULL, pipefd[0], IO_READ);
+static void pipe_init(event_loop_t *loop) {
+ int result = pipe(loop->pipefd);
+ assert(result == 0);
+
+ if(result == 0) {
+ io_add(loop, &loop->signalio, signalio_handler, NULL, loop->pipefd[0], IO_READ);
+ }
}
-void signal_add(signal_t *sig, signal_cb_t cb, void *data, int signum) {
- if(sig->cb)
+static void pipe_exit(event_loop_t *loop) {
+ io_del(loop, &loop->signalio);
+
+ close(loop->pipefd[0]);
+ close(loop->pipefd[1]);
+
+ loop->pipefd[0] = -1;
+ loop->pipefd[1] = -1;
+}
+
+void signal_trigger(event_loop_t *loop, signal_t *sig) {
+ if(atomic_flag_test_and_set(&sig->set)) {
return;
+ }
+
+ uint8_t signum = sig->signum;
+ write(loop->pipefd[1], &signum, 1);
+ return;
+}
+
+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;
- if(pipefd[0] == -1)
- pipe_init();
+ atomic_flag_clear(&sig->set);
- signal(sig->signum, signal_handler);
+ if(loop->pipefd[0] == -1) {
+ pipe_init(loop);
+ }
- splay_insert_node(&signal_tree, &sig->node);
+ if(!splay_insert_node(&loop->signals, &sig->node)) {
+ abort();
+ }
}
-void signal_del(signal_t *sig) {
- if(!sig->cb)
- return;
+void signal_del(event_loop_t *loop, signal_t *sig) {
+ assert(sig->cb);
- signal(sig->signum, SIG_DFL);
+ loop->deletion = true;
- splay_unlink_node(&signal_tree, &sig->node);
+ splay_unlink_node(&loop->signals, &sig->node);
sig->cb = NULL;
+
+ if(!loop->signals.count && loop->pipefd[0] != -1) {
+ pipe_exit(loop);
+ }
}
-#endif
-bool event_loop(void) {
- running = true;
+void idle_set(event_loop_t *loop, idle_cb_t cb, void *data) {
+ loop->idle_cb = cb;
+ loop->idle_data = data;
+}
+
+bool event_loop_run(event_loop_t *loop, pthread_mutex_t *mutex) {
+ assert(mutex);
fd_set readable;
fd_set writable;
- while(running) {
- gettimeofday(&now, NULL);
- struct timeval diff, *tv = NULL;
+ while(loop->running) {
+ clock_gettime(EVENT_CLOCK, &loop->now);
+ struct timespec it, ts = {3600, 0};
- while(timeout_tree.head) {
- timeout_t *timeout = timeout_tree.head->data;
- timersub(&timeout->tv, &now, &diff);
+ while(loop->timeouts.head) {
+ timeout_t *timeout = loop->timeouts.head->data;
- if(diff.tv_sec <= 0) {
- timeout->cb(timeout->data);
- if(timercmp(&timeout->tv, &now, <))
- timeout_del(timeout);
+ if(timespec_lt(&timeout->tv, &loop->now)) {
+ timeout_disable(loop, timeout);
+ timeout->cb(loop, timeout->data);
} else {
- tv = &diff;
+ timespec_sub(&timeout->tv, &loop->now, &ts);
break;
}
}
- memcpy(&readable, &readfds, sizeof readable);
- memcpy(&writable, &writefds, sizeof writable);
+ 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(io_tree.tail) {
- io_t *last = io_tree.tail->data;
+ if(loop->ios.tail) {
+ io_t *last = loop->ios.tail->data;
fds = last->fd + 1;
}
-#ifdef HAVE_MINGW
- LeaveCriticalSection(&mutex);
-#endif
- int n = select(fds, &readable, &writable, NULL, tv);
-#ifdef HAVE_MINGW
- EnterCriticalSection(&mutex);
+ // release mesh mutex during select
+ assert(pthread_mutex_unlock(mutex) == 0);
+
+#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
+ assert(pthread_mutex_lock(mutex) == 0);
+
+ clock_gettime(EVENT_CLOCK, &loop->now);
+
if(n < 0) {
- if(sockwouldblock(errno))
+ if(sockwouldblock(errno)) {
continue;
- else
+ } else {
return false;
+ }
}
- if(!n)
+ 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);
+ }
- for splay_each(io_t, io, &io_tree) {
- if(FD_ISSET(io->fd, &writable))
- io->cb(io->data, IO_WRITE);
- else if(FD_ISSET(io->fd, &readable))
- io->cb(io->data, IO_READ);
+ if(loop->deletion) {
+ break;
+ }
}
}
return true;
}
-void event_exit(void) {
- running = false;
+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);
+ }
}