/*
event.c -- I/O, timeout and signal event handling
- Copyright (C) 2012-2013 Guus Sliepen <guus@tinc-vpn.org>
+ Copyright (C) 2012-2022 Guus Sliepen <guus@tinc-vpn.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
#include "system.h"
+#include <assert.h>
+
+#ifdef HAVE_SYS_EPOLL_H
+#include <sys/epoll.h>
+#endif
+
#include "dropin.h"
#include "event.h"
-#include "net.h"
#include "utils.h"
-#include "xalloc.h"
+#include "net.h"
struct timeval now;
-
#ifndef HAVE_MINGW
+
+#ifdef HAVE_SYS_EPOLL_H
+static int epollset = 0;
+#else
static fd_set readfds;
static fd_set writefds;
+#endif
+
#else
static const long READ_EVENTS = FD_READ | FD_ACCEPT | FD_CLOSE;
static const long WRITE_EVENTS = FD_WRITE | FD_CONNECT;
#endif
static bool running;
+#ifdef HAVE_SYS_EPOLL_H
+static inline int event_epoll_init(void) {
+ /* NOTE: 1024 limit is only used on ancient (pre 2.6.27) kernels.
+ Decent kernels will ignore this value making it unlimited.
+ epoll_create1 might be better, but these kernels would not be supported
+ in that case.
+ */
+ return epoll_create(1024);
+}
+#endif
+
static int io_compare(const io_t *a, const io_t *b) {
#ifndef HAVE_MINGW
return a->fd - b->fd;
#else
- return a->event - b->event;
+
+ if(a->event < b->event) {
+ return -1;
+ }
+
+ if(a->event > b->event) {
+ return 1;
+ }
+
+ return 0;
#endif
}
io_set(io, flags);
+#ifndef HAVE_SYS_EPOLL_H
+
if(!splay_insert_node(&io_tree, &io->node)) {
abort();
}
+
+#endif
}
#ifdef HAVE_MINGW
#endif
void io_set(io_t *io, int flags) {
+#ifdef HAVE_SYS_EPOLL_H
+
+ if(!epollset) {
+ epollset = event_epoll_init();
+ }
+
+#endif
+
if(flags == io->flags) {
return;
}
}
#ifndef HAVE_MINGW
+#ifdef HAVE_SYS_EPOLL_H
+ epoll_ctl(epollset, EPOLL_CTL_DEL, io->fd, NULL);
+
+ struct epoll_event ev = {
+ .events = 0,
+ .data.ptr = io,
+ };
+
+ if(flags & IO_READ) {
+ ev.events |= EPOLLIN;
+ }
+
+ if(flags & IO_WRITE) {
+ ev.events |= EPOLLOUT;
+ } else if(ev.events == 0) {
+ io_tree.generation++;
+ return;
+ }
+
+ if(epoll_ctl(epollset, EPOLL_CTL_ADD, io->fd, &ev) < 0) {
+ perror("epoll_ctl_add");
+ }
+
+#else
if(flags & IO_READ) {
FD_SET(io->fd, &readfds);
FD_CLR(io->fd, &writefds);
}
+#endif
#else
long events = 0;
event_count--;
#endif
+#ifndef HAVE_SYS_EPOLL_H
splay_unlink_node(&io_tree, &io->node);
+#endif
io->cb = NULL;
}
}
#ifndef HAVE_MINGW
-static int signal_compare(const signal_t *a, const signal_t *b) {
- return a->signum - b->signum;
-}
+
+// From Matz's Ruby
+#ifndef NSIG
+# define NSIG (_SIGMAX + 1) /* For QNX */
+#endif
+
static io_t signalio;
static int pipefd[2] = {-1, -1};
-static splay_tree_t signal_tree = {.compare = (splay_compare_t)signal_compare};
+static signal_t *signal_handle[NSIG + 1] = {NULL};
static void signal_handler(int signum) {
unsigned char num = signum;
- write(pipefd[1], &num, 1);
+
+ if(write(pipefd[1], &num, 1) != 1) {
+ // Pipe full or broken, nothing we can do about it.
+ }
}
static void signalio_handler(void *data, int flags) {
+ (void)data;
+ (void)flags;
unsigned char signum;
if(read(pipefd[0], &signum, 1) != 1) {
return;
}
- signal_t *sig = splay_search(&signal_tree, &((signal_t) {
- .signum = signum
- }));
+ signal_t *sig = signal_handle[signum];
if(sig) {
sig->cb(sig->data);
return;
}
+ sig->signum = signum;
sig->cb = cb;
sig->data = data;
- sig->signum = signum;
- sig->node.data = sig;
if(pipefd[0] == -1) {
pipe_init();
}
- signal(sig->signum, signal_handler);
+ signal(signum, signal_handler);
- if(!splay_insert_node(&signal_tree, &sig->node)) {
- abort();
- }
+ signal_handle[signum] = sig;
}
void signal_del(signal_t *sig) {
signal(sig->signum, SIG_DFL);
- splay_unlink_node(&signal_tree, &sig->node);
+ signal_handle[sig->signum] = NULL;
sig->cb = NULL;
}
#endif
-static struct timeval *get_time_remaining(struct timeval *diff) {
+static struct timeval *timeout_execute(struct timeval *diff) {
gettimeofday(&now, NULL);
struct timeval *tv = NULL;
running = true;
#ifndef HAVE_MINGW
+
+#ifdef HAVE_SYS_EPOLL_H
+
+ if(!epollset) {
+ epollset = event_epoll_init();
+ }
+
+#else
fd_set readable;
fd_set writable;
+#endif
while(running) {
struct timeval diff;
- struct timeval *tv = get_time_remaining(&diff);
+ struct timeval *tv = timeout_execute(&diff);
+#ifndef HAVE_SYS_EPOLL_H
memcpy(&readable, &readfds, sizeof(readable));
memcpy(&writable, &writefds, sizeof(writable));
+#endif
+
- int fds = 0;
+#ifdef HAVE_SYS_EPOLL_H
+ struct epoll_event events[EPOLL_MAX_EVENTS_PER_LOOP];
+ long timeout = (tv->tv_sec * 1000) + (tv->tv_usec / 1000);
+
+ if(timeout > INT_MAX) {
+ timeout = INT_MAX;
+ }
+
+ int n = epoll_wait(epollset, events, EPOLL_MAX_EVENTS_PER_LOOP, (int)timeout);
+#else
+ int maxfds = 0;
if(io_tree.tail) {
io_t *last = io_tree.tail->data;
- fds = last->fd + 1;
+ maxfds = last->fd + 1;
}
- int n = select(fds, &readable, &writable, NULL, tv);
+ int n = select(maxfds, &readable, &writable, NULL, tv);
+#endif
if(n < 0) {
if(sockwouldblock(sockerrno)) {
continue;
}
+ unsigned int curgen = io_tree.generation;
+
+
+#ifdef HAVE_SYS_EPOLL_H
+
+ for(int i = 0; i < n; i++) {
+ io_t *io = events[i].data.ptr;
+
+ if(events[i].events & EPOLLOUT && io->flags & IO_WRITE) {
+ io->cb(io->data, IO_WRITE);
+ }
+
+ if(curgen != io_tree.generation) {
+ break;
+ }
+
+ if(events[i].events & EPOLLIN && io->flags & IO_READ) {
+ io->cb(io->data, IO_READ);
+ }
+
+ if(curgen != io_tree.generation) {
+ break;
+ }
+ }
+
+#else
+
for splay_each(io_t, io, &io_tree) {
if(FD_ISSET(io->fd, &writable)) {
io->cb(io->data, IO_WRITE);
}
/*
- There are scenarios in which the callback will remove another io_t from the tree
- (e.g. closing a double connection). Since splay_each does not support that, we
- need to exit the loop now. That's okay, since any remaining events will get picked
- up by the next select() call.
- */
- break;
+ There are scenarios in which the callback will remove another io_t from the tree
+ (e.g. closing a double connection). Since splay_each does not support that, we
+ need to exit the loop if that happens. That's okay, since any remaining events will
+ get picked up by the next select() call.
+ */
+ if(curgen != io_tree.generation) {
+ break;
+ }
}
+
+#endif
}
#else
+ assert(WSA_WAIT_EVENT_0 == 0);
while(running) {
struct timeval diff;
- struct timeval *tv = get_time_remaining(&diff);
- DWORD timeout_ms = tv ? (tv->tv_sec * 1000 + tv->tv_usec / 1000 + 1) : WSA_INFINITE;
+ struct timeval *tv = timeout_execute(&diff);
+ DWORD timeout_ms = tv ? (DWORD)(tv->tv_sec * 1000 + tv->tv_usec / 1000 + 1) : WSA_INFINITE;
if(!event_count) {
Sleep(timeout_ms);
Note that technically FD_CLOSE has the same problem, but it's okay because user code does not rely on
this event being fired again if ignored.
*/
- io_t *writeable_io = NULL;
+ unsigned int curgen = io_tree.generation;
- for splay_each(io_t, io, &io_tree)
+ for splay_each(io_t, io, &io_tree) {
if(io->flags & IO_WRITE && send(io->fd, NULL, 0, 0) == 0) {
- writeable_io = io;
- break;
+ io->cb(io->data, IO_WRITE);
+
+ if(curgen != io_tree.generation) {
+ break;
+ }
}
+ }
- if(writeable_io) {
- writeable_io->cb(writeable_io->data, IO_WRITE);
- continue;
+ if(event_count > WSA_MAXIMUM_WAIT_EVENTS) {
+ WSASetLastError(WSA_INVALID_PARAMETER);
+ return(false);
}
- WSAEVENT *events = xmalloc(event_count * sizeof(*events));
+ WSAEVENT events[WSA_MAXIMUM_WAIT_EVENTS];
+ io_t *io_map[WSA_MAXIMUM_WAIT_EVENTS];
DWORD event_index = 0;
for splay_each(io_t, io, &io_tree) {
events[event_index] = io->event;
+ io_map[event_index] = io;
event_index++;
}
- DWORD result = WSAWaitForMultipleEvents(event_count, events, FALSE, timeout_ms, FALSE);
+ /*
+ * If the generation number changes due to event addition
+ * or removal by a callback we restart the loop.
+ */
+ curgen = io_tree.generation;
- WSAEVENT event;
+ for(DWORD event_offset = 0; event_offset < event_count;) {
+ DWORD result = WSAWaitForMultipleEvents(event_count - event_offset, &events[event_offset], FALSE, timeout_ms, FALSE);
- if(result >= WSA_WAIT_EVENT_0 && result < WSA_WAIT_EVENT_0 + event_count) {
- event = events[result - WSA_WAIT_EVENT_0];
- }
+ if(result == WSA_WAIT_TIMEOUT) {
+ break;
+ }
- free(events);
+ if(result >= event_count - event_offset) {
+ return false;
+ }
- if(result == WSA_WAIT_TIMEOUT) {
- continue;
- }
+ /* Look up io in the map by index. */
+ event_index = result + event_offset;
+ io_t *io = io_map[event_index];
- if(result < WSA_WAIT_EVENT_0 || result >= WSA_WAIT_EVENT_0 + event_count) {
- return false;
- }
+ if(io->fd == -1) {
+ io->cb(io->data, 0);
- io_t *io = splay_search(&io_tree, &((io_t) {
- .event = event
- }));
+ if(curgen != io_tree.generation) {
+ break;
+ }
+ } else {
+ WSANETWORKEVENTS network_events;
- if(!io) {
- abort();
- }
+ if(WSAEnumNetworkEvents(io->fd, io->event, &network_events) != 0) {
+ return(false);
+ }
- if(io->fd == -1) {
- io->cb(io->data, 0);
- } else {
- WSANETWORKEVENTS network_events;
+ if(network_events.lNetworkEvents & READ_EVENTS) {
+ io->cb(io->data, IO_READ);
- if(WSAEnumNetworkEvents(io->fd, io->event, &network_events) != 0) {
- return false;
- }
+ if(curgen != io_tree.generation) {
+ break;
+ }
+ }
- if(network_events.lNetworkEvents & READ_EVENTS) {
- io->cb(io->data, IO_READ);
+ /*
+ The fd might be available for write too. However, if we already fired the read callback, that
+ callback might have deleted the io (e.g. through terminate_connection()), so we can't fire the
+ write callback here. Instead, we loop back and let the writable io loop above handle it.
+ */
}
- /*
- The fd might be available for write too. However, if we already fired the read callback, that
- callback might have deleted the io (e.g. through terminate_connection()), so we can't fire the
- write callback here. Instead, we loop back and let the writable io loop above handle it.
- */
+ /* Continue checking the rest of the events. */
+ event_offset = event_index + 1;
+
+ /* Just poll the next time through. */
+ timeout_ms = 0;
}
}
projects / tinc / blobdiff