/*
* mini_event.c - implementation of part of libevent api, portably.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
/**
* \file
* fake libevent implementation. Less broad in functionality, and only
* supports select(2).
*/
#include "config.h"
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#include <sys/time.h>
#if defined(USE_MINI_EVENT) && !defined(USE_WINSOCK)
#include <signal.h>
#include "util/mini_event.h"
#include "util/fptr_wlist.h"
/** compare events in tree, based on timevalue, ptr for uniqueness */
int mini_ev_cmp(const void* a, const void* b)
{
const struct event *e = (const struct event*)a;
const struct event *f = (const struct event*)b;
if(e->ev_timeout.tv_sec < f->ev_timeout.tv_sec)
return -1;
if(e->ev_timeout.tv_sec > f->ev_timeout.tv_sec)
return 1;
if(e->ev_timeout.tv_usec < f->ev_timeout.tv_usec)
return -1;
if(e->ev_timeout.tv_usec > f->ev_timeout.tv_usec)
return 1;
if(e < f)
return -1;
if(e > f)
return 1;
return 0;
}
/** set time */
static int
settime(struct event_base* base)
{
if(gettimeofday(base->time_tv, NULL) < 0) {
return -1;
}
#ifndef S_SPLINT_S
*base->time_secs = (time_t)base->time_tv->tv_sec;
#endif
return 0;
}
/** create event base */
void *event_init(time_t* time_secs, struct timeval* time_tv)
{
struct event_base* base = (struct event_base*)malloc(
sizeof(struct event_base));
if(!base)
return NULL;
memset(base, 0, sizeof(*base));
base->time_secs = time_secs;
base->time_tv = time_tv;
if(settime(base) < 0) {
event_base_free(base);
return NULL;
}
base->times = rbtree_create(mini_ev_cmp);
if(!base->times) {
event_base_free(base);
return NULL;
}
base->capfd = MAX_FDS;
#ifdef FD_SETSIZE
if((int)FD_SETSIZE < base->capfd)
base->capfd = (int)FD_SETSIZE;
#endif
base->fds = (struct event**)calloc((size_t)base->capfd,
sizeof(struct event*));
if(!base->fds) {
event_base_free(base);
return NULL;
}
base->signals = (struct event**)calloc(MAX_SIG, sizeof(struct event*));
if(!base->signals) {
event_base_free(base);
return NULL;
}
#ifndef S_SPLINT_S
FD_ZERO(&base->reads);
FD_ZERO(&base->writes);
#endif
return base;
}
/** get version */
const char *event_get_version(void)
{
return "mini-event-"PACKAGE_VERSION;
}
/** get polling method, select */
const char *event_get_method(void)
{
return "select";
}
/** call timeouts handlers, and return how long to wait for next one or -1 */
static void handle_timeouts(struct event_base* base, struct timeval* now,
struct timeval* wait)
{
struct event* p;
#ifndef S_SPLINT_S
wait->tv_sec = (time_t)-1;
#endif
while((rbnode_t*)(p = (struct event*)rbtree_first(base->times))
!=RBTREE_NULL) {
#ifndef S_SPLINT_S
if(p->ev_timeout.tv_sec > now->tv_sec ||
(p->ev_timeout.tv_sec==now->tv_sec &&
p->ev_timeout.tv_usec > now->tv_usec)) {
/* there is a next larger timeout. wait for it */
wait->tv_sec = p->ev_timeout.tv_sec - now->tv_sec;
if(now->tv_usec > p->ev_timeout.tv_usec) {
wait->tv_sec--;
wait->tv_usec = 1000000 - (now->tv_usec -
p->ev_timeout.tv_usec);
} else {
wait->tv_usec = p->ev_timeout.tv_usec
- now->tv_usec;
}
return;
}
#endif
/* event times out, remove it */
(void)rbtree_delete(base->times, p);
p->ev_events &= ~EV_TIMEOUT;
fptr_ok(fptr_whitelist_event(p->ev_callback));
(*p->ev_callback)(p->ev_fd, EV_TIMEOUT, p->ev_arg);
}
}
/** call select and callbacks for that */
static int handle_select(struct event_base* base, struct timeval* wait)
{
fd_set r, w;
int ret, i;
#ifndef S_SPLINT_S
if(wait->tv_sec==(time_t)-1)
wait = NULL;
#endif
memmove(&r, &base->reads, sizeof(fd_set));
memmove(&w, &base->writes, sizeof(fd_set));
memmove(&base->ready, &base->content, sizeof(fd_set));
if((ret = select(base->maxfd+1, &r, &w, NULL, wait)) == -1) {
ret = errno;
if(settime(base) < 0)
return -1;
errno = ret;
if(ret == EAGAIN || ret == EINTR)
return 0;
return -1;
}
if(settime(base) < 0)
return -1;
for(i=0; i<base->maxfd+1; i++) {
short bits = 0;
if(!base->fds[i] || !(FD_ISSET(i, &base->ready))) {
continue;
}
if(FD_ISSET(i, &r)) {
bits |= EV_READ;
ret--;
}
if(FD_ISSET(i, &w)) {
bits |= EV_WRITE;
ret--;
}
bits &= base->fds[i]->ev_events;
if(bits) {
fptr_ok(fptr_whitelist_event(
base->fds[i]->ev_callback));
(*base->fds[i]->ev_callback)(base->fds[i]->ev_fd,
bits, base->fds[i]->ev_arg);
if(ret==0)
break;
}
}
return 0;
}
/** run select in a loop */
int event_base_dispatch(struct event_base* base)
{
struct timeval wait;
if(settime(base) < 0)
return -1;
while(!base->need_to_exit)
{
/* see if timeouts need handling */
handle_timeouts(base, base->time_tv, &wait);
if(base->need_to_exit)
return 0;
/* do select */
if(handle_select(base, &wait) < 0) {
if(base->need_to_exit)
return 0;
return -1;
}
}
return 0;
}
/** exit that loop */
int event_base_loopexit(struct event_base* base,
struct timeval* ATTR_UNUSED(tv))
{
base->need_to_exit = 1;
return 0;
}
/* free event base, free events yourself */
void event_base_free(struct event_base* base)
{
if(!base)
return;
free(base->times);
free(base->fds);
free(base->signals);
free(base);
}
/** set content of event */
void event_set(struct event* ev, int fd, short bits,
void (*cb)(int, short, void *), void* arg)
{
ev->node.key = ev;
ev->ev_fd = fd;
ev->ev_events = bits;
ev->ev_callback = cb;
fptr_ok(fptr_whitelist_event(ev->ev_callback));
ev->ev_arg = arg;
ev->added = 0;
}
/* add event to a base */
int event_base_set(struct event_base* base, struct event* ev)
{
ev->ev_base = base;
ev->added = 0;
return 0;
}
/* add event to make it active, you may not change it with event_set anymore */
int event_add(struct event* ev, struct timeval* tv)
{
if(ev->added)
event_del(ev);
if(ev->ev_fd != -1 && ev->ev_fd >= ev->ev_base->capfd)
return -1;
if( (ev->ev_events&(EV_READ|EV_WRITE)) && ev->ev_fd != -1) {
ev->ev_base->fds[ev->ev_fd] = ev;
if(ev->ev_events&EV_READ) {
FD_SET(FD_SET_T ev->ev_fd, &ev->ev_base->reads);
}
if(ev->ev_events&EV_WRITE) {
FD_SET(FD_SET_T ev->ev_fd, &ev->ev_base->writes);
}
FD_SET(FD_SET_T ev->ev_fd, &ev->ev_base->content);
FD_CLR(FD_SET_T ev->ev_fd, &ev->ev_base->ready);
if(ev->ev_fd > ev->ev_base->maxfd)
ev->ev_base->maxfd = ev->ev_fd;
}
if(tv && (ev->ev_events&EV_TIMEOUT)) {
#ifndef S_SPLINT_S
struct timeval *now = ev->ev_base->time_tv;
ev->ev_timeout.tv_sec = tv->tv_sec + now->tv_sec;
ev->ev_timeout.tv_usec = tv->tv_usec + now->tv_usec;
while(ev->ev_timeout.tv_usec > 1000000) {
ev->ev_timeout.tv_usec -= 1000000;
ev->ev_timeout.tv_sec++;
}
#endif
(void)rbtree_insert(ev->ev_base->times, &ev->node);
}
ev->added = 1;
return 0;
}
/* remove event, you may change it again */
int event_del(struct event* ev)
{
if(ev->ev_fd != -1 && ev->ev_fd >= ev->ev_base->capfd)
return -1;
if((ev->ev_events&EV_TIMEOUT))
(void)rbtree_delete(ev->ev_base->times, &ev->node);
if((ev->ev_events&(EV_READ|EV_WRITE)) && ev->ev_fd != -1) {
ev->ev_base->fds[ev->ev_fd] = NULL;
FD_CLR(FD_SET_T ev->ev_fd, &ev->ev_base->reads);
FD_CLR(FD_SET_T ev->ev_fd, &ev->ev_base->writes);
FD_CLR(FD_SET_T ev->ev_fd, &ev->ev_base->ready);
FD_CLR(FD_SET_T ev->ev_fd, &ev->ev_base->content);
}
ev->added = 0;
return 0;
}
/** which base gets to handle signals */
static struct event_base* signal_base = NULL;
/** signal handler */
static RETSIGTYPE sigh(int sig)
{
struct event* ev;
if(!signal_base || sig < 0 || sig >= MAX_SIG)
return;
ev = signal_base->signals[sig];
if(!ev)
return;
fptr_ok(fptr_whitelist_event(ev->ev_callback));
(*ev->ev_callback)(sig, EV_SIGNAL, ev->ev_arg);
}
/** install signal handler */
int signal_add(struct event* ev, struct timeval* ATTR_UNUSED(tv))
{
if(ev->ev_fd == -1 || ev->ev_fd >= MAX_SIG)
return -1;
signal_base = ev->ev_base;
ev->ev_base->signals[ev->ev_fd] = ev;
ev->added = 1;
if(signal(ev->ev_fd, sigh) == SIG_ERR) {
return -1;
}
return 0;
}
/** remove signal handler */
int signal_del(struct event* ev)
{
if(ev->ev_fd == -1 || ev->ev_fd >= MAX_SIG)
return -1;
ev->ev_base->signals[ev->ev_fd] = NULL;
ev->added = 0;
return 0;
}
#else /* USE_MINI_EVENT */
#ifndef USE_WINSOCK
int mini_ev_cmp(const void* ATTR_UNUSED(a), const void* ATTR_UNUSED(b))
{
return 0;
}
#endif /* not USE_WINSOCK */
#endif /* USE_MINI_EVENT */
