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/***************************************************************************
* Copyright (C) 07/2007 by Olaf Rempel *
* razzor@kopf-tisch.de *
* *
* 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; version 2 of the License *
* *
* 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., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#include "list.h"
#include "logging.h"
#include "event.h"
static LIST_HEAD(event_fd_list);
static LIST_HEAD(event_timeout_list);
struct event_fd {
struct list_head list;
unsigned int flags;
int fd;
int (*read_cb)(int fd, void *privdata);
int (*write_cb)(int fd, void *privdata);
void *read_priv;
void *write_priv;
};
struct event_timeout {
struct list_head list;
unsigned int flags;
struct timeval intervall;
struct timeval nextrun;
int (*callback)(void *privdata);
void *privdata;
};
struct event_fd * event_add_fd(
struct event_fd *entry,
int fd,
int type,
int (*callback)(int fd, void *privdata),
void *privdata)
{
/* check valid filediskriptor */
if (fd < 0 || fd > FD_SETSIZE) {
log_print(LOG_ERROR, "event_add_fd(): invalid fd");
return NULL;
}
/* check valid type (read/write) */
if (!(type & FD_TYPES)) {
log_print(LOG_ERROR, "event_add_fd(): invalid type");
return NULL;
}
/* create new entry */
if (entry == NULL) {
entry = malloc(sizeof(struct event_fd));
if (entry == NULL) {
log_print(LOG_ERROR, "event_add_fd(): out of memory");
return NULL;
}
memset(entry, 0, sizeof(struct event_fd));
entry->flags |= EVENT_NEW;
entry->fd = fd;
/* put it on the list */
list_add_tail(&entry->list, &event_fd_list);
}
if (type & FD_READ) {
entry->flags = (callback != NULL) ? (entry->flags | FD_READ | EVENT_NEW) : (entry->flags & ~FD_READ);
entry->read_cb = callback;
entry->read_priv = privdata;
} else if (type & FD_WRITE) {
entry->flags = (callback != NULL) ? (entry->flags | FD_WRITE | EVENT_NEW) : (entry->flags & ~FD_WRITE);
entry->write_cb = callback;
entry->write_priv = privdata;
}
return entry;
}
int event_get_fd(struct event_fd *entry)
{
return (entry != NULL) ? entry->fd: -1;
}
void event_remove_fd(struct event_fd *entry)
{
/* mark the event as deleted -> remove in select() loop */
entry->flags |= EVENT_DELETE;
}
static void add_timeval(struct timeval *ret, struct timeval *a, struct timeval *b)
{
ret->tv_usec = a->tv_usec + b->tv_usec;
ret->tv_sec = a->tv_sec + b->tv_sec;
if (ret->tv_usec >= 1000000) {
ret->tv_usec -= 1000000;
ret->tv_sec++;
}
}
static void sub_timeval(struct timeval *ret, struct timeval *a, struct timeval *b)
{
ret->tv_usec = a->tv_usec - b->tv_usec;
ret->tv_sec = a->tv_sec - b->tv_sec;
if (ret->tv_usec < 0) {
ret->tv_usec += 1000000;
ret->tv_sec--;
}
}
static int cmp_timeval(struct timeval *a, struct timeval *b)
{
if (a->tv_sec > b->tv_sec)
return -1;
if (a->tv_sec < b->tv_sec)
return 1;
if (a->tv_usec > b->tv_usec)
return -1;
if (a->tv_usec < b->tv_usec)
return 1;
return 0;
}
static void schedule_nextrun(struct event_timeout *entry, struct timeval *now)
{
add_timeval(&entry->nextrun, now, &entry->intervall);
struct event_timeout *search;
list_for_each_entry(search, &event_timeout_list, list) {
if (search->nextrun.tv_sec > entry->nextrun.tv_sec) {
list_add_tail(&entry->list, &search->list);
return;
} else if (search->nextrun.tv_sec == entry->nextrun.tv_sec &&
search->nextrun.tv_usec > entry->nextrun.tv_usec) {
list_add_tail(&entry->list, &search->list);
return;
}
}
list_add_tail(&entry->list, &event_timeout_list);
}
struct event_timeout * event_add_timeout(
struct timeval *timeout,
int (*callback)(void *privdata),
void *privdata)
{
struct event_timeout *entry;
entry = malloc(sizeof(struct event_timeout));
if (entry == NULL) {
log_print(LOG_ERROR, "event_add_timeout(): out of memory");
return NULL;
}
entry->flags = 0;
memcpy(&entry->intervall, timeout, sizeof(entry->intervall));
entry->callback = callback;
entry->privdata = privdata;
struct timeval now;
gettimeofday(&now, NULL);
schedule_nextrun(entry, &now);
return entry;
}
void event_remove_timeout(struct event_timeout *entry)
{
/* mark the event as deleted -> remove in select() loop */
entry->flags |= EVENT_DELETE;
}
int event_loop(void)
{
fd_set *fdsets = malloc(sizeof(fd_set) * 2);
if (fdsets == NULL) {
log_print(LOG_ERROR, "event_loop(): out of memory");
return -1;
}
while (1) {
struct timeval timeout, *timeout_p = NULL;
if (!list_empty(&event_timeout_list)) {
struct timeval now;
gettimeofday(&now, NULL);
struct event_timeout *entry, *tmp;
list_for_each_entry_safe(entry, tmp, &event_timeout_list, list) {
if (entry->flags & EVENT_DELETE) {
list_del(&entry->list);
free(entry);
continue;
}
/* first timeout not elapsed, exit search (since list is sorted) */
if (cmp_timeval(&entry->nextrun, &now) == -1)
break;
/* remove event from list */
list_del(&entry->list);
/* execute callback, when callback returns 0 -> schedule event again */
if (entry->callback(entry->privdata)) {
free(entry);
} else {
schedule_nextrun(entry, &now);
}
}
if (!list_empty(&event_timeout_list)) {
entry = list_entry(event_timeout_list.next, typeof(*entry), list);
/* calc select() timeout */
sub_timeval(&timeout, &entry->nextrun, &now);
timeout_p = &timeout;
}
}
fd_set *readfds = NULL, *writefds = NULL;
struct event_fd *entry, *tmp;
list_for_each_entry_safe(entry, tmp, &event_fd_list, list) {
entry->flags &= ~EVENT_NEW;
if (entry->flags & EVENT_DELETE) {
list_del(&entry->list);
free(entry);
continue;
}
if (entry->flags & FD_READ) {
if (readfds == NULL) {
readfds = &fdsets[0];
FD_ZERO(readfds);
}
FD_SET(entry->fd, readfds);
}
if (entry->flags & FD_WRITE) {
if (writefds == NULL) {
writefds = &fdsets[1];
FD_ZERO(writefds);
}
FD_SET(entry->fd, writefds);
}
}
int i = select(FD_SETSIZE, readfds, writefds, NULL, timeout_p);
if (i <= 0) {
/* On error, -1 is returned, and errno is set
* appropriately; the sets and timeout become
* undefined, so do not rely on their contents
* after an error.
*/
continue;
}
list_for_each_entry(entry, &event_fd_list, list) {
if (((entry->flags & (FD_READ | EVENT_NEW)) == FD_READ) && FD_ISSET(entry->fd, readfds))
if (entry->read_cb(entry->fd, entry->read_priv) != 0)
entry->flags |= EVENT_DELETE;
if (((entry->flags & (FD_WRITE | EVENT_NEW)) == FD_WRITE) && FD_ISSET(entry->fd, writefds))
if (entry->write_cb(entry->fd, entry->write_priv) != 0)
entry->flags |= EVENT_DELETE;
}
}
free(fdsets);
}