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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* Generic Event Handling
*
* Copyright (C) 2018 Laurent Pinchart
*
* This file comes from the omap3-isp-live project
* (git://git.ideasonboard.org/omap3-isp-live.git)
*
* Copyright (C) 2010-2011 Ideas on board SPRL
*
* Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
*/
#define _DEFAULT_SOURCE
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/select.h>
#include "events.h"
#include "list.h"
#include "tools.h"
#define SELECT_TIMEOUT 2000 /* in milliseconds */
struct event_fd {
struct list_entry list;
int fd;
enum event_type type;
void (*callback)(void *priv);
void *priv;
};
void events_watch_fd(struct events *events, int fd, enum event_type type,
void(*callback)(void *), void *priv)
{
struct event_fd *event;
event = malloc(sizeof *event);
if (event == NULL)
return;
event->fd = fd;
event->type = type;
event->callback = callback;
event->priv = priv;
switch (event->type) {
case EVENT_READ:
FD_SET(fd, &events->rfds);
break;
case EVENT_WRITE:
FD_SET(fd, &events->wfds);
break;
case EVENT_EXCEPTION:
FD_SET(fd, &events->efds);
break;
}
events->maxfd = max(events->maxfd, fd);
list_append(&event->list, &events->events);
}
void events_unwatch_fd(struct events *events, int fd, enum event_type type)
{
struct event_fd *event = NULL;
struct event_fd *entry;
int maxfd = 0;
list_for_each_entry(entry, &events->events, list) {
if (entry->fd == fd && entry->type == type)
event = entry;
else
maxfd = max(maxfd, entry->fd);
}
if (event == NULL)
return;
switch (event->type) {
case EVENT_READ:
FD_CLR(fd, &events->rfds);
break;
case EVENT_WRITE:
FD_CLR(fd, &events->wfds);
break;
case EVENT_EXCEPTION:
FD_CLR(fd, &events->efds);
break;
}
events->maxfd = maxfd;
list_remove(&event->list);
free(event);
}
static void events_dispatch(struct events *events, const fd_set *rfds,
const fd_set *wfds, const fd_set *efds)
{
struct event_fd *event;
list_for_each_entry(event, &events->events, list) {
if (event->type == EVENT_READ &&
FD_ISSET(event->fd, rfds))
event->callback(event->priv);
else if (event->type == EVENT_WRITE &&
FD_ISSET(event->fd, wfds))
event->callback(event->priv);
else if (event->type == EVENT_EXCEPTION &&
FD_ISSET(event->fd, efds))
event->callback(event->priv);
/* If the callback stopped events processing, we're done. */
if (events->done)
break;
}
}
bool events_loop(struct events *events)
{
events->done = false;
while (!events->done) {
fd_set rfds;
fd_set wfds;
fd_set efds;
int ret;
rfds = events->rfds;
wfds = events->wfds;
efds = events->efds;
ret = select(events->maxfd + 1, &rfds, &wfds, &efds, NULL);
if (ret < 0) {
/* EINTR means that a signal has been received, continue
* to the next iteration in that case.
*/
if (errno == EINTR)
continue;
printf("error: select failed with %d\n", errno);
break;
}
events_dispatch(events, &rfds, &wfds, &efds);
}
return !events->done;
}
void events_stop(struct events *events)
{
events->done = true;
}
void events_init(struct events *events)
{
memset(events, 0, sizeof *events);
FD_ZERO(&events->rfds);
FD_ZERO(&events->wfds);
FD_ZERO(&events->efds);
events->maxfd = 0;
list_init(&events->events);
}
void events_cleanup(struct events *events)
{
while (!list_empty(&events->events)) {
struct event_fd *event;
event = list_first_entry(&events->events, typeof(*event), list);
list_remove(&event->list);
free(event);
}
}
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