rockbox/firmware/events.c
William Wilgus e180e45e01 events.c clean-up
check for invalid userdata by assigning the address of 'invalid_userdata'
this cleans up the functions a bit and removes some extra conditionals

Change-Id: Ic5e13147796e629010a1436eb60042f6550a959c
2022-12-30 07:23:29 -05:00

128 lines
3.8 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2008 by Miika Pekkarinen
*
* 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; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <stdio.h>
#include "events.h"
#include "panic.h"
#define MAX_SYS_EVENTS 28
struct sysevent {
unsigned short id;
bool oneshot;
union {
void (*cb)(unsigned short id, void *event_data);
void (*cb_ex)(unsigned short id, void *event_data, void *user_data);
} handler;
void *user_data;
};
static struct sysevent events[MAX_SYS_EVENTS];
static int invalid_userdata;
static bool do_add_event(unsigned short id, bool oneshot,
void *handler, void *user_data)
{
size_t free = MAX_SYS_EVENTS;
struct sysevent *ev;
/* Check if the event already exists. & lowest free slot available */
for (size_t i = MAX_SYS_EVENTS - 1; i < MAX_SYS_EVENTS; i--)
{
ev = &events[i];
if (ev->handler.cb == NULL)
free = i;
if (ev->id == id && ev->handler.cb == handler && user_data == ev->user_data)
{
return false;
}
}
/* is there a free slot? */
if (free < MAX_SYS_EVENTS)
{
ev = &events[free];
ev->id = id;
ev->handler.cb = handler;
ev->user_data = user_data;
ev->oneshot = oneshot;
return true;
}
panicf("event line full");
return false;
}
bool add_event(unsigned short id, void (*handler)(unsigned short id, void *data))
{
return do_add_event(id, false, handler, &invalid_userdata);
}
bool add_event_ex(unsigned short id, bool oneshot,
void (*handler)(unsigned short id, void *event_data, void *user_data), void *user_data)
{
return do_add_event(id, oneshot, handler, user_data);
}
static void do_remove_event(unsigned short id, void *handler, void *user_data)
{
for (size_t i = 0; i < MAX_SYS_EVENTS; i++)
{
struct sysevent *ev = &events[i];
if (ev->id == id && ev->handler.cb == handler && user_data == ev->user_data)
{
ev->handler.cb = NULL;
return;
}
}
}
void remove_event(unsigned short id, void (*handler)(unsigned short id, void *data))
{
do_remove_event(id, handler, &invalid_userdata);
}
void remove_event_ex(unsigned short id,
void (*handler)(unsigned short id, void *event_data, void *user_data),
void *user_data)
{
do_remove_event(id, handler, user_data);
}
void send_event(unsigned short id, void *data)
{
for (size_t i = 0; i < MAX_SYS_EVENTS; i++)
{
struct sysevent *ev = &events[i];
if (ev->id == id && ev->handler.cb != NULL)
{
if (ev->user_data != &invalid_userdata)
{
ev->handler.cb_ex(id, data, ev->user_data);
if (ev->oneshot) /* only _ex events have option of oneshot */
ev->handler.cb = NULL;
}
else
ev->handler.cb(id, data);
}
}
}