rockbox/firmware/kernel.h
Linus Nielsen Feltzing bd2561dcbb Added queue handling stuff - NOT INTERRUPT SAFE
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@315 a1c6a512-1295-4272-9138-f99709370657
2002-04-29 14:25:44 +00:00

55 lines
1.6 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2002 by Björn Stenberg
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef _KERNEL_H_
#define _KERNEL_H_
/* wrap-safe macros for tick comparison */
#define TIME_AFTER(a,b) ((long)(b) - (long)(a) < 0)
#define TIME_BEFORE(a,b) TIME_AFTER(b,a)
#define HZ 100 /* number of ticks per second */
#define QUEUE_LENGTH 16 /* MUST be a power of 2 */
#define QUEUE_LENGTH_MASK (QUEUE_LENGTH - 1)
struct event
{
int id;
void *data;
};
struct event_queue
{
struct event events[QUEUE_LENGTH];
unsigned int read;
unsigned int write;
};
/* global tick variable */
extern long current_tick;
/* kernel functions */
extern void yield(void);
extern void sleep(int ticks);
extern void queue_init(struct event_queue *q);
extern struct event *queue_wait(struct event_queue *q);
extern void queue_post(struct event_queue *q, int id, void *data);
#endif