/*
 * Copyright (c) 1995, 1994, 1993, 1992, 1991, 1990  
 * Open Software Foundation, Inc. 
 *  
 * Permission to use, copy, modify, and distribute this software and 
 * its documentation for any purpose and without fee is hereby granted, 
 * provided that the above copyright notice appears in all copies and 
 * that both the copyright notice and this permission notice appear in 
 * supporting documentation, and that the name of ("OSF") or Open Software 
 * Foundation not be used in advertising or publicity pertaining to 
 * distribution of the software without specific, written prior permission. 
 *  
 * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE 
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
 * FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL OSF BE LIABLE FOR ANY 
 * SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 
 * ACTION OF CONTRACT, NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING 
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE 
 */
/*
 * OSF Research Institute MK6.1 (unencumbered) 1/31/1995
 */
/* CMU_HIST */
/*
 * Revision 2.5  91/05/14  16:27:39  mrt
 * 	Correcting copyright
 * 
 * Revision 2.4  91/02/05  17:19:24  mrt
 * 	Changed to new Mach copyright
 * 	[91/02/01  17:45:50  mrt]
 * 
 * Revision 2.3  90/11/26  14:50:35  rvb
 * 	jsb bet me to XMK34, sigh ...
 * 	[90/11/26            rvb]
 * 	Synched 2.5 & 3.0 at I386q (r1.5.1.3) & XMK35 (r2.3)
 * 	[90/11/15            rvb]
 * 
 * Revision 2.2  90/05/21  13:27:29  dbg
 * 	First checkin.
 * 	[90/05/17  15:43:38  dbg]
 * 
 * Revision 1.5.1.2  90/02/28  15:50:29  rvb
 * 	Fix numerous typo's in Olivetti disclaimer.
 * 	[90/02/28            rvb]
 * 
 * Revision 1.5.1.1  90/01/08  13:30:48  rvb
 * 	Add Olivetti copyright.
 * 	[90/01/08            rvb]
 * 
 * Revision 1.5  89/07/17  10:41:36  rvb
 * 	Olivetti Changes to X79 upto 5/9/89:
 * 	[89/07/11            rvb]
 * 
 * Revision 1.1.1.1  89/04/27  12:35:55  kupfer
 * X79 from CMU.
 * 
 * Revision 1.4  89/03/09  20:06:54  rpd
 * 	More cleanup.
 * 
 * Revision 1.3  89/02/26  12:42:46  gm0w
 * 	Changes for cleanup.
 * 
 */
/* CMU_ENDHIST */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/* 
 */
 
/* 
 *  File:         kd_queue.c
 *  Description:  Event queue code for keyboard/display (and mouse) driver.
 * 
 *  $ Header: $
 * 
 *  Copyright Ing. C. Olivetti & C. S.p.A. 1989.
 *  All rights reserved.
 * 
 *   Copyright 1988, 1989 by Olivetti Advanced Technology Center, Inc.,
 * Cupertino, California.
 * 
 * 		All Rights Reserved
 * 
 *   Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby
 * granted, provided that the above copyright notice appears in all
 * copies and that both the copyright notice and this permission notice
 * appear in supporting documentation, and that the name of Olivetti
 * not be used in advertising or publicity pertaining to distribution
 * of the software without specific, written prior permission.
 * 
 *   OLIVETTI DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
 * IN NO EVENT SHALL OLIVETTI BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
 * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUR OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */


#include <i386/AT386/kd_queue.h>

/*
 * Notice that when adding an entry to the queue, the caller provides 
 * its own storage, which is copied into the queue.  However, when 
 * removing an entry from the queue, the caller is given a pointer to a 
 * queue element.  This means that the caller must either process the 
 * element or copy it into its own storage before unlocking the queue.
 *
 * These routines should be called only at a protected SPL.
 */

#define q_next(index)	(((index)+1) % KDQSIZE)

boolean_t
kdq_empty(
	kd_event_queue *q)
{
	return(q->firstfree == q->firstout);
}

boolean_t
kdq_full(
	kd_event_queue *q)
{
	return(q_next(q->firstfree) == q->firstout);
}

void
kdq_put(
	kd_event_queue *q,
	kd_event *ev)
{
	kd_event *qp = q->events + q->firstfree;

	qp->type = ev->type;
	qp->time = ev->time;
	qp->value = ev->value;
	q->firstfree = q_next(q->firstfree);
}

kd_event *
kdq_get(
	kd_event_queue *q)
{
	kd_event *result = q->events + q->firstout;

	q->firstout = q_next(q->firstout);
	return(result);
}

void
kdq_reset(
	kd_event_queue *q)
{
	spinlock_init(&q->lock);
	q->firstout = q->firstfree = 0;
}
