xref: /illumos-gate/usr/src/uts/common/sys/vuid_queue.h (revision f3041bfa)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright (c) 1985,1997-1998 by Sun Microsystems, Inc.
24  * All rights reserved.
25  */
26 
27 /*
28  * This file describes a virtual user input device (vuid) event queue
29  * maintainence package (see ../sundev/vuid_event.h for a description
30  * of what vuid is).  This header file defines the interface that a
31  * client of this package sees.	 This package is used to maintain queues
32  * of firm events awaiting deliver to some consumer.
33  */
34 
35 #ifndef _SYS_VUID_QUEUE_H
36 #define	_SYS_VUID_QUEUE_H
37 
38 #pragma ident	"%Z%%M%	%I%	%E% SMI"	/* SunOS 1.6 */
39 
40 #ifdef	__cplusplus
41 extern "C" {
42 #endif
43 
44 /*
45  * Vuid input queue structure.
46  */
47 typedef struct	vuid_queue {
48 	struct	vuid_q_node *top;	/* input queue head (first in line) */
49 	struct	vuid_q_node *bottom;	/* input queue head (last in line) */
50 	struct	vuid_q_node *free;	/* input queue free list */
51 	int	num;			/* number of items currently on queue */
52 	int	size;			/* number of items allowed on queue */
53 } Vuid_queue;
54 #define	VUID_QUEUE_NULL ((Vuid_queue *)0)
55 #define	vq_used(vq) ((vq)->num)
56 #define	vq_avail(vq) ((vq)->size - (vq)->num)
57 #define	vq_size(vq) ((vq)->size)
58 #define	vq_is_empty(vq) ((vq)->top == VUID_Q_NODE_NULL)
59 #define	vq_is_full(vq) ((vq)->num == (vq)->size)
60 
61 /*
62  * Vuid input queue node structure.
63  */
64 typedef struct	vuid_q_node {
65 	struct	vuid_q_node *next;	/* Next item in queue */
66 	struct	vuid_q_node *prev;	/* Previous item in queue */
67 	Firm_event firm_event;		/* Firm event */
68 } Vuid_q_node;
69 #define	VUID_Q_NODE_NULL	((Vuid_q_node *)0)
70 
71 /*
72  * Vuid input queue status codes.
73  */
74 typedef enum	vuid_q_code {
75 	VUID_Q_OK = 0,		/* OK */
76 	VUID_Q_OVERFLOW = 1,	/* overflow */
77 	VUID_Q_EMPTY = 2	/* empty */
78 } Vuid_q_code;
79 
80 extern	void vq_initialize(); /* (Vuid_queue *vq, caddr_t data, uint_t bytes) */
81 				/* Client allocates bytes worth of storage */
82 				/* and pass in a data. Client destroys the q */
83 				/* simply by releasing data. */
84 extern	Vuid_q_code vq_put();	/* (Vuid_queue *vq, Firm_event *firm_event) */
85 				/* Place firm_event on queue, position is */
86 				/* dependent on the firm event's time.	Can */
87 				/* return VUID_Q_OVERFLOW if no more room. */
88 extern	Vuid_q_code vq_get();	/* (Vuid_queue *vq, Firm_event *firm_event) */
89 				/* Place event on top of queue in firm_event. */
90 				/* Can return VUID_Q_EMPTY if no more events */
91 extern	Vuid_q_code vq_peek();	/* Like vq_get but doesn't remove from queue */
92 extern	Vuid_q_code vq_putback(); /* (Vuid_queue *vq, Firm_event *firm_event) */
93 				/* Push firm_event on top of queue.  Can */
94 				/* return VUID_Q_OVERFLOW if no more room. */
95 
96 extern	int vq_compress();	/* (Vuid_queue *vq, factor)  Try to */
97 				/* collapse the queue to a size of 1/factor */
98 				/* by squeezing like valuator events together */
99 				/* Returns number collapsed */
100 extern	int vq_is_valuator();	/* (Vuid_q_node *vqn) if value is not 0 or 1 */
101 				/* || pair_type is FE_PAIR_DELTA or */
102 				/* FE_PAIR_ABSOLUTE */
103 extern	void vq_delete_node();	/* (Vuid_queue *vq, Vuid_q_node *vqn) */
104 				/* Deletes vqn from vq */
105 
106 #ifdef	__cplusplus
107 }
108 #endif
109 
110 #endif	/* _SYS_VUID_QUEUE_H */
111