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Arquivotheca.SunOS-4.1.4/sys/sundev/vuid_queue.h
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2021-10-11 18:37:13 -03:00

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C

/* @(#)vuid_queue.h 1.1 94/10/31 SMI */
/*
* Copyright (c) 1985 by Sun Microsystems, Inc.
*/
/*
* This file describes a virtual user input device (vuid) event queue
* maintainence package (see ../sundev/vuid_event.h for a description
* of what vuid is). This header file defines the interface that a
* client of this package sees. This package is used to maintain queues
* of firm events awaiting deliver to some consumer.
*/
#ifndef _sundev_vuid_queue_h
#define _sundev_vuid_queue_h
/*
* Vuid input queue structure.
*/
typedef struct vuid_queue {
struct vuid_q_node *top; /* input queue head (first in line) */
struct vuid_q_node *bottom; /* input queue head (last in line) */
struct vuid_q_node *free; /* input queue free list */
int num; /* number of items currently on queue */
int size; /* number of items allowed on queue */
} Vuid_queue;
#define VUID_QUEUE_NULL ((Vuid_queue *)0)
#define vq_used(vq) ((vq)->num)
#define vq_avail(vq) ((vq)->size - (vq)->num)
#define vq_size(vq) ((vq)->size)
#define vq_is_empty(vq) ((vq)->top == VUID_Q_NODE_NULL)
#define vq_is_full(vq) ((vq)->num == (vq)->size)
/*
* Vuid input queue node structure.
*/
typedef struct vuid_q_node {
struct vuid_q_node *next; /* Next item in queue */
struct vuid_q_node *prev; /* Previous item in queue */
Firm_event firm_event; /* Firm event */
} Vuid_q_node;
#define VUID_Q_NODE_NULL ((Vuid_q_node *)0)
/*
* Vuid input queue status codes.
*/
typedef enum vuid_q_code {
VUID_Q_OK=0, /* OK */
VUID_Q_OVERFLOW=1, /* overflow */
VUID_Q_EMPTY=2, /* empty */
} Vuid_q_code;
extern void vq_initialize(); /* (Vuid_queue *vq, caddr_t data, u_int bytes)
Client allocates bytes worth of storage
and pass in a data. Client destroys the q
simply by releasing data. */
extern Vuid_q_code vq_put(); /* (Vuid_queue *vq, Firm_event *firm_event)
Place firm_event on queue, position is
dependent on the firm event's time. Can
return VUID_Q_OVERFLOW if no more room. */
extern Vuid_q_code vq_get(); /* (Vuid_queue *vq, Firm_event *firm_event)
Place event on top of queue into firm_event.
Can return VUID_Q_EMPTY if no more events */
extern Vuid_q_code vq_peek(); /* Like vq_get but doesn't remove from queue */
extern Vuid_q_code vq_putback();/* (Vuid_queue *vq, Firm_event *firm_event)
Push firm_event on top of queue. Can
return VUID_Q_OVERFLOW if no more room. */
extern int vq_compress(); /* (Vuid_queue *vq, factor) Try to
collapse the queue to a size of 1/factor
by squeezing like valuator events together.
Returns number collapsed */
extern int vq_is_valuator(); /* (Vuid_q_node *vqn) if value is not 0 or 1 ||
pair_type is FE_PAIR_DELTA or
FE_PAIR_ABSOLUTE */
extern void vq_delete_node(); /* (Vuid_queue *vq, Vuid_q_node *vqn)
Deletes vqn from vq */
#endif /*!_sundev_vuid_queue_h*/