1 /* $Id: dqueue.c,v 1.5 2003/04/12 21:40:49 schindler Exp $
2 *
3 * Driver for Eicon DIVA Server ISDN cards.
4 * User Mode IDI Interface
5 *
6 * Copyright 2000-2003 by Armin Schindler (mac@melware.de)
7 * Copyright 2000-2003 Cytronics & Melware (info@melware.de)
8 *
9 * This software may be used and distributed according to the terms
10 * of the GNU General Public License, incorporated herein by reference.
11 */
12
13 #include "platform.h"
14 #include "dqueue.h"
15
16 int
diva_data_q_init(diva_um_idi_data_queue_t * q,int max_length,int max_segments)17 diva_data_q_init(diva_um_idi_data_queue_t *q,
18 int max_length, int max_segments)
19 {
20 int i;
21
22 q->max_length = max_length;
23 q->segments = max_segments;
24
25 for (i = 0; i < q->segments; i++) {
26 q->data[i] = NULL;
27 q->length[i] = 0;
28 }
29 q->read = q->write = q->count = q->segment_pending = 0;
30
31 for (i = 0; i < q->segments; i++) {
32 if (!(q->data[i] = diva_os_malloc(0, q->max_length))) {
33 diva_data_q_finit(q);
34 return (-1);
35 }
36 }
37
38 return (0);
39 }
40
diva_data_q_finit(diva_um_idi_data_queue_t * q)41 int diva_data_q_finit(diva_um_idi_data_queue_t *q)
42 {
43 int i;
44
45 for (i = 0; i < q->segments; i++) {
46 if (q->data[i]) {
47 diva_os_free(0, q->data[i]);
48 }
49 q->data[i] = NULL;
50 q->length[i] = 0;
51 }
52 q->read = q->write = q->count = q->segment_pending = 0;
53
54 return (0);
55 }
56
diva_data_q_get_max_length(const diva_um_idi_data_queue_t * q)57 int diva_data_q_get_max_length(const diva_um_idi_data_queue_t *q)
58 {
59 return (q->max_length);
60 }
61
diva_data_q_get_segment4write(diva_um_idi_data_queue_t * q)62 void *diva_data_q_get_segment4write(diva_um_idi_data_queue_t *q)
63 {
64 if ((!q->segment_pending) && (q->count < q->segments)) {
65 q->segment_pending = 1;
66 return (q->data[q->write]);
67 }
68
69 return NULL;
70 }
71
72 void
diva_data_q_ack_segment4write(diva_um_idi_data_queue_t * q,int length)73 diva_data_q_ack_segment4write(diva_um_idi_data_queue_t *q, int length)
74 {
75 if (q->segment_pending) {
76 q->length[q->write] = length;
77 q->count++;
78 q->write++;
79 if (q->write >= q->segments) {
80 q->write = 0;
81 }
82 q->segment_pending = 0;
83 }
84 }
85
diva_data_q_get_segment4read(const diva_um_idi_data_queue_t * q)86 const void *diva_data_q_get_segment4read(const diva_um_idi_data_queue_t *
87 q)
88 {
89 if (q->count) {
90 return (q->data[q->read]);
91 }
92 return NULL;
93 }
94
diva_data_q_get_segment_length(const diva_um_idi_data_queue_t * q)95 int diva_data_q_get_segment_length(const diva_um_idi_data_queue_t *q)
96 {
97 return (q->length[q->read]);
98 }
99
diva_data_q_ack_segment4read(diva_um_idi_data_queue_t * q)100 void diva_data_q_ack_segment4read(diva_um_idi_data_queue_t *q)
101 {
102 if (q->count) {
103 q->length[q->read] = 0;
104 q->count--;
105 q->read++;
106 if (q->read >= q->segments) {
107 q->read = 0;
108 }
109 }
110 }
111