blob: 245fb8e136c3137da8864f9ef5909d127e5ee693 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
/*
* fifo.c
*
* (c) 2012 Thomas White <taw@bitwiz.org.uk>
*
* This file is part of MIDInator.
*
* MIDInator is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* MIDInator is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with MIDInator. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include <stdlib.h>
#include <pthread.h>
#include "fifo.h"
struct _fifo
{
pthread_mutex_t lock;
unsigned char *buf;
size_t sz;
size_t n_used;
size_t r; /* Read pointer */
size_t w; /* Write pointer */
};
FIFO *fifo_new()
{
FIFO *f;
f = malloc(sizeof(struct _fifo));
if ( f == NULL ) return NULL;
f->sz = 64*1024;
f->buf = malloc(f->sz);
if ( f->buf == NULL ) {
free(f);
return NULL;
}
f->r = 0;
f->w = 0;
f->n_used = 0;
pthread_mutex_init(&f->lock, NULL);
return f;
}
void fifo_push(FIFO *f, unsigned char c)
{
pthread_mutex_lock(&f->lock);
f->buf[f->w++] = c;
f->n_used++;
if ( f->w == f->sz ) {
f->w = 0;
}
pthread_mutex_unlock(&f->lock);
}
unsigned char fifo_pop(FIFO *f, int *err)
{
unsigned char c;
pthread_mutex_lock(&f->lock);
if ( f->n_used == 0 ) {
pthread_mutex_unlock(&f->lock);
*err = 1;
return 0;
}
*err = 0;
c = f->buf[f->r++];
f->n_used--;
pthread_mutex_unlock(&f->lock);
return c;
}
|
