1 /**************************************************************************
2 *
3 * Copyright © 2009 Jakob Bornecrantz
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22 * DEALINGS IN THE SOFTWARE.
23 *
24 **************************************************************************/
25
26 #ifndef U_FIFO_H
27 #define U_FIFO_H
28
29 #include "util/u_memory.h"
30
31 struct util_fifo
32 {
33 size_t head;
34 size_t tail;
35 size_t num;
36 size_t size;
37 };
38
39 static inline struct util_fifo *
u_fifo_create(size_t size)40 u_fifo_create(size_t size)
41 {
42 struct util_fifo *fifo;
43 fifo = MALLOC(sizeof(*fifo) + size * sizeof(void*));
44
45 fifo->head = 0;
46 fifo->tail = 0;
47 fifo->num = 0;
48 fifo->size = size;
49
50 return fifo;
51 }
52
53 static inline boolean
u_fifo_add(struct util_fifo * fifo,void * ptr)54 u_fifo_add(struct util_fifo *fifo, void *ptr)
55 {
56 void **array = (void**)&fifo[1];
57 if (fifo->num >= fifo->size)
58 return FALSE;
59
60 if (++fifo->head >= fifo->size)
61 fifo->head = 0;
62
63 array[fifo->head] = ptr;
64
65 ++fifo->num;
66
67 return TRUE;
68 }
69
70 static inline boolean
u_fifo_pop(struct util_fifo * fifo,void ** ptr)71 u_fifo_pop(struct util_fifo *fifo, void **ptr)
72 {
73 void **array = (void**)&fifo[1];
74
75 if (!fifo->num)
76 return FALSE;
77
78 if (++fifo->tail >= fifo->size)
79 fifo->tail = 0;
80
81 *ptr = array[fifo->tail];
82
83 --fifo->num;
84
85 return TRUE;
86 }
87
88 static inline void
u_fifo_destroy(struct util_fifo * fifo)89 u_fifo_destroy(struct util_fifo *fifo)
90 {
91 FREE(fifo);
92 }
93
94 #endif
95