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
31struct util_fifo
32{
33   size_t head;
34   size_t tail;
35   size_t num;
36   size_t size;
37};
38
39static INLINE struct util_fifo *
40u_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
53static INLINE boolean
54u_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
70static INLINE boolean
71u_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
88static INLINE void
89u_fifo_destroy(struct util_fifo *fifo)
90{
91   FREE(fifo);
92}
93
94#endif
95