xref: /third_party/mesa3d/src/util/u_idalloc.h (revision bf215546) 
1/**************************************************************************
2 *
3 * Copyright 2017 Valve Corporation
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL THE AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28/* Allocator of IDs (e.g. OpenGL object IDs), or simply an allocator of
29 * numbers.
30 *
31 * The allocator uses a bit array to track allocated IDs.
32 */
33
34#ifndef U_IDALLOC_H
35#define U_IDALLOC_H
36
37#include <inttypes.h>
38#include <stdbool.h>
39#include "simple_mtx.h"
40
41#ifdef __cplusplus
42extern "C" {
43#endif
44
45struct util_idalloc
46{
47   uint32_t *data;
48   unsigned num_elements;    /* number of allocated elements of "data" */
49   unsigned lowest_free_idx;
50};
51
52void
53util_idalloc_init(struct util_idalloc *buf, unsigned initial_num_ids);
54
55void
56util_idalloc_fini(struct util_idalloc *buf);
57
58unsigned
59util_idalloc_alloc(struct util_idalloc *buf);
60
61unsigned
62util_idalloc_alloc_range(struct util_idalloc *buf, unsigned num);
63
64void
65util_idalloc_free(struct util_idalloc *buf, unsigned id);
66
67void
68util_idalloc_reserve(struct util_idalloc *buf, unsigned id);
69
70static inline bool
71util_idalloc_exists(struct util_idalloc *buf, unsigned id)
72{
73   return id / 32 < buf->num_elements &&
74          buf->data[id / 32] & BITFIELD_BIT(id % 32);
75}
76
77#define util_idalloc_foreach(buf, id) \
78   for (uint32_t i = 0, mask = (buf)->num_elements ? (buf)->data[0] : 0, id, \
79                 count = (buf)->num_elements; \
80        i < count; mask = ++i < count ? (buf)->data[i] : 0) \
81      while (mask) \
82         if ((id = i * 32 + u_bit_scan(&mask)), true)
83
84
85/* Thread-safe variant. */
86struct util_idalloc_mt {
87   struct util_idalloc buf;
88   simple_mtx_t mutex;
89   bool skip_zero;
90};
91
92void
93util_idalloc_mt_init(struct util_idalloc_mt *buf,
94                     unsigned initial_num_ids, bool skip_zero);
95
96void
97util_idalloc_mt_init_tc(struct util_idalloc_mt *buf);
98
99void
100util_idalloc_mt_fini(struct util_idalloc_mt *buf);
101
102unsigned
103util_idalloc_mt_alloc(struct util_idalloc_mt *buf);
104
105void
106util_idalloc_mt_free(struct util_idalloc_mt *buf, unsigned id);
107
108
109#ifdef __cplusplus
110}
111#endif
112
113#endif /* U_IDALLOC_H */
114