1 /**************************************************************************
2  *
3  * Copyright 2009 VMware, Inc.
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,
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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
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27 
28 /**
29  * @file
30  * Generic bitmask.
31  *
32  * @author Jose Fonseca <jfonseca@vmware.com>
33  */
34 
35 #ifndef U_HANDLE_BITMASK_H_
36 #define U_HANDLE_BITMASK_H_
37 
38 
39 #include "pipe/p_compiler.h"
40 
41 
42 #ifdef __cplusplus
43 extern "C" {
44 #endif
45 
46 
47 #define UTIL_BITMASK_INVALID_INDEX (~0U)
48 
49 
50 /**
51  * Abstract data type to represent arbitrary set of bits.
52  */
53 struct util_bitmask;
54 
55 
56 struct util_bitmask *
57 util_bitmask_create(void);
58 
59 
60 /**
61  * Search a cleared bit and set it.
62  *
63  * It searches for the first cleared bit.
64  *
65  * Returns the bit index on success, or UTIL_BITMASK_INVALID_INDEX on out of
66  * memory growing the bitmask.
67  */
68 unsigned
69 util_bitmask_add(struct util_bitmask *bm);
70 
71 /**
72  * Set a bit.
73  *
74  * Returns the input index on success, or UTIL_BITMASK_INVALID_INDEX on out of
75  * memory growing the bitmask.
76  */
77 unsigned
78 util_bitmask_set(struct util_bitmask *bm,
79                  unsigned index);
80 
81 void
82 util_bitmask_clear(struct util_bitmask *bm,
83                    unsigned index);
84 
85 boolean
86 util_bitmask_get(struct util_bitmask *bm,
87                  unsigned index);
88 
89 
90 void
91 util_bitmask_destroy(struct util_bitmask *bm);
92 
93 
94 /**
95  * Search for the first set bit.
96  *
97  * Returns UTIL_BITMASK_INVALID_INDEX if a set bit cannot be found.
98  */
99 unsigned
100 util_bitmask_get_first_index(struct util_bitmask *bm);
101 
102 
103 /**
104  * Search for the first set bit, starting from the giving index.
105  *
106  * Returns UTIL_BITMASK_INVALID_INDEX if a set bit cannot be found.
107  */
108 unsigned
109 util_bitmask_get_next_index(struct util_bitmask *bm,
110                             unsigned index);
111 
112 
113 #ifdef __cplusplus
114 }
115 #endif
116 
117 #endif /* U_HANDLE_BITMASK_H_ */
118