7 * Mesa 3-D graphics library
9 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
11 * Permission is hereby granted, free of charge, to any person obtaining a
12 * copy of this software and associated documentation files (the "Software"),
13 * to deal in the Software without restriction, including without limitation
14 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
15 * and/or sell copies of the Software, and to permit persons to whom the
16 * Software is furnished to do so, subject to the following conditions:
18 * The above copyright notice and this permission notice shall be included
19 * in all copies or substantial portions of the Software.
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
22 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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25 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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39 #include "c11/threads.h"
42 * Magic GLuint object name that gets stored outside of the struct hash_table.
44 * The hash table needs a particular pointer to be the marker for a key that
45 * was deleted from the table, along with NULL for the "never allocated in the
46 * table" marker. Legacy GL allows any GLuint to be used as a GL object name,
47 * and we use a 1:1 mapping from GLuints to key pointers, so we need to be
48 * able to track a GLuint that happens to match the deleted key outside of
49 * struct hash_table. We tell the hash table to use "1" as the deleted key
50 * value, so that we test the deleted-key-in-the-table path as best we can.
52 #define DELETED_KEY_VALUE 1
55 * Mapping from our use of GLuint as both the key and the hash value to the
58 * There exist many integer hash functions, designed to avoid collisions when
59 * the integers are spread across key space with some patterns. In GL, the
60 * pattern (in the case of glGen*()ed object IDs) is that the keys are unique
61 * contiguous integers starting from 1. Because of that, we just use the key
62 * as the hash value, to minimize the cost of the hash function. If objects
63 * are never deleted, we will never see a collision in the table, because the
64 * table resizes itself when it approaches full, and thus key % table_size ==
67 * The case where we could have collisions for genned objects would be
68 * something like: glGenBuffers(&a, 100); glDeleteBuffers(&a + 50, 50);
69 * glGenBuffers(&b, 100), because objects 1-50 and 101-200 are allocated at
70 * the end of that sequence, instead of 1-150. So far it doesn't appear to be
74 uint_key_compare(const void *a
, const void *b
)
79 static inline uint32_t
85 static inline uint32_t
86 uint_key_hash(const void *key
)
88 return uint_hash((uintptr_t)key
);
94 return (void *)(uintptr_t) id
;
99 * The hash table data structure.
101 struct _mesa_HashTable
{
102 struct hash_table
*ht
;
103 GLuint MaxKey
; /**< highest key inserted so far */
104 mtx_t Mutex
; /**< mutual exclusion lock */
105 GLboolean InDeleteAll
; /**< Debug check */
106 /** Value that would be in the table for DELETED_KEY_VALUE. */
107 void *deleted_key_data
;
110 extern struct _mesa_HashTable
*_mesa_NewHashTable(void);
112 extern void _mesa_DeleteHashTable(struct _mesa_HashTable
*table
);
114 extern void *_mesa_HashLookup(struct _mesa_HashTable
*table
, GLuint key
);
116 extern void _mesa_HashInsert(struct _mesa_HashTable
*table
, GLuint key
, void *data
);
118 extern void _mesa_HashRemove(struct _mesa_HashTable
*table
, GLuint key
);
121 * Lock the hash table mutex.
123 * This function should be used when multiple objects need
124 * to be looked up in the hash table, to avoid having to lock
125 * and unlock the mutex each time.
127 * \param table the hash table.
130 _mesa_HashLockMutex(struct _mesa_HashTable
*table
)
133 mtx_lock(&table
->Mutex
);
138 * Unlock the hash table mutex.
140 * \param table the hash table.
143 _mesa_HashUnlockMutex(struct _mesa_HashTable
*table
)
146 mtx_unlock(&table
->Mutex
);
149 extern void *_mesa_HashLookupLocked(struct _mesa_HashTable
*table
, GLuint key
);
151 extern void _mesa_HashInsertLocked(struct _mesa_HashTable
*table
,
152 GLuint key
, void *data
);
154 extern void _mesa_HashRemoveLocked(struct _mesa_HashTable
*table
, GLuint key
);
157 _mesa_HashDeleteAll(struct _mesa_HashTable
*table
,
158 void (*callback
)(GLuint key
, void *data
, void *userData
),
162 _mesa_HashWalk(const struct _mesa_HashTable
*table
,
163 void (*callback
)(GLuint key
, void *data
, void *userData
),
167 _mesa_HashWalkLocked(const struct _mesa_HashTable
*table
,
168 void (*callback
)(GLuint key
, void *data
, void *userData
),
171 extern void _mesa_HashPrint(const struct _mesa_HashTable
*table
);
173 extern GLuint
_mesa_HashFindFreeKeyBlock(struct _mesa_HashTable
*table
, GLuint numKeys
);
176 _mesa_HashNumEntries(const struct _mesa_HashTable
*table
);
178 extern void _mesa_test_hash_functions(void);