1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
40
41 static __inline int
hash_mflags(int flags)42 hash_mflags(int flags)
43 {
44
45 return ((flags & HASH_NOWAIT) ? M_NOWAIT : M_WAITOK);
46 }
47
48 /*
49 * General routine to allocate a hash table with control of memory flags.
50 */
51 void *
hashinit_flags(int elements,struct malloc_type * type,u_long * hashmask,int flags)52 hashinit_flags(int elements, struct malloc_type *type, u_long *hashmask,
53 int flags)
54 {
55 long hashsize, i;
56 LIST_HEAD(generic, generic) *hashtbl;
57
58 KASSERT(elements > 0, ("%s: bad elements", __func__));
59 /* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */
60 KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT),
61 ("Bad flags (0x%x) passed to hashinit_flags", flags));
62
63 for (hashsize = 1; hashsize <= elements; hashsize <<= 1)
64 continue;
65 hashsize >>= 1;
66
67 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type,
68 hash_mflags(flags));
69 if (hashtbl != NULL) {
70 for (i = 0; i < hashsize; i++)
71 LIST_INIT(&hashtbl[i]);
72 *hashmask = hashsize - 1;
73 }
74 return (hashtbl);
75 }
76
77 /*
78 * Allocate and initialize a hash table with default flag: may sleep.
79 */
80 void *
hashinit(int elements,struct malloc_type * type,u_long * hashmask)81 hashinit(int elements, struct malloc_type *type, u_long *hashmask)
82 {
83
84 return (hashinit_flags(elements, type, hashmask, HASH_WAITOK));
85 }
86
87 void
hashdestroy(void * vhashtbl,struct malloc_type * type,u_long hashmask)88 hashdestroy(void *vhashtbl, struct malloc_type *type, u_long hashmask)
89 {
90 LIST_HEAD(generic, generic) *hashtbl, *hp;
91
92 hashtbl = vhashtbl;
93 for (hp = hashtbl; hp <= &hashtbl[hashmask]; hp++)
94 KASSERT(LIST_EMPTY(hp), ("%s: hashtbl %p not empty "
95 "(malloc type %s)", __func__, hashtbl, type->ks_shortdesc));
96 free(hashtbl, type);
97 }
98
99 static const int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531,
100 2039, 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143,
101 6653, 7159, 7673, 8191, 12281, 16381, 24571, 32749 };
102 #define NPRIMES nitems(primes)
103
104 /*
105 * General routine to allocate a prime number sized hash table with control of
106 * memory flags.
107 */
108 void *
phashinit_flags(int elements,struct malloc_type * type,u_long * nentries,int flags)109 phashinit_flags(int elements, struct malloc_type *type, u_long *nentries, int flags)
110 {
111 long hashsize, i;
112 LIST_HEAD(generic, generic) *hashtbl;
113
114 KASSERT(elements > 0, ("%s: bad elements", __func__));
115 /* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */
116 KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT),
117 ("Bad flags (0x%x) passed to phashinit_flags", flags));
118
119 for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
120 i++;
121 if (i == NPRIMES)
122 break;
123 hashsize = primes[i];
124 }
125 hashsize = primes[i - 1];
126
127 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type,
128 hash_mflags(flags));
129 if (hashtbl == NULL)
130 return (NULL);
131
132 for (i = 0; i < hashsize; i++)
133 LIST_INIT(&hashtbl[i]);
134 *nentries = hashsize;
135 return (hashtbl);
136 }
137
138 /*
139 * Allocate and initialize a prime number sized hash table with default flag:
140 * may sleep.
141 */
142 void *
phashinit(int elements,struct malloc_type * type,u_long * nentries)143 phashinit(int elements, struct malloc_type *type, u_long *nentries)
144 {
145
146 return (phashinit_flags(elements, type, nentries, HASH_WAITOK));
147 }
148