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36 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
39 #include <sys/cdefs.h>
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
45 hash_mflags(int flags)
48 return ((flags & HASH_NOWAIT) ? M_NOWAIT : M_WAITOK);
52 * General routine to allocate a hash table with control of memory flags.
55 hashinit_flags(int elements, struct malloc_type *type, u_long *hashmask,
59 LIST_HEAD(generic, generic) *hashtbl;
61 KASSERT(elements > 0, ("%s: bad elements", __func__));
62 /* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */
63 KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT),
64 ("Bad flags (0x%x) passed to hashinit_flags", flags));
66 for (hashsize = 1; hashsize <= elements; hashsize <<= 1)
70 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type,
72 if (hashtbl != NULL) {
73 for (i = 0; i < hashsize; i++)
74 LIST_INIT(&hashtbl[i]);
75 *hashmask = hashsize - 1;
81 * Allocate and initialize a hash table with default flag: may sleep.
84 hashinit(int elements, struct malloc_type *type, u_long *hashmask)
87 return (hashinit_flags(elements, type, hashmask, HASH_WAITOK));
91 hashdestroy(void *vhashtbl, struct malloc_type *type, u_long hashmask)
93 LIST_HEAD(generic, generic) *hashtbl, *hp;
96 for (hp = hashtbl; hp <= &hashtbl[hashmask]; hp++)
97 KASSERT(LIST_EMPTY(hp), ("%s: hashtbl %p not empty "
98 "(malloc type %s)", __func__, hashtbl, type->ks_shortdesc));
102 static const int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531,
103 2039, 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143,
104 6653, 7159, 7673, 8191, 12281, 16381, 24571, 32749 };
105 #define NPRIMES nitems(primes)
108 * General routine to allocate a prime number sized hash table with control of
112 phashinit_flags(int elements, struct malloc_type *type, u_long *nentries, int flags)
115 LIST_HEAD(generic, generic) *hashtbl;
117 KASSERT(elements > 0, ("%s: bad elements", __func__));
118 /* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */
119 KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT),
120 ("Bad flags (0x%x) passed to phashinit_flags", flags));
122 for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
126 hashsize = primes[i];
128 hashsize = primes[i - 1];
130 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type,
135 for (i = 0; i < hashsize; i++)
136 LIST_INIT(&hashtbl[i]);
137 *nentries = hashsize;
142 * Allocate and initialize a prime number sized hash table with default flag:
146 phashinit(int elements, struct malloc_type *type, u_long *nentries)
149 return (phashinit_flags(elements, type, nentries, HASH_WAITOK));