1 /*- 2 * Copyright (c) 1982, 1986, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/malloc.h> 43 44 static __inline int 45 hash_mflags(int flags) 46 { 47 48 return ((flags & HASH_NOWAIT) ? M_NOWAIT : M_WAITOK); 49 } 50 51 /* 52 * General routine to allocate a hash table with control of memory flags. 53 */ 54 void * 55 hashinit_flags(int elements, struct malloc_type *type, u_long *hashmask, 56 int flags) 57 { 58 long hashsize; 59 LIST_HEAD(generic, generic) *hashtbl; 60 int i; 61 62 KASSERT(elements > 0, ("%s: bad elements", __func__)); 63 /* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */ 64 KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT), 65 ("Bad flags (0x%x) passed to hashinit_flags", flags)); 66 67 for (hashsize = 1; hashsize <= elements; hashsize <<= 1) 68 continue; 69 hashsize >>= 1; 70 71 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, 72 hash_mflags(flags)); 73 if (hashtbl != NULL) { 74 for (i = 0; i < hashsize; i++) 75 LIST_INIT(&hashtbl[i]); 76 *hashmask = hashsize - 1; 77 } 78 return (hashtbl); 79 } 80 81 /* 82 * Allocate and initialize a hash table with default flag: may sleep. 83 */ 84 void * 85 hashinit(int elements, struct malloc_type *type, u_long *hashmask) 86 { 87 88 return (hashinit_flags(elements, type, hashmask, HASH_WAITOK)); 89 } 90 91 void 92 hashdestroy(void *vhashtbl, struct malloc_type *type, u_long hashmask) 93 { 94 LIST_HEAD(generic, generic) *hashtbl, *hp; 95 96 hashtbl = vhashtbl; 97 for (hp = hashtbl; hp <= &hashtbl[hashmask]; hp++) 98 KASSERT(LIST_EMPTY(hp), ("%s: hashtbl %p not empty " 99 "(malloc type %s)", __func__, hashtbl, type->ks_shortdesc)); 100 free(hashtbl, type); 101 } 102 103 static const int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 104 2039, 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 105 6653, 7159, 7673, 8191, 12281, 16381, 24571, 32749 }; 106 #define NPRIMES nitems(primes) 107 108 /* 109 * General routine to allocate a prime number sized hash table with control of 110 * memory flags. 111 */ 112 void * 113 phashinit_flags(int elements, struct malloc_type *type, u_long *nentries, int flags) 114 { 115 long hashsize; 116 LIST_HEAD(generic, generic) *hashtbl; 117 int i; 118 119 KASSERT(elements > 0, ("%s: bad elements", __func__)); 120 /* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */ 121 KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT), 122 ("Bad flags (0x%x) passed to phashinit_flags", flags)); 123 124 for (i = 1, hashsize = primes[1]; hashsize <= elements;) { 125 i++; 126 if (i == NPRIMES) 127 break; 128 hashsize = primes[i]; 129 } 130 hashsize = primes[i - 1]; 131 132 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, 133 hash_mflags(flags)); 134 if (hashtbl == NULL) 135 return (NULL); 136 137 for (i = 0; i < hashsize; i++) 138 LIST_INIT(&hashtbl[i]); 139 *nentries = hashsize; 140 return (hashtbl); 141 } 142 143 /* 144 * Allocate and initialize a prime number sized hash table with default flag: 145 * may sleep. 146 */ 147 void * 148 phashinit(int elements, struct malloc_type *type, u_long *nentries) 149 { 150 151 return (phashinit_flags(elements, type, nentries, HASH_WAITOK)); 152 } 153