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 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/malloc.h> 45 46 static __inline int 47 hash_mflags(int flags) 48 { 49 50 return ((flags & HASH_NOWAIT) ? M_NOWAIT : M_WAITOK); 51 } 52 53 /* 54 * General routine to allocate a hash table with control of memory flags. 55 */ 56 void * 57 hashinit_flags(int elements, struct malloc_type *type, u_long *hashmask, 58 int flags) 59 { 60 long hashsize, i; 61 LIST_HEAD(generic, generic) *hashtbl; 62 63 KASSERT(elements > 0, ("%s: bad elements", __func__)); 64 /* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */ 65 KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT), 66 ("Bad flags (0x%x) passed to hashinit_flags", flags)); 67 68 for (hashsize = 1; hashsize <= elements; hashsize <<= 1) 69 continue; 70 hashsize >>= 1; 71 72 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, 73 hash_mflags(flags)); 74 if (hashtbl != NULL) { 75 for (i = 0; i < hashsize; i++) 76 LIST_INIT(&hashtbl[i]); 77 *hashmask = hashsize - 1; 78 } 79 return (hashtbl); 80 } 81 82 /* 83 * Allocate and initialize a hash table with default flag: may sleep. 84 */ 85 void * 86 hashinit(int elements, struct malloc_type *type, u_long *hashmask) 87 { 88 89 return (hashinit_flags(elements, type, hashmask, HASH_WAITOK)); 90 } 91 92 void 93 hashdestroy(void *vhashtbl, struct malloc_type *type, u_long hashmask) 94 { 95 LIST_HEAD(generic, generic) *hashtbl, *hp; 96 97 hashtbl = vhashtbl; 98 for (hp = hashtbl; hp <= &hashtbl[hashmask]; hp++) 99 KASSERT(LIST_EMPTY(hp), ("%s: hashtbl %p not empty " 100 "(malloc type %s)", __func__, hashtbl, type->ks_shortdesc)); 101 free(hashtbl, type); 102 } 103 104 static const int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 105 2039, 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 106 6653, 7159, 7673, 8191, 12281, 16381, 24571, 32749 }; 107 #define NPRIMES nitems(primes) 108 109 /* 110 * General routine to allocate a prime number sized hash table with control of 111 * memory flags. 112 */ 113 void * 114 phashinit_flags(int elements, struct malloc_type *type, u_long *nentries, int flags) 115 { 116 long hashsize, i; 117 LIST_HEAD(generic, generic) *hashtbl; 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