1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /*
28 * Much like calloc, but with functions to report the size of the
29 * allocation given only the pointer.
30 */
31
32 #include <assert.h>
33 #include <string.h>
34 #include <malloc.h>
35 #include "sized_array.h"
36
37 /*
38 * Assumes that int is at least 32 bits and that nothing needs more than
39 * 8-byte alignment.
40 */
41
42 /* COOKIE provides some bad-pointer protection. */
43 #define COOKIE "SACOOKIE"
44
45 struct sized_array {
46 int n;
47 int sz;
48 #if defined(COOKIE)
49 char cookie[8];
50 #endif
51 };
52
53
54 void *
sized_array(size_t n,size_t sz)55 sized_array(size_t n, size_t sz)
56 {
57 struct sized_array *sa;
58 size_t total;
59
60 total = sizeof (struct sized_array) + n*sz;
61
62 sa = malloc(total);
63
64 if (sa == NULL)
65 return (NULL);
66
67 (void) memset(sa, 0, total);
68
69 sa->n = n;
70 sa->sz = sz;
71
72 #if defined(COOKIE)
73 (void) memcpy(sa->cookie, COOKIE, sizeof (sa->cookie));
74 #endif
75
76 return ((void *)(sa + 1));
77 }
78
79 void
sized_array_free(void * p)80 sized_array_free(void *p)
81 {
82 struct sized_array *sa;
83
84 if (p == NULL)
85 return;
86
87 sa = ((struct sized_array *)p)-1;
88
89 #if defined(COOKIE)
90 assert(memcmp(sa->cookie, COOKIE, sizeof (sa->cookie)) == 0);
91 #endif
92
93 free(sa);
94 }
95
96 size_t
sized_array_n(void * p)97 sized_array_n(void *p)
98 {
99 struct sized_array *sa;
100
101 sa = ((struct sized_array *)p)-1;
102
103 #if defined(COOKIE)
104 assert(memcmp(sa->cookie, COOKIE, sizeof (sa->cookie)) == 0);
105 #endif
106
107 return (sa->n);
108 }
109
110 size_t
sized_array_sz(void * p)111 sized_array_sz(void *p)
112 {
113 struct sized_array *sa;
114
115 sa = ((struct sized_array *)p)-1;
116
117 #if defined(COOKIE)
118 assert(memcmp(sa->cookie, COOKIE, sizeof (sa->cookie)) == 0);
119 #endif
120
121 return (sa->sz);
122 }
123