xref: /dragonfly/stand/lib/zalloc_malloc.c (revision 655933d6)
1 /*
2  * This module derived from code donated to the FreeBSD Project by
3  * Matthew Dillon <dillon@backplane.com>
4  *
5  * Copyright (c) 1998 The FreeBSD Project
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD: src/lib/libstand/zalloc_malloc.c,v 1.5 1999/08/28 00:05:35 peter Exp $
30  * $DragonFly: src/lib/libstand/zalloc_malloc.c,v 1.3 2005/03/13 15:10:03 swildner Exp $
31  */
32 
33 /*
34  * MALLOC.C - malloc equivalent, runs on top of zalloc and uses sbrk
35  */
36 
37 #include "zalloc_defs.h"
38 
39 static MemPool	MallocPool;
40 
41 #ifdef DMALLOCDEBUG
42 static int MallocMax;
43 static int MallocCount;
44 
45 void mallocstats(void);
46 #endif
47 
48 #ifdef malloc
49 #undef malloc
50 #undef free
51 #endif
52 
53 void *
54 malloc(size_t bytes)
55 {
56     Guard *res;
57 
58 #ifdef USEENDGUARD
59     bytes += MALLOCALIGN + 1;
60 #else
61     bytes += MALLOCALIGN;
62 #endif
63 
64     while ((res = znalloc(&MallocPool, bytes)) == NULL) {
65 	int incr = (bytes + BLKEXTENDMASK) & ~BLKEXTENDMASK;
66 	char *base;
67 
68 	if ((base = sbrk(incr)) == (char *)-1)
69 	    return(NULL);
70 	zextendPool(&MallocPool, base, incr);
71 	zfree(&MallocPool, base, incr);
72     }
73 #ifdef DMALLOCDEBUG
74     if (++MallocCount > MallocMax)
75 	MallocMax = MallocCount;
76 #endif
77 #ifdef USEGUARD
78     res->ga_Magic = GAMAGIC;
79 #endif
80     res->ga_Bytes = bytes;
81 #ifdef USEENDGUARD
82     *((char *)res + bytes - 1) = -2;
83 #endif
84     return((char *)res + MALLOCALIGN);
85 }
86 
87 void
88 free(void *ptr)
89 {
90     size_t bytes;
91 
92     if (ptr != NULL) {
93 	Guard *res = (void *)((char *)ptr - MALLOCALIGN);
94 
95 #ifdef USEGUARD
96 	if (res->ga_Magic != GAMAGIC)
97 	    panic("free: guard1x fail @ %p", ptr);
98 	res->ga_Magic = -1;
99 #endif
100 #ifdef USEENDGUARD
101 	if (*((char *)res + res->ga_Bytes - 1) != -2) {
102 	    panic("free: guard2 fail @ %p + %zu %d/-2",
103 		  ptr,
104 		  res->ga_Bytes - MALLOCALIGN - 1,
105 		  *((char *)res + res->ga_Bytes - 1));
106 	}
107 	*((char *)res + res->ga_Bytes - 1) = -1;
108 #endif
109 
110 	bytes = res->ga_Bytes;
111 	zfree(&MallocPool, res, bytes);
112 #ifdef DMALLOCDEBUG
113 	--MallocCount;
114 #endif
115     }
116 }
117 
118 
119 void *
120 calloc(size_t n1, size_t n2)
121 {
122     uintptr_t bytes = (uintptr_t)n1 * (uintptr_t)n2;
123     void *res;
124 
125     if ((res = malloc(bytes)) != NULL) {
126 	bzero(res, bytes);
127     }
128     return(res);
129 }
130 
131 /*
132  * realloc() - I could be fancier here and free the old buffer before
133  * 	       allocating the new one (saving potential fragmentation
134  *	       and potential buffer copies).  But I don't bother.
135  */
136 
137 void *
138 realloc(void *ptr, size_t size)
139 {
140     void *res;
141     size_t old;
142 
143     if ((res = malloc(size)) != NULL) {
144 	if (ptr) {
145 	    old = *(size_t *)((char *)ptr - MALLOCALIGN) - MALLOCALIGN;
146 #ifdef USEENDGUARD
147 	    --old;
148 #endif
149 	    if (old < size)
150 		bcopy(ptr, res, old);
151 	    else
152 		bcopy(ptr, res, size);
153 	    free(ptr);
154 	} else {
155 #ifdef DMALLOCDEBUG
156 #ifdef EXITSTATS
157 	    if (DidAtExit == 0) {
158 		DidAtExit = 1;
159 		atexit(mallocstats);
160 	    }
161 #endif
162 #endif
163 	}
164     }
165     return(res);
166 }
167 
168 void *
169 reallocf(void *ptr, size_t size)
170 {
171     void *res;
172 
173     if ((res = realloc(ptr, size)) == NULL)
174 	free(ptr);
175     return(res);
176 }
177 
178 #ifdef DMALLOCDEBUG
179 
180 void
181 mallocstats(void)
182 {
183     printf("Active Allocations: %d/%d\n", MallocCount, MallocMax);
184 #ifdef ZALLOCDEBUG
185     zallocstats(&MallocPool);
186 #endif
187 }
188 
189 #endif
190 
191