1 /*
2 This is a version (aka dlmalloc) of malloc/free/realloc written by
3 Doug Lea and released to the public domain. Use, modify, and
4 redistribute this code without permission or acknowledgement in any
5 way you wish. Send questions, comments, complaints, performance
6 data, etc to dl@cs.oswego.edu
7
8 VERSION 2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee)
9
10 Note: There may be an updated version of this malloc obtainable at
11 ftp://gee.cs.oswego.edu/pub/misc/malloc.c
12 Check before installing!
13
14 Hacked up for uClibc by Erik Andersen <andersen@codepoet.org>
15 */
16
17 #include "malloc.h"
18
19
20 /* ------------------------------ calloc ------------------------------ */
calloc(size_t n_elements,size_t elem_size)21 void* calloc(size_t n_elements, size_t elem_size)
22 {
23 mchunkptr p;
24 unsigned long clearsize;
25 unsigned long nclears;
26 size_t size, *d;
27 void* mem;
28
29
30 /* guard vs integer overflow, but allow nmemb
31 * to fall through and call malloc(0) */
32 size = n_elements * elem_size;
33 if (n_elements && elem_size != (size / n_elements)) {
34 __set_errno(ENOMEM);
35 return NULL;
36 }
37
38 __MALLOC_LOCK;
39 mem = malloc(size);
40 if (mem != 0) {
41 p = mem2chunk(mem);
42
43 if (!chunk_is_mmapped(p))
44 {
45 /*
46 Unroll clear of <= 36 bytes (72 if 8byte sizes)
47 We know that contents have an odd number of
48 size_t-sized words; minimally 3.
49 */
50
51 d = (size_t*)mem;
52 clearsize = chunksize(p) - (sizeof(size_t));
53 nclears = clearsize / sizeof(size_t);
54 assert(nclears >= 3);
55
56 if (nclears > 9)
57 memset(d, 0, clearsize);
58
59 else {
60 *(d+0) = 0;
61 *(d+1) = 0;
62 *(d+2) = 0;
63 if (nclears > 4) {
64 *(d+3) = 0;
65 *(d+4) = 0;
66 if (nclears > 6) {
67 *(d+5) = 0;
68 *(d+6) = 0;
69 if (nclears > 8) {
70 *(d+7) = 0;
71 *(d+8) = 0;
72 }
73 }
74 }
75 }
76 }
77 #if 0
78 else
79 {
80 /* Standard unix mmap using /dev/zero clears memory so calloc
81 * doesn't need to actually zero anything....
82 */
83 d = (size_t*)mem;
84 /* Note the additional (sizeof(size_t)) */
85 clearsize = chunksize(p) - 2*(sizeof(size_t));
86 memset(d, 0, clearsize);
87 }
88 #endif
89 }
90 __MALLOC_UNLOCK;
91 return mem;
92 }
93
94 /* glibc compatibilty */
95 weak_alias(calloc, __libc_calloc)
96