mirror of
https://github.com/omar-polo/gmid.git
synced 2024-08-03 17:53:23 +02:00
c7949fd545
original commit from claudio@: Type-cast getpagesize() from int to size_t for the comparison with d. getpagesize() will only return positive numbers (there is no negative page size system) and it can not fail. Should fix some compiler warnings seen in -portable projects. OK otto@
91 lines
2.5 KiB
C
91 lines
2.5 KiB
C
/* $OpenBSD: recallocarray.c,v 1.2 2021/03/18 11:16:58 claudio Exp $ */
|
|
/*
|
|
* Copyright (c) 2008, 2017 Otto Moerbeek <otto@drijf.net>
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
|
|
#include "../config.h"
|
|
|
|
#include <errno.h>
|
|
#include <stdlib.h>
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
/*
|
|
* This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
|
|
* if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
|
|
*/
|
|
#define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4))
|
|
|
|
/*
|
|
* Even though specified in POSIX, the PAGESIZE and PAGE_SIZE
|
|
* macros have very poor portability. Since we only use this
|
|
* to avoid free() overhead for small shrinking, simply pick
|
|
* an arbitrary number.
|
|
*/
|
|
#define getpagesize() (1UL << 12)
|
|
|
|
void *
|
|
recallocarray(void *ptr, size_t oldnmemb, size_t newnmemb, size_t size)
|
|
{
|
|
size_t oldsize, newsize;
|
|
void *newptr;
|
|
|
|
if (ptr == NULL)
|
|
return calloc(newnmemb, size);
|
|
|
|
if ((newnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
|
|
newnmemb > 0 && SIZE_MAX / newnmemb < size) {
|
|
errno = ENOMEM;
|
|
return NULL;
|
|
}
|
|
newsize = newnmemb * size;
|
|
|
|
if ((oldnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
|
|
oldnmemb > 0 && SIZE_MAX / oldnmemb < size) {
|
|
errno = EINVAL;
|
|
return NULL;
|
|
}
|
|
oldsize = oldnmemb * size;
|
|
|
|
/*
|
|
* Don't bother too much if we're shrinking just a bit,
|
|
* we do not shrink for series of small steps, oh well.
|
|
*/
|
|
if (newsize <= oldsize) {
|
|
size_t d = oldsize - newsize;
|
|
|
|
if (d < oldsize / 2 && d < (size_t)getpagesize()) {
|
|
memset((char *)ptr + newsize, 0, d);
|
|
return ptr;
|
|
}
|
|
}
|
|
|
|
newptr = malloc(newsize);
|
|
if (newptr == NULL)
|
|
return NULL;
|
|
|
|
if (newsize > oldsize) {
|
|
memcpy(newptr, ptr, oldsize);
|
|
memset((char *)newptr + oldsize, 0, newsize - oldsize);
|
|
} else
|
|
memcpy(newptr, ptr, newsize);
|
|
|
|
explicit_bzero(ptr, oldsize);
|
|
free(ptr);
|
|
|
|
return newptr;
|
|
}
|