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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
* All rights reserved.
*/
/** \file
* \ingroup bli
* \brief Efficient memory allocation for many small chunks.
* \section aboutmemarena Memory Arena
*
* Memory arena's are commonly used when the program
* needs to quickly allocate lots of little bits of data,
* which are all freed at the same moment.
*
* \note Memory can't be freed during the arenas lifetime.
*/
#include <stdlib.h>
#include <string.h>
#include "MEM_guardedalloc.h"
#include "BLI_asan.h"
#include "BLI_memarena.h"
#include "BLI_strict_flags.h"
#include "BLI_utildefines.h"
#ifdef WITH_MEM_VALGRIND
# include "valgrind/memcheck.h"
#else
# define VALGRIND_CREATE_MEMPOOL(pool, rzB, is_zeroed) UNUSED_VARS(pool, rzB, is_zeroed)
# define VALGRIND_DESTROY_MEMPOOL(pool) UNUSED_VARS(pool)
# define VALGRIND_MEMPOOL_ALLOC(pool, addr, size) UNUSED_VARS(pool, addr, size)
#endif
struct MemBuf {
struct MemBuf *next;
uchar data[0];
};
struct MemArena {
unsigned char *curbuf;
const char *name;
struct MemBuf *bufs;
size_t bufsize, cursize;
size_t align;
bool use_calloc;
};
static void memarena_buf_free_all(struct MemBuf *mb)
{
while (mb != NULL) {
struct MemBuf *mb_next = mb->next;
/* Unpoison memory because MEM_freeN might overwrite it. */
BLI_asan_unpoison(mb, (uint)MEM_allocN_len(mb));
MEM_freeN(mb);
mb = mb_next;
}
}
MemArena *BLI_memarena_new(const size_t bufsize, const char *name)
{
MemArena *ma = MEM_callocN(sizeof(*ma), "memarena");
ma->bufsize = bufsize;
ma->align = 8;
ma->name = name;
VALGRIND_CREATE_MEMPOOL(ma, 0, false);
return ma;
}
void BLI_memarena_use_calloc(MemArena *ma)
{
ma->use_calloc = 1;
}
void BLI_memarena_use_malloc(MemArena *ma)
{
ma->use_calloc = 0;
}
void BLI_memarena_use_align(struct MemArena *ma, const size_t align)
{
/* Align must be a power of two. */
BLI_assert((align & (align - 1)) == 0);
ma->align = align;
}
void BLI_memarena_free(MemArena *ma)
{
memarena_buf_free_all(ma->bufs);
VALGRIND_DESTROY_MEMPOOL(ma);
MEM_freeN(ma);
}
/** Pad num up by \a amt (must be power of two). */
#define PADUP(num, amt) (((num) + ((amt)-1)) & ~((amt)-1))
/** Align alloc'ed memory (needed if `align > 8`). */
static void memarena_curbuf_align(MemArena *ma)
{
unsigned char *tmp;
tmp = (unsigned char *)PADUP((intptr_t)ma->curbuf, (int)ma->align);
ma->cursize -= (size_t)(tmp - ma->curbuf);
ma->curbuf = tmp;
}
void *BLI_memarena_alloc(MemArena *ma, size_t size)
{
void *ptr;
/* Ensure proper alignment by rounding size up to multiple of 8. */
size = PADUP(size, ma->align);
if (UNLIKELY(size > ma->cursize)) {
if (size > ma->bufsize - (ma->align - 1)) {
ma->cursize = PADUP(size + 1, ma->align);
}
else {
ma->cursize = ma->bufsize;
}
struct MemBuf *mb = (ma->use_calloc ? MEM_callocN : MEM_mallocN)(sizeof(*mb) + ma->cursize,
ma->name);
ma->curbuf = mb->data;
mb->next = ma->bufs;
ma->bufs = mb;
BLI_asan_poison(ma->curbuf, ma->cursize);
memarena_curbuf_align(ma);
}
ptr = ma->curbuf;
ma->curbuf += size;
ma->cursize -= size;
VALGRIND_MEMPOOL_ALLOC(ma, ptr, size);
BLI_asan_unpoison(ptr, size);
return ptr;
}
void *BLI_memarena_calloc(MemArena *ma, size_t size)
{
void *ptr;
/* No need to use this function call if we're calloc'ing by default. */
BLI_assert(ma->use_calloc == false);
ptr = BLI_memarena_alloc(ma, size);
memset(ptr, 0, size);
return ptr;
}
/**
* Clear for reuse, avoids re-allocation when an arena may
* otherwise be free'd and recreated.
*/
void BLI_memarena_clear(MemArena *ma)
{
if (ma->bufs) {
unsigned char *curbuf_prev;
size_t curbuf_used;
if (ma->bufs->next) {
memarena_buf_free_all(ma->bufs->next);
ma->bufs->next = NULL;
}
curbuf_prev = ma->curbuf;
ma->curbuf = ma->bufs->data;
memarena_curbuf_align(ma);
/* restore to original size */
curbuf_used = (size_t)(curbuf_prev - ma->curbuf);
ma->cursize += curbuf_used;
if (ma->use_calloc) {
memset(ma->curbuf, 0, curbuf_used);
}
BLI_asan_poison(ma->curbuf, ma->cursize);
}
VALGRIND_DESTROY_MEMPOOL(ma);
VALGRIND_CREATE_MEMPOOL(ma, 0, false);
}
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