blender-archive/source/blender/blenlib/BLI_memarena.h

/* SPDX-License-Identifier: GPL-2.0-or-later
 * Copyright 2001-2002 NaN Holding BV. All rights reserved. */

/** \file
 * \ingroup bli
 */

#pragma once

#include "BLI_compiler_attrs.h"

#ifdef __cplusplus
extern "C" {
#endif

/**
 * A reasonable standard buffer size, big enough to not cause much internal fragmentation,
 * small enough not to waste resources
 */
#define BLI_MEMARENA_STD_BUFSIZE MEM_SIZE_OPTIMAL(1 << 14)

struct MemArena;
typedef struct MemArena MemArena;

struct MemArena *BLI_memarena_new(size_t bufsize,
                                  const char *name) ATTR_WARN_UNUSED_RESULT ATTR_RETURNS_NONNULL
    ATTR_NONNULL(2) ATTR_MALLOC;
void BLI_memarena_free(struct MemArena *ma) ATTR_NONNULL(1);
void BLI_memarena_use_malloc(struct MemArena *ma) ATTR_NONNULL(1);
void BLI_memarena_use_calloc(struct MemArena *ma) ATTR_NONNULL(1);
void BLI_memarena_use_align(struct MemArena *ma, size_t align) ATTR_NONNULL(1);
void *BLI_memarena_alloc(struct MemArena *ma, size_t size) ATTR_WARN_UNUSED_RESULT
    ATTR_NONNULL(1) ATTR_MALLOC ATTR_ALLOC_SIZE(2);
void *BLI_memarena_calloc(struct MemArena *ma, size_t size) ATTR_WARN_UNUSED_RESULT
    ATTR_NONNULL(1) ATTR_MALLOC ATTR_ALLOC_SIZE(2);

/**
 * Transfer ownership of allocated blocks from `ma_src` into `ma_dst`,
 * cleaning the contents of `ma_src`.
 *
 * \note Useful for multi-threaded tasks that need a thread-local #MemArena
 * that is kept after the multi-threaded operation is completed.
 *
 * \note Avoid accumulating memory pools where possible
 * as any unused memory in `ma_src` is wasted every merge.
 */
void BLI_memarena_merge(MemArena *ma_dst, MemArena *ma_src) ATTR_NONNULL(1, 2);

/**
 * Clear for reuse, avoids re-allocation when an arena may
 * otherwise be free'd and recreated.
 */
void BLI_memarena_clear(MemArena *ma) ATTR_NONNULL(1);

#ifdef __cplusplus
}
#endif