/* ----------------------------------------------------------------------------
 * Copyright (c) Huawei Technologies Co., Ltd. 2013-2015. All rights reserved.
 * Description: LiteOS memory Module Implementation
 * Author: Huawei LiteOS Team
 * Create: 2013-05-12
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 1. Redistributions of source code must retain the above copyright notice, this list of
 * conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
 * of conditions and the following disclaimer in the documentation and/or other materials
 * provided with the distribution.
 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
 * to endorse or promote products derived from this software without specific prior written
 * permission.
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * --------------------------------------------------------------------------- */
/*以上代码是关于内存管理中的slab功能的实现。Slab是一种分配固定大小的内存块的机制，用于提高内存分配和释放的效率。以上代码提供了对slab内存分配器的配置和定义*/
/**
 * @defgroup los_slab Slab
 * @ingroup kernel
 */

#ifndef _LOS_SLAB_H
#define _LOS_SLAB_H

#include "los_base.h"

#ifdef __cplusplus
#if __cplusplus
extern "C" {
#endif /* __cplusplus */
#endif /* __cplusplus */

/**
 * @ingroup los_slab
 * total size of each slab class.
 */
#define SLAB_MEM_ALLOCATOR_SIZE     512U /*宏定义SLAB_MEM_ALLOCATOR_SIZE表示每个slab class（一种内存分配方式）所需要的总大小为512字节*/

#define SLAB_BASIC_NEED_SIZE        0x1000 /*宏定义SLAB_BASIC_NEED_SIZE表示内存分配时最小需要的空间为0x1000字节（即4KB）。*/

/**
 * @ingroup los_slab
 * slab bucket size type.
 */
#ifdef LOSCFG_KERNEL_MEM_SLAB_AUTO_EXPANSION_MODE
enum SlabBucketSizeType {
    SLAB_BUCKET_SIZE_HALF_OF_HEAP    = 0x1UL,   /**< a half of heap size slab mem can use */
    SLAB_BUCKET_SIZE_QUARTER_OF_HEAP,           /**< one quarter of heap size slab mem can use */
    SLAB_BUCKET_SIZE_TYPE_MAX
};

#define SLAB_MEM_BUCKET_SIZE_TYPE   SLAB_BUCKET_SIZE_HALF_OF_HEAP
#endif
/*这段代码主要是用于配置和定义slab内存分配器中内存块大小的相关选项。*/
/*这段代码定义了一个枚举类型SlabBucketSizeType，用于表示slab bucket（内存块）的大小类型
如果宏定义LOSCFG_KERNEL_MEM_SLAB_AUTO_EXPANSION_MODE被定义，那么枚举类型SlabBucketSizeType将会被定义。
枚举类型SlabBucketSizeType包含以下取值：
SLAB_BUCKET_SIZE_HALF_OF_HEAP：表示slab内存块可以使用堆内存大小的一半。
SLAB_BUCKET_SIZE_QUARTER_OF_HEAP：表示slab内存块可以使用堆内存大小的四分之一。
SLAB_BUCKET_SIZE_TYPE_MAX：表示枚举类型的最大取值。
宏定义SLAB_MEM_BUCKET_SIZE_TYPE被设置为SLAB_BUCKET_SIZE_HALF_OF_HEAP，表示默认情况下slab内存块的大小为堆内存大小的一半。*/
/**
 * @ingroup los_slab
 * @brief configure slab size.
 *
 * @par Description:
 * This API is used to configure slab size.
 * @attention
 * <ul>
 * <li>The function should be called before function LOS_MemInit if necessary.</li>
 * <li>The function takes effect when LOSCFG_KERNEL_MEM_SLAB_AUTO_EXPANSION_MODE is NO.</li>
 * </ul>
 *
 * @param cfg     [IN] the pointer to slab size config table. Note that the pointer cannot be null.
 * @param cnt     [IN] slab class size, must be equal to SLAB_MEM_COUNT(the number of slab class).
 *
 * @retval None.
 * @par Dependency:
 * <ul>
 * <li>los_slab.h: the header file that contains the API declaration.</li>
 * </ul>
 * @since Huawei LiteOS V200R003C00
 */
extern VOID LOS_SlabSizeCfg(UINT32 *cfg, UINT32 cnt);/*段代码是关于操作系统内存管理中的slab功能的配置函数。Slab是一种分配固定大小的内存块的机制，
用于提高内存分配和释放的效率*/
/*该函数LOS_SlabSizeCfg用于配置slab的大小。它接受两个参数：
cfg：指向slab大小配置表的指针。这个配置表包含了每个slab类的大小信息。
cnt：slab类的数量，必须与配置表中的项数相匹配*/
#ifdef __cplusplus
#if __cplusplus
}
#endif /* __cplusplus */
#endif /* __cplusplus */

#endif /* _LOS_SLAB_H */
