UINT32 fl = OsMemFlGet(size);
    if (fl < OS_MEM_SMALL_BUCKET_COUNT) {
        index = fl;
    } else {
        sl = OsMemSlGet(size, fl);
        curIndex = ((fl - OS_MEM_SMALL_BUCKET_COUNT) << OS_MEM_SLI) + sl + OS_MEM_SMALL_BUCKET_COUNT;
        // 基于TLSF的内存分配算法实现，在遇到size>=128的内存分配时，index+1，向上一级申请更大的内存。 
        index = curIndex + 1;
    }

STATIC INLINE UINT32 OsMemSlGet(UINT32 size, UINT32 fl)
{
    if ((fl < OS_MEM_SMALL_BUCKET_COUNT) || (size < OS_MEM_SMALL_BUCKET_MAX_SIZE)) {
        PRINT_ERR("fl or size is too small, fl = %u, size = %u\n", fl, size);
        return 0;
    }

    UINT32 add = size & ((1 << (fl - OS_MEM_SMALL_BUCKET_COUNT + OS_MEM_SLI + 1)) - 1) ? 1 : 0;
    UINT32 sl = (size << OS_MEM_SLI) >> (fl - OS_MEM_SMALL_BUCKET_COUNT + OS_MEM_LARGE_START_BUCKET);
    return (sl - (1 << OS_MEM_SLI) + add);
}

STATIC INLINE struct OsMemFreeNodeHead *OsMemFindNextSuitableBlock(VOID *pool, UINT32 size, UINT32 *outIndex)
{
    struct OsMemPoolHead *poolHead = (struct OsMemPoolHead *)pool;
    struct OsMemFreeNodeHead *node = NULL;
    UINT32 index, curIndex;

    // check every freeListBitmap.32bit, if greater or equal bit valid, match success.
    for (curIndex = OsMemFreeListIndexGet(size); 
         curIndex < OS_MEM_FREE_LIST_COUNT; 
         curIndex = LOS_Align(curIndex + 1, 32)) {
        for (index = curIndex; index < LOS_Align(curIndex + 1, 32); ++index) {
            if (((index = OsMemNotEmptyIndexGet(poolHead, index)) != OS_MEM_FREE_LIST_COUNT) &&
                ((node = OsMemFindCurSuitableBlock(poolHead, index, size)) != NULL)) {
                *outIndex = index;
                return node;
            }
        }
    }
    // all freeListBitmap.32bit match failed.
    return NULL;
}