Class _pool_alloc

src/libcpp/allocators/alloc_pool.hpp:70–184

    std::size_t S = 64 * 1024
             >
    class  _pool_alloc : public A
    {
/*--- local memory pool: delegate to base alloc otherwise */
    public  :

    typedef A                           base_type ;

    std::size_t static constexpr pool_size  = S ;

    typedef typename
            base_type::size_type        size_type ;
    typedef typename
            base_type::diff_type        diff_type ;

    typedef _pool_alloc <
             base_type  ,
             pool_size  >               self_type ;

    private :

/*-------------------------------- local allocation lists */
    char_type*  _alloc ;        // pointer to block
    char_type*  _shift ;        // pointer to block
    char_type*  _block ;
    char_type*  _cache ;        // cached item list

/*-------------------------------- local allocation sizes */
    size_type   _item_size ;    // size of alloc.
    size_type   _slab_size ;    // size of buffer

    /*
    --------------------------------------------------------
     * local helper: access encoded list pointers.
    --------------------------------------------------------
     */

    #define __nextblock(__block)    \
        *((char **)(__block  +      \
        this->_slab_size*this->_item_size))

    #define __nextcache(__cache)    \
            * (char **)(__cache)

    #define __slabbytes             \
        this->_slab_size *          \
        this->_item_size + sizeof (char *)

    /*
    --------------------------------------------------------
     * local helper: allocate and push new buffer.
    --------------------------------------------------------
     */

    __inline_call void_type push_block ( // push new buffer
        )
    {
    /*------------------------- allocate new buffer item  */
        char_type *_this_slab =