Bug#215448: di_mem_chunk_alloc() should return sizeof(long) or better alignment

[Falk Hueffner <falk.hueffner@student.uni-tuebingen.de>]

First, IMHO we should drop this stuff and just use malloc. I don't see
any point in increasing code size and introducing new bugs thereby.

Anyway:

> struct di_mem_area
> {
>   di_mem_area *next;           /**< the next mem area */
>   di_mem_area *prev;           /**< the previous mem area */
>   di_ksize_t index;            /**< the current index into the "mem" array */
>   di_ksize_t free;             /**< the number of free bytes in this mem area */
>   di_ksize_t allocated;        /**< the number of atoms allocated from this area */
>   char mem[MEM_AREA_SIZE];     /**< the mem array from which atoms get allocated
>                                 *   the actual size of this array is determined by
>                                 *   the mem chunk "area_size". ANSI says that it
>                                 *   must be declared to be the maximum size it
>                                 *   can possibly be (even though the actual size
>                                 *   may be less).
>                                 */
> };
> 
> 
> I also wonder about MEM_AREA_SIZE being hardwired at 4, although I
> didn't dig in to the code far enough to see if it should be 8 on 64
> bit platforms.

Just use long mem[] there, we can assume a C99 compiler, and it will
ensure alignment (at least for all Linux platforms).

-- 
	Falk