Re: [Qemu-devel] [PATCH] use qemu_malloc and friends consistently

[Anthony Liguori <anthony@codemonkey.ws>]

Gerd Hoffmann wrote:
> On 05/29/09 23:12, David Turner wrote:
>> I would even suggest providing helper macros to make the programmer's
>> intent
>> even more clear
>> and less error-prone, as in:
>>
>> #define  QEMU_NEW(ptr)                    (ptr) =
>> qemu_alloc(sizeof(*(ptr)))
>> #define  QEMU_NEW_ARRAY(ptr,cnt)   (ptr) =
>> qemu_calloc((cnt),sizeof(*(ptr)))
>> #define  QEMU_RENEW_ARRAY(ptr,cnt)  (ptr) =
>> qemu_realloc((ptr),(cnt),sizeof(*(ptr)))
>> #define  QEMU_FREE_ARRAY(ptr)        qemu_free(ptr)
>
> The idea to have allocators for arrays (and have them allow
> zero-length arrays) is fine.  I wouldn't create two macros for new and
> renew array, you can just use usual realloc semantics (ptr == NULL ->
> alloc).
>
> Also I don't like the syntax that much as you'll have the IMHO
> non-intuitive code like this:
>
>   QEMU_NEW_ARRAY(ptr, ...);
>
> instead of
>
>   ptr = QEMU_NEW_ARRAY(...);
>
> then.  I don't see another easy way to get the automagic sizeof(*ptr)
> stuff done though.

I've always liked glib's memory functions.  It does OOM error handling
and returns NULL when size == 0.

http://library.gnome.org/devel/glib/stable/glib-Memory-Allocation.html

Regards,

Anthony Liguori
> cheers,
>   Gerd
>
>
>