[Mono-dev] How To Convince Mono To Allocate Big Arrays

[Rodrigo Kumpera]

On Thu, May 8, 2008 at 1:54 PM, Luis F. Ortiz <LuisOrtiz at verizon.net> wrote:

> On May 7, 2008, at 10:50 PM, Rodrigo Kumpera wrote:
>
> Hi Luis,
>
> To have your patch integrated, some changes are needed. First, we want to
> default to 32bits sized arrays on 64bits machines, so your changes must be
> conditionally compiled. To help with that some changed to your patch are
> due. Next are some comments about it:
> ...
>  /* helper macros to check for overflow when calculating the size of arrays
> */
> -#define MYGUINT32_MAX 4294967295U
> +#if (GLIB_SIZEOF_SIZE_T < 4 )
> +#define MYGUINT32_MAX 0xFFFFFFFFUL
> +#define MYGUINT_MAX MYGUINT32_MAX
>
> This #if seens bogus, don't you mean "if ((GLIB_SIZEOF_SIZE_T == 4 )" as
> mono never supported 16bits machines.
> The macros can be unified by using MYGUINT_MAX and the 'array_size_t' type
> I talked before. The definition of MYGUINT_MAX
> should be put together in the same place we define 'array_size_t'. And we
> could go with a meaningful name, don't you think?
>
>
> The whole MYGUINT32 thing was there before made my changes and appears in
> other places in interpreter/interp.c as well.
> I don't understand why the GLIB define of G_MAXUINT32 was not used instead
> these private definitions.
>
> I get nervous when I see magic constants, either in hexadecimal or decimal.
>
> I would rather see a definition of MONO_ARRAY_MAX_INDEX set to either
> G_MAXINT32 or G_MAXINT64 and a definition
> of MONO_ARRAY_MAX_SIZE set to either G_MAXUNIT32 or G_MAXUNIT64, in
> object.h .
>
> Then this code could lose the #if here and the magic numbers would be kept
> in one place.
>
> /Ortiz/Luis
>
>
>
I agree with on the naming, my argument was against the existing code which
don't give a clue about what it is supposed to be.


Rodrigo
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