From: "Iñaki Baz Castillo" <ibc@...>
Date: 2011-12-02T06:01:02+09:00
Subject: Re: GC.malloc_allocated_size and GC.malloc_allocations not available (#if CALC_EXACT_MALLOC_SIZE)

2011/12/1 Eric Wong <normalperson@yhbt.net>:
> Iñaki Baz Castillo <ibc@aliax.net> wrote:
>> So it seems that in my system CALC_EXACT_MALLOC_SIZE is not set since
>> gc.c file also contains:
>>
>> #define CALC_EXACT_MALLOC_SIZE 0
>>
>> Why is it unavailable?
>
> Enabling that breaks any C extensions that (incorrectly) mix
> x{m,c,re}alloc() calls with regular free() and vice-versa.
>
> Even worse, this breakage isn't noticeable at build/compile time,
> so it's not easy to find/fix everywhere, especially if it's not
> in regular code paths.
>
> Maybe Ruby should have a alternative *alloc API that enforce this:
> (rb_emalloc, rb_ecalloc, rb_erealloc, rb_efree) and we can deprecate
> the x* one slowly without breaking existing extensions.

Thanks for the explanation, good to know.

BTW I will enable it to test my Ruby C extensions :)

-- 
Iñaki Baz Castillo
<ibc@aliax.net>