Re: Is the Ada run-time required to detect out-of-memory conditions?

[Martin Krischik <krischik@users.sourceforge.net>]

Wojtek Narczynski wrote:

> Hello,
> 
>> I have received a bug report [1] against GNAT 3.15p and reproduced the
>> same behaviour with GCC 3.4.  I would like the advice of language
>> lawyers on the issue.
>> 
>> [1] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=250076
>> 
>> The program allocates memory in an infinite loop using "new" and the
>> default storage pool, and of course exhausts all available storage.
>> The issue is whether or not Storage_Error should be raised.  With
>> GNAT, no exception is raised; instead the program receives SIGKILL
>> (not even SIGSEGV) from Linux.
> 
> I noticed, that if the program allocates memory in 6Kb chunks or
> larger, Storate_Error is raised. If the chunk size is 5Kb or less, the
> program only prints "Killed". In between I have not tested.
> 
> Also, shouldn't cases like this one, as a rule, eventually become part
> of ACATS?

Just a thought: The page size on Intel CPU's is 4 kb. So most OS's on Intel
CPU will only handle memory requests of at least one page.

I find it interesting that with request significantly larger then one page
everything seems Ok.

Lets Think: With GNAT allocation from the standart storrage pool are just
passed down to C's malloc ().

When smaller memory is requested most C compiler will bundele several
requests into one page request.

When larger  memory is requested some C compiler will just pass the request
on to the OS and some other will allways bundle.

With Regards

Martin

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