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

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

Robert I. Eachus wrote:

> Ludovic Brenta wrote:
> 
>> I just closed your bug report after determining that the issue was not
>> in libgnat but in the kernel.  Basically, Linux sends SIGKILL to
>> programs that exhaust physical RAM; as you know, SIGKILL cannot be
>> caught so libgnat has no chance to raise an exception.  If the virtual
>> memory is exhausted before physical memory is, then libgnat does raise
>> Storage_Error.
> 
> Did you refile the bug against the kernel?  As I understand it now, the
> problem is not that the kernel raises SIGKILL if physical RAM is
> exhausted, but that malloc doesn't check that the allocation can succeed
> before making it.

one could use calloc. calloc zeros memory and therefore touches every page.

BTW It's not a bug its a feature:

/work  Linux  martin@linux2  Mi Mai 26 08:09:24  standart
>man malloc
[....]
       Linux follows an optimistic memory allocation strategy.  This means
that when malloc() returns non-NULL  there
       is  no  guarantee  that the memory really is available. In case it
turns out that the system is out of memory,
       one or more processes will be killed by the infamous OOM killer.



GNU                         1993-04-04                  MALLOC(3)
 Manual page malloc(3) line 37/72 (END)

With Regards

Martin
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