[C-safe-secure-studygroup] dynamic memory prohibition

[Robert Seacord]

Thanks y'all.

On Wed, Nov 13, 2019, 1:13 PM Wilson, Charles <Charles.Wilson at draeger.com>
wrote:

> There’s also the timing indeterminacy if the memory allocator can compact.
>
>
>
> *From:* C-safe-secure-studygroup <
> c-safe-secure-studygroup-bounces at lists.trustable.io> *On Behalf Of *Clive
> Pygott
> *Sent:* Wednesday, November 13, 2019 12:49 PM
> *To:* C Safety and Security Study Group Discussion <
> c-safe-secure-studygroup at lists.trustable.io>
> *Subject:* Re: [C-safe-secure-studygroup] dynamic memory prohibition
>
>
>
> Short answer - it may fail. You cannot have a safety critical system
> depend on a resource that may not be available.
>
>
>
> One work around is to say you can allocate during a safe start-up phase
> (e.g. when an aircraft is on the ground) and free during close down - this
> is JSF++'s approach, alternatively you'd have to prove that it is
> impossible for the program to make an allocation request that cannot be
> satisfied. MISRA says 'no dynamic allocation', but that allows projects to
> deviate - either with one of these arguments or something equivalent.
>
>
>
>       Clive
>
>
>
>
>
> On Wed, Nov 13, 2019 at 9:37 AM Robert Seacord <rcseacord at gmail.com>
> wrote:
>
> What is the argument against using dynamically allocated memory in
> safety critical systems?  Can someone provide (or provide a pointer to) a
> well-reasoned explanation?
>
>
>
> Thanks,
>
> rCs
>
> _______________________________________________
> C-safe-secure-studygroup mailing list
> C-safe-secure-studygroup at lists.trustable.io
>
> https://lists.trustable.io/cgi-bin/mailman/listinfo/c-safe-secure-studygroup
> <https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.trustable.io%2Fcgi-bin%2Fmailman%2Flistinfo%2Fc-safe-secure-studygroup&data=02%7C01%7CCharles.Wilson%40draeger.com%7Cb6350ef091b345ea4f7608d76861d8d5%7Ce8d897a8f4004625858a6f3ae627542b%7C1%7C0%7C637092641766229209&sdata=O2t6cVVpwMbIWWqtwKoa2%2FNhnks331wt33Dsc4rQiuk%3D&reserved=0>
>
> _______________________________________________
> C-safe-secure-studygroup mailing list
> C-safe-secure-studygroup at lists.trustable.io
>
> https://lists.trustable.io/cgi-bin/mailman/listinfo/c-safe-secure-studygroup
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.trustable.io/pipermail/c-safe-secure-studygroup/attachments/20191113/532ada35/attachment.html>