[Xenomai] shared heap access mixing 32 and 64 bits applications

Stéphane Ancelot sancelot at numalliance.com
Fri Jan 27 08:54:53 CET 2017



Le 26/01/2017 à 11:12, Lassi Niemistö a écrit :
>> Is it possible to access same shared memory heaps , between 32 and 64 bits processes ?
> In regular linux I faced the wall when trying to protect the usage of the shared memory area by (pthread iirc) mutex/semaphore - those structures had differences between 32/64bit platforms. I don't know if situation is same in Xenomai but pay attention also to what you are going to put in the shared memory.
>
> -Lassi

I have now the answer regarding xenomai shared heaps between 32 and 64  
bits processes , here is the status, if you use the latest next xenomai 
branch.
within a system running 64 bits xenomai kernel, you can :
* use shared heap areas with 32 bits xenomai processes
* use shared heap areas with 64 bits xenomai processes
* you can not use shared heap areas between 32 and 64 bits xenomai 
processes.
Each area (32/64) are insulated, this incompatibility issue comes mainly 
from usage of size_t type in the xenomai  heap library which are 
different between 32 and 64 bits systems.
and maybe more other reasons ...

So, this is good to know that incompatibility , you can not mix both 
kind of processes in xenomai.



Regards,
S.Ancelot



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