Re: [Xenomai-core] Native skin: user space handles sharable between processes?

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Jan Kiszka wrote:
> Gilles Chanteperdrix wrote:
>> Jan Kiszka wrote:
>>> Hi,
>>>
>>> what is the policy for the user space handles the native skin generates:
>>> Can the user share them between processes via putting them into shared
>>> memory (like it is allowed for some POSIX objects)?
>>>
>>> I'm wondering if I have to use the POSIX pattern to resolve the address
>>> of a fast mutex: If shared, look to global heap, otherwise use
>>> process-local heap.
>> The posix skin does only this only the first time. If the address is
>> local, it is computed and stored locally and never recomputed again.
> 
> What remains is "if (shadow->attr.pshared) ...", so a condition + some
> bit in the shadow data structure.
> 
> I could merged that bit into the lowest bit of the lock pointer, OK, but
> would still have to check for it. If native defines that a handle is
> only valid within the process that obtained it, I could skip that dance
> altogether.

Ok. I understand what you mean. I wanted to work this around for the
POSIX API, but let us consider a real-life fact: the process-shared
objects are a corner-case. So, let us not spend too much sweat on it.

-- 
                                                 Gilles.