From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Mon, 25 Aug 2008 14:16:50 +0200
From: Jan Kiszka <jan.kiszka@domain.hid>
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Subject: Re: [Xenomai-core] Native skin: user space handles sharable between
 processes?
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To: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
Cc: xenomai-core <xenomai@xenomai.org>

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.

Jan

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