Re: [Xenomai-core] Re: RT-CAN tx_sem

[Jan Kiszka <jan.kiszka@domain.hid>]

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Wolfgang Grandegger wrote:
> Jan Kiszka wrote:
>> Jan Kiszka wrote:
>>> I thought about this issue again and found the reason for my vague bad
>>> feeling: re-init is not atomic, thus racy. But also the test+sem_init
>>> pattern I suggested is not save.
>>>
>>> I guess we need to enhance rtdm_XXX_init in this regard to make the
>>> RT-CAN use case an officially allowed one. /me is planning to spend more
>>> thoughts on this the next days.
>>
>> OK, done, rtdm_{event,sem,mutex}_init are now protected by the nklock in
>> trunk. This should make the in-place re-initialisation of RTDM IPC
>> objects race-free and allow to use them in RT-CAN as originally
>> intended. I think I will back-port that pieces also to v2.3.x later.
>>
>> What patch should now go in to avoid double init/destroy and fix
>> rtcan_virt?
> 
> Attached. Thanks.
> 

Just applied to trunk.

To avoid lock nesting where possible, I reordered some code in
rtcan_raw_sendmsg. Please re-check if I messed anything up. Then I could
commit to stable, too.

Jan


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