Re: [Xenomai-core] [Xenomai-git] Jan Kiszka : Make xnarch_init_timeconv an uninlined weak function

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

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Gilles Chanteperdrix wrote:
> Jan Kiszka wrote:
>> Gilles Chanteperdrix wrote:
>>> Jan Kiszka wrote:
>>>> Gilles Chanteperdrix wrote:
>>>>> Jan Kiszka wrote:
>>>>>> Gilles Chanteperdrix wrote:
>>>>>>> Jan Kiszka wrote:
>>>>>>>> Gilles Chanteperdrix wrote:
>>>>>>>>> GIT version control wrote:
>>>>>>>>>> Module: xenomai-jki
>>>>>>>>>> Branch: for-upstream
>>>>>>>>>> Commit: 6b40653e9c3c4a2433bb4e91344fc378eb860f75
>>>>>>>>>> URL:    http://git.xenomai.org/?p=xenomai-jki.git;a=commit;h=6b40653e9c3c4a2433bb4e91344fc378eb860f75
>>>>>>>>>>
>>>>>>>>>> Author: Jan Kiszka <jan.kiszka@domain.hid>
>>>>>>>>>> Date:   Wed Feb 10 13:24:29 2010 +0100
>>>>>>>>>>
>>>>>>>>>> Make xnarch_init_timeconv an uninlined weak function
>>>>>>>>>>
>>>>>>>>>> Otherwise the wrong set of time conversion variables might get
>>>>>>>>>> initialized when using > 1 skin libraries.
>>>>>>>>> If that would be possible, then it is the conversion variables which
>>>>>>>>> should made be weak, not the function.
>>>>>>>>>
>>>>>>>>> The way I see it, the posix and native skins currently get a different
>>>>>>>>> set of variables and functions, which works, but with your change, since
>>>>>>>>> there is only one function, only one set of variable gets initialized by
>>>>>>>>> the two function calls. And one skin just broke.
>>>>>>>>>
>>>>>>>>> Or am I missing something? Does the patch fix a problem you really had?
>>>>>>>> Frankly, I wasn't able to test in the field yet as replacing the libs
>>>>>>>> there is non-trivial. But I was able to observe that only one set of
>>>>>>>> functions is used - which is logical considering the weak marks. And
>>>>>>>> this breaks due to the static inline initialization.
>>>>>>>>
>>>>>>>> However, let's mark both functions and variables weak to fix the issue
>>>>>>>> and avoid leaving unused variables around. Will update my patch in a minute.
>>>>>>> Ok. I am reverting this patch until you provide me with another
>>>>>>> solution. It causes latency to segfault purely and simply at startup on
>>>>>>> my dual PIII.
>>>>>>>
>>>>>> Cannot reproduce yet. Do you have a backtrace?
>>>>> No. But the problem is probably the same as the one signaled by Henri,
>>>>> a misplaced weak directive ending up in a symbol with no address at all.
>>>>> Since the current situation works, I am going to wait for the "clean"
>>>>> fix which puts some code/data in the src/skins/common directory.
>>>>>
>>>> Find it in my tree. But it's not yet well tested.
>>> I do not like it either. Functions which are in src/skins/common should
>>> still be weak, since this lib is included in all the skins libraries.
>> Those functions are now in libxeno_common only, so I see no point in
>> allowing them to be overloaded.
> 
> Yes, but libxeno_common is included in libpthread_rt.so and
> libnative.so. So, if you link with both libraries, you get
> libxeno_common twice.
> 

Do we link libxeno_common statically? Otherwise, this conflict is not
logical to me. Also, there are other symbols in bind.c that are non-weak.

Jan


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