[debian-mysql] Bug#450535: Bug#450535: libmysqlclient16: Please version symbols differently in libmysqlclient_r and libmysqlclient

Stefan Fritsch sf at sfritsch.de
Fri Nov 9 12:16:37 UTC 2007


> The *_r and the normal version only differ in that _r is
> "reentrant"/multithreading
> ready, right?

I think so. But I don't really know that much about mysql.


>> Other suggested solutions were
>>
>> - link php-mysql to libmysqlclient_r
>
> The problem would appear soon for other applications that happen to link
> a lot of shared libraries again, or? Do you know how libpostgres, libxml
> or
> other libraries handle this case? Or if mod_auth_mysql starts using it.

I think most libraries just have a thread save version. Apr/apr-util can
be compiled both ways but the apache maintainers decided to only ship the
thread save version in Debian.

>
>> - make libmysqlclient symlink to libmysqlclient_r
>
>> but these might cause unnecessary performance degradation. (Although I
>> don't
>> know whether this is really an issue).
>
> Would that work? The performance degradation would indeed be neglible
> as most time is usually spend in the server and not in fetching the result
> data.

It would certainly not be binary compatible to other distributions. And 
mysql_config would need to be modified so that --libs includes -lthread as
--libs_r does. I don't know what else needs to be changed.

Cheers,
Stefan






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