Sergei Golubchik wrote:
> Hi, Jay!
>
> On May 12, Jay Pipes wrote:
>>> However, do you know of any other interfaces that work this way? I am
>>> personally not aware of any other, but then I don't know every corner
>>> of the code like Serg does. :)
>> "External" interfaces? See all the plugin "interfaces". There's no
>> enforcement of types really at all. Just passing void *'s around.
>
> Where ? Plugin interfaces don't pass void* around much.
> They do it in two places (that I remember out of my head):
> - init() function. Brian added that to pass handlerton down.
> it is ignored by any clean plugin API and should've been done
> differently for storage engines and I_S tables.
>
> - MYSQL_THD is defined as void*, which is fine as it's an opaque
> pointer, plugins are never expected to look inside to cast it to
> anything.
>
>> As for the internal interfaces, I would suggest cleaning up the class
>> interfaces of THD, JOIN, and other major classes to enforce public
>> accessors and getters, protecting private member variables behind a clean
>> API. This would, eventually, make some of these classes semi-usable in
>> public interfaces.
>
> We don't have public interfaces for them (besides few thd_* accessors
> functions) in plugin.h. And doubt that we want to have them.
> We're working on new APIs to access these objects, instead of putting
> lipstick on old ones.
>
>> Another thing to think about in your refactoring efforts is detaching the
>> THD from its current inheritance from Statement, Query_arena and ilink.
>> Without doing this, and using encapsulation so that a THD can have multiple
>> Statements, it will be very difficult to work on any future parallelization
>> efforts.
>
> You mean, a Statement can have multiple THDs, I suppose :)
...or many threads (not THDs) per Statement if you ever asked me.
Thanks,
Roy
