[Qt-creator] Couple of questions about the design of Qt Creator

[Elvis Stansvik]

2017-09-10 13:58 GMT+02:00 André Pönitz <apoenitz at t-online.de>:
> On Sun, Sep 10, 2017 at 11:31:58AM +0200, Elvis Stansvik wrote:
>> As soon as I hit send, I realized I have a third question:
>>
>> 3. Communication Between Plugins:
>>
>> There seems to be two main mechanisms through which plugins
>> communicate: Either objects that implement shared interfaces are added
>> to the plugin manager object pool and picked up by downstream or
>> upstream plugins (in the top-down or bottom-up phase of plugin
>> initialization, respectively), or a singleton instance is acquired and
>> calls made on it.
>>
>> Is the former approach used when dependants provide functionality to
>> their dependees (which are unknown), and the latter approach used when
>> dependees use their dependants (which are known)? Is that the deciding
>> factor?
>
> I am not sure there is a strict deciding factor or even policy.
> There are certainly historical and personal aspects involved.
>
> The object pool has some systematic quadratic behaviour built-in,

The quadratic behavior, do you mean when a plugin is destroyed and it
calls removeObject(..) for each of it's auto-released object in
d->addedObjectsInReverseOrder (which could possibly be many)?. Or are
there other inherently quadratic operations on the pool?

Elvis

> so even if it is still ok, it won't scale arbitrarily. So I am
> trying to reduce it's use in well-known cases where one side
> depends on the other anyway, e.g. replace various factories
> hat so far ended up in the pool with explicit registration of
> their upstream users, and only use the pool where it's flexibility
> is really needed.
>
> Andre'