ModuleLayer.Controller strongly references Module

[Alan Bateman]

On 28/11/2021 22:29, Michał Kłeczek wrote:
> :
> It looks like ML.Controller.addExport(source, pn, target) does not update the target module ClassLoader view of exported packages in the default ClassLoader implementation (jdk.internal.loader.Loader).
> What is the reasoning behind such implementation? I am wondering now how useful Controller.addExport() really is...
>
The addXXX methods are about accessibility. In the case of addExports 
then maybe you want to export an internal package so that code in a 
module in the child layer can make use of (via reflection) public 
classes in that package.

You are right that the addXXX methods doesn't do any magic for 
visibility. For super advanced cases where someone is using their own 
class loaders then they need to ensure that the class loader delegation 
supports the readability graph. Same thing when they use addExports 
where they may need to their class loaders to adjust their delegation to 
support changes at run-time.

-Alan