> From: Alan Bateman <alan.bate...@oracle.com>
> To: Thomas Watson/Austin/IBM@IBMUS, jigsaw-dev@openjdk.java.net
> Date: 03/09/2017 10:07 AM
> Subject: Re: Controller ensureInLayer is slow when using addReads/
> addOpens for Layers with large numbers of modules
>
> There wasn't any text in your mail (don't know if this was intentional
> or not).
>
> In any case, this is trivially improved, it just hasn't come up before,
> probably because the Controller API is somewhat niche.
>
> -Alan
>
Sorry, my mail system adds stuff that the mailing list doesn't like, let
me try this again:
The Controller ensureInLayer method has this.
private void ensureInLayer(Module source) {
if (!layer.modules().contains(source))
throw new IllegalArgumentException(source + " not in
layer");
}
The implementation of Layer.modules() is terribly expensive when trying to
collect the complete set of modules only to perform a contains check. Can
this be changed to something more simple like this:
private void ensureInLayer(Module source) {
if (!layer.equals(source.getLayer()))
throw new IllegalArgumentException(source + " not in
layer");
}
It also seems like Layer.modules() should be optimized since the set of
modules never changes for a Layer instance. But that method has to do a
new set collection each call.
Tom
