Hi Joel, I see, there is a dilema how to cache type annotations. To satisfy single-annotation-returning methods and repeating annotation logic, a HashMap would be a logical choice, but it has much bigger footprint than simple arrays of annotations...
I experimented with an idea of using a special purpose immutable Map implementation: https://github.com/plevart/jdk8-tl/blob/anno-map/jdk/src/share/classes/sun/reflect/annotation/UniqueIndex.java and: https://github.com/plevart/jdk8-tl/blob/anno-map/jdk/src/share/classes/sun/reflect/annotation/AnnotationMap.java This is just a preview. I still have to create some tests to see how it compares to HashMap. Being an immutable wrapper for a single array of annotations it has a nice feature that a reference to it can be passed to other threads via a data race with no danger of data inconsistency, which simplifies caching mechanisms and helps scalability. Might even be a space-saving replacement for existing HashMaps of annotations. Depending on performance, of course. What do you think? Is it worth pursuing this further? Regards, Peter On Jan 17, 2013 5:24 PM, "Joel Borggrén-Franck" <joel.fra...@oracle.com> wrote: > Hi, > > Here is a webrev for core reflection support for type annotations: > > http://cr.openjdk.java.net/~jfranck/8004698/webrev.00/ > > This code is based on the tl/jdk repository, but in order to run the tests > you need a javac with type annotations support and also a recent copy of > the VM that includes this change set: > http://hg.openjdk.java.net/hsx/hotspot-main/hotspot/rev/35431a769282(This > also means this code can't be pushed until all supporting pieces are > in place.) > > Type annotations are still a bit of a moving target so there will be > follow up work on this. There is no caching of annotations in this version > and I am not sure how we want to do the space/time trade of for type > annotations. > > cheers > /Joel
