On Nov 3, 2013, at 1:07 PM, Niko Matsakis wrote: > > In any case, Brendan's e-mail suggesting tenuring weakly referenced > objects offered one possible workaround for maintaining top nursery > performance in the face of weak refs. (I have no idea, of course, if > this is what the JVM does.) >
Tenured (if by that you mean stays around until an exhaustive GC) seems somewhat contrary to the whole point of using a weak map. Many apps may never trigger that level of GC in which case using a WeakMap (even with explicit deletes) under that policy would actually be worse than using a regular Map. But the basic concept isn't all that crazy. One of the advantages of having a hierarchy of generations is that you can apply different policies at different levels of the hierarchy (in my experience an Ungar GS-style configuration is too simplistic). For example, in the nursery you might treat WeakMaps as having strong reference and also any remembered set entries into the nursery also as strong references. Hence, little, if any, WeakMap overhead needed to scavenge the nursery. Allen _______________________________________________ dev-tech-js-engine-internals mailing list dev-tech-js-engine-internals@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-tech-js-engine-internals
