On Fri, 3 Sep 2021 14:41:45 GMT, Vladimir Ivanov <vliva...@openjdk.org> wrote:
>> `MethodHandle.asTypeCache` keeps a strong reference to adapted >> `MethodHandle` and it can introduce a class loader leak through its >> `MethodType`. >> >> Proposed fix introduces a 2-level cache (1 element each) where 1st level can >> only contain `MethodHandle`s which are guaranteed to not introduce any >> dependencies on new class loaders compared to the original `MethodHandle`. >> 2nd level is backed by a `SoftReference` and is used as a backup when the >> result of `MethodHandle.asType()` conversion can't populate the higher level >> cache. >> >> The fix is based on [the >> work](http://cr.openjdk.java.net/~plevart/jdk9-dev/MethodHandle.asTypeCacheLeak/) >> made by Peter Levart @plevart back in 2015. >> >> Testing: tier1 - tier6 > > Vladimir Ivanov has updated the pull request incrementally with one > additional commit since the last revision: > > Address review comments I don't have a strong opinion on whether this should use a SoftReference or a WeakReference. (In fact, one might say that I have a phantom opinion.) The main thing was that the bug report mentioned WeakReference but the commit here uses SoftReferences, and I didn't see any discussion about this change. You gave some reasons above for why SoftReference is preferable, and that's ok with me. ------------- PR: https://git.openjdk.java.net/jdk/pull/5246