On Tue, 30 Nov 2021 11:25:48 GMT, Roman Kennke <rken...@openjdk.org> wrote:
>> The caches in ObjectStreamClass basically map WeakReference<Class> to >> SoftReference<ObjectStreamClass>, where the ObjectStreamClass also >> references the same Class. That means that the cache entry, and thus the >> class and its class-loader, will not get reclaimed, unless the GC determines >> that memory pressure is very high. >> >> However, this seems bogus, because that unnecessarily keeps ClassLoaders and >> all its classes alive much longer than necessary: as soon as a ClassLoader >> (and all its classes) become unreachable, there is no point in retaining the >> stuff in OSC's caches. >> >> The proposed change is to use WeakReference instead of SoftReference for the >> values in caches. >> >> Testing: >> - [x] tier1 >> - [x] tier2 >> - [x] tier3 >> - [ ] tier4 > > Roman Kennke has updated the pull request with a new target base due to a > merge or a rebase. The incremental webrev excludes the unrelated changes > brought in by the merge/rebase. The pull request contains six additional > commits since the last revision: > > - Merge remote-tracking branch 'jdk-plevart/JDK-8277072-peter' into > JDK-8277072 > - Use ClassValue to solve JDK-8277072 > - Use ForceGC instead of System.gc() > - Convert test to testng > - Fix indentation of new testcase > - 8277072: ObjectStreamClass caches keep ClassLoaders alive ...I think that you could remove now obsolete java.io.ObjectStreamClass.EntryFuture nested class. It's not used any more. It would be nice to follow-up this patch with patches that make use of ClassValue also for: - java.io.ObjectInputStream.Caches#subclassAudits - java.io.ObjectOutputStream.Caches#subclassAudits ...this way the common static machinery like: - java.io.ObjectStreamClass#processQueue - java.io.ObjectStreamClass.WeakClassKey ...could get removed as it is not used in ObjectStreamClass any more. ------------- PR: https://git.openjdk.java.net/jdk/pull/6375
