http://cr.openjdk.java.net/~vlivanov/8057020/webrev.00/ https://bugs.openjdk.java.net/browse/JDK-8057020
There are 2 major LambdaForm caches: LambdaFormEditor-based and MethodTypeForm. The former is per-LambdaForm and the latter is per method type erased to basic types. The problem is that these caches don't support eviction, so they can hold LambdaForms forever.
Usually, it's not a problem since an application has very limited number of unique erased method types (e.g. on Octane/Nashorn it varies 1,5-3k shapes).
The fix is to use SoftReferences to keep LambdaForms alive as long as possible, but avoid throwing OOME until the caches are evicted. I experimented with WeakReferences, but it doesn't hold LambdaForms for long enough: LambdaForm cache hit rate degrades significantly and it negatively affects application startup and warmup, since every instantiated LambdaForm is precompiled to bytecode before usage.
Testing: jdk/java/lang/invoke/LFCache in stress mode + jck (api/java_lang/invoke), jdk/java/lang/invoke, jdk/java/util/streams, octane
Thanks! Best regards, Vladimir Ivanov
