3.7.1: uninferredTypeArgumentScanner consumes significant amount of memory in AnnotatedTypeMirror

[vlsi]

Apparently, verification of Calcite codebase requires to bump -Xmx to 2g or something like that, and it turns out noticeable memory is taken by SimpleAnnotatedTypeScanner:

checker-framework/framework/src/main/java/org/checkerframework/framework/type/AnnotatedTypeMirror.java

Lines 813 to 820 in 9dbf0c7

	/** The implementation of the visitor for #containsUninferredTypeArguments. */
	private final SimpleAnnotatedTypeScanner<Boolean, Void> uninferredTypeArgumentScanner =
	new SimpleAnnotatedTypeScanner<>(
	(type, p) ->
	type.getKind() == TypeKind.WILDCARD
	&& ((AnnotatedWildcardType) type).isUninferredTypeArgument(),
	Boolean::logicalOr,
	false);

Could it be a static instance and/or ThreadLocal?

NullnessAnnotatedTypeFactory consumed ~50MiB

~ 50% of that was consumed by empty IdentityHashMap in SimpleAnnotatedTypeScanner

There are 72226 SimpleAnnotatedTypeScanner instances which are referenced from AnnotatedTypeMirror$... classes

[smillst]

Thanks for tracking this down! I opened #3852 which clears the IdentityHashMap as soon as possible. That should help, but I haven't tested it.