Re: RFR: 8261954: Dependencies: Improve iteration over class hierarchy under context class
On Thu, 18 Feb 2021 17:05:08 GMT, Vladimir Ivanov <[hidden email]> wrote:
> Simplify `ClassHierarchyWalker::find_witness_anywhere()` which iterates over class hierarchy under context class searching for witnesses.
> Current implementation traverses the hierarchy in a breadth-first manner and keeps a stack-allocated array to keep a worklist.
> But all the subclasses are already part of a singly linked list formed by `Klass::subklass()`/`next_sibling()`/`superklass()`.
> Proposed refactoring gets rid of the explicit worklist and switches to the traversal over the linked list (encapsulated into `ClassHierarchyIterator`). It performs depth-first pre-order hierarchy traversal.
> (There are some other minor refactorings applied in `ClassHierarchyWalker` along the way.)
> - [x] hs-tier1 - hs-tier8
> - [x] additional verification that CHA decisions aren't affected