The fix implements support for flat value object by heapwalking API. FollowReferences/IterateThroughHeap are executed at safepoint and agent callbacks may request to set/update tags for the reported object. To store tags for flattened object at safepoint a special tag table is used (entries contain strong references to holder objects), entries from the table are converted to entries in main tag table outside of safepoint.
------------- Commit messages: - jcheck - heapwalking Changes: https://git.openjdk.org/valhalla/pull/1576/files Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1576&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8271910 Stats: 1749 lines in 6 files changed: 1405 ins; 102 del; 242 mod Patch: https://git.openjdk.org/valhalla/pull/1576.diff Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1576/head:pull/1576 PR: https://git.openjdk.org/valhalla/pull/1576
