On Mon, 24 Mar 2025 20:49:25 GMT, Frederic Parain <[email protected]> wrote:
> Strict final instance fields are not subject to concurrent writes during a > read access, so they can be flattened even if they are nullable and bigger > than 64 bits. The NULLABLE_NON_ATOMIC_FLAT layout is added for this > particular case. > This new layout can also be used in the special case of nullable empty value > classes, because their payload contains a single entry, the null-marker, > which is naturally atomic. src/hotspot/share/classfile/classFileParser.hpp line 101: > 99: _non_atomic_size_in_bytes(-1), > _non_atomic_alignment(-1), > 100: _atomic_layout_size_in_bytes(-1), > _nullable_atomic_layout_size_in_bytes(-1), > 101: _nullable_non_atomic_layout_size_in_bytes(-1), Do we need `nullable_non_atomic_alignment`, similar to `non_atomic_alignment`. Besides, it may be better to rename the `null_free` fields, too. ------------- PR Review Comment: https://git.openjdk.org/valhalla/pull/1407#discussion_r2678654545
