On Sat, 21 Feb 2026 08:01:48 GMT, Serguei Spitsyn <[email protected]> wrote:
>> The `interp-only` mechanism is based on the `JavaThread` objects. Carrier >> and virtual threads can temporary share the same `JavaThread`. The >> `java_thread->jvmti_thread_state()` is re-linked to a virtual thread at >> `mount` and to the carrier thread at `unmount`. The `JvmtiThreadState` has a >> back link to the `JavaThread` which is also set for virtual thread at a >> `mount` and carrier thread at an `unmount`. Just one of these two links at >> the same time is set to the `JavaThread`, the other one has to be set to >> `nullptr`. The `interp-only` mechanism needs this invariant. >> However, there is a corner case when this invariant is broken. It happens >> when the `JvmtiThreadState` for carrier thread has just been created. In >> such case, the link to `JavaThread` is always `non-nullptr` even though a >> virtual thread is currently mounted on a carrier thread. This simple update >> fixes the issue in the `JvmtiThreadState` ctor. >> >> Also, this update the includes the `interp_only` implementation >> simplifications and more asserts are added to relevant places. One of the >> simplification is a removal of the field `JvmtiThreadState::_thread_saved`. >> >> Testing: >> - TBD: Mach5 tiers 1-6 > > Serguei Spitsyn has updated the pull request incrementally with one > additional commit since the last revision: > > review: restore assert, will remove it as a separate bug fix I've pushed one more update converting a couple of runtime checks into asserts. Those were discussed in a walk through with @alexmenkov . ------------- PR Comment: https://git.openjdk.org/jdk/pull/29436#issuecomment-3954255182
