On Wed, 9 Oct 2024 22:58:33 GMT, Serguei Spitsyn <sspit...@openjdk.org> wrote:
>> This fixes a problem in the VTMS (Virtual Thread Mount State) transition >> frames hiding mechanism. >> Please, see a fix description in the first comment. >> >> Testing: >> - Verified with new test `vthread/CheckHiddenFrames` >> - Mach5 tiers 1-6 are passed > > Serguei Spitsyn has updated the pull request incrementally with one > additional commit since the last revision: > > Disallow NotifyFramePop for > enter/enter0/VirtualThread.run/VThreadContinuation.run I've pushed two updates. The first one addresses the suggestions from Leonid: - minor tweaks in new test - moved skipping hidden methods `yield()` and `yield0()` from `check_and_skip_hidden_frames()` to a separate function - explained in a comment of `JvmtiHandshake::execute()` why all VTMS transitions are disabled for platform thread - added extra safety/stability checks and a couple of asserts around calls to `check_and_skip_hidden_frames()` Second update fixes one more `NotifyFramePop` issue with the frames at the virtual thread start: - `enter()`, `enter0`, `VThreadContinuation$1.run()` and `VirtualThread.run()` This the bottom of stack trace from debugger: 0: java/lang/VirtualThread: run(Ljava/lang/Runnable;)V 1: java/lang/VirtualThread$VThreadContinuation$1: run()V 2: jdk/internal/vm/Continuation: enter0()V 3: jdk/internal/vm/Continuation: enter(Ljdk/internal/vm/Continuation;Z)V The fix includes three parts: - the `notifyJvmtiStart()`/`notifyJvmtiEnd()` notification calls are moved from `VirtualThread.run()` to the `VThreadContinuation$1.run()` - the annotation `@JvmtiMountTransition` has been added to the `VThreadContinuation$1.run()` - the `NotifyFramePop` is changed to return `JVMTI_ERRO_OPAQUE_FRAME` for frames with `enter()` and methods annotated with `@JvmtiMountTransition` ------------- PR Comment: https://git.openjdk.org/jdk/pull/21397#issuecomment-2404706773
