On Tue, 23 Sep 2025 23:21:30 GMT, Serguei Spitsyn <[email protected]> wrote:
>>> Can you please explain why this change is required? Doesn't >>> 'invalidate_cur_stack_depth' make sense only when interp_only mode is >>> enabled for the threads only? >> >> This is a right question to ask, thanks. I agree this confusing. The issue >> is with the pure continuations which are executed not in a context of a >> virtual thread. Without this check the following test is stably failed: >> >> test/hotspot/jtreg/serviceability/jvmti/vthread/ContStackDepthTest >> >> I'm currently kind of puzzled on how to make this check better. > >> It seems odd to me that a method called invalidate_jvmti_stack() sometimes >> doesn't invalidate the stack. Even before this change it was not >> invalidating unless it was in interp_only mode, which also seems odd. If the >> cached value is not used for compiled frames, why bother with the >> interp_only check? > > I can rename this function to `cond_ invalidate_jvmti_stack()` if you want. > The `interp_only` check is needed for optimization to avoid a performance > overhead of current stack depth invalidation. I was thinking a lot on how to get rid of this current stack depth recalculation mechanism used in `interp_only` mode but have not come with a good approach yet. We have a constant trouble from this mechanism needed for debugger optimization purposes. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/27403#discussion_r2373667768
