On Thu, 3 Jul 2025 04:27:13 GMT, David Holmes <dhol...@openjdk.org> wrote:
> Okay - still took me a little while to understand the double-indirection of > the "tail ptr" in `add`, but I get it now. So looking at the acquire/release > requirements: > > * all additions are done with `cmpxchg` which is effectively a > release-store > > * when you iterate the list all loads of the "next" agent must be a > load-acquire, this means > > * when you create the iterator you need a load-acquire (which you have > when you pass `head()` ) > * In `Iterator::next()` you need a load-acquire on each read of the > `_next` field which is most simply done by defining `JvmtiAgent::next()` as a > load-acquire and using that in the iterator code instead of direct field > access. > > * `JvmtiAgent::set_next` should be a release-store though as far as I can > see it is not used. Thank you for the detailed analysis. Updated as suggested. ------------- PR Comment: https://git.openjdk.org/jdk/pull/26083#issuecomment-3033349842
