On Fri, 5 Nov 2021 15:38:27 GMT, Daniel D. Daugherty <dcu...@openjdk.org> wrote:
>> Should the ThreadsListHandle protect JvmtiThreadState::first also? If >> state->next() needs it why doesn't the first entry need this? There's no >> atomic load on the _head field. > > The `ThreadsListHandle` protects `JavaThread` objects not `JvmtiThreadState` > objects. > `JvmtiThreadState::first()` returns the head of the global list of > `JvmtiThreadState` > objects for the system. Each `JvmtiThreadState` object contains a > `JavaThread*` and > we have to protect use of the `JavaThread*` which can happen in the > `recompute_thread_enabled(state)` call below. JvmtiThreadState objects point to JavaThread and vice versa, so I still don't see why you don't protect the first element. ------------- PR: https://git.openjdk.java.net/jdk/pull/4677
