On Wed, 7 Apr 2021 14:31:05 GMT, Richard Reingruber <rr...@openjdk.org> wrote:
>> I removed that line, not sure if the comment needs additional fixing. > > I think David requested updating of the comment for > `JavaThread::java_suspend_self_with_safepoint_check()`. > > I hope to delete the whole method soon and build on the new suspend > mechanism, if Robbin is ok with that. For now I'd like to propose the > following: > > // Wait for another thread to perform object reallocation and relocking on > behalf of > // this thread. > // Raw thread state transition to _thread_blocked and back again to the > original > // state before returning are performed. The current thread is required to > // change to _thread_blocked in order to be seen to be safepoint/handshake > safe > // whilst suspended and only after becoming handshake safe, the other thread > can > // complete the handshake used to synchronize with this thread and then > perform > // the reallocation and relocking. We cannot use the thread state transition > // helpers because we arrive here in various states and also because the > helpers > // indirectly call this method. After leaving _thread_blocked we have to > check > // for safepoint/handshake, except if _thread_in_native. The thread is safe > // without blocking then. Allowed states are enumerated in > // SafepointSynchronize::block(). See also EscapeBarrier::sync_and_suspend_*() Thanks! ------------- PR: https://git.openjdk.java.net/jdk/pull/3191
