On Mon, 14 Sep 2020 04:57:21 GMT, David Holmes <dhol...@openjdk.org> wrote:
>> Hi, >> >> this is the continuation of the review of the implementation for: >> >> https://bugs.openjdk.java.net/browse/JDK-8227745 >> https://bugs.openjdk.java.net/browse/JDK-8233915 >> >> It allows for JIT optimizations based on escape analysis even if JVMTI >> agents acquire capabilities to access references >> to objects that are subject to such optimizations, e.g. scalar replacement. >> The implementation reverts such >> optimizations just before access very much as when switching from JIT >> compiled execution to the interpreter, aka >> "deoptimization". Webrev.8 was the last one before before the transition to >> Git/Github: >> >> http://cr.openjdk.java.net/~rrich/webrevs/8227745/webrev.8/ >> >> Thanks, Richard. > > src/hotspot/share/compiler/compileBroker.cpp line 831: > >> 829: MonitorLocker ml(dt, EscapeBarrier_lock, >> Mutex::_no_safepoint_check_flag); >> 830: static int single_thread_count = 0; >> 831: enter_single_loop = single_thread_count++ < >> DeoptimizeObjectsALotThreadCountSingle; > > The update to `single_thread_count` is not atomic. I think it is atomic because it is never accessed without holding EscapeBarrier_lock ------------- PR: https://git.openjdk.java.net/jdk/pull/119
