On Mon, 17 Jun 2024 13:00:11 GMT, Alan Bateman <al...@openjdk.org> wrote:
>> test/hotspot/jtreg/serviceability/dcmd/thread/PrintMountedVirtualThread.java >> line 43: >> >>> 41: public void run(CommandExecutor executor) throws >>> InterruptedException { >>> 42: var shouldFinish = new AtomicBoolean(false); >>> 43: var started = new AtomicBoolean(); >> >> Not sure how this change make things better? Why would we want to sleep and >> poll rather than park until signalled? > > `started.countDown()` is replaced with `started.set(true)` to remove the > possibility that "Dummy Vthread" unmounts here. @AlanBateman explained to me why that is possible in https://github.com/openjdk/jdk/pull/19482#issuecomment-2166116062 and https://github.com/openjdk/jdk/pull/19482#issuecomment-2167374446. Alan can correct me if I'm wrong, but I think that the dummy thread trying to unpark the main (virtual) thread needs to run as the carrier to avoid nested parking. See: https://github.com/openjdk/jdk/blob/412e306d81209c05f55aee7663f7abb80286e361/src/java.base/share/classes/java/lang/VirtualThread.java#L707 ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/19744#discussion_r1642814467