On Sat, 3 Jun 2023 07:09:54 GMT, Alan Bateman <al...@openjdk.org> wrote:
> Would it be possible to expand a bit on why jdk.trackAllThreads is needed? I > would have expected jdb "threads" command to be sensitive to whether the > debuggee is launched with the JDWP includevirtualthreads option but > jdk.trackAllThreads isn't used by the JDWP agent, it is instead used to > determine if virtual threads created directly with the Thread API show up in > thread dumps or not. I think you are right that this change should not be needed. I was working on addressing a number of different issues with launching debuggees properly and the tests being able to discover virtual threads, and I think maybe I had done this "fix" at some point, and then did [JDK-8309334](https://bugs.openjdk.org/browse/JDK-8309334), (and [JDK-8309396](https://bugs.openjdk.org/browse/JDK-8309396)), and thought that this fix was still needed. I thought for sure it was helping, but I've removed it and the tests still seem to pass with just JDK-8309334 and JDK-8309396. jdb by default does not track all virtual threads. It does have a a `-trackallthreads` command line option, which triggers passing `includevirtualthreads=y` to the debug agent (assuming jdb is actually doing the launching and not just attaching). However, given that these tests do not pass `includevirtualthreads=y`, I didn't find myself wondering how they were passing after just fixing [JDK-8309334](https://bugs.openjdk.org/browse/JDK-8309334). The answer is that jdb does track any virtual thread that it gets an event for, so as it turns out when these 4 jdb tests look for a specific thread in the `threads` output, it's always a thread that jdb already learned about via an event. I might do a separate PR just to force either `-trackallthreads` or `includevirtualthreads=y`, but currently that doesn't seem to be needed by any of the jdb tests. So I think I should close this PR and update the [JDK-8309334](https://bugs.openjdk.org/browse/JDK-8309334) PR to remove the 3 tests that seem to pass with it and don't also need this PR to pass. The 4th test `com/sun/jdi/JdbMethodExitTest.java` needs an additional fix that I need to push separately. ------------- PR Comment: https://git.openjdk.org/jdk/pull/14293#issuecomment-1575129126
