On 3/18/20 12:48 PM, Igor Ignatyev wrote:
Hi Leonid,
I've started looking at your webrev, and so far have a couple questions:
Test
vmTestbase/nsk/jdi/ObjectReference/referringObjects/referringObjects003/referringObjects003a.java
was updated to don't use Wicket. (The lock has a reference to thread which
affects test.)
can't you use just a volatile boolean field?
I can, but I don't see any benefits to use volatile fields instead of
atomics. I prefer to use Atomic* anywhere because of it's clearer
semantics. Using of explicit get/set and other similar accessors.
Wicket "finished" in class ThreadsRunner was changed to atomicInt/sleep to
avoid OOME in j.u.c.l.Condition::await() which might happened in stress GC tests.
won't j.u.c.CountDownLatch be more appropriate and cleaner solution here?
Unfortunately no. The CountDownLatch would be a nice solution but it is
possible to get OOME in gc/lock (might be other) tests. I replaced
Wicked by the same reason. Updating the AtomicInteger doesn't allocate
any memory and don't cause OOME.
Leonid
I need more time to get grasp of Wicket and your changes in it; will come back
to you after I understand them.
-- Igor
On Mar 18, 2020, at 12:37 PM, Leonid Mesnik <[email protected]> wrote:
Hi
Could you please review following fix which slightly refactor vmTestbase stress
test harness. This refactoring helps to add virtual threads testing support.
The Wicket uses plain sync/wait/notify mechanism which cause carrier thread
starvation and should not be used in virtual threads. The ManagedThread is a
subclass of Thread so it couldn't be virtual thread.
Following fix changes Wicket to use locks/conditions to don't pin vthread to
carrier thread while starting testing.
ManagedThread is fixed to keep execution thread as the thread variable and
isolate it's creation.
Test
vmTestbase/nsk/jdi/ObjectReference/referringObjects/referringObjects003/referringObjects003a.java
was updated to don't use Wicket. (The lock has a reference to thread which
affects test.)
Wicket "finished" in class ThreadsRunner was changed to atomicInt/sleep to
avoid OOME in j.u.c.l.Condition::await() which might happened in stress GC tests.
webrev: http://cr.openjdk.java.net/~lmesnik/8241123/webrev.00/
bug: https://bugs.openjdk.java.net/browse/JDK-8241123
Leonid
