On Wed, 18 Oct 2023 18:20:49 GMT, Stuart Marks <sma...@openjdk.org> wrote:
>> test/jdk/javax/rmi/ssl/SSLSocketParametersTest.java line 77:
>>
>>> 75:
>>> 76: public void testRmiCommunication(RMIServerSocketFactory
>>> serverFactory) throws Exception {
>>> 77: Hello stub = (Hello)UnicastRemoteObject.exportObject(new
>>> HelloImpl(),
>>
>> by not retaining an explicit reference to the test rmi server, you are
>> exposing it to potentially being GCed during the test execution and
>> potentially prior to client invocation... this might sound fanciful but
>> this has been observed in a few scenarios due to the GC changes ...
>> althought it doesn't seem to have been an issue, the structure of the test
>> appears to be inherently racy, with the potential for the client invocation
>> to getting ahead of the server with the rmi server launching background
>> threads.
>> Anyways, caution on not retaining a sever reference and GC interference.
>
> Yes, this can still happen even if the reference to the server object is held
> in a local variable. It's unlikely to occur, but to prevent any possibility
> of unexpected GC, you need to use reachabilityFence. Something like:
>
> HelloImpl server = new HelloImpl();
> try {
> // ... use server ...
> } finally {
> Reference.reachabilityFence(server);
> }
>
> I would go ahead and add this out of an abundance of caution.
yes, good advice on reachability fence ... added some -Xcomp args to test runs
and no failures detected
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/14932#discussion_r1364479317
