On Tue, 7 Oct 2025 15:50:30 GMT, Mark Sheppard <[email protected]> wrote:
>> I believe that increasing the timeout might help, as it seems to be
>> happening due to the machine load. I'm going to make a pr increasing the
>> timeout to 20 from 5 (similar to what it was when timeout factor was 4).
>
> The extending of the stop duration may not have the desired effect of
> eliminating what appears to be a race condition in the test
>
> One of the recorded failures is for the temporal condition
>
> // The shutdown should take at least as long as the exchange duration
> if (elapsed < exchangeDuration.toNanos()) {
> fail("HttpServer.stop terminated before exchange completed");
> }
>
> This is a somewhat dubious constraint and can’t always be met
>
> The test assumes that the participating threads are all actively executing
> simultaneously, which may not be true
> They may be scheduled to run rather than actually running.
>
> Restating the objective of the test
> Objective: to ensure that the stop request is not processed while there are
> extant exchanges
>
> Potential race scenario:
>
> Server started creates exchange which waits for a signal to complete
>
> Exchange completion thread starts waits for 1 seconds before it can signal
> exchange to compete — the complete signal will be thus invoked sometime after
> 1 second depending on OS thread scheduling
>
> Main thread continues and invokes a stop which has a max wait time of 5
> seconds for extant exchanges to complete — so max completion time of stop is
> 5 seconds ++ i.e. could be slightly longer than 5 seconds again subject to OS
> scheduling
>
> Temporal condition imposed by test
>
> // The shutdown should take at least as long as the exchange duration
> if (elapsed < exchangeDuration.toNanos()) {
> fail("HttpServer.stop terminated before exchange completed");
> }
>
> // The delay should not have expired
> if (elapsed >= delayDuration.toNanos()) {
> fail("HttpServer.stop terminated after delay expired");
> }
>
> 1. States elapsed time of stop should be less than the duration of the
> exchange exchangeDuration. BUT exchangeDuration is not the
> duration of the exchange completion. Rather, it is the time delay before the
> exchange thread is signalled to complete.
> The actual completion of the exchange may be sometime later, again depending
> on OS thread scheduling.
>
> Second condition is that the elapsed time of the stop should be less than or
> equal to the stop delay. BUT if the full timeout for the
> stop expires as per
>
> server.stop will wait a max of N (5) seconds before terminating as per
>
> try {
> // waiting for the duration of the delay, unless released before
> finishedLatch.await(delay, TimeUnit.SECONDS);
>
> } catch (InterruptedExceptio...
@msheppar @dfuch thanks for the review! I believe it should be fixed in the
latest commit
-------------
PR Comment: https://git.openjdk.org/jdk/pull/27670#issuecomment-3389904485
