RFR [14] 8151678: com/sun/jndi/ldap/LdapTimeoutTest.java failed due to timeout on DeadServerNoTimeoutTest is incorrect

[Martin Buchholz]

I took another look at LdapTimeoutTest.java.

I was surprised to see RIGHT_MARGIN.  In jsr166 we succeed in having one
timeout that is long enough to "never happen".  I'm still advocating the 10
second value.

I was surprised to see LEFT_MARGIN.  We just fixed Thread.sleep, so we have
no known problems with JDK methods returning early - you can trust timed
get!
You start measuring, by calling nanoTime, before you start the activity you
are measuring, so there should be no need for LEFT_MARGIN.

We have some fresh thread-awaiting code here:
http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/test/tck/JSR166TestCase.java?view=markup#l1443

Instead of communicating startTime from the test thread back to the main
thread, I would do my loMillis checking in the test thread, and hiMillis
checking in the main thread, like e.g. compare with a fresh test
method testTimedOffer
http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/test/tck/ArrayBlockingQueueTest.java?view=markup#l394

Timeouts should be adjusted via Utils.adjustTimeout


On Fri, Sep 6, 2019 at 4:31 AM Pavel Rappo <pavel.rappo at oracle.com> wrote:

> Martin, thanks for having a look at it.
>
> I'd appreciate if you could have a look at the timeout measuring mechanics
> in assertCompletion/assertIncompletion specifically, maybe to spot
> something that is grossly inadequate.
>
> I tried to accommodate some usual suspects of timeout measurements
> failures. I understand that since we're not working with real-time systems,
> my attempts to build bullet-proof measurement mechanics are futile.
>
> -Pavel
>
> > On 30 Aug 2019, at 18:19, Martin Buchholz <martinrb at google.com> wrote:
> >
> > Not really a review, but:
> >
> > For many years we've been using 10 seconds (scaled by timeout factor) as
> a duration long enough that a timeout is a real failure.
> > Which is close to your own 20 seconds.  Of course, no value is surely
> safe.
> >
> > Probably, parallel testing infrastructure for timeouts should be a test
> library method.  I do something similar in JSR166TestCase
> >
> >     /**
> >      * Runs all the given actions in parallel, failing if any fail.
> >      * Useful for running multiple variants of tests that are
> >      * necessarily individually slow because they must block.
> >      */
> >     void testInParallel(Action ... actions) {
> >         ExecutorService pool = Executors.newCachedThreadPool();
> >         try (PoolCleaner cleaner = cleaner(pool)) {
> >
> > On Fri, Aug 30, 2019 at 6:23 AM Daniel Fuchs <daniel.fuchs at oracle.com>
> wrote:
> > On 30/08/2019 13:54, Pavel Rappo wrote:
> > > Updated,
> > >
> > >      http://cr.openjdk.java.net/~prappo/8151678/webrev.01/
> > >
> >
> > Changes look good!
> >
> > best regards,
> >
> > -- daniel
>
>