RFR [8038982]: java/lang/ref/EarlyTimeout.java failed again

[Brent Christian]

Hi, Ivan

This sounds like an issue we saw in FX a while ago with imprecise timers 
on Windows.  If it is, you might check out:

https://bugs.openjdk.java.net/browse/JDK-6435126

It describes a workaround to enable higher-precision timing on Windows 
(using a long-sleeping daemon thread).  That might be a third 
alternative solution...

-Brent

On 4/14/14 6:21 AM, Ivan Gerasimov wrote:
> Hello!
>
> The test EarlyTimeout.java failed again, now with message "elapsed time
> 981 is less than timeout 1000."
>
> The root cause seems to be non-accurate time measurement in Windows:
> http://msdn.microsoft.com/en-us/library/windows/desktop/ms724397(v=vs.85).aspx
>
>
> Because of this we can achieve this result:
> long start1 = System.currentTimeMillis();
> long start2 = System.nanoTime();
> ~~~~~~~~
> long elapsed2 = (System.nanoTime() - start2) / 1000000;
> long elapsed1 = System.currentTimeMillis() - start1;
>
> assert elapsed2 < elapsed1; // can fail
>
>
> There might be two ways to address the issue:
> - add a tolerance > 15 ms, or
> - use System.nanoTime() for the measurement.
>
> I did both.
>
> Would you please help review the test fix?
>
> BUGURL: https://bugs.openjdk.java.net/browse/JDK-8038982
> WEBREV: http://cr.openjdk.java.net/~igerasim/8038982/0/webrev/
>
> Sincerely yours,
> Ivan