RFR(S): 8146096: [TEST BUG] compiler/loopopts/UseCountedLoopSafepoints.java Timeouts

[Vladimir Ivanov]

As an idea to improve the test: spawn a thread which executes the 
counted loop and then use WhiteBox.forceSafepoint() to trigger a safepoint.

If the test times out, it means there's no safepoint in the loop.

Also, it also simplifies the implementation - no need to spawn a child 
process, the check can be done in-process.

Best regards,
Vladimir Ivanov

On 1/19/16 3:32 PM, Andreas Eriksson wrote:
> Hi,
>
> Can I please have a review for the removal of
> hotspot/test/compiler/loopopts/UseCountedLoopSafepoints.java.
>
> The test needs to do a loop that takes more than two seconds to execute
> fully without doing a safepointing call. For this expensive atomic
> operations were used. The problem is that on certain embedded platforms
> they are too expensive, and the test times out.
> The loop length could probably be reduced, and it should still work on
> faster machines. However, the test is not very useful, so I think it's
> better to just remove it to avoid future problems.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8146096
> Test to be removed:
> http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/file/d84a55e7aaf8/test/compiler/loopopts/UseCountedLoopSafepoints.java
>
> (I can create a webrev if you think it necessary.)
>
> Thanks,
> Andreas