RFR: 8367302: New test jdk/jfr/event/profiling/TestCPUTimeSampleQueueAutoSizes.java from JDK-8366082 is failing [v2]

[Andrei Pangin]

On Thu, 18 Sep 2025 14:02:53 GMT, Johannes Bechberger <jbechberger at openjdk.org> wrote:

>> This change hopefully fixes the test failures by making the test cases more resilient.
>
> Johannes Bechberger has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Simplify code

Thanks! Much better, indeed. Added a few more minor comments.

test/jdk/jdk/jfr/event/profiling/TestCPUTimeSampleQueueAutoSizes.java line 74:

> 72:         private final List<Long> timeBoxEnds = new ArrayList<>();
> 73: 
> 74:         public synchronized void addEvent(LossEvent event) {

Since the test is now single-threaded, all `synchronized` are redundant.

test/jdk/jdk/jfr/event/profiling/TestCPUTimeSampleQueueAutoSizes.java line 106:

> 104:         try (RecordingStream rs = new RecordingStream()) {
> 105:             // setup recording
> 106:             AtomicLong burstThreadId = new AtomicLong();

Does not need to be `AtomicLong`. Can be `long` and initialized right here.

test/jdk/jdk/jfr/event/profiling/TestCPUTimeSampleQueueAutoSizes.java line 130:

> 128:                 WHITE_BOX.busyWaitCPUTime(1000);
> 129:                 // going out-of-native at the end of the previous call should have triggered
> 130:                 // the safepoint handler, thereby also triggering the stack walkingand creation

typo: walking_and

test/jdk/jdk/jfr/event/profiling/TestCPUTimeSampleQueueAutoSizes.java line 145:

> 143:     static void disableOutOfStackWalking() {
> 144:         boolean supported = WHITE_BOX.cpuSamplerSetOutOfStackWalking(false);
> 145:         if (!supported) {

Why not simply `assertTrue(supported, ...)`?

-------------

PR Review: https://git.openjdk.org/jdk/pull/27293#pullrequestreview-3239996378
PR Review Comment: https://git.openjdk.org/jdk/pull/27293#discussion_r2359507524
PR Review Comment: https://git.openjdk.org/jdk/pull/27293#discussion_r2359518683
PR Review Comment: https://git.openjdk.org/jdk/pull/27293#discussion_r2359523702
PR Review Comment: https://git.openjdk.org/jdk/pull/27293#discussion_r2359530422