RFR: 8370887: DelayScheduler.replace method may break the 4-ary heap in certain scenarios

[Alan Bateman]

On Sun, 23 Nov 2025 09:56:57 GMT, Viktor Klang <vklang at openjdk.org> wrote:

>> DelayScheduler.replace missing check to sift up when replaced with smaller value. checkHeap checks invariants when replacing. Executing tests with make run-test or other targets runs tests with -esa so assume is enabled.
>> 
>> New regression test to ensure delayed tests executes in expected delay order.
>
> src/java.base/share/classes/java/util/concurrent/DelayScheduler.java line 401:
> 
>> 399:             }
>> 400:         }
>> 401:         assert checkHeap(h, n);
> 
> It's great to have this run during debug builds 👍

The tests runs are done with -esa so the assert is always enabled in test runs. So all good.

> test/jdk/java/util/concurrent/DelayScheduler/AscendingOrderAfterReplace.java line 45:
> 
>> 43:                 .mapToObj(i -> Integer.valueOf(i).toString())
>> 44:                 .collect(Collectors.joining(", "));
>> 45:         System.out.println("Delays: " + delays);
> 
> I presume this is to be removed.

The trace messages are there to help diagnose in the event of a failure.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28469#discussion_r2554800800
PR Review Comment: https://git.openjdk.org/jdk/pull/28469#discussion_r2554797410