RFR: 8370975: Test runtime/ErrorHandling/AccessZeroNKlassHitsProtectionZone.java can still fail on macos 26

[Stefan Karlsson]

On Thu, 30 Oct 2025 22:53:59 GMT, Ioi Lam <iklam at openjdk.org> wrote:

> In the previous fix (https://github.com/openjdk/jdk/pull/28035), I added `OutputAnalyzer::match(String regexp)`, but it didn't work because by default regular expressions do not match across newlines.
> 
> I fixed this by re-working `OutputAnalyzer::match()`, etc, to use `Pattern.MULTILINE`.
> 
> I tried rerunning the test on macos 26 but couldn't reproduce the condition in the bug report. However, I added sanity test in this version (https://github.com/openjdk/jdk/commit/e690e97262575d083017635fa837ab267686bfe9) and the new regexp seems to catch the output and correctly come to this part of the test case:
> 
> 
> if (forceBase >= end) {
>     throw new SkippedException("Failed to force ccs to any of the given bases. Skipping test.");
> }

Changes requested by stefank (Reviewer).

test/lib/jdk/test/lib/process/OutputAnalyzer.java line 359:

> 357:     private boolean matchesHelper(String s, Pattern pattern) {
> 358:         return s != null && pattern.matcher(s).find();
> 359:     }

This function is named `matchesX` so why is it using `Matcher::find` instead of `Matcher::matches`? That seems confusing.

test/lib/jdk/test/lib/process/OutputAnalyzer.java line 364:

> 362:         Pattern pattern = Pattern.compile(regexp, Pattern.MULTILINE);
> 363:         return matchesHelper(stdout, pattern) || matchesHelper(stderr, pattern);
> 364:     }

I'd like to suggest that you don't hard-code `stdout` and `stderr` here and use something like this (with updated name as suggested above):
Suggestion:

    private boolean findIn(String regexp, String... strings) {
        Pattern pattern = Pattern.compile(regexp, Pattern.MULTILINE);
        for (String string : strings) {
            if (pattern.matcher(string).find()) {
                return true;
            }
        }

        return false;
    }


and then the code you have that looks like this:

return matchesHelper(getStdout(), null, regexp);

can get rid of the `null`:

return findIn(regexp, getStdout());

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

PR Review: https://git.openjdk.org/jdk/pull/28077#pullrequestreview-3402888668
PR Review Comment: https://git.openjdk.org/jdk/pull/28077#discussion_r2480391654
PR Review Comment: https://git.openjdk.org/jdk/pull/28077#discussion_r2480406005