RFR: 8356438: Update OutputAnalyzer to optionally print process output as it happens [v2]

[David Holmes]

On Thu, 5 Jun 2025 09:36:37 GMT, Alice Pellegrini <duke at openjdk.org> wrote:

>> The implemented solution modifies the `OutputBuffer` implementation instead of the `OutputAnalyzer` implementation.
>> This is because the **OutputBuffer implementation which handles processes** (LazyOutputBuffer) starts a thread in its constructor, so we would need to add a strange additional constructor parameter to the `OutputBuffer.of(Process, Charset)` static method, while the printing through to stdout (and stderr) only makes sense for LazyOutputBuffer.
>> 
>> I believe changing the config option from `outputanalyzer.verbose` to `output buffer.verbose` would make it cleaner, and avoid referencing the OutputAnalyzer in the OutputBuffer implementation.
>
> Alice Pellegrini has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - Merge remote-tracking branch 'origin/master' into 8356438-outputanalyzer-optional-print
>  - Update test/lib/jdk/test/lib/process/OutputBuffer.java
>    
>    Co-authored-by: Chen Liang <liach at openjdk.org>
>  - Initial working solution

> A lot of tests use the test.debug system property to enable more verbose test output. It's enabled when someone runs the test e.g., jtreg -Dtest.debug=true ...

I see a few tests that do that, nearly all of which are network tests. It is not something I was familiar with. But it doesn't seem right to me that a particular test would use that property to change the behaviour of `OutputAnalyzer`. I also don't think the test should have to opt-in to this kind of behaviour rather than it being directly controlled by the person running the tests. To that end I would see `OutputAnalyzer` examining a  specific property, e.g. `OutputAnalyzer.printToStdStreams` to control this.

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PR Comment: https://git.openjdk.org/jdk/pull/25587#issuecomment-2982650756