RFR: 8226416: MonitorUsedDeflationThreshold can cause repeated async deflation requests [v4]

[Daniel D.Daugherty]

On Wed, 13 Jan 2021 16:14:43 GMT, Daniel D. Daugherty <dcubed at openjdk.org> wrote:

>> I added a call to output_detail.reportDiagnosticSummary().
>> I didn't use OutputAnalyzer.shouldContain() intentionally
>> because of this output line:
>> 
>> `System.out.println("too_many='" + too_many + "'");`
>> 
>> which is there for diagnostic purposes.
>
> Manually tested the use of `output_detail.reportDiagnosticSummary()`
> by temporarily setting `too_many = null;` before the check. It caused
> nice diagnostic output to be printed. I like this technique!

For the record, when the test passes, the output looks like this:

[2021-01-13T16:12:47.673259Z] Gathering output for process 15104
Found beginning of a deflation cycle.
too_many='Too many deflations without progress; bumping in_use_list_ceiling from 36 to 40'
PASSED.
----------System.err:(1/15)----------
STATUS:Passed.
----------rerun:(34/5039)*----------

so there's just a bit of diagnostic output from the test in the passing case.

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PR: https://git.openjdk.java.net/jdk/pull/1993