RFR: 8330077: Allow max number of events to be buffered to be configurable to avoid OVERFLOW_EVENT [v8]

[Fabian Meumertzheim]

On Thu, 18 Apr 2024 17:24:04 GMT, Brian Burkhalter <bpb at openjdk.org> wrote:

>> Fabian Meumertzheim has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Rephrase implNote
>
> test/jdk/java/nio/file/WatchService/LotsOfEntries.java line 32:
> 
>> 30:  * @run main/othervm -Djdk.nio.file.WatchService.maxEventsPerPoll=invalid LotsOfEntries 600 fail
>> 31:  * @run main/othervm -Djdk.nio.file.WatchService.maxEventsPerPoll=-5 LotsOfEntries 5 fail
>> 32:  * @run main/othervm -Djdk.nio.file.WatchService.maxEventsPerPoll=5 LotsOfEntries 5 pass
> 
> I ran 100 repeats of this test on each of four different platforms. 398 executions passed, but two failed, both in the sub-test at line 32. I do not know what happened in these two cases for the sub-tests at lines 33-35 as these were not run. The output was like:
> 
> 
> jtreg_open_test_jdk_java_nio_file_WatchService_LotsOfEntries_java/tmp/name7869734652501521174/entry1]
> 	at LotsOfEntries.testCreateLotsOfEntries(LotsOfEntries.java:84)
> 	at LotsOfEntries.main(LotsOfEntries.java:96)
> 	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
> 	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
> 	at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
> 	at java.base/java.lang.Thread.run(Thread.java:1575)
> 
> JavaTest Message: Test threw exception: java.lang.RuntimeException: Expected events on: [multiple flle names omitted]

I slightly lowered/raised the numbers of files to be created. We can tune this more if needed, I don't think fully precise control over the number of events is required.

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PR Review Comment: https://git.openjdk.org/jdk/pull/18739#discussion_r1571139359