RFR: 8355071: Fix nsk/jdi test to not require lookup of main thread in order to set the breakpoint used for communication

[Leonid Mesnik]

On Sat, 19 Apr 2025 05:19:22 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

> Remove the need for many nsk/jdi tests to discover the main thread, resulting in the test needing to be run with includevirtualthreads=y. Details in first comment.
> 
> Tested with all tier2, tier3, and tier5 svc tests

Good to see more simplification of common code patterns. 
See my small comment inline.
Also, you need to update a copyrights for changed files.

test/hotspot/jtreg/vmTestbase/nsk/share/jdi/JDIBase.java line 122:

> 120:                     breakpRequest = eventRManager.createBreakpointRequest(lineLocation);
> 121:                     breakpRequest.putProperty("number", property);
> 122:                     if (thread != null) {

The change might hide failure if thread is not set in the test.
I would prefer to have
private settingBreakpoint(ThreadReference thread,.,.) that allows null
and 

protected final BreakpointRequest settingBreakpoint(ThreadReference thread,
                                                     ReferenceType testedClass,
                                                     String methodName,
                                                     String bpLine,
                                                     String property)

that still fails early if thread is null. (I think now it should fail in 
`
 breakpRequest.addThreadFilter(thread);
`
string. 
So for any test that don't have proper thread - test fails early when setting breakpoint and not because it hasn't find it.

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

Changes requested by lmesnik (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/24768#pullrequestreview-2782060944
PR Review Comment: https://git.openjdk.org/jdk/pull/24768#discussion_r2052889087