RFR: JDK-8315486: vmTestbase/nsk/jdwp/ThreadReference/ForceEarlyReturn/forceEarlyReturn002/forceEarlyReturn002.java timed out

[Chris Plummer]

On Wed, 6 Sep 2023 20:02:44 GMT, Alex Menkov <amenkov at openjdk.org> wrote:

> To test ForceEarlyReturn command for NO_MORE_FRAMES case the test creates ThreadStartEventRequest with SUSPEND_ALL policy and requests debuggee to start new thread.
> If debuggee JVM starts some internal threads before the request is cleared (i.e. we have several ThreadStart events), 2nd event suspends debuggee again and the test fails with timeout.
> The change adds THREAD_ONLY modifier to the ThreadStartEventRequest to generate event only for desired thread.
> It requires thread ID, so debuggee was updated to create Thread object in advance, debugger reads the thread ID from static field (it does not need to be static, but Debugee class has convenient methods to retrieve class ID and static field value).
> 
> Testing: 100 runs of the test on windows-x64-debug,linux-x64-debug,macosx-x64-debug with JTREG_TEST_THREAD_FACTORY=Virtual, with and without "-XX:+UseZGC -XX:+ZGenerational"

Overall looks good. Just one minor comment suggestion.

test/hotspot/jtreg/vmTestbase/nsk/jdwp/ThreadReference/ForceEarlyReturn/forceEarlyReturn002/forceEarlyReturn002.java line 164:

> 162:             command.addByte(JDWP.EventKind.THREAD_START);
> 163:             command.addByte(JDWP.SuspendPolicy.ALL);
> 164:             // THREAD_ONLY modifier

Maybe add a bit more of a comment here that explains we only want the THREAD_START event for the specified test thread and not any others that might start up.

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Marked as reviewed by cjplummer (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/15601#pullrequestreview-1614398877
PR Review Comment: https://git.openjdk.org/jdk/pull/15601#discussion_r1317959286