RFR: 8369505: jhsdb jstack cannot handle continuation stub [v5]

[Yasumasa Suenaga]

On Mon, 13 Oct 2025 19:57:54 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

>> I updated testcase to run this on other platforms - runs `jhsdb jstack` without `--mixed` and checks stderr.
>> 
>> I tested on Windows, but I didn't see any errors - I guess `jhsdb jstack` couldn't unwind stacks on Windows, thus it did not reach continuation stub. But it is different problem.
>
> On Windows I am seeing the exception (with your fix disabled):
> 
> 
> "ForkJoinPool-1-worker-1" #30 daemon prio=5 tid=0x000001567d6bcdc0 nid=2588 runnable [0x00000002d35fe000]
>    java.lang.Thread.State: RUNNABLE
>    JavaThread state: _thread_in_native
>  - java.lang.invoke.LambdaForm$MH+0x0000000026047800.invoke(java.lang.Object, long, int) @bci=10 (Interpreted frame)
>  - java.lang.invoke.LambdaForm$MH+0x000000002604e400.invokeExact_MT(java.lang.Object, long, int, java.lang.Object) @bci=21 (Interpreted frame)
>  - jdk.internal.foreign.abi.DowncallStub+0x0000000026048800.invoke(java.lang.foreign.SegmentAllocator, java.lang.foreign.MemorySegment, int) @bci=44 (Interpreted frame)
>  - java.lang.invoke.LambdaForm$DMH+0x0000000026048c00.invokeStaticInit(java.lang.Object, java.lang.Object, java.lang.Object, int) @bci=14 (Interpreted frame)
>  - java.lang.invoke.LambdaForm$MH+0x000000002604d800.invoke(java.lang.Object, int) @bci=44 (Interpreted frame)
>  - java.lang.invoke.LambdaForm$MH+0x000000002604d400.invoke_MT(java.lang.Object, int, java.lang.Object) @bci=18 (Interpreted frame)
>  - LingeredAppWithVirtualThread.run() @bci=15, line=65 (Interpreted frame)
> 
> Error occurred during stack walking:
> sun.jvm.hotspot.utilities.AssertionFailure: must have non-zero frame size
> 
> With your fix enabled, I see the full expected stack, so it seems to be working.

I tested only mixed mode, sorry. I could reproduce the problem on Windows, and I confirmed the problem has gone with this PR.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27728#discussion_r2427647746