serviceability/sa/ClhsdbJstack.java and serviceability/sa/ClhsdbCDSJstackPrintAll.java sometimes fail with the following. Only seems to happen in windows-x64.

 LingeredApp exitValue = 0
java.lang.RuntimeException: Test ERROR java.lang.RuntimeException: 'LingeredApp.main' missing from stdout/stderr

at ClhsdbCDSJstackPrintAll.main(ClhsdbCDSJstackPrintAll.java:117)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:832)
Caused by: java.lang.RuntimeException: 'LingeredApp.main' missing from stdout/stderr

at jdk.test.lib.process.OutputAnalyzer.shouldMatch(OutputAnalyzer.java:306)
at ClhsdbLauncher.runCmd(ClhsdbLauncher.java:163)
at ClhsdbLauncher.run(ClhsdbLauncher.java:200)
at ClhsdbCDSJstackPrintAll.main(ClhsdbCDSJstackPrintAll.java:113)
... 6 more

The issue seems to be that for some reason when dumping the main thread, there is no stack trace:

"main" #1 prio=5 tid=0x000001ba6cdaa000 nid=0xfb58 runnable [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE
   JavaThread state: _thread_in_java

Locked ownable synchronizers:
    - None

Other threads are properly showing the full stack trace. The main thread must have been in some sort of state that made SA not try, but there's no clue in the log as to why.