The following test failed in the jdk11 CI:

serviceability/sa/TestClhsdbJstackLock.java

Snipped from the log:

Locked ownable synchronizers:
    - None

"Reference Handler" #2 daemon prio=10 tid=0x000001ddbb5c0800 nid=0xae34 waiting on condition [0x00000071547ff000]
   java.lang.Thread.State: RUNNABLE
   JavaThread state: _thread_blocked
 - java.lang.ref.Reference.waitForReferencePendingList() @bci=0 (Interpreted frame)
 - java.lang.ref.Reference.processPendingReferences() @bci=0, line=241 (Interpreted frame)
 - java.lang.ref.Reference$ReferenceHandler.run() @bci=0, line=213 (Interpreted frame)

Locked ownable synchronizers:
    - None

"main" #1 prio=5 tid=0x000001dd97830800 nid=0x6c84 waiting on condition [0x00000071540ff000]
   java.lang.Thread.State: TIMED_WAITING (sleeping)
   JavaThread state: _thread_blocked
 - java.lang.Thread.sleep(long) @bci=0 (Interpreted frame)
 - jdk.test.lib.apps.LingeredApp.main(java.lang.String[]) @bci=53, line=511 (Interpreted frame)
 - LingeredAppWithLock.main(java.lang.String[]) @bci=72, line=50 (Interpreted frame)

Locked ownable synchronizers:
    - None

]
 exitValue = -1

 LingeredApp stdout: [];
 LingeredApp stderr: []
 LingeredApp exitValue = 0
java.lang.RuntimeException: Test ERROR java.lang.RuntimeException: '^\s+- waiting to lock <0x[0-9a-f]+> \(a java\.lang\.Class for LingeredAppWithLock\)$' missing from stdout/stderr

at TestClhsdbJstackLock.main(TestClhsdbJstackLock.java:68)
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:566)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.RuntimeException: '^\s+- waiting to lock <0x[0-9a-f]+> \(a java\.lang\.Class for LingeredAppWithLock\)$' missing from stdout/stderr

at jdk.test.lib.process.OutputAnalyzer.shouldMatch(OutputAnalyzer.java:282)
at ClhsdbLauncher.runCmd(ClhsdbLauncher.java:141)
at ClhsdbLauncher.run(ClhsdbLauncher.java:178)
at TestClhsdbJstackLock.main(TestClhsdbJstackLock.java:64)
... 6 more

JavaTest Message: Test threw exception: java.lang.RuntimeException: Test ERROR java.lang.RuntimeException: '^\s+- waiting to lock <0x[0-9a-f]+> \(a java\.lang\.Class for LingeredAppWithLock\)$' missing from stdout/stderr

JavaTest Message: shutting down test

STATUS:Failed.`main' threw exception: java.lang.RuntimeException: Test ERROR java.lang.RuntimeException: '^\s+- waiting to lock <0x[0-9a-f]+> \(a java\.lang\.Class for LingeredAppWithLock\)$' missing from stdout/stderr