RequestHandlerThreads seem to get stuck in parsing test results. We have multiple times seen in the thread dump traces like this:

"Handling GET /hudson/job/.../190/ : RequestHandlerThread10" Id=328 Group=main RUNNABLE
at java.util.WeakHashMap.get(WeakHashMap.java:355)
at hudson.tasks.test.TestObject.uniquifyName(TestObject.java:335)

• locked hudson.tasks.junit.CaseResult@3f7e9c00
  at hudson.tasks.junit.CaseResult.getSafeName(CaseResult.java:223)

"Handling GET /hudson/job/.../lastCompletedBuild/testReport/ : RequestHandlerThread29" Id=18760 Group=main RUNNABLE
at java.util.WeakHashMap.get(WeakHashMap.java:355)
at hudson.tasks.test.TestObject.uniquifyName(TestObject.java:335)

• locked hudson.tasks.junit.CaseResult@592d41ae
  at hudson.tasks.junit.CaseResult.getSafeName(CaseResult.java:223)

It looks a lot like e.g. https://issues.apache.org/jira/browse/BEANUTILS-318

With my limited Java skills it would appear like the static map UNIQUIFIED_NAMES could be accessed by multiple threads simultaneously through different instances of TestObjects.