Prevent ConcurrentModificationException in TempTableThread shutdown

[labkey-tchad]

Rationale

TempTableThread.shutdownStarted() enumerates createdTableNames.values() and calls CleanupState.run(), which may end up removing elements from createdTableNames.values(). All operations are synchronized, but values() is not a concurrent collection.
Iterating over a copy will prevent this exception.

INFO  ContextListener          2026-02-26T13:42:09,901 gApplicationShutdownHook : Calling Temp table cleanup shutdownStarted()
ERROR ContextListener          2026-02-26T13:42:09,933 gApplicationShutdownHook : Exception during shutdownStarted(): 
java.util.ConcurrentModificationException
    at java.base/java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1522)
    at java.base/java.util.TreeMap$ValueIterator.next(TreeMap.java:1567)
    at org.labkey.api.data.TempTableTracker$TempTableThread.shutdownStarted(TempTableTracker.java:289)
    at org.labkey.api.util.ContextListener.callShutdownListeners(ContextListener.java:148)
    at org.labkey.api.util.ContextListener.contextDestroyed(ContextListener.java:99)
    at org.apache.catalina.core.StandardContext.listenerStop(StandardContext.java:4048)

Related Pull Requests

• N/A

Changes

• Prevent ConcurrentModificationException in TempTableThread shutdown

[labkey-jeckels]

I did no testing but seems straightforward