Decoration Calculation waits for Indexing

I just saw a very long running Decoration Job.
It was because of the usage of
IJavaSearchConstants.WAIT_UNTIL_READY_TO_SEARCH
in
org.eclipse.jdt.internal.ui.InterfaceIndicatorLabelDecorator.addOverlaysWithSearchEngine(ITypeRoot, String, IDecoration)

I am not sure about the consequences but i guess it will stall all other Decorations till indexer is ready... is that really smart when indexing takes a long time - say minutes?