ConcurrentModificationException in saved diagram index

[philip-alldredge]

A ConcurrentModificationException can occur when opening a diagram using the context menu.

org.eclipse.e4.core.di.InjectionException: java.util.ConcurrentModificationException
at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:65)
at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:305)
at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:239)
at org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:132)
at org.eclipse.e4.core.commands.internal.HandlerServiceHandler.execute(HandlerServiceHandler.java:152)
at org.eclipse.core.commands.Command.executeWithChecks(Command.java:494)
at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:487)
at org.eclipse.e4.core.commands.internal.HandlerServiceImpl.executeHandler(HandlerServiceImpl.java:210)
at org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem.executeItem(HandledContributionItem.java:431)
at org.eclipse.e4.ui.workbench.renderers.swt.AbstractContributionItem.handleWidgetSelection(AbstractContributionItem.java:446)
at org.eclipse.e4.ui.workbench.renderers.swt.AbstractContributionItem.lambda$2(AbstractContributionItem.java:472)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:86)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4428)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1079)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4238)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3817)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1150)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1039)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:153)
at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:680)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:594)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:148)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:151)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:388)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:243)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:653)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:590)
at org.eclipse.equinox.launcher.Main.run(Main.java:1499)
Caused by: java.util.ConcurrentModificationException
at java.util.HashMap$EntrySpliterator.forEachRemaining(Unknown Source)
at java.util.stream.ReferencePipeline$Head.forEach(Unknown Source)
at java.util.stream.ReferencePipeline$7$1.accept(Unknown Source)
at java.util.HashMap$KeySpliterator.forEachRemaining(Unknown Source)
at java.util.stream.AbstractPipeline.copyInto(Unknown Source)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source)
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(Unknown Source)
at java.util.stream.AbstractPipeline.evaluate(Unknown Source)
at java.util.stream.ReferencePipeline.collect(Unknown Source)
at org.osate.ge.internal.indexing.SavedDiagramIndex.getDiagramsByContexts(SavedDiagramIndex.java:367)
at org.osate.ge.internal.indexing.SavedDiagramIndex.getDiagramsByContext(SavedDiagramIndex.java:357)
at org.osate.ge.internal.services.impl.DefaultDiagramService.findDiagramsByContextBusinessObject(DefaultDiagramService.java:190)
at org.osate.ge.internal.services.impl.DefaultDiagramService.openOrCreateDiagramForBusinessObject(DefaultDiagramService.java:199)
at org.osate.ge.internal.services.DiagramService.openOrCreateDiagramForBusinessObject(DiagramService.java:70)
at org.osate.ge.internal.ui.handlers.GoToImplementationDiagramHandler.execute(GoToImplementationDiagramHandler.java:53)
at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:291)
at org.eclipse.ui.internal.handlers.E4HandlerProxy.execute(E4HandlerProxy.java:92)
at sun.reflect.GeneratedMethodAccessor159.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:55)
... 36 more

[philip-alldredge]

Several code reviews have been conducted. So far, the only plausible explanation so far is that SavedDiagramIndexInvalidator, a resource change listener, is being called while fetching information about the diagrams. Adjustments to the saved diagram index is protected by synchronized blocks but it appears that the invalidator is being called by the same thread. Although the issue hasn't been reliably reproduced, it has been confirmed that the change listeners will be notified in the running thread under certain circumstances. The theory is that while walking the workspace tree, Eclipse determined that something has changed and sends out notifications.

[lwrage]

@philip-alldredge Is this fixed with PR #1613?

[philip-alldredge]

Yes. Closing...