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Created attachment 233796 [details] Zip file that reproduces the problem in question. I'm on 3.8.2 and have installed WTP plug-ins from the Juno update site. ----------------- 1. Unzip the attached zip file. 2. Import deadlock-bug into your outer Eclipse. 3. Start your inner Eclipse and import bug-setup into that other workspace. 4. Refresh the many folders of bug-setup to ensure that everything is in synch with what's on disk. 5. Close your inner Eclipse. 6. Open WorkbenchURIConverterImpl and find the createPlatformResourceInputStream(*) method. 7. Put a breakpoint in the isSynchronized(*) call contained within the if statement. 8. Start your inner Eclipse. It should hit the breakpoint that we just added. Thread [Worker-2] (Suspended (breakpoint at line 497 in WorkbenchURIConverterImpl)) owns: ModuleStructuralModel (id=79) ComponentCoreURIConverter(WorkbenchURIConverterImpl).createPlatformResourceInputStream(String) line: 497 ComponentCoreURIConverter(URIConverterImpl).createInputStream(URI) line: 435 ComponentCoreURIConverter(URIConverterImpl).createInputStream(URI, Map<?,?>) line: 451 WTPModulesResource(ResourceImpl).load(Map<?,?>) line: 1256 WTPModulesResource(CompatibilityXMIResourceImpl).load(Map) line: 272 WTPModulesResource(TranslatorResourceImpl).load(Map) line: 423 ProjectResourceSetEditImpl(ResourceSetImpl).demandLoad(Resource) line: 259 ProjectResourceSetEditImpl(ProjectResourceSetImpl).demandLoad(Resource) line: 811 ProjectResourceSetEditImpl(ResourceSetImpl).demandLoadHelper(Resource) line: 274 ProjectResourceSetEditImpl(ProjectResourceSetImpl).getResource(URI, boolean) line: 1064 WorkbenchResourceHelper.getOrCreateResource(URI, ResourceSet) line: 380 ModuleStructuralModel(EditModel).getResource(URI) line: 685 ModuleStructuralModel.getPrimaryResource() line: 332 ModuleStructuralModel.prepareProjectModulesIfNecessary() line: 240 ModuleStructuralModel.getPrimaryRootObject() line: 119 StructureEdit.getComponentModelRoot() line: 471 StructureEdit.getWorkbenchModules() line: 506 StructureEdit.getComponent() line: 949 J2EEModuleVirtualComponent(VirtualComponent).createResource() line: 124 J2EEModuleVirtualComponent(VirtualComponent).initializeResource() line: 113 J2EEModuleVirtualComponent(VirtualComponent).<init>(IProject, IPath) line: 148 J2EEModuleVirtualComponent.<init>(IProject, IPath) line: 92 J2EEModuleVirtualComponent.createComponent(IProject) line: 96 ComponentImplManager.createComponent(IProject, boolean) line: 215 ComponentImplManager.createComponent(IProject) line: 203 ComponentCore.createComponent(IProject) line: 64 DependencyGraphImpl$GraphUpdateJob$1.run() line: 494 SafeRunner.run(ISafeRunnable) line: 42 DependencyGraphImpl$GraphUpdateJob.run(IProgressMonitor) line: 462 Worker.run() line: 54 9. Open the 'Progress' view. 10. Ensure all other startup-related operations have completed. 11. Put a breakpoint in StructureEdit's getComponentModelRoot() method. 12. Click the 'Initiate Deadlock' button in the workbench window's toolbar. 13. A breakpoint should be hit. Thread [Worker-3] (Suspended (breakpoint at line 461 in StructureEdit)) owns: DeadlockOperation (id=138) StructureEdit.getComponentModelRoot() line: 461 StructureEdit.getWorkbenchModules() line: 506 StructureEdit.getComponent() line: 949 J2EEModuleVirtualComponent(VirtualComponent).createResource() line: 124 J2EEModuleVirtualComponent(VirtualComponent).initializeResource() line: 113 J2EEModuleVirtualComponent(VirtualComponent).<init>(IProject, IPath) line: 148 J2EEModuleVirtualComponent.<init>(IProject, IPath) line: 92 J2EEModuleVirtualComponent.createComponent(IProject) line: 96 ComponentImplManager.createComponent(IProject, boolean) line: 215 ComponentImplManager.createComponent(IProject) line: 203 ComponentCore.createComponent(IProject) line: 64 J2EEElementChangedListener.processJavaProject(IJavaProject, int, int, IJavaElementDelta) line: 101 J2EEElementChangedListener.processJavaElementDelta(IJavaElementDelta) line: 87 J2EEElementChangedListener.processJavaElementDelta(IJavaElementDelta) line: 80 J2EEElementChangedListener.elementChanged(ElementChangedEvent) line: 67 DeltaProcessor$4.run() line: 1682 SafeRunner.run(ISafeRunnable) line: 42 DeltaProcessor.notifyListeners(IJavaElementDelta, int, IElementChangedListener[], int[], int) line: 1672 DeltaProcessor.firePostChangeDelta(IJavaElementDelta, IElementChangedListener[], int[], int) line: 1506 DeltaProcessor.fire(IJavaElementDelta, int) line: 1482 DeltaProcessor.resourceChanged(IResourceChangeEvent) line: 2094 DeltaProcessingState.resourceChanged(IResourceChangeEvent) line: 470 NotificationManager$1.run() line: 291 SafeRunner.run(ISafeRunnable) line: 42 NotificationManager.notify(ResourceChangeListenerList$ListenerEntry[], IResourceChangeEvent, boolean) line: 285 NotificationManager.broadcastChanges(ElementTree, ResourceChangeEvent, boolean) line: 149 Workspace.broadcastPostChange() line: 395 Workspace.endOperation(ISchedulingRule, boolean, IProgressMonitor) line: 1530 Workspace.run(IWorkspaceRunnable, ISchedulingRule, int, IProgressMonitor) line: 2353 DeadlockOperation(WorkspaceModifyOperation).run(IProgressMonitor) line: 118 DeadlockAction$1.run(IProgressMonitor) line: 31 Worker.run() line: 54 14. Go back to the first thread that's suspended in WorkbenchURIConverterImpl. 15. F6 through the if statement. It should detect that the file is out-of-sync and try to refresh. The refresh will hang. Thread [Worker-2] (Suspended) owns: ModuleStructuralModel (id=79) waiting for: Object (id=162) Object.wait(long) line: not available [native method] Object.wait() line: 503 ThreadJob.waitForRun(ThreadJob, IProgressMonitor, InternalJob, Thread) line: 270 ThreadJob.joinRun(ThreadJob, IProgressMonitor) line: 197 ImplicitJobs.begin(ISchedulingRule, IProgressMonitor, boolean) line: 92 JobManager.beginRule(ISchedulingRule, IProgressMonitor) line: 286 WorkManager.checkIn(ISchedulingRule, IProgressMonitor) line: 118 Workspace.prepareOperation(ISchedulingRule, IProgressMonitor) line: 2282 File(Resource).refreshLocal(int, IProgressMonitor) line: 1691 File.refreshLocal(int, IProgressMonitor) line: 333 ComponentCoreURIConverter(WorkbenchURIConverterImpl).createPlatformResourceInputStream(String) line: 501 ComponentCoreURIConverter(URIConverterImpl).createInputStream(URI) line: 435 ComponentCoreURIConverter(URIConverterImpl).createInputStream(URI, Map<?,?>) line: 451 WTPModulesResource(ResourceImpl).load(Map<?,?>) line: 1256 WTPModulesResource(CompatibilityXMIResourceImpl).load(Map) line: 272 WTPModulesResource(TranslatorResourceImpl).load(Map) line: 423 ProjectResourceSetEditImpl(ResourceSetImpl).demandLoad(Resource) line: 259 ProjectResourceSetEditImpl(ProjectResourceSetImpl).demandLoad(Resource) line: 811 ProjectResourceSetEditImpl(ResourceSetImpl).demandLoadHelper(Resource) line: 274 ProjectResourceSetEditImpl(ProjectResourceSetImpl).getResource(URI, boolean) line: 1064 WorkbenchResourceHelper.getOrCreateResource(URI, ResourceSet) line: 380 ModuleStructuralModel(EditModel).getResource(URI) line: 685 ModuleStructuralModel.getPrimaryResource() line: 332 ModuleStructuralModel.prepareProjectModulesIfNecessary() line: 240 ModuleStructuralModel.getPrimaryRootObject() line: 119 StructureEdit.getComponentModelRoot() line: 471 StructureEdit.getWorkbenchModules() line: 506 StructureEdit.getComponent() line: 949 J2EEModuleVirtualComponent(VirtualComponent).createResource() line: 124 J2EEModuleVirtualComponent(VirtualComponent).initializeResource() line: 113 J2EEModuleVirtualComponent(VirtualComponent).<init>(IProject, IPath) line: 148 J2EEModuleVirtualComponent.<init>(IProject, IPath) line: 92 J2EEModuleVirtualComponent.createComponent(IProject) line: 96 ComponentImplManager.createComponent(IProject, boolean) line: 215 ComponentImplManager.createComponent(IProject) line: 203 ComponentCore.createComponent(IProject) line: 64 DependencyGraphImpl$GraphUpdateJob$1.run() line: 494 SafeRunner.run(ISafeRunnable) line: 42 DependencyGraphImpl$GraphUpdateJob.run(IProgressMonitor) line: 462 Worker.run() line: 54 16. Go back to the second thread from DeadlockOperation. 17. F6 through the code. It should stall when trying to acquire the lock. Thread [Worker-3] (Suspended) owns: DeadlockOperation (id=138) waiting for: Semaphore (id=169) Object.wait(long) line: not available [native method] Semaphore.acquire(long) line: 39 OrderedLock.doAcquire(Semaphore, long) line: 176 OrderedLock.acquire(long) line: 110 OrderedLock.acquire() line: 84 StructureEdit.getComponentModelRoot() line: 467 StructureEdit.getWorkbenchModules() line: 506 StructureEdit.getComponent() line: 949 J2EEModuleVirtualComponent(VirtualComponent).createResource() line: 124 J2EEModuleVirtualComponent(VirtualComponent).initializeResource() line: 113 J2EEModuleVirtualComponent(VirtualComponent).<init>(IProject, IPath) line: 148 J2EEModuleVirtualComponent.<init>(IProject, IPath) line: 92 J2EEModuleVirtualComponent.createComponent(IProject) line: 96 ComponentImplManager.createComponent(IProject, boolean) line: 215 ComponentImplManager.createComponent(IProject) line: 203 ComponentCore.createComponent(IProject) line: 64 J2EEElementChangedListener.processJavaProject(IJavaProject, int, int, IJavaElementDelta) line: 101 J2EEElementChangedListener.processJavaElementDelta(IJavaElementDelta) line: 87 J2EEElementChangedListener.processJavaElementDelta(IJavaElementDelta) line: 80 J2EEElementChangedListener.elementChanged(ElementChangedEvent) line: 67 DeltaProcessor$4.run() line: 1682 SafeRunner.run(ISafeRunnable) line: 42 DeltaProcessor.notifyListeners(IJavaElementDelta, int, IElementChangedListener[], int[], int) line: 1672 DeltaProcessor.firePostChangeDelta(IJavaElementDelta, IElementChangedListener[], int[], int) line: 1506 DeltaProcessor.fire(IJavaElementDelta, int) line: 1482 DeltaProcessor.resourceChanged(IResourceChangeEvent) line: 2094 DeltaProcessingState.resourceChanged(IResourceChangeEvent) line: 470 NotificationManager$1.run() line: 291 SafeRunner.run(ISafeRunnable) line: 42 NotificationManager.notify(ResourceChangeListenerList$ListenerEntry[], IResourceChangeEvent, boolean) line: 285 NotificationManager.broadcastChanges(ElementTree, ResourceChangeEvent, boolean) line: 149 Workspace.broadcastPostChange() line: 395 Workspace.endOperation(ISchedulingRule, boolean, IProgressMonitor) line: 1530 Workspace.run(IWorkspaceRunnable, ISchedulingRule, int, IProgressMonitor) line: 2353 DeadlockOperation(WorkspaceModifyOperation).run(IProgressMonitor) line: 118 DeadlockAction$1.run(IProgressMonitor) line: 31 Worker.run() line: 54 18. The deadlock is now in place. You can see that the 'Progress' view is stalled. Basically, thread A acquires a lock on StructureEdit and then thread B acquires a workspace lock. Now thread A tries to refresh the file but it can't because thread B has a workspace lock. Meanwhile, thread B wants to talk to StructureEdit but it can't because thread A's got a lock on it. It seems to be that any asynchronous operation on thread B that locks the workspace (or just that one file really) as thread A is trying to refresh the file will cause a deadlock.
This is the classic resource change event deadlock. Someone is trying to acquire a lock from within a resource change event callback, that is also sometimes held while modifying resources. From the contract of resource change events, this could only be resolved at the platform level by allowing resource changes to occur in other threads during resource change events, which would be a breaking change for listeners (I tried this many years ago and it was not successful). There are two basic ways to fix this: - Don't lock StructureEdit during resource change events. The classic solution here is to pull the data you need out of the resource change event, and perform your model updates asynchronously (e.g., in another job). - Don't hold StructureEdit lock while modifying resources. This is probably the better option. Holding this lock while modifying resources exposes you to various forms of deadlock because arbitrary third party code can be executed within the context of a resource change.
Created attachment 234066 [details] Proposed patch Proposed patch that moves all required processing using Component models inside a Job.
Committed/released to R3_4_2_patches
