Created attachment 92784 [details]
The complete ThreadDump from VisualVM

The complete Netbeans UI was not responding. The only thing I could do was to kill the netbeans prozess. Before I usesd VisualVM 1.2.1 with the ThreadAnalyser Plugin to generate a report. ThreadAnalyser found one deadlock inside the java threads:


Found one Java-level deadlock 

"Versioning long tasks":
  waiting to lock monitor 0x0b32d0cc (object 0x1450c2a8, a org.netbeans.spi.project.support.LookupProviderSupport$DelegatingLookupImpl),
  which is held by "Parsing & Indexing Loop (nbms-and-javadoc-4502-on-091210)"
 "Parsing & Indexing Loop (nbms-and-javadoc-4502-on-091210)":
  waiting to lock monitor 0x0c23e454 (object 0x1450c088, a java.lang.Object),
  which is held by "org.netbeans.spi.project.ui.support.NodeFactorySupport"
 "org.netbeans.spi.project.ui.support.NodeFactorySupport":
  waiting to lock monitor 0x0b32d0cc (object 0x1450c2a8, a org.netbeans.spi.project.support.LookupProviderSupport$DelegatingLookupImpl),
  which is held by "Parsing & Indexing Loop (nbms-and-javadoc-4502-on-091210)"


 Java stack information for the threads listed above 

"Versioning long tasks":
	at org.openide.util.lookup.ProxyLookup.lookup(ProxyLookup.java:200)
	- waiting to lock <0x1450c2a8> (a org.netbeans.spi.project.support.LookupProviderSupport$DelegatingLookupImpl)
	at org.openide.util.lookup.ProxyLookup.lookup(ProxyLookup.java:205)
	at org.netbeans.modules.maven.api.PluginPropertyUtils.getPluginProperty(PluginPropertyUtils.java:85)
	at org.netbeans.modules.maven.j2ee.web.WebModuleImpl.getContentDirectory(WebModuleImpl.java:321)
	at org.netbeans.modules.j2ee.deployment.devmodules.api.J2eeModule.getContentDirectory(J2eeModule.java:265)
	at org.netbeans.modules.maven.j2ee.web.CopyOnSave.isInPlace(CopyOnSave.java:126)
	at org.netbeans.modules.maven.j2ee.web.CopyOnSave.fileDeleted(CopyOnSave.java:262)
	at org.openide.filesystems.FCLSupport$DispatchEventWrapper.dispatchEventImpl(FCLSupport.java:145)
	at org.openide.filesystems.FCLSupport$DispatchEventWrapper.dispatchEvent(FCLSupport.java:125)
	at org.openide.filesystems.FCLSupport.dispatchEvent(FCLSupport.java:102)
	at org.openide.filesystems.FileObject$ED.dispatch(FileObject.java:1109)
	at org.openide.filesystems.FileSystem$EventDispatcher.run(FileSystem.java:912)
	at org.openide.filesystems.EventControl.dispatchEvent(EventControl.java:79)
	at org.openide.filesystems.FileSystem.dispatchEvent(FileSystem.java:574)
	at org.openide.filesystems.FileObject.dispatchEvent(FileObject.java:526)
	at org.openide.filesystems.FileObject.fireFileDeletedEvent(FileObject.java:502)
	at org.netbeans.modules.masterfs.filebasedfs.fileobjects.BaseFileObj.fireFileDeletedEvent(BaseFileObj.java:547)
	at org.netbeans.modules.masterfs.filebasedfs.fileobjects.FolderObj.delete(FolderObj.java:329)
	at org.netbeans.modules.masterfs.filebasedfs.fileobjects.BaseFileObj$2.call(BaseFileObj.java:594)
	at org.netbeans.modules.masterfs.filebasedfs.fileobjects.BaseFileObj$2.call(BaseFileObj.java:589)
	at org.netbeans.modules.masterfs.filebasedfs.FileBasedFileSystem.runAsInconsistent(FileBasedFileSystem.java:112)
	at org.netbeans.modules.masterfs.filebasedfs.fileobjects.BaseFileObj.delete(BaseFileObj.java:602)
	at org.openide.filesystems.FileObject.delete(FileObject.java:360)
	at org.netbeans.modules.versioning.diff.DiffSidebar.deleteTempFolder(DiffSidebar.java:1076)
	at org.netbeans.modules.versioning.diff.DiffSidebar.getText(DiffSidebar.java:882)
	at org.netbeans.modules.versioning.diff.DiffSidebar.access$1200(DiffSidebar.java:99)
	at org.netbeans.modules.versioning.diff.DiffSidebar$RefreshDiffTask.fetchOriginalContent(DiffSidebar.java:832)
	at org.netbeans.modules.versioning.diff.DiffSidebar$RefreshDiffTask.computeDiff(DiffSidebar.java:803)
	at org.netbeans.modules.versioning.diff.DiffSidebar$RefreshDiffTask.run(DiffSidebar.java:793)
	at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:641)
	at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1123)
 "Parsing & Indexing Loop (nbms-and-javadoc-4502-on-091210)":
	at org.netbeans.modules.maven.MavenSourcesImpl.getSourceGroups(MavenSourcesImpl.java:198)
	- waiting to lock <0x1450c088> (a java.lang.Object)
	at org.netbeans.spi.project.support.LookupProviderSupport$SourcesImpl.getSourceGroups(LookupProviderSupport.java:285)
	at org.netbeans.modules.j2ee.ddloaders.web.DDDataObject.refreshSourceFolders(DDDataObject.java:146)
	at org.netbeans.modules.j2ee.ddloaders.web.DDDataObject.stateChanged(DDDataObject.java:670)
	at org.openide.util.ChangeSupport.fireChange(ChangeSupport.java:130)
	at org.openide.util.ChangeSupport.fireChange(ChangeSupport.java:116)
	at org.netbeans.spi.project.support.LookupProviderSupport$SourcesImpl.setLookup(LookupProviderSupport.java:278)
	at org.netbeans.spi.project.support.LookupProviderSupport$SourcesImpl.access$200(LookupProviderSupport.java:253)
	at org.netbeans.spi.project.support.LookupProviderSupport$SourcesMerger.merge(LookupProviderSupport.java:248)
	at org.netbeans.spi.project.support.LookupProviderSupport$SourcesMerger.merge(LookupProviderSupport.java:237)
	at org.netbeans.spi.project.support.LookupProviderSupport$DelegatingLookupImpl.doDelegate(LookupProviderSupport.java:223)
	- locked <0x1450c2a8> (a org.netbeans.spi.project.support.LookupProviderSupport$DelegatingLookupImpl)
	at org.netbeans.spi.project.support.LookupProviderSupport$DelegatingLookupImpl.resultChanged(LookupProviderSupport.java:157)
	at org.openide.util.lookup.ProxyLookup$1Notify.run(ProxyLookup.java:173)
	at org.openide.util.lookup.ProxyLookup.setLookups(ProxyLookup.java:179)
	at org.openide.util.lookup.ProxyLookup.setLookups(ProxyLookup.java:119)
	at org.netbeans.modules.projectapi.LazyLookupProviders$1$1.beforeLookup(LazyLookupProviders.java:85)
	at org.openide.util.lookup.ProxyLookup.lookup(ProxyLookup.java:197)
	at org.openide.util.lookup.ProxyLookup.lookup(ProxyLookup.java:205)
	at org.openide.util.lookup.ExcludingLookup.lookup(ExcludingLookup.java:105)
	at org.openide.util.lookup.ProxyLookup.lookup(ProxyLookup.java:205)
	at org.openide.util.lookup.ProxyLookup.lookup(ProxyLookup.java:205)
	at org.netbeans.modules.j2ee.persistenceapi.ProjectEntityClassScopeProvider.findEntityClassScope(ProjectEntityClassScopeProvider.java:60)
	at org.netbeans.modules.j2ee.persistence.api.EntityClassScope.getEntityClassScope(EntityClassScope.java:89)
	at org.netbeans.modules.j2ee.jpa.model.ModelUtils.getModel(ModelUtils.java:228)
	at org.netbeans.modules.j2ee.jpa.verification.JPAProblemFinder.run(JPAProblemFinder.java:125)
	- locked <0x17c5e030> (a java.lang.Object)
	at org.netbeans.modules.j2ee.jpa.verification.JPAProblemFinder$ProblemFinderCompInfo.run(JPAProblemFinder.java:384)
	at org.netbeans.modules.java.source.JavaSourceAccessor$CancelableTaskWrapper.run(JavaSourceAccessor.java:291)
	at org.netbeans.modules.parsing.impl.TaskProcessor$CompilationJob.run(TaskProcessor.java:654)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
	at java.util.concurrent.FutureTask.run(FutureTask.java:138)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:619)
 "org.netbeans.spi.project.ui.support.NodeFactorySupport":
	at org.openide.util.lookup.ProxyLookup.lookup(ProxyLookup.java:200)
	- waiting to lock <0x1450c2a8> (a org.netbeans.spi.project.support.LookupProviderSupport$DelegatingLookupImpl)
	at org.openide.util.lookup.ProxyLookup.lookup(ProxyLookup.java:205)
	at org.netbeans.modules.maven.api.PluginPropertyUtils.getPluginPropertyList(PluginPropertyUtils.java:252)
	at org.netbeans.modules.maven.NbMavenProjectImpl.getGeneratedSourceRoots(NbMavenProjectImpl.java:740)
	at org.netbeans.modules.maven.MavenSourcesImpl.checkChanges(MavenSourcesImpl.java:144)
	- locked <0x1450c088> (a java.lang.Object)
	at org.netbeans.modules.maven.MavenSourcesImpl.getSourceGroups(MavenSourcesImpl.java:200)
	- locked <0x1450c088> (a java.lang.Object)
	at org.netbeans.spi.project.support.LookupProviderSupport$SourcesImpl.getSourceGroups(LookupProviderSupport.java:285)
	at org.netbeans.modules.maven.nodes.SourcesNodeFactory$NList.keys(SourcesNodeFactory.java:92)
	at org.netbeans.spi.project.ui.support.NodeFactorySupport$DelegateChildren$2.run(NodeFactorySupport.java:259)
	at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:641)
	at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1123)


If you search in bugzilla, there are more bugs related to dealocks and maven, but I don't know if they are related:

http://netbeans.org/bugzilla/buglist.cgi?query_format=advanced&short_desc_type=allwordssubstr&short_desc=deadlock+maven&long_desc_type=substring&long_desc=&bug_file_loc_type=allwordssubstr&bug_file_loc=&status_whiteboard_type=allwordssubstr&status_whiteboard=&keywords_type=anywords&keywords=&emailtype1=substring&email1=&emailtype2=substring&email2=&bugidtype=include&bug_id=&votes=&chfieldfrom=&chfieldto=Now&chfieldvalue=&cmdtype=doit&order=Reuse+same+sort+as+last+time&field0-0-0=noop&type0-0-0=noop&value0-0-0=