Flakey test in testNoTestClassesInDeploymentAssembly

[briandealwis]

Haven't seen this failure previously. On Oxygen.

testNoTestClassesInDeploymentAssembly(com.google.cloud.tools.eclipse.appengine.newproject.flex.CreateAppEngineFlexWtpProjectTest)  Time elapsed: 3.068 sec  <<< ERROR!
java.lang.NullPointerException: null
	at org.eclipse.wst.common.componentcore.internal.impl.WorkbenchComponentImpl.findResourcesBySourcePath(WorkbenchComponentImpl.java:556)
	at com.google.cloud.tools.eclipse.appengine.newproject.DeployAssemblyEntryRemoveJobTest.hasSourcePathInDeployAssembly(DeployAssemblyEntryRemoveJobTest.java:57)
	at com.google.cloud.tools.eclipse.appengine.newproject.CreateAppEngineWtpProjectTest.testNoTestClassesInDeploymentAssembly(CreateAppEngineWtpProjectTest.java:199)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
	at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)
	at com.google.cloud.tools.eclipse.test.util.ThreadDumpingWatchdog$1.evaluate(ThreadDumpingWatchdog.java:94)
	at org.junit.rules.RunRules.evaluate(RunRules.java:20)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.mockito.internal.runners.JUnit45AndHigherRunnerImpl.run(JUnit45AndHigherRunnerImpl.java:37)
	at org.mockito.runners.MockitoJUnitRunner.run(MockitoJUnitRunner.java:62)
	at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:264)
	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153)
	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:124)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray2(ReflectionUtils.java:208)
	at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:156)
	at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:82)
	at org.eclipse.tycho.surefire.osgibooter.OsgiSurefireBooter.run(OsgiSurefireBooter.java:95)
	at org.eclipse.tycho.surefire.osgibooter.AbstractUITestApplication$1.run(AbstractUITestApplication.java:35)
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:37)
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:182)
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4577)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:4186)
	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.tycho.surefire.osgibooter.UITestApplication.runApplication(UITestApplication.java:31)
	at org.eclipse.tycho.surefire.osgibooter.AbstractUITestApplication.run(AbstractUITestApplication.java:120)
	at org.eclipse.tycho.surefire.osgibooter.UITestApplication.start(UITestApplication.java:37)
	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(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	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)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1472)

[chanseokoh]

Both this and #2781 may fail for the same reason. They both fail in org.eclipse.wst.common.componentcore.internal.impl.WorkbenchComponentImpl. This test fails in findResourcesBySourcePath(), while #2781 fails in findResourcesByRuntimePath(). In both cases, the NPE is at resourceTreeRoot.findModuleResources().

	public ComponentResource[] findResourcesByRuntimePath(IPath aDeployPath) { 
		ResourceTreeRoot resourceTreeRoot = ResourceTreeRoot.getDeployResourceTreeRoot(this);
		return resourceTreeRoot.findModuleResources(aDeployPath, ResourceTreeNode.CREATE_NONE); 
	}

	public ComponentResource[] findResourcesBySourcePath(IPath aSourcePath, int resourceFlag) { 
		ResourceTreeRoot resourceTreeRoot = ResourceTreeRoot.getSourceResourceTreeRoot(this);
		return resourceTreeRoot.findModuleResources(aSourcePath, resourceFlag); 
	}

[briandealwis]

Hmm… the code in hasSourcePathInDeployAssembly does its read with a StructureEdit lock on the project, but it looks like DeployAssemblyEntryRemoveJob#run() does not.

[briandealwis]

…but VirtualResource#removeLink() does.

[chanseokoh]

Just leaving some notes.

1. The first hasSourcePathInDeployAssembly() was successful, so something happened before the failure of the second call.
2. I wonder if there is a concurrency issue in the Eclipse class ResourceTreeRoot:

  public static ResourceTreeRoot getDeployResourceTreeRoot(WorkbenchComponent aModule) {
    ResourceTreeRootAdapter resourceTreeAdapter = (...) ExtendedEcoreUtil.getAdapter(aModule, aModule.eAdapters(), ...);
    if (resourceTreeAdapter != null)
      return resourceTreeAdapter.getResourceTreeRoot();

    resourceTreeAdapter = new ResourceTreeRootAdapter(...);
    aModule.eAdapters().add(resourceTreeAdapter);
    return resourceTreeAdapter.getResourceTreeRoot();
  }

It seems like aModule should add a singleton ResourceTreeRootAdapter instance to its adapter list, but if this is called concurrently, it may end up adding more than one adapter.

• ResourceTreeRootAdapter.getResourceTreeRoot() OTOH creates a singleton instance in a thread-safe way.