Description Martin Fluegge 2010-07-25 04:44:14 EDT

When loading a contained object before ist container legacy crashes with the following exception:


java.lang.IllegalStateException: Failing event PREPARE in state CLEAN for CDOLegacyWrapper[OID3, org.eclipse.emf.cdo.tests.legacy.model4.impl.ContainedElementNoOppositeImpl] (data=Pair[CDOTransaction[3:1], []])
	at org.eclipse.net4j.util.fsm.FiniteStateMachine.process(FiniteStateMachine.java:153)
	at org.eclipse.emf.internal.cdo.CDOStateMachine.prepare(CDOStateMachine.java:229)
	at org.eclipse.emf.internal.cdo.CDOStateMachine.attach(CDOStateMachine.java:191)
	at org.eclipse.emf.cdo.eresource.impl.CDOResourceImpl.attached(CDOResourceImpl.java:827)
	at org.eclipse.emf.cdo.eresource.impl.CDOResourceImpl.attached(CDOResourceImpl.java:818)
	at org.eclipse.emf.ecore.impl.BasicEObjectImpl.eBasicSetContainer(BasicEObjectImpl.java:1342)
	at org.eclipse.emf.ecore.impl.BasicEObjectImpl.eInverseAdd(BasicEObjectImpl.java:1423)
	at org.eclipse.emf.cdo.tests.legacy.model4.impl.RefSingleContainedNPLImpl.setElement(RefSingleContainedNPLImpl.java:121)
	at org.eclipse.emf.cdo.tests.legacy.model4.impl.RefSingleContainedNPLImpl.eSet(RefSingleContainedNPLImpl.java:180)
	at org.eclipse.emf.ecore.impl.BasicEObjectImpl.eSet(BasicEObjectImpl.java:1081)
	at org.eclipse.emf.internal.cdo.CDOLegacyWrapper.revisionToInstanceFeature(CDOLegacyWrapper.java:554)
	at org.eclipse.emf.internal.cdo.CDOLegacyWrapper.revisionToInstance(CDOLegacyWrapper.java:423)
	at org.eclipse.emf.internal.cdo.CDOLegacyWrapper.cdoInternalPostLoad(CDOLegacyWrapper.java:298)
	at org.eclipse.emf.internal.cdo.view.CDOViewImpl.cleanObject(CDOViewImpl.java:1179)
	at org.eclipse.emf.internal.cdo.view.CDOViewImpl.createObject(CDOViewImpl.java:1130)
	at org.eclipse.emf.internal.cdo.view.CDOViewImpl.getObject(CDOViewImpl.java:1005)
	at org.eclipse.emf.internal.cdo.transaction.CDOTransactionImpl.getObject(CDOTransactionImpl.java:878)
	at org.eclipse.emf.internal.cdo.transaction.CDOTransactionImpl.getObject(CDOTransactionImpl.java:1)
	at org.eclipse.emf.internal.cdo.CDOLegacyWrapper.getEObjectFromPotentialID(CDOLegacyWrapper.java:796)
	at org.eclipse.emf.internal.cdo.CDOLegacyWrapper.revisionToInstanceContainment(CDOLegacyWrapper.java:456)
	at org.eclipse.emf.internal.cdo.CDOLegacyWrapper.revisionToInstance(CDOLegacyWrapper.java:419)
	at org.eclipse.emf.internal.cdo.CDOLegacyWrapper.cdoInternalPostLoad(CDOLegacyWrapper.java:298)
	at org.eclipse.emf.internal.cdo.view.CDOViewImpl.cleanObject(CDOViewImpl.java:1179)
	at org.eclipse.emf.internal.cdo.view.CDOViewImpl.createObject(CDOViewImpl.java:1130)
	at org.eclipse.emf.internal.cdo.view.CDOViewImpl.getObject(CDOViewImpl.java:1005)
	at org.eclipse.emf.internal.cdo.transaction.CDOTransactionImpl.getObject(CDOTransactionImpl.java:878)
	at org.eclipse.emf.internal.cdo.view.CDOViewImpl.getObject(CDOViewImpl.java:1048)
	at org.eclipse.emf.cdo.tests.bugzilla.Bugzilla_320690_Tests.testLockRefTargets(Bugzilla_320690_Tests.java:60)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:585)
	at junit.framework.TestCase.runTest(TestCase.java:168)
	at org.eclipse.net4j.util.tests.AbstractOMTest.runBare(AbstractOMTest.java:150)
	at org.eclipse.emf.cdo.tests.config.impl.ConfigTest.runBare(ConfigTest.java:422)
	at junit.framework.TestResult$1.protect(TestResult.java:110)
	at junit.framework.TestResult.runProtected(TestResult.java:128)
	at junit.framework.TestResult.run(TestResult.java:113)
	at junit.framework.TestCase.run(TestCase.java:124)
	at org.eclipse.net4j.util.tests.AbstractOMTest.run(AbstractOMTest.java:196)
	at junit.framework.TestSuite.runTest(TestSuite.java:232)
	at org.eclipse.emf.cdo.tests.config.impl.ConfigTestSuite$TestWrapper.runTest(ConfigTestSuite.java:126)
	at junit.framework.TestSuite.run(TestSuite.java:227)
	at junit.framework.TestSuite.runTest(TestSuite.java:232)
	at junit.framework.TestSuite.run(TestSuite.java:227)
	at junit.framework.TestSuite.runTest(TestSuite.java:232)
	at junit.framework.TestSuite.run(TestSuite.java:227)
	at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)


I ran through the problem and it seems that the caus of the problem can be described as follows:

If the contained element is loaded, the wrapper will be created by CDO, set to state CLEAN and afterwards cdoInternalPostLoad() will be called which sets the information from the revision to the instance. 

Thereby the container of the element is set. This lead to a creation of the container object, which itself transforms the revision data to its instance. This leads to setting the contained object to its related feature in the container.

At this point the contained elements resource is null wherefore it will be attached to the containers resource (BasicEObjectImpl, 1342). This results in attaching the object to the CDOResource and processing an ATTACH operation in the CDOStateMachine. Remember that the contained object which should be attached to the resource it already in state CLEAN. So, the state machine denies preparing it. 

This does not happen if the container is loaded before, because the contained object will be created during the containers creation.