Community
Participate
Working Groups
Build ID: 3.4.0.v20080604-1400 Steps To Reproduce: See description of problem below. More information: I am a performance analyst for an adopting product. I ran into a deadlock (CPU idle) during one of my many automated runs (a build of the workspace) that I haven't run into before. While it might be nigh impossible to reproduce, I thought I'd document it. A javacore dump showed that the build thread was stuck: ******************************************************* "Worker-4" TID:0x18FC4200, j9thread_t:0x1F6596F0, state:CW, prio=2 (native thread ID:0xE7C, native priority:0x2, native policy:UNKNOWN) at java/lang/Object.wait(Native Method) at java/lang/Object.wait(Object.java:167) at org/eclipse/wst/sse/core/internal/model/ModelManagerImpl$SharedObject.waitForLoadAttempt(ModelManagerImpl.java:127) at org/eclipse/wst/sse/core/internal/model/ModelManagerImpl._commonGetModel(ModelManagerImpl.java:433) at org/eclipse/wst/sse/core/internal/model/ModelManagerImpl._commonGetModel(ModelManagerImpl.java:416) at org/eclipse/wst/sse/core/internal/model/ModelManagerImpl.getModelForEdit(ModelManagerImpl.java:1276) at org/eclipse/wst/xml/core/internal/emf2xml/EMF2DOMSSERenderer.initializeXMLModel(EMF2DOMSSERenderer.java:360) at org/eclipse/wst/xml/core/internal/emf2xml/EMF2DOMSSERenderer.createDocument(EMF2DOMSSERenderer.java:183) at org/eclipse/wst/common/internal/emf/resource/EMF2DOMRenderer.createDOMTree(EMF2DOMRenderer.java:127) at org/eclipse/wst/xml/core/internal/emf2xml/EMF2DOMSSERenderer.createDOMTreeIfNecessary(EMF2DOMSSERenderer.java:192) at org/eclipse/wst/xml/core/internal/emf2xml/EMF2DOMSSERenderer.doSave(EMF2DOMSSERenderer.java:249) at org/eclipse/wst/common/internal/emf/resource/TranslatorResourceImpl.doSave(TranslatorResourceImpl.java:180) at org/eclipse/wst/common/internal/emf/resource/TranslatorResourceImpl.save(TranslatorResourceImpl.java:160) at org/eclipse/wst/common/internal/emf/resource/ReferencedXMIResourceImpl.saveIfNecessary(ReferencedXMIResourceImpl.java:272) at org/eclipse/jst/j2ee/ejb/componentcore/util/EJBArtifactEdit.addEJBJarIfNecessary(EJBArtifactEdit.java:372) at org/eclipse/jst/j2ee/ejb/componentcore/util/EJBArtifactEdit.getDeploymentDescriptorRoot(EJBArtifactEdit.java:325) at org/eclipse/jst/j2ee/ejb/componentcore/util/EJBArtifactEdit.getEJBJar(EJBArtifactEdit.java:301) <product code> at org/eclipse/core/internal/resources/Workspace.run(Workspace.java:1800) at org/eclipse/core/internal/resources/Workspace.run(Workspace.java:1782) <product code> at org/eclipse/core/internal/events/BuildManager$2.run(BuildManager.java:633) at org/eclipse/core/runtime/SafeRunner.run(SafeRunner.java:37(Compiled Code)) at org/eclipse/core/internal/events/BuildManager.basicBuild(BuildManager.java:170) at org/eclipse/core/internal/events/BuildManager.basicBuild(BuildManager.java:201) at org/eclipse/core/internal/events/BuildManager$1.run(BuildManager.java:253) at org/eclipse/core/runtime/SafeRunner.run(SafeRunner.java:37(Compiled Code)) at org/eclipse/core/internal/events/BuildManager.basicBuild(BuildManager.java:256) at org/eclipse/core/internal/events/BuildManager.basicBuildLoop(BuildManager.java:309) at org/eclipse/core/internal/events/BuildManager.build(BuildManager.java:341) at org/eclipse/core/internal/resources/Workspace.build(Workspace.java:330) at org/eclipse/ui/actions/GlobalBuildAction$1.run(GlobalBuildAction.java:182) at org/eclipse/core/internal/jobs/Worker.run(Worker.java:55(Compiled Code)) ******************************************************* The .log file showed a highly suspect entry. A ResourceException that occurred exactly when the CPU went idle (according to my perf logs): ********************************************************* !ENTRY org.eclipse.wst.xml.core 4 4 2008-09-25 19:02:58.046 !MESSAGE Resource '/DMPackingSlipServiceEJB/ejbModule/META-INF/ejb-jar.xml' already exists. !STACK 1 org.eclipse.core.internal.resources.ResourceException: Resource '/DMPackingSlipServiceEJB/ejbModule/META-INF/ejb-jar.xml' already exists. at org.eclipse.core.internal.resources.Resource.checkDoesNotExist(Resource.java:296) at org.eclipse.core.internal.resources.Resource.checkDoesNotExist(Resource.java:283) at org.eclipse.core.internal.resources.File.create(File.java:116) at org.eclipse.core.internal.resources.File.create(File.java:186) at org.eclipse.wst.xml.core.internal.emf2xml.EMF2DOMSSERenderer.createDocument(EMF2DOMSSERenderer.java:172) at org.eclipse.wst.common.internal.emf.resource.EMF2DOMRenderer.createDOMTree(EMF2DOMRenderer.java:127) at org.eclipse.wst.xml.core.internal.emf2xml.EMF2DOMSSERenderer.createDOMTreeIfNecessary(EMF2DOMSSERenderer.java:192) at org.eclipse.wst.xml.core.internal.emf2xml.EMF2DOMSSERenderer.doSave(EMF2DOMSSERenderer.java:249) at org.eclipse.wst.common.internal.emf.resource.TranslatorResourceImpl.doSave(TranslatorResourceImpl.java:180) at org.eclipse.wst.common.internal.emf.resource.TranslatorResourceImpl.save(TranslatorResourceImpl.java:160) at org.eclipse.wst.common.internal.emf.resource.ReferencedXMIResourceImpl.saveIfNecessary(ReferencedXMIResourceImpl.java:272) at org.eclipse.jst.j2ee.ejb.componentcore.util.EJBArtifactEdit.addEJBJarIfNecessary(EJBArtifactEdit.java:372) at org.eclipse.jst.j2ee.ejb.componentcore.util.EJBArtifactEdit.getDeploymentDescriptorRoot(EJBArtifactEdit.java:325) at org.eclipse.jst.j2ee.ejb.componentcore.util.EJBArtifactEdit.getEJBJar(EJBArtifactEdit.java:301) <product code> at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1800) at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1782) <product code> at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:633) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37) at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:170) at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:201) at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:253) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37) at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:256) at org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:309) at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:341) at org.eclipse.core.internal.resources.Workspace.build(Workspace.java:330) at org.eclipse.ui.actions.GlobalBuildAction$1.run(GlobalBuildAction.java:182) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55) !SUBENTRY 1 org.eclipse.core.resources 4 374 2008-09-25 19:02:58.046 !MESSAGE Resource '/DMPackingSlipServiceEJB/ejbModule/META-INF/ejb-jar.xml' already exists. ********************************************************* I tried looking through the code a bunch, but I can't figure out why on this rare occasion that it tried to create a document that was already there. Why wouldn't it always fail? The deadlocking code is just shortly after the ResourceException was thrown, so that obviously put something into a weird state.
Are these the only threads running? It's not obvious what is blocking your second trace, if anything.
I only gave the callstack for one thread. The second callstack is from the .log file (not the javacore dump). I only included one thread because the javacore dump didn't show anything else that could have caused this thread to block. It simply waited on an object that never notified. I have never seen this deadlock again, so it is obviously very difficult to reproduce. However, please take a quick look at the code involved and see if anything jumps out as possibly causing this problem. Otherwise, this bug can probably be closed as not reproducible.
(In reply to comment #2) > I have never seen this deadlock again, so it is obviously very difficult to > reproduce. However, please take a quick look at the code involved and see if > anything jumps out as possibly causing this problem. Otherwise, this bug can > probably be closed as not reproducible. Vote to resolve, if it is ever seen again maybe we can get some more information on it.
Thanks for the details you've provided. A ton of work has gone into the model manager to reduce the likelihood of deadlock. Not an easily reproducible report.
