Bugzilla – Full Text Bug Listing
| Summary: | [WorkingSets] The working set were not restored at the eclipse launching. | ||||||
|---|---|---|---|---|---|---|---|
| Product: | [Eclipse Project] Platform | Reporter: | Hiroyuki Inaba <hiroyuki.inaba> | ||||
| Component: | UI | Assignee: | Hitesh <hsoliwal> | ||||
| Status: | RESOLVED DUPLICATE | QA Contact: | |||||
| Severity: | normal | ||||||
| Priority: | P3 | CC: | emoffatt, hinaba, masashi.sato | ||||
| Version: | 3.3 | ||||||
| Target Milestone: | 3.6 | ||||||
| Hardware: | PC | ||||||
| OS: | Windows XP | ||||||
| Whiteboard: | |||||||
| Attachments: |
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The problem originates in the XML parser (xerces base) included in Sun JDK.
The problem occurs in Sun JDK 1.5+Eclipse 3.2.1.
org.eclipse.ui.XMLMemento is called from two threads.
But, XML DOM(org.w3c.dom.Element) is the thread un-safe.
Processing where NPE was occurred should change the thread safely
by using the Java synchronized statement.
/* (non-Javadoc)
* Method declared in IMemento.
*/
public IMemento getChild(String type) {
==> synchronized (element) {
// Get the nodes.
NodeList nodes = element.getChildNodes();
int size = nodes.getLength();
if (size == 0) {
return null;
}
// Find the first node which is a child of this node.
for (int nX = 0; nX < size; nX++) {
Node node = nodes.item(nX);
if (node instanceof Element) {
Element element = (Element) node;
if (element.getNodeName().equals(type)) {
return new XMLMemento(factory, element);
}
}
}
// A child was not found.
return null;
==> }
}
It is thought that other methods of XMLMemoto also use
the Java synchronized sentence, and it is necessary to
change the thread safely.
Created attachment 111549 [details]
a sample patch for Eclipse 3.4
(In reply to comment #1) > The problem originates in the XML parser (xerces base) included in Sun JDK. > The problem occurs in Sun JDK 1.5+Eclipse 3.2.1. > > org.eclipse.ui.XMLMemento is called from two threads. > But, XML DOM(org.w3c.dom.Element) is the thread un-safe. > Processing where NPE was occurred should change the thread safely > by using the Java synchronized statement. > What other threads were tryign to read from this? This may be a case where we fix the caller rather than the memento itself... Adding Eric as this may be a [Model] issue. At least, there is a problem in the following codes if Xerces is not a thread safe.
----------------------------
org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchWindow.java
restoreState(IMemento, IPerspectiveDescriptor)
:
final IMemento fastViewMem = memento
.getChild(IWorkbenchConstants.TAG_FAST_VIEW_DATA);
if (fastViewMem != null) {
if (fastViewBar != null) {
StartupThreading.runWithoutExceptions(new StartupRunnable() {
public void runWithException() {
* fastViewBar.restoreState(fastViewMem);
}});
}
}
----------------------------
Because the line of the sign "*" is executed by another thread, the access to same Document will be done from different threads.
Is this still an issue? We haven't seen any duplicates so it's not a commonly encountered scenario... I think that it is clear that there is a problem from the source which I mentioned though it is rare that the problem actually occurs.
> What other threads were tryign to read from this? This may be a case where we
> fix the caller rather than the memento itself...
Please investigate the thread I mentioned.
Hitesh, we have to either act on this or change the target milestone... I think we are better off changing the target milestone. I haven't come across a single occurrence of this problem.I'll take a look at this anyways. I agree... *** This bug has been marked as a duplicate of bug 170205 *** |
Build ID: I20070323-1616 The problem occurred on the following conditions. - Many projects exists in the workspace. About 700: That are Eclipse Project SDK projects, WTP projects, EMF projects and etc. - 25 or more working sets exists in the workspace. More information: NPE occurred at the eclipse launching. !SESSION 2007-04-17 10:22:29.812 ----------------------------------------------- eclipse.buildId=I20070323-1616 java.version=1.6.0_02-ea java.vendor=Sun Microsystems Inc. BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=en Framework arguments: -startup c:\eclipse33x.org\eclipse\plugins\org.eclipse.equinox.launcher_1.0.0.v20070319.jar Command-line arguments: -os win32 -ws win32 -arch x86 -startup c:\eclipse33x.org\eclipse\plugins\org.eclipse.equinox.launcher_1.0.0.v20070319.jar -clean -debug -data C:\eclipse33x.org\workspace !ENTRY org.eclipse.jdt.ui 4 2 2007-04-17 10:22:41.484 !MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.jdt.ui". !STACK 0 java.lang.NullPointerException at org.eclipse.ui.XMLMemento.getChildren(XMLMemento.java:235) at org.eclipse.ui.internal.WorkingSet.restoreWorkingSet(WorkingSet.java:144) at org.eclipse.ui.internal.AbstractWorkingSet.getElementsArray(AbstractWorkingSet.java:151) at org.eclipse.ui.internal.AbstractWorkingSet.getElements(AbstractWorkingSet.java:139) at org.eclipse.jdt.internal.ui.workingsets.WorkingSetModel$ElementMapper.put(WorkingSetModel.java:157) at org.eclipse.jdt.internal.ui.workingsets.WorkingSetModel$ElementMapper.rebuild(WorkingSetModel.java:95) at org.eclipse.jdt.internal.ui.workingsets.WorkingSetModel.<init>(WorkingSetModel.java:247) at org.eclipse.jdt.internal.ui.packageview.PackageExplorerPart$10.run(PackageExplorerPart.java:1539) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37) at org.eclipse.jdt.internal.ui.packageview.PackageExplorerPart.createWorkingSetModel(PackageExplorerPart.java:1537) at org.eclipse.jdt.internal.ui.packageview.PackageExplorerPart.init(PackageExplorerPart.java:473) at org.eclipse.ui.internal.ViewReference.createPartHelper(ViewReference.java:336) at org.eclipse.ui.internal.ViewReference.createPart(ViewReference.java:219) at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:592) at org.eclipse.ui.internal.PartPane.setVisible(PartPane.java:299) at org.eclipse.ui.internal.ViewPane.setVisible(ViewPane.java:531) at org.eclipse.ui.internal.presentations.PresentablePart.setVisible(PresentablePart.java:179) at org.eclipse.ui.internal.presentations.util.PresentablePartFolder.select(PresentablePartFolder.java:268) at org.eclipse.ui.internal.presentations.util.LeftToRightTabOrder.select(LeftToRightTabOrder.java:65) at org.eclipse.ui.internal.presentations.util.TabbedStackPresentation.selectPart(TabbedStackPresentation.java:394) at org.eclipse.ui.internal.PartStack.refreshPresentationSelection(PartStack.java:1208) at org.eclipse.ui.internal.PartStack.createControl(PartStack.java:639) at org.eclipse.ui.internal.PartStack.createControl(PartStack.java:551) at org.eclipse.ui.internal.PartSashContainer.createControl(PartSashContainer.java:563) at org.eclipse.ui.internal.PerspectiveHelper.activate(PerspectiveHelper.java:259) at org.eclipse.ui.internal.Perspective.onActivate(Perspective.java:884) at org.eclipse.ui.internal.WorkbenchPage.onActivate(WorkbenchPage.java:2467) at org.eclipse.ui.internal.WorkbenchWindow$23.run(WorkbenchWindow.java:2790) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:67) at org.eclipse.ui.internal.WorkbenchWindow.setActivePage(WorkbenchWindow.java:2771) at org.eclipse.ui.internal.WorkbenchWindow$17.runWithException(WorkbenchWindow.java:2116) at org.eclipse.ui.internal.StartupThreading$StartupRunnable.run(StartupThreading.java:31) at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35) at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:123) at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3650) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3287) at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2260) at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2176) at org.eclipse.ui.internal.Workbench$4.run(Workbench.java:463) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:289) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:458) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149) at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:101) at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:146) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:106) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:76) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:356) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:171) 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:597) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:476) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:416) at org.eclipse.equinox.launcher.Main.run(Main.java:1141)