Bug 307405 [CommonNavigator] Deadlock in NavigatorContentServiceContentProvider
We are using an adopting product and one of our users encountered this deadlock when starting up their workspace: 1LKDEADLOCK Deadlock detected !!! NULL --------------------- NULL 2LKDEADLOCKTHR Thread "main" (0x41591300) 3LKDEADLOCKWTR is waiting for: 4LKDEADLOCKMON sys_mon_t:0x43134548 infl_mon_t: 0x43134580: 4LKDEADLOCKOBJ org/eclipse/ui/internal/navigator/NavigatorSaveablesService@0x05DB48A8/0x05DB48B4: 3LKDEADLOCKOWN which is owned by: 2LKDEADLOCKTHR Thread "Framework Event Dispatcher" (0x42467700) 3LKDEADLOCKWTR which is waiting for: 4LKDEADLOCKMON sys_mon_t:0x43BA6AB8 infl_mon_t: 0x43BA6AF0: 4LKDEADLOCKOBJ org/eclipse/ui/internal/navigator/NavigatorContentServiceContentProvider@0x0306F6E8/0x0306F6F4: 3LKDEADLOCKOWN which is owned by: 2LKDEADLOCKTHR Thread "main" (0x41591300) I will attach the stack trace.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentServiceContentProvider.java
*/
	public NavigatorContentServiceContentProvider(NavigatorContentService aContentService) {
		super();
		contentService = aContentService;
		INavigatorViewerDescriptor vDesc = contentService.getViewerDescriptor();
		enforceHasChildren = vDesc.getBooleanConfigProperty(NavigatorViewerDescriptor.PROP_ENFORCE_HAS_CHILDREN);
	}
	public synchronized void inputChanged(Viewer aViewer, Object anOldInput, Object aNewInput) {
		viewer = aViewer;
		contentService.updateService(aViewer, anOldInput, aNewInput);
	}
	public synchronized Object[] getElements(Object anInputElement) {
		Set rootContentExtensions = contentService.findRootContentExtensions(anInputElement);
		return internalGetChildren(anInputElement, anInputElement, rootContentExtensions, ELEMENTS);
	}
	public synchronized Object[] getChildren(Object aParentElement) {
		Set enabledExtensions = contentService.findContentExtensionsByTriggerPoint(aParentElement);
		return internalGetChildren(aParentElement, aParentElement, enabledExtensions, !ELEMENTS);
	}
	public synchronized Object[] getChildren(TreePath parentPath) {
		Object aParentElement = internalAsElement(parentPath);
		Set enabledExtensions = contentService.findContentExtensionsByTriggerPoint(aParentElement);
		return internalGetChildren(aParentElement, parentPath, enabledExtensions, !ELEMENTS);
	}
	
	private static final boolean ELEMENTS = true;
	private Object[] internalGetChildren(Object aParentElement, Object aParentElementOrPath, Set enabledExtensions, boolean elements) {
		if (enabledExtensions.size() == 0) {
			return NO_CHILDREN;
		}