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/NavigatorContentService.java
* 
	 * @param anElement
	 *            An element from the tree (any element contributed to the
	 *            tree).
	 * @return A Collection of NCEs sorted in the correct order for label provider application
	 */
	public Collection findPossibleLabelExtensions(Object anElement) {
		LinkedHashSet contributors = new LinkedHashSet();
		INavigatorContentDescriptor sourceDescriptor = getSourceOfContribution(anElement);
		
		if (sourceDescriptor != null) {
			findOverridingLabelExtensions(anElement, sourceDescriptor, contributors);
		}
		
		
		Set possibleChildDescriptors = findDescriptorsWithPossibleChild(anElement, false);
		for (Iterator iter = possibleChildDescriptors.iterator(); iter.hasNext();) {
			NavigatorContentDescriptor ncd = (NavigatorContentDescriptor) iter.next();
			findOverridingLabelExtensions(anElement, ncd, contributors);
		}
		return contributors;
	}
	private void findOverridingLabelExtensions(Object anElement,
			INavigatorContentDescriptor descriptor, LinkedHashSet contributors) {
		ListIterator iter = ((NavigatorContentDescriptor) descriptor).getOverridingExtensionsListIterator(false);
		while (iter.hasPrevious()) {
			INavigatorContentDescriptor child = (INavigatorContentDescriptor) iter.previous();
			if (assistant.isVisibleAndActive(child) && child.isPossibleChild(anElement)) {
				findOverridingLabelExtensions(anElement, child, contributors);
			}