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
* take precedence over the originally contributing NCE.  However in the case of different first class NCEs, the first one 
		 * wins, so we don't update the contribution memory. 
		 */
		if (contributionMemory.get(element) == null || contributionMemoryFirstClass.get(element) == firstClassSource) {
			if (Policy.DEBUG_RESOLUTION)
				System.out.println("rememberContribution: " + Policy.getObjectString(element) + " source: " + source);  
			contributionMemory.put(element, source);
			contributionMemoryFirstClass.put(element, firstClassSource);
		}
	}
	
	/**
	 * Forget about the specified element
	 * 
	 * @param element
	 *            The element to forget.
	 */
	public void forgetContribution(Object element) {
		contributionMemory.remove(element);
		contributionMemoryFirstClass.remove(element);
	}
	
	/**
	 * @param element
	 * @return the remembered NavigatorContentDescriptor
	 */
	public NavigatorContentDescriptor getContribution(Object element)
	{
		NavigatorContentDescriptor desc = (NavigatorContentDescriptor) contributionMemory.get(element);
		return desc;