Potential deadlock during concurrent bottom-up/top-down queue traversal

objects.(*Queue).DecAllocatedResource { sq.Lock() } <<<<<
objects.(*Queue).DecAllocatedResource { } }
objects.(*Queue).DecAllocatedResource { if sq.parent != nil { }
scheduler.(*PartitionContext).removeAllocation { if resources.StrictlyGreaterThanZero(total) { }
scheduler.(*ClusterContext).processAllocationReleases { // notify the RM of the exact released allocations }
scheduler.(*ClusterContext).handleRMUpdateAllocationEvent { } }
scheduler.(*Scheduler).handleRMEvent { case ev := <-s.pendingEvents: }

objects.(*Queue).MarkQueueForRemoval { sq.Lock() } <<<<<
objects.(*Queue).MarkQueueForRemoval { // need to lock for write as we don't want to add a queue while marking for removal }
objects.(*Queue).MarkQueueForRemoval { if len(sq.children) > 0 { }
scheduler.(*partitionManager).remove { // remove applications: we do not care about return values or issues }
scheduler.(*partitionManager).Stop { manager.remove() }
scheduler.(*ClusterContext).Stop { part.partitionManager.Stop() }
scheduler.(*Scheduler).Stop { s.clusterContext.Stop() }
entrypoint.(*ServiceContext).StopAll { s.Scheduler.Stop() }
tests.TestBasicScheduler.deferwrap1 { ms := &mockScheduler{} }
tests.TestBasicScheduler { waitForPendingAppResource(t, app, 0, 1000) }

func (t *Type) topDown() {
  t.Lock()
  defer t.Unlock()

  for _, ch := range t.children {   
    ch.topDown()   // lock must not be hold here
  }
}

func (t *Type) bottomUp() {
  t.Lock()
  defer t.Unlock()

  if t.parent != nil {
    t.parent.bottumUp()  // lock must not be hold here
  }
 }