defer e.lock.Unlock()
	e.alloc.ForEach(fn)
}

// tryUpdate performs a read-update to persist the latest snapshot state of allocation.
func (e *Etcd) tryUpdate(fn func() error) error {
	err := e.storage.GuaranteedUpdate(context.TODO(), e.baseKey, &api.RangeAllocation{}, true, nil,
		storage.SimpleUpdate(func(input runtime.Object) (output runtime.Object, err error) {
			existing := input.(*api.RangeAllocation)