2 * (C) Copyright 2016 Pantheon Technologies, s.r.o. and others.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
16 package org.opendaylight.yangtools.triemap;
18 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
20 abstract class MainNode<K, V> extends BasicNode {
22 public static final AtomicReferenceFieldUpdater<MainNode, MainNode> updater = AtomicReferenceFieldUpdater.newUpdater (MainNode.class, MainNode.class, "prev");
24 public volatile MainNode<K, V> prev = null;
26 abstract int cachedSize(TrieMap<K, V> ct);
28 public boolean CAS_PREV (final MainNode<K, V> oldval, final MainNode<K, V> nval) {
29 return updater.compareAndSet (this, oldval, nval);
32 public void WRITE_PREV (final MainNode<K, V> nval) {
33 updater.set (this, nval);
36 // do we need this? unclear in the javadocs...
37 // apparently not - volatile reads are supposed to be safe
38 // regardless of whether there are concurrent ARFU updates
39 public MainNode<K, V> READ_PREV () {
40 return updater.get (this);