2 * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.yangtools.yang.data.impl.schema.tree;
10 import com.google.common.base.Preconditions;
11 import java.util.Arrays;
12 import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
13 import javax.annotation.Nonnull;
14 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
15 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
16 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshotCursor;
18 abstract class AbstractCursor<T extends AbstractCursorAware> implements DataTreeSnapshotCursor {
19 @SuppressWarnings("rawtypes")
20 private static final AtomicIntegerFieldUpdater<AbstractCursor> CLOSED_UPDATER =
21 AtomicIntegerFieldUpdater.newUpdater(AbstractCursor.class, "closed");
22 private final YangInstanceIdentifier rootPath;
23 private final T parent;
24 // closed isn't unused, it's updated by CLOSED_UPDATER but data-flow analysers can't see that
25 @SuppressWarnings("unused")
26 private volatile int closed;
28 AbstractCursor(final T parent, final YangInstanceIdentifier rootPath) {
29 this.rootPath = Preconditions.checkNotNull(rootPath);
30 this.parent = Preconditions.checkNotNull(parent);
37 final YangInstanceIdentifier getRootPath() {
42 final void ensureNotClosed() {
43 Preconditions.checkState(closed == 0, "Modification cursor has been closed");
47 public final void enter(@Nonnull final PathArgument... path) {
48 enter(Arrays.asList(path));
52 public final void exit() {
57 public final void close() {
58 if (CLOSED_UPDATER.compareAndSet(this, 0, 1)) {
59 parent.closeCursor(this);