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 static com.google.common.base.Preconditions.checkState;
11 import static java.util.Objects.requireNonNull;
13 import java.util.Arrays;
14 import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
15 import javax.annotation.Nonnull;
16 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
17 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
18 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshotCursor;
20 abstract class AbstractCursor<T extends AbstractCursorAware> implements DataTreeSnapshotCursor {
21 @SuppressWarnings("rawtypes")
22 private static final AtomicIntegerFieldUpdater<AbstractCursor> CLOSED_UPDATER =
23 AtomicIntegerFieldUpdater.newUpdater(AbstractCursor.class, "closed");
24 private final YangInstanceIdentifier rootPath;
25 private final T parent;
26 // closed isn't unused, it's updated by CLOSED_UPDATER but data-flow analysers can't see that
27 @SuppressWarnings("unused")
28 private volatile int closed;
30 AbstractCursor(final T parent, final YangInstanceIdentifier rootPath) {
31 this.rootPath = requireNonNull(rootPath);
32 this.parent = requireNonNull(parent);
39 final YangInstanceIdentifier getRootPath() {
44 final void ensureNotClosed() {
45 checkState(closed == 0, "Modification cursor has been closed");
49 public final void enter(@Nonnull final PathArgument... path) {
50 enter(Arrays.asList(path));
54 public final void exit() {
59 public final void close() {
60 if (CLOSED_UPDATER.compareAndSet(this, 0, 1)) {
61 parent.closeCursor(this);