BUG-509: fix ModifiedNode locking

[controller.git] / opendaylight / md-sal / sal-dom-broker / src / main / java / org / opendaylight / controller / md / sal / dom / store / impl / tree / data / InMemoryDataTreeModification.java

diff --git a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/tree/data/InMemoryDataTreeModification.java b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/tree/data/InMemoryDataTreeModification.java
index 7d0c81e39de8efe564c33925280c9dbb9c71ff22..d3e4bf07144e0e99ebe3be6e8e322c5fb9cf4b1d 100644 (file)
--- a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/tree/data/InMemoryDataTreeModification.java
+++ b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/tree/data/InMemoryDataTreeModification.java
@@ -7,14 +7,14 @@
  */
 package org.opendaylight.controller.md.sal.dom.store.impl.tree.data;
 
-import static com.google.common.base.Preconditions.checkState;
-
 import java.util.Map.Entry;
-import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
+
+import javax.annotation.concurrent.GuardedBy;
 
 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeModification;
 import org.opendaylight.controller.md.sal.dom.store.impl.tree.StoreUtils;
 import org.opendaylight.controller.md.sal.dom.store.impl.tree.TreeNodeUtils;
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.spi.TreeNode;
 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.PathArgument;
 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
@@ -28,26 +28,20 @@ import com.google.common.base.Preconditions;
 
 final class InMemoryDataTreeModification implements DataTreeModification {
     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDataTreeModification.class);
-
-    /*
-     * FIXME: the thread safety of concurrent write/delete/read/seal operations
-     *        needs to be evaluated.
-     */
-    private static final AtomicIntegerFieldUpdater<InMemoryDataTreeModification> SEALED_UPDATER =
-            AtomicIntegerFieldUpdater.newUpdater(InMemoryDataTreeModification.class, "sealed");
-    private volatile int sealed = 0;
-
     private final ModificationApplyOperation strategyTree;
     private final InMemoryDataTreeSnapshot snapshot;
-    private final NodeModification rootNode;
+    private final ModifiedNode rootNode;
+
+    @GuardedBy("this")
+    private boolean sealed = false;
 
     InMemoryDataTreeModification(final InMemoryDataTreeSnapshot snapshot, final ModificationApplyOperation resolver) {
         this.snapshot = Preconditions.checkNotNull(snapshot);
         this.strategyTree = Preconditions.checkNotNull(resolver);
-        this.rootNode = NodeModification.createUnmodified(snapshot.getRootNode());
+        this.rootNode = ModifiedNode.createUnmodified(snapshot.getRootNode());
     }
 
-    NodeModification getRootModification() {
+    ModifiedNode getRootModification() {
         return rootNode;
     }
 
@@ -56,13 +50,13 @@ final class InMemoryDataTreeModification implements DataTreeModification {
     }
 
     @Override
-    public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> value) {
+    public synchronized void write(final InstanceIdentifier path, final NormalizedNode<?, ?> value) {
         checkSealed();
         resolveModificationFor(path).write(value);
     }
 
     @Override
-    public void merge(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
+    public synchronized void merge(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
         checkSealed();
         mergeImpl(resolveModificationFor(path),data);
     }
@@ -81,23 +75,23 @@ final class InMemoryDataTreeModification implements DataTreeModification {
     }
 
     @Override
-    public void delete(final InstanceIdentifier path) {
+    public synchronized void delete(final InstanceIdentifier path) {
         checkSealed();
         resolveModificationFor(path).delete();
     }
 
     @Override
-    public Optional<NormalizedNode<?, ?>> readNode(final InstanceIdentifier path) {
+    public synchronized Optional<NormalizedNode<?, ?>> readNode(final InstanceIdentifier path) {
         /*
          * Walk the tree from the top, looking for the first node between root and
          * the requested path which has been modified. If no such node exists,
          * we use the node itself.
          */
-        final Entry<InstanceIdentifier, NodeModification> entry = TreeNodeUtils.findClosestsOrFirstMatch(rootNode, path, NodeModification.IS_TERMINAL_PREDICATE);
+        final Entry<InstanceIdentifier, ModifiedNode> entry = TreeNodeUtils.findClosestsOrFirstMatch(rootNode, path, ModifiedNode.IS_TERMINAL_PREDICATE);
         final InstanceIdentifier key = entry.getKey();
-        final NodeModification mod = entry.getValue();
+        final ModifiedNode mod = entry.getValue();
 
-        final Optional<StoreMetadataNode> result = resolveSnapshot(key, mod);
+        final Optional<TreeNode> result = resolveSnapshot(key, mod);
         if (result.isPresent()) {
             NormalizedNode<?, ?> data = result.get().getData();
             return NormalizedNodeUtils.findNode(key, data, path);
@@ -106,9 +100,9 @@ final class InMemoryDataTreeModification implements DataTreeModification {
         }
     }
 
-    private Optional<StoreMetadataNode> resolveSnapshot(final InstanceIdentifier path,
-            final NodeModification modification) {
-        final Optional<Optional<StoreMetadataNode>> potentialSnapshot = modification.getSnapshotCache();
+    private Optional<TreeNode> resolveSnapshot(final InstanceIdentifier path,
+            final ModifiedNode modification) {
+        final Optional<Optional<TreeNode>> potentialSnapshot = modification.getSnapshotCache();
         if(potentialSnapshot.isPresent()) {
             return potentialSnapshot.get();
         }
@@ -128,7 +122,7 @@ final class InMemoryDataTreeModification implements DataTreeModification {
     }
 
     private OperationWithModification resolveModificationFor(final InstanceIdentifier path) {
-        NodeModification modification = rootNode;
+        ModifiedNode modification = rootNode;
         // We ensure strategy is present.
         ModificationApplyOperation operation = resolveModificationStrategy(path);
         for (PathArgument pathArg : path.getPath()) {
@@ -138,14 +132,15 @@ final class InMemoryDataTreeModification implements DataTreeModification {
     }
 
     @Override
-    public void seal() {
-        final boolean success = SEALED_UPDATER.compareAndSet(this, 0, 1);
-        Preconditions.checkState(success, "Attempted to seal an already-sealed Data Tree.");
+    public synchronized void seal() {
+        Preconditions.checkState(!sealed, "Attempted to seal an already-sealed Data Tree.");
+        sealed = true;
         rootNode.seal();
     }
 
+    @GuardedBy("this")
     private void checkSealed() {
-        checkState(sealed == 0, "Data Tree is sealed. No further modifications allowed.");
+        Preconditions.checkState(!sealed, "Data Tree is sealed. No further modifications allowed.");
     }
 
     @Override
@@ -154,7 +149,9 @@ final class InMemoryDataTreeModification implements DataTreeModification {
     }
 
     @Override
-    public DataTreeModification newModification() {
+    public synchronized DataTreeModification newModification() {
+        Preconditions.checkState(sealed, "Attempted to chain on an unsealed modification");
+
         // FIXME: transaction chaining
         throw new UnsupportedOperationException("Implement this as part of transaction chaining");
     }