Improve listener dispatch

Both RPC and action listeners should always be ImmutableLists, make sure
that is captured in their definition. This is an invariant useful for
JIT, as we bind directly to implementation -- and do not throw
Collections.emptyList() into the mix.

Change-Id: I7fe71819f11b80399734759bf774c629adfe12bf
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>

diff --git a/dom/mdsal-dom-broker/src/main/java/org/opendaylight/mdsal/dom/broker/DOMRpcRouter.java b/dom/mdsal-dom-broker/src/main/java/org/opendaylight/mdsal/dom/broker/DOMRpcRouter.java
index 37713fd58cc2512e45ca0840f70c717254d93942..34344509ce5d8b96c1b3d9b19eeee06cb4e6bc44 100644 (file)
--- a/dom/mdsal-dom-broker/src/main/java/org/opendaylight/mdsal/dom/broker/DOMRpcRouter.java
+++ b/dom/mdsal-dom-broker/src/main/java/org/opendaylight/mdsal/dom/broker/DOMRpcRouter.java
@@ -28,7 +28,6 @@ import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -101,10 +100,10 @@ public final class DOMRpcRouter extends AbstractRegistration
     private final @NonNull DOMRpcService rpcService = new RpcServiceFacade();
 
     @GuardedBy("this")
-    private Collection<Registration<?>> listeners = Collections.emptyList();
+    private ImmutableList<Registration<?>> listeners = ImmutableList.of();
 
     @GuardedBy("this")
-    private Collection<ActionRegistration<?>> actionListeners = Collections.emptyList();
+    private ImmutableList<ActionRegistration<?>> actionListeners = ImmutableList.of();
 
     private volatile DOMRpcRoutingTable routingTable = DOMRpcRoutingTable.EMPTY;
 
@@ -269,7 +268,7 @@ public final class DOMRpcRouter extends AbstractRegistration
     }
 
     @VisibleForTesting
-    synchronized Collection<?> listeners() {
+    synchronized List<?> listeners() {
         return listeners;
     }
 
@@ -297,7 +296,7 @@ public final class DOMRpcRouter extends AbstractRegistration
         }
 
         void initialTable() {
-            final Collection<DOMRpcIdentifier> added = new ArrayList<>();
+            final List<DOMRpcIdentifier> added = new ArrayList<>();
             for (Entry<QName, Set<YangInstanceIdentifier>> e : prevRpcs.entrySet()) {
                 added.addAll(Collections2.transform(e.getValue(), i -> DOMRpcIdentifier.create(e.getKey(), i)));
             }
@@ -315,7 +314,7 @@ public final class DOMRpcRouter extends AbstractRegistration
             final Map<QName, Set<YangInstanceIdentifier>> rpcs = verifyNotNull(newTable.getOperations(l));
             final MapDifference<QName, Set<YangInstanceIdentifier>> diff = Maps.difference(prevRpcs, rpcs);
 
-            final Collection<DOMRpcIdentifier> added = new ArrayList<>();
+            final List<DOMRpcIdentifier> added = new ArrayList<>();
             for (Entry<QName, Set<YangInstanceIdentifier>> e : diff.entriesOnlyOnRight().entrySet()) {
                 added.addAll(Collections2.transform(e.getValue(), i -> DOMRpcIdentifier.create(e.getKey(), i)));
             }
@@ -340,7 +339,7 @@ public final class DOMRpcRouter extends AbstractRegistration
             final Map<QName, Set<YangInstanceIdentifier>> rpcs = verifyNotNull(newTable.getOperations(l));
             final MapDifference<QName, Set<YangInstanceIdentifier>> diff = Maps.difference(prevRpcs, rpcs);
 
-            final Collection<DOMRpcIdentifier> removed = new ArrayList<>();
+            final List<DOMRpcIdentifier> removed = new ArrayList<>();
             for (Entry<QName, Set<YangInstanceIdentifier>> e : diff.entriesOnlyOnLeft().entrySet()) {
                 removed.addAll(Collections2.transform(e.getValue(), i -> DOMRpcIdentifier.create(e.getKey(), i)));
             }
@@ -377,7 +376,7 @@ public final class DOMRpcRouter extends AbstractRegistration
         }
 
         void initialTable() {
-            final Collection<DOMActionInstance> added = new ArrayList<>();
+            final List<DOMActionInstance> added = new ArrayList<>();
             for (Entry<Absolute, Set<DOMDataTreeIdentifier>> e : prevActions.entrySet()) {
                 added.addAll(Collections2.transform(e.getValue(), i -> DOMActionInstance.of(e.getKey(), i)));
             }