From 0ad6f7f4892816c84542bf0dbe6fbc7c61febd2d Mon Sep 17 00:00:00 2001
From: jonmv <venstad@gmail.com>
Date: Fri, 29 Apr 2022 20:18:30 +0200
Subject: Simplify shared resource setup with Memoized

---
 .../jdisc/messagebus/NetworkMultiplexerHolder.java | 27 ++++++++--------------
 .../container/jdisc/messagebus/SessionCache.java   | 18 +++++----------
 2 files changed, 16 insertions(+), 29 deletions(-)

(limited to 'container-messagebus/src')

diff --git a/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/NetworkMultiplexerHolder.java b/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/NetworkMultiplexerHolder.java
index cb28807ac73..8b3b2664cd1 100644
--- a/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/NetworkMultiplexerHolder.java
+++ b/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/NetworkMultiplexerHolder.java
@@ -7,6 +7,9 @@ import com.yahoo.messagebus.network.NetworkMultiplexer;
 import com.yahoo.messagebus.network.rpc.RPCNetwork;
 import com.yahoo.messagebus.network.rpc.RPCNetworkParams;
 import com.yahoo.messagebus.shared.NullNetwork;
+import com.yahoo.yolean.concurrent.Memoized;
+
+import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * Holds a reference to a singleton {@link NetworkMultiplexer}.
@@ -15,21 +18,17 @@ import com.yahoo.messagebus.shared.NullNetwork;
  */
 public class NetworkMultiplexerHolder extends AbstractComponent {
 
-    private final Object monitor = new Object();
-    private boolean destroyed = false;
-    private NetworkMultiplexer net;
+    private final AtomicReference<RPCNetworkParams> params = new AtomicReference<>();
+    private final Memoized<NetworkMultiplexer, RuntimeException> net = new Memoized<>(() -> NetworkMultiplexer.shared(newNetwork(params.get())),
+                                                                                      NetworkMultiplexer::disown);
 
     /** Get the singleton RPCNetworkAdapter, creating it if this hasn't yet been done. */
     public NetworkMultiplexer get(RPCNetworkParams params) {
-        synchronized (monitor) {
-            if (destroyed)
-                throw new IllegalStateException("Component already destroyed");
-
-            return net = net != null ? net : NetworkMultiplexer.shared(newNetwork(params));
-        }
+        this.params.set(params);
+        return net.get();
     }
 
-    private Network newNetwork(RPCNetworkParams params) {
+    private static Network newNetwork(RPCNetworkParams params) {
         return params.getSlobroksConfig() != null && params.getSlobroksConfig().slobrok().isEmpty()
                ? new NullNetwork() // For LocalApplication, test setup.
                : new RPCNetwork(params);
@@ -37,13 +36,7 @@ public class NetworkMultiplexerHolder extends AbstractComponent {
 
     @Override
     public void deconstruct() {
-        synchronized (monitor) {
-            if (net != null) {
-                net.disown();
-                net = null;
-            }
-            destroyed = true;
-        }
+        net.close();
     }
 
 }
diff --git a/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/SessionCache.java b/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/SessionCache.java
index 91a3181cb68..612eb8bb8e0 100644
--- a/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/SessionCache.java
+++ b/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/SessionCache.java
@@ -29,6 +29,7 @@ import com.yahoo.messagebus.shared.SharedMessageBus;
 import com.yahoo.messagebus.shared.SharedSourceSession;
 import com.yahoo.vespa.config.content.DistributionConfig;
 import com.yahoo.vespa.config.content.LoadTypeConfig;
+import com.yahoo.yolean.concurrent.Memoized;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -55,8 +56,7 @@ public final class SessionCache extends AbstractComponent {
     private static final Logger log = Logger.getLogger(SessionCache.class.getName());
 
     private final Object monitor = new Object();
-    private Supplier<SharedMessageBus> messageBuses;
-    private SharedMessageBus messageBus;
+    private Memoized<SharedMessageBus, RuntimeException> messageBus;
 
     private final Object intermediateLock = new Object();
     private final Map<String, SharedIntermediateSession> intermediates = new HashMap<>();
@@ -96,24 +96,18 @@ public final class SessionCache extends AbstractComponent {
 
     public SessionCache(Supplier<NetworkMultiplexer> net, ContainerMbusConfig containerMbusConfig,
                         MessagebusConfig messagebusConfig, Protocol protocol) {
-        this.messageBuses = () -> createSharedMessageBus(net.get(), containerMbusConfig, messagebusConfig, protocol);
+        this.messageBus = new Memoized<>(() -> createSharedMessageBus(net.get(), containerMbusConfig, messagebusConfig, protocol),
+                                         SharedMessageBus::release);
     }
 
     @Override
     public void deconstruct() {
-        synchronized (monitor) {
-            messageBuses = () -> { throw new IllegalStateException("Session cache already deconstructed"); };
-
-            if (messageBus != null)
-                messageBus.release();
-        }
+        messageBus.close();
     }
 
     // Lazily create shared message bus.
     private SharedMessageBus bus() {
-        synchronized (monitor) {
-            return messageBus = messageBus != null ? messageBus : messageBuses.get();
-        }
+        return messageBus.get();
     }
 
     private static SharedMessageBus createSharedMessageBus(NetworkMultiplexer net,
-- 
cgit v1.2.3