Use Netty future/promise in AsyncResolveConnectHelper to remove unecessary concurrency - fixes #3142

src/main/java/io/vertx/core/http/impl/HttpServerImpl.java

@@ -17,6 +17,7 @@ import io.netty.channel.ChannelHandler;
 import io.netty.channel.group.ChannelGroup;
 import io.netty.channel.group.ChannelGroupFuture;
 import io.netty.channel.group.DefaultChannelGroup;
+import io.netty.util.concurrent.GenericFutureListener;
 import io.netty.util.concurrent.GlobalEventExecutor;
 import io.vertx.core.*;
 import io.vertx.core.buffer.Buffer;
@@ -71,7 +72,7 @@ public class HttpServerImpl implements HttpServer, Closeable, MetricsProvider {
 
   private ChannelGroup serverChannelGroup;
   private volatile boolean listening;
-  private AsyncResolveConnectHelper bindFuture;
+  private io.netty.util.concurrent.Future<Channel> bindFuture;
   private ServerID id;
   private HttpServerImpl actualServer;
   private volatile int actualPort;
@@ -243,13 +244,13 @@ public class HttpServerImpl implements HttpServer, Closeable, MetricsProvider {
         addHandlers(this, listenContext);
         try {
           bindFuture = AsyncResolveConnectHelper.doBind(vertx, address, bootstrap);
-          bindFuture.addListener(res -> {
-            if (res.failed()) {
+          bindFuture.addListener((GenericFutureListener<io.netty.util.concurrent.Future<Channel>>) res -> {
+            if (!res.isSuccess()) {
               synchronized (sharedHttpServers) {
                 sharedHttpServers.remove(id);
               }
             } else {
-              Channel serverChannel = res.result();
+              Channel serverChannel = res.getNow();
               if (serverChannel.localAddress() instanceof InetSocketAddress) {
                 HttpServerImpl.this.actualPort = ((InetSocketAddress)serverChannel.localAddress()).getPort();
               } else {
@@ -279,17 +280,17 @@ public class HttpServerImpl implements HttpServer, Closeable, MetricsProvider {
         VertxMetrics metrics = vertx.metricsSPI();
         this.metrics = metrics != null ? metrics.createHttpServerMetrics(options, address) : null;
       }
-      actualServer.bindFuture.addListener(future -> {
+      actualServer.bindFuture.addListener((GenericFutureListener<io.netty.util.concurrent.Future<Channel>>) future -> {
         if (listenHandler != null) {
           final AsyncResult<HttpServer> res;
-          if (future.succeeded()) {
+          if (future.isSuccess()) {
             res = Future.succeededFuture(HttpServerImpl.this);
           } else {
             res = Future.failedFuture(future.cause());
             listening = false;
           }
           listenContext.runOnContext((v) -> listenHandler.handle(res));
-        } else if (future.failed()) {
+        } else if (!future.isSuccess()) {
           listening  = false;
           if (metrics != null) {
             metrics.close();

src/main/java/io/vertx/core/net/impl/AsyncResolveConnectHelper.java

@@ -14,67 +14,36 @@ package io.vertx.core.net.impl;
 import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
-import io.vertx.core.AsyncResult;
-import io.vertx.core.Future;
-import io.vertx.core.Handler;
+import io.netty.util.concurrent.Promise;
 import io.vertx.core.impl.VertxInternal;
 import io.vertx.core.net.SocketAddress;
 
 import java.net.InetSocketAddress;
-import java.util.ArrayList;
-import java.util.List;
 
 /**
  * @author <a href="http://tfox.org">Tim Fox</a>
  */
 public class AsyncResolveConnectHelper {
 
-  private List<Handler<AsyncResult<Channel>>> handlers = new ArrayList<>();
-  private ChannelFuture future;
-  private AsyncResult<Channel> result;
-
-  public synchronized void addListener(Handler<AsyncResult<Channel>> handler) {
-    if (result != null) {
-      if (future != null) {
-        future.addListener(v -> handler.handle(result));
-      } else {
-        handler.handle(result);
-      }
-    } else {
-      handlers.add(handler);
-    }
-  }
-
-  private synchronized void handle(ChannelFuture cf, AsyncResult<Channel> res) {
-    if (result == null) {
-      for (Handler<AsyncResult<Channel>> handler: handlers) {
-        handler.handle(res);
-      }
-      future = cf;
-      result = res;
-    } else {
-      throw new IllegalStateException("Already complete!");
-    }
-  }
-
   private static void checkPort(int port) {
     if (port < 0 || port > 65535) {
       throw new IllegalArgumentException("Invalid port " + port);
     }
   }
 
-  public static AsyncResolveConnectHelper doBind(VertxInternal vertx, SocketAddress socketAddress,
-                                                 ServerBootstrap bootstrap) {
-    AsyncResolveConnectHelper asyncResolveConnectHelper = new AsyncResolveConnectHelper();
+  public static io.netty.util.concurrent.Future<Channel> doBind(VertxInternal vertx,
+                                                                SocketAddress socketAddress,
+                                                                ServerBootstrap bootstrap) {
+    Promise<Channel> promise = vertx.getAcceptorEventLoopGroup().next().newPromise();
     bootstrap.channelFactory(vertx.transport().serverChannelFactory(socketAddress.path() != null));
     if (socketAddress.path() != null) {
       java.net.SocketAddress converted = vertx.transport().convert(socketAddress, true);
       ChannelFuture future = bootstrap.bind(converted);
       future.addListener(f -> {
         if (f.isSuccess()) {
-          asyncResolveConnectHelper.handle(future, Future.succeededFuture(future.channel()));
+          promise.setSuccess(future.channel());
         } else {
-          asyncResolveConnectHelper.handle(future, Future.failedFuture(f.cause()));
+          promise.setFailure(f.cause());
         }
       });
     } else {
@@ -86,16 +55,16 @@ public class AsyncResolveConnectHelper {
           ChannelFuture future = bootstrap.bind(t);
           future.addListener(f -> {
             if (f.isSuccess()) {
-              asyncResolveConnectHelper.handle(future, Future.succeededFuture(future.channel()));
+              promise.setSuccess(future.channel());
             } else {
-              asyncResolveConnectHelper.handle(future, Future.failedFuture(f.cause()));
+              promise.setFailure(f.cause());
             }
           });
         } else {
-          asyncResolveConnectHelper.handle(null, Future.failedFuture(res.cause()));
+          promise.setFailure(res.cause());
         }
       });
     }
-    return asyncResolveConnectHelper;
+    return promise;
   }
 }

src/main/java/io/vertx/core/net/impl/NetServerImpl.java

@@ -23,6 +23,7 @@ import io.netty.handler.ssl.SniHandler;
 import io.netty.handler.ssl.SslHandler;
 import io.netty.handler.stream.ChunkedWriteHandler;
 import io.netty.handler.timeout.IdleStateHandler;
+import io.netty.util.concurrent.GenericFutureListener;
 import io.netty.util.concurrent.GlobalEventExecutor;
 import io.vertx.core.*;
 import io.vertx.core.impl.ContextInternal;
@@ -71,7 +72,7 @@ public class NetServerImpl implements Closeable, MetricsProvider, NetServer {
   private Handler<NetSocket> registeredHandler;
   private volatile ServerID id;
   private NetServerImpl actualServer;
-  private AsyncResolveConnectHelper bindFuture;
+  private io.netty.util.concurrent.Future<Channel> bindFuture;
   private volatile int actualPort;
   private ContextInternal listenContext;
   private TCPMetrics metrics;
@@ -182,7 +183,7 @@ public class NetServerImpl implements Closeable, MetricsProvider, NetServer {
 
         bootstrap.childHandler(new ChannelInitializer<Channel>() {
           @Override
-          protected void initChannel(Channel ch) throws Exception {
+          protected void initChannel(Channel ch) {
             if (!accept()) {
               ch.close();
               return;
@@ -225,9 +226,9 @@ public class NetServerImpl implements Closeable, MetricsProvider, NetServer {
 
         try {
           bindFuture = AsyncResolveConnectHelper.doBind(vertx, socketAddress, bootstrap);
-          bindFuture.addListener(res -> {
-            if (res.succeeded()) {
-              Channel ch = res.result();
+          bindFuture.addListener((GenericFutureListener<io.netty.util.concurrent.Future<Channel>>) res -> {
+            if (res.isSuccess()) {
+              Channel ch = res.getNow();
               log.trace("Net server listening on " + (hostOrPath) + ":" + ch.localAddress());
               // Update port to actual port - wildcard port 0 might have been used
               if (NetServerImpl.this.actualPort != -1) {
@@ -274,10 +275,10 @@ public class NetServerImpl implements Closeable, MetricsProvider, NetServer {
       }
 
       // just add it to the future so it gets notified once the bind is complete
-      actualServer.bindFuture.addListener(res -> {
+      actualServer.bindFuture.addListener((GenericFutureListener<io.netty.util.concurrent.Future<Channel>>) res -> {
         if (listenHandler != null) {
           AsyncResult<Void> ares;
-          if (res.succeeded()) {
+          if (res.isSuccess()) {
             ares = Future.succeededFuture();
           } else {
             listening = false;
@@ -287,14 +288,13 @@ public class NetServerImpl implements Closeable, MetricsProvider, NetServer {
           // Netty will call future handler immediately with calling thread
           // which might be a non Vert.x thread (if running embedded)
           listenContext.runOnContext(v -> listenHandler.handle(ares));
-        } else if (res.failed()) {
+        } else if (!res.isSuccess()) {
           // No handler - log so user can see failure
           log.error("Failed to listen", res.cause());
           listening = false;
         }
       });
     }
-    return;
   }
 
   public Future<Void> close() {
@@ -429,7 +429,7 @@ public class NetServerImpl implements Closeable, MetricsProvider, NetServer {
     return !listening;
   }
 
-  public synchronized int actualPort() {
+  public int actualPort() {
     return actualPort;
   }
 

src/test/java/io/vertx/core/SharedServersConcurrencyTest.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2011-2019 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+ * which is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+ */
+
+package io.vertx.core;
+
+import io.vertx.core.http.HttpServerOptions;
+import io.vertx.core.net.NetServerOptions;
+import io.vertx.test.core.Repeat;
+import io.vertx.test.core.VertxTestBase;
+import org.junit.Test;
+
+/**
+ * Orginial reproducer from https://github.com/LarsKrogJensen
+ */
+public class SharedServersConcurrencyTest extends VertxTestBase {
+
+  @Test
+  @Repeat(times = 100)
+  public void testConcurrency() {
+    deployVerticle(vertx, new MonitorVerticle())
+      .compose(__ -> deployVerticle(vertx, new RestVerticle()))
+      .compose(__ -> deployVerticle(vertx, new ApiVerticle()))
+      .setHandler(onSuccess(__ -> testComplete()));
+    await();
+  }
+
+  private static class ApiVerticle extends AbstractVerticle {
+    @Override
+    public void start(Promise<Void> startPromise) {
+      vertx.deployVerticle(() -> new NetVerticle(), new DeploymentOptions().setInstances(32), ar -> {
+        if (ar.succeeded()) {
+          startPromise.complete();
+        } else {
+          startPromise.fail(ar.cause());
+        }
+      });
+    }
+  }
+
+  private static class NetVerticle extends AbstractVerticle {
+    @Override
+    public void start(Promise<Void> startPromise) {
+      vertx.createNetServer(new NetServerOptions().setPort(20152))
+        .connectHandler(netSocket -> {
+        })
+        .listen(ar -> {
+          if (ar.succeeded()) {
+            startPromise.complete();
+          } else {
+            startPromise.fail(ar.cause());
+          }
+        });
+    }
+  }
+
+  private static class RestVerticle extends AbstractVerticle {
+    @Override
+    public void start(Promise<Void> startPromise) {
+      vertx.createHttpServer(new HttpServerOptions())
+        .requestHandler(req -> {
+        })
+        .listen(15152, ar -> {
+          if (ar.succeeded()) {
+            System.out.println("REST listening on port: " + ar.result().actualPort());
+            startPromise.complete();
+          } else {
+            startPromise.fail(ar.cause());
+          }
+        });
+    }
+  }
+
+  private static class MonitorVerticle extends AbstractVerticle {
+    @Override
+    public void start(Promise<Void> startPromise) {
+      vertx.createHttpServer(new HttpServerOptions())
+        .requestHandler(req -> {
+        })
+        .listen(16152, ar -> {
+          if (ar.succeeded()) {
+            System.out.println("Monitor listening on port: " + ar.result().actualPort());
+            startPromise.complete();
+          } else {
+            startPromise.fail(ar.cause());
+          }
+        });
+    }
+  }
+
+  private static Future<String> deployVerticle(Vertx vertx, Verticle verticle) {
+    return Future.future(promise -> vertx.deployVerticle(verticle, promise));
+  }
+}