Fixed issues when closing a channel that was already closed.

src/dorkbox/network/connection/ConnectionManager.java

@@ -15,7 +15,15 @@
  */
 package dorkbox.network.connection;
 
+import java.io.IOException;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
+
+import org.slf4j.Logger;
+
 import com.esotericsoftware.kryo.util.IdentityMap;
+
 import dorkbox.network.connection.bridge.ConnectionBridgeServer;
 import dorkbox.network.connection.bridge.ConnectionExceptSpecifiedBridgeServer;
 import dorkbox.network.connection.listenerManagement.OnConnectedManager;
@@ -25,12 +33,6 @@ import dorkbox.network.connection.listenerManagement.OnMessageReceivedManager;
 import dorkbox.util.ClassHelper;
 import dorkbox.util.Property;
 import dorkbox.util.collections.ConcurrentEntry;
-import org.slf4j.Logger;
-
-import java.io.IOException;
-import java.util.List;
-import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
 
 // .equals() compares the identity on purpose,this because we cannot create two separate objects that are somehow equal to each other.
 @SuppressWarnings("unchecked")
@@ -650,6 +652,7 @@ class ConnectionManager<C extends Connection> implements ListenerBridge, ISessio
      *
      * @see dorkbox.network.connection.ConnectionPoint#flush()
      */
+    @Override
     public
     void flush() {
         ConcurrentEntry<C> current = connectionsREF.get(this);
@@ -667,6 +670,7 @@ class ConnectionManager<C extends Connection> implements ListenerBridge, ISessio
      * Sends the object to all server connections (except the specified one) over the network using TCP. (or via LOCAL when it's a local
      * channel).
      */
+    @Override
     public
     ConnectionPoint TCP(final C connection, final Object message) {
         ConcurrentEntry<C> current = connectionsREF.get(this);
@@ -687,6 +691,7 @@ class ConnectionManager<C extends Connection> implements ListenerBridge, ISessio
      * Sends the object to all server connections (except the specified one) over the network using UDP (or via LOCAL when it's a local
      * channel).
      */
+    @Override
     public
     ConnectionPoint UDP(final C connection, final Object message) {
         ConcurrentEntry<C> current = connectionsREF.get(this);
@@ -707,6 +712,7 @@ class ConnectionManager<C extends Connection> implements ListenerBridge, ISessio
      * Sends the object to all server connections (except the specified one) over the network using UDT. (or via LOCAL when it's a local
      * channel).
      */
+    @Override
     public
     ConnectionPoint UDT(final C connection, final Object message) {
         ConcurrentEntry<C> current = connectionsREF.get(this);
@@ -726,6 +732,7 @@ class ConnectionManager<C extends Connection> implements ListenerBridge, ISessio
     /**
      * Sends the message to other listeners INSIDE this endpoint for EVERY connection. It does not send it to a remote address.
      */
+    @Override
     public
     void self(final Object message) {
         ConcurrentEntry<C> current = connectionsREF.get(this);
@@ -741,6 +748,7 @@ class ConnectionManager<C extends Connection> implements ListenerBridge, ISessio
     /**
      * Sends the object all server connections over the network using TCP. (or via LOCAL when it's a local channel).
      */
+    @Override
     public
     ConnectionPoint TCP(final Object message) {
         ConcurrentEntry<C> current = connectionsREF.get(this);
@@ -758,6 +766,7 @@ class ConnectionManager<C extends Connection> implements ListenerBridge, ISessio
     /**
      * Sends the object all server connections over the network using UDP. (or via LOCAL when it's a local channel).
      */
+    @Override
     public
     ConnectionPoint UDP(final Object message) {
         ConcurrentEntry<C> current = connectionsREF.get(this);
@@ -776,6 +785,7 @@ class ConnectionManager<C extends Connection> implements ListenerBridge, ISessio
     /**
      * Sends the object all server connections over the network using UDT. (or via LOCAL when it's a local channel).
      */
+    @Override
     public
     ConnectionPoint UDT(final Object message) {
         ConcurrentEntry<C> current = connectionsREF.get(this);

src/dorkbox/network/connection/EndPoint.java

@@ -15,6 +15,24 @@
  */
 package dorkbox.network.connection;
 
+import java.io.IOException;
+import java.security.AccessControlException;
+import java.security.SecureRandom;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
+import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
+import org.bouncycastle.crypto.params.ECPublicKeyParameters;
+import org.slf4j.Logger;
+
 import dorkbox.network.Configuration;
 import dorkbox.network.connection.bridge.ConnectionBridgeBase;
 import dorkbox.network.connection.ping.PingSystemListener;
@@ -41,22 +59,6 @@ import io.netty.util.NetUtil;
 import io.netty.util.concurrent.EventExecutor;
 import io.netty.util.concurrent.Future;
 import io.netty.util.internal.PlatformDependent;
-import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
-import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
-import org.bouncycastle.crypto.params.ECPublicKeyParameters;
-import org.slf4j.Logger;
-
-import java.io.IOException;
-import java.security.AccessControlException;
-import java.security.SecureRandom;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.Executor;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * represents the base of a client/server end point
@@ -566,9 +568,11 @@ class EndPoint<C extends Connection> {
             // now we stop all of our channels
             for (ChannelFuture f : this.shutdownChannelList) {
                 Channel channel = f.channel();
-                channel.close()
-                       .awaitUninterruptibly(maxShutdownWaitTimeInMilliSeconds);
-                Thread.yield();
+                if (channel.isOpen()) {
+                    channel.close()
+                           .awaitUninterruptibly(maxShutdownWaitTimeInMilliSeconds);
+                    Thread.yield();
+                }
             }
 
             // we have to clear the shutdown list. (
@@ -622,8 +626,10 @@ class EndPoint<C extends Connection> {
             // a client/server thread executor, it will deadlock while waiting for the threadpool to terminate.
             boolean isInEventLoop = false;
             for (EventLoopGroup loopGroup : this.eventLoopGroups) {
-                for (EventExecutor child : loopGroup.children()) {
-                    if (child.inEventLoop()) {
+                Iterator<EventExecutor> iterator = loopGroup.iterator();
+                while (iterator.hasNext()) {
+                    EventExecutor next = iterator.next();
+                    if (next.inEventLoop()) {
                         isInEventLoop = true;
                         break;
                     }

src/dorkbox/network/connection/registration/MetaChannel.java

@@ -15,12 +15,13 @@
  */
 package dorkbox.network.connection.registration;
 
-import dorkbox.network.connection.ConnectionImpl;
-import io.netty.channel.Channel;
+import java.net.InetSocketAddress;
+
 import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
 import org.bouncycastle.crypto.params.ECPublicKeyParameters;
 
-import java.net.InetSocketAddress;
+import dorkbox.network.connection.ConnectionImpl;
+import io.netty.channel.Channel;
 
 // @formatter:off
 public
@@ -80,22 +81,22 @@ class MetaChannel {
 
     public
     void close(final long maxShutdownWaitTimeInMilliSeconds) {
-        if (this.localChannel != null) {
+        if (this.localChannel != null && this.localChannel.isOpen()) {
             this.localChannel.close();
         }
 
-        if (this.tcpChannel != null) {
+        if (this.tcpChannel != null && this.tcpChannel.isOpen()) {
             this.tcpChannel.close()
                            .awaitUninterruptibly(maxShutdownWaitTimeInMilliSeconds);
         }
 
-        if (this.udtChannel != null) {
+        if (this.udtChannel != null && this.udtChannel.isOpen()) {
             this.udtChannel.close()
                            .awaitUninterruptibly(maxShutdownWaitTimeInMilliSeconds);
         }
 
         // only the CLIENT will have this.
-        if (this.udpChannel != null && this.udpRemoteAddress == null) {
+        if (this.udpChannel != null && this.udpRemoteAddress == null && this.udpChannel.isOpen()) {
             this.udpChannel.close()
                            .awaitUninterruptibly(maxShutdownWaitTimeInMilliSeconds);
         }