OF-857: Synchronize I/O for C2S connection

Use a lock to ensure the integrity of IoSession (MINA), especially when
using compression or TLS filters

src/java/org/jivesoftware/openfire/nio/NIOConnection.java

@@ -19,9 +19,9 @@
 
 package org.jivesoftware.openfire.nio;
 
+import static org.jivesoftware.openfire.spi.ConnectionManagerImpl.COMPRESSION_FILTER_NAME;
 import static org.jivesoftware.openfire.spi.ConnectionManagerImpl.EXECUTOR_FILTER_NAME;
 import static org.jivesoftware.openfire.spi.ConnectionManagerImpl.TLS_FILTER_NAME;
-import static org.jivesoftware.openfire.spi.ConnectionManagerImpl.COMPRESSION_FILTER_NAME;
 
 import java.io.IOException;
 import java.net.InetSocketAddress;
@@ -31,6 +31,7 @@ import java.nio.charset.CharsetEncoder;
 import java.nio.charset.CodingErrorAction;
 import java.security.KeyStore;
 import java.security.cert.Certificate;
+import java.util.concurrent.Semaphore;
 
 import javax.net.ssl.KeyManager;
 import javax.net.ssl.SSLContext;
@@ -114,11 +115,17 @@ public class NIOConnection implements Connection {
      */
     private boolean closed;
     
+    /**
+     * Lock used to ensure the integrity of the underlying IoSession 
+     * (refer to https://issues.apache.org/jira/browse/DIRMINA-653 for details)
+     */
+    private Semaphore ioSessionLock;
 
     public NIOConnection(IoSession session, PacketDeliverer packetDeliverer) {
         this.ioSession = session;
         this.backupDeliverer = packetDeliverer;
         closed = false;
+        ioSessionLock = new Semaphore(1, true);
     }
 
     public boolean validate() {
@@ -253,11 +260,13 @@ public class NIOConnection implements Connection {
             backupDeliverer.deliver(packet);
         }
         else {
+            boolean errorDelivering = false;
+            try {
+            	ioSessionLock.acquire();
+
             	IoBuffer buffer = IoBuffer.allocate(4096);
                 buffer.setAutoExpand(true);
 
-            boolean errorDelivering = false;
-            try {
             	// OF-464: if the connection has been dropped, fail over to backupDeliverer (offline)
             	if (!ioSession.isConnected()) {
             		throw new IOException("Connection reset/closed by peer");
@@ -276,6 +285,9 @@ public class NIOConnection implements Connection {
                 Log.debug("Error delivering packet:\n" + packet, e);
                 errorDelivering = true;
             }
+            finally {
+            	ioSessionLock.release();
+            }
             if (errorDelivering) {
                 close();
                 // Retry sending the packet again. Most probably if the packet is a
@@ -295,11 +307,14 @@ public class NIOConnection implements Connection {
 
     private void deliverRawText(String text, boolean asynchronous) {
         if (!isClosed()) {
-            IoBuffer buffer = IoBuffer.allocate(text.length());
-            buffer.setAutoExpand(true);
 
             boolean errorDelivering = false;
             try {
+            	ioSessionLock.acquire();
+
+            	IoBuffer buffer = IoBuffer.allocate(text.length());
+                buffer.setAutoExpand(true);
+
                 //Charset charset = Charset.forName(CHARSET);
                 //buffer.putString(text, charset.newEncoder());
                 buffer.put(text.getBytes(CHARSET));
@@ -327,6 +342,9 @@ public class NIOConnection implements Connection {
                 Log.debug("Error delivering raw text:\n" + text, e);
                 errorDelivering = true;
             }
+            finally {
+            	ioSessionLock.release();
+            }
             // Close the connection if delivering text fails and we are already not closing the connection
             if (errorDelivering && asynchronous) {
                 close();