1. code clean and added documentation for debugging protocol

2. upgrade to version 0.14 since I trimmed the debug message types

build.xml

@@ -1,5 +1,5 @@
 <project default="all">
-	<property name="version" value="0.13"/>
+	<property name="version" value="0.14"/>
 
 	<target name="clean">
 		<delete dir="build"/>

src/core/org/luaj/vm/DebugNetSupport.java

@@ -19,11 +19,4 @@ public interface DebugNetSupport {
      * Disconnect all connected clients.
      */
     public abstract void disconnect();
-
-    /**
-     * Disconnect the client with the given id.
-     * @param id -- client id
-     */
-    public abstract void disconnect(int id);
-
 }

src/debug/org/luaj/debug/DebugLuaState.java

@@ -29,7 +29,6 @@ import org.luaj.compiler.LexState;
 import org.luaj.debug.event.DebugEventBreakpoint;
 import org.luaj.debug.event.DebugEventError;
 import org.luaj.debug.net.DebugNetSupportBase;
-import org.luaj.debug.request.DebugRequestDisconnect;
 import org.luaj.debug.request.DebugRequestLineBreakpointToggle;
 import org.luaj.debug.request.DebugRequestListener;
 import org.luaj.debug.request.DebugRequestStack;
@@ -49,6 +48,110 @@ import org.luaj.vm.LuaState;
 import org.luaj.vm.Platform;
 
 
+/**
+ * <code>DebugLuaState</code> extends <code>LuaState</code> to provide the 
+ * debugging support for luaj-vm. It defines the debugging protocol between a 
+ * debugger, such as LuaJEclipse in Eclipse, and the luaj-vm. The 
+ * debugger and luaj-vm communicates via <code>DebugMessage</code>. The
+ * debugger sends requests to the luaj-vm and receive responses and events from 
+ * the luaj-vm. For requests that require immediately replies, luaj-vm responds
+ * synchronously. For events occurs in the luaj-vm, for instance, an exception 
+ * is raised or a breakpoint is hit, luaj-vm informs the debugger when the event
+ * occurs.  
+ * <p>
+ * <i>Debugger Requests:</i>
+ * <ul>
+ * <li><code>DebugMessageType.start</code>: The first message for the handshake 
+ * between the debugger and the luaj-vm. The VM responds with 
+ * <code>DebugMessageType.started</code> immediately. If the VM is paused 
+ * on start, it will now resume the execution.
+ * <li><code>DebugMessageType.resume</code>: The debugger instructs the 
+ * luaj-vm to resume the execution when the VM is suspended. No reply is needed.
+ * <li><code>DebugMessageType.suspend</code>: The debugger instructs the luaj-vm
+ * to suspend. VM replies with <code>DebugMessageType.suspendedByClient</code> 
+ * when it is suspended.
+ * <li><code>DebugMessageType.lineBreakpointSet</code>: The debugger informs the 
+ * VM that a breakpoint at the given source and line number is set. No reply 
+ * is needed. For future improvement, VM should check if the breakpoint is
+ * valid and gives the debugger feedback. 
+ * <li><code>DebugMessageType.lineBreakpointClear</code>: The debugger informs 
+ * the VM to clear a breakpoint at the given source and line number. No reply 
+ * is needed. For future enhancement, VM should check if the breakpoint is
+ * valid and gives the debugger feedback.
+ * <li><code>DebugMessageType.watchpointSet</code>: The debugger sets a watchpoint
+ * on the given source and line number. Not implemented yet.
+ * <li><code>DebugMessageType.watchpointClear</code>: The debugger clears a 
+ * watchpoint at the given source and line number. Not implemented yet.
+ * <li><code>DebugMessageType.callgraph</code>: The debugger requests for the 
+ * current call graph. VM replies with the call graph immediately in a debug
+ * message of type <code>DebugMessageType.clientRequestCallgraphReply</code>.
+ * <li><code>DebugMessageType.stack</code>: The debugger request for the stack 
+ * information for the given stack. VM replies with the variables on the stack 
+ * immediately in a debug message of type 
+ * <code>DebugMessageType.clientRequestStackReply</code>.
+ * <li><code>DebugMessageType.stepInto</code>: The debugger instructs the VM
+ * to begin stepping in stepInto mode. No reply is needed.
+ * <li><code>DebugMessageType.stepOver</code>: The debugger instructs the VM to
+ * begin stepping in stepOver mode. No rely is needed.
+ * <li><code>DebugMessageType.stepReturn</code>: The debugger instructs the VM 
+ * to begin stepping in stepReturn mode. No reply is needed.
+ * <li><code>DebugMessageType.global</code>: The debug request the information
+ * about the globals. VM replies with global variables in a debug message of
+ * type <code>DebugMessageType.clientRequestGlobalReply</code>. 
+ * <li><code>DebugMessageType.disconnect</code>: The debugger informs the VM 
+ * that it is about to disconnect from the VM. VM resets its state and responds
+ * with <code>DebugMessageType.disconnected</code> immediately.
+ * <li><code>DebugMessageType.exit</code>: The debugger instructs the VM to 
+ * terminate. VM prepares for termination and responds with 
+ * <code>DebugMessageType.terminated</code>.
+ * <li><code>DebugMessageType.reset</code>: This is an internal debug message. 
+ * When the communication layer detects that the debugger or the debug service
+ * exits abnormally, it sends the message to the VM for reset. VM acts upon the
+ * message and reset its internal state.
+ * <li><code>DebugMessageType.debugServiceDown</code>: This message is sent from 
+ * the debug service (on-device remote debugging) when the debug service observed
+ * that the debugger exits abnormally. Before the debug service restarts the debug
+ * session, it informs the VM to reset itself.
+ * </ul>
+ * <p>
+ * <i>VM Responses and Events:</i>
+ * <ul>
+ * <li><code>DebugMessageType.clientRequestCallgraphReply</code>: VM replies to
+ * the <code>DebugMessageType.callgraph</code> request with the information
+ * about the current call graph. A call graph is made of a list of call stacks.
+ * Call stacks are organized chronically with the most recent call on the top
+ * of the stack. 
+ * <li><code>DebugMessageType.clientRequestStackReply</code>: VM replies
+ * to the <code>DebugMessageType.stack</code> request with the variables visible
+ * on the call stack <code>i</code> where <code>i</code> the call stack index 
+ * ranging between 0 and <code>LuaState.calls.length</code>.
+ * <li><code>DebugMessageType.clientRequestGlobalReply</code>: VM replies to the 
+ * <code>DebugMessageType.global</code> request with all the globals.
+ * <li><code>DebugMessageType.started</code>: VM replies when a 
+ * <code>DebugMessageType.start</code> request is received.
+ * <li><code>DebugMessageType.resumedOnSteppingEnd</code>: VM informs the debugger
+ * that VM is getting out of the stepping mode upon step return because it has 
+ * reached the last call stack.
+ * <li><code>DebugMessageType.suspendedByClient</code>: VM sends the event to
+ * respond to a debugger pause action.
+ * <li><code>DebugMessageType.suspendedOnBreakpoint</code>: VM sends the event
+ * when a breakpoint is hit during the execution.
+ * <li><code>DebugMessageType.suspendedOnWatchpoint</code>: Not implemented yet. 
+ * VM sends the event when VM is paused to evaluate a watchpoint.
+ * <li><code>DebugMessageType.suspendedOnStepping</code>: VM sends the event when
+ * VM is paused during the stepping. The debugger has instructed the VM to begin
+ * stepping into, over or return earlier.
+ * <li><code>DebugMessageType.suspendedOnError</code>: VM sends the event when
+ * an error is raised in VM.
+ * <li><code>DebugMessageType.terminated</code>: VM sends the event when it is
+ * ready to exit. 
+ * <li><code>DebugMessageType.disconnected</code>: VM sends the event when it 
+ * has de-attached the debugger from the debug session. 
+ * <li><code>DebugMessageType.outputRedirect</code>: VM forwards the print 
+ * output to the debugger console.
+ * </ul>
+ * <p> 
+ */
 public class DebugLuaState extends LuaState implements DebugRequestListener {   
     private static final boolean TRACE = (null != System.getProperty("TRACE"));
 
@@ -328,10 +431,7 @@ public class DebugLuaState extends LuaState implements DebugRequestListener {
         } else if (DebugMessageType.exit == requestType) {
             stop();
         } else if (DebugMessageType.disconnect == requestType) {
-            DebugRequestDisconnect disconnectRequest 
+            disconnect();
-                = (DebugRequestDisconnect) request;
-            int connectionId = disconnectRequest.getSessionId();
-            disconnect(connectionId);
         } else if (DebugMessageType.debugServiceDown == requestType) {
             disconnectFromDebugService();
         } else if (DebugMessageType.reset == requestType) {
@@ -437,7 +537,7 @@ public class DebugLuaState extends LuaState implements DebugRequestListener {
         }
     }
 
-    public void disconnect(int connectionId) {
+    public void disconnect() {
         if (this.debugSupport == null) {
             throw new IllegalStateException(
                     "DebugNetSupportBase must be defined.");
@@ -446,7 +546,7 @@ public class DebugLuaState extends LuaState implements DebugRequestListener {
         reset();
         DebugMessage event = new DebugMessage(DebugMessageType.disconnected);
         debugSupport.notifyDebugEvent(event);
-        debugSupport.disconnect(connectionId);                   
+        debugSupport.disconnect();                   
     }
     
     public void disconnectFromDebugService() {
@@ -505,7 +605,7 @@ public class DebugLuaState extends LuaState implements DebugRequestListener {
     }
 
     /**
-     * return the current call graph (i.e. stack frames from old to new, include
+     * return the current call graph (i.e. stack frames from new to old, include
      * information about file, method, etc.)
      */
     public StackFrame[] getCallgraph() {
@@ -514,11 +614,12 @@ public class DebugLuaState extends LuaState implements DebugRequestListener {
         if (n < 0 || n >= calls.length)
             return new StackFrame[0];
 
-        StackFrame[] frames = new StackFrame[n + 1];
+        int length = n + 1;
-        for (int i = 0; i <= n; i++) {
+        StackFrame[] frames = new StackFrame[length];
+        for (int i = 0; i < length; i++) {
             CallInfo ci = calls[i];
             String src = getSourceFileName(ci.closure.p.source);
-            frames[i] = new StackFrame(src, getLineNumber(ci));
+            frames[length - i - 1] = new StackFrame(src, getLineNumber(ci));
         }
         return frames;
     }

src/debug/org/luaj/debug/DebugMessageType.java

@@ -31,44 +31,45 @@ public class DebugMessageType extends EnumType {
     public static final DebugMessageType resume = new DebugMessageType("resume", 1);
     public static final DebugMessageType suspend = new DebugMessageType("suspend", 2);
     public static final DebugMessageType exit = new DebugMessageType("exit", 3); 
-    public static final DebugMessageType lineBreakpointSet = new DebugMessageType("lineBreakpointSet", 4); 
+    public static final DebugMessageType disconnect = new DebugMessageType("disconnect", 4);
-    public static final DebugMessageType lineBreakpointClear = new DebugMessageType("lineBreakpointClear", 5);
+    public static final DebugMessageType lineBreakpointSet = new DebugMessageType("lineBreakpointSet", 5); 
-    public static final DebugMessageType watchpointSet = new DebugMessageType("watchpointSet", 6);
+    public static final DebugMessageType lineBreakpointClear = new DebugMessageType("lineBreakpointClear", 6);
-    public static final DebugMessageType watchpointClear = new DebugMessageType("watchpointClear", 7);
+    public static final DebugMessageType watchpointSet = new DebugMessageType("watchpointSet", 7);
-    public static final DebugMessageType callgraph = new DebugMessageType("callgraph", 8);
+    public static final DebugMessageType watchpointClear = new DebugMessageType("watchpointClear", 8);
-    public static final DebugMessageType stack = new DebugMessageType("stack", 9);
+    public static final DebugMessageType callgraph = new DebugMessageType("callgraph", 9);
-    public static final DebugMessageType stepInto = new DebugMessageType("stepInto", 10);
+    public static final DebugMessageType stack = new DebugMessageType("stack", 10);
-    public static final DebugMessageType stepOver = new DebugMessageType("stepOver", 11);
+    public static final DebugMessageType stepInto = new DebugMessageType("stepInto", 11);
-    public static final DebugMessageType stepReturn = new DebugMessageType("stepReturn", 12);
+    public static final DebugMessageType stepOver = new DebugMessageType("stepOver", 12);
-    public static final DebugMessageType global = new DebugMessageType("global", 13);
+    public static final DebugMessageType stepReturn = new DebugMessageType("stepReturn", 13);
-    public static final DebugMessageType disconnect = new DebugMessageType("disconnect", 14);
+    public static final DebugMessageType global = new DebugMessageType("global", 14);
     public static final DebugMessageType reset = new DebugMessageType("reset", 15);
-    public static final DebugMessageType session = new DebugMessageType("session", 16);
+    public static final DebugMessageType debugServiceDown = new DebugMessageType("debugServiceDown", 16);
-    
+
+    // responses
+    public static final DebugMessageType clientRequestCallgraphReply = new DebugMessageType("clientRequestCallgraphReply", 17);
+    public static final DebugMessageType clientRequestStackReply = new DebugMessageType("clientRequestStackReply", 18);
+    public static final DebugMessageType clientRequestGlobalReply = new DebugMessageType("clientRequestGlobalReply", 19);
+
     // events
-    public static final DebugMessageType started = new DebugMessageType("started", 17);
+    public static final DebugMessageType started = new DebugMessageType("started", 20);
-    public static final DebugMessageType suspendedByClient = new DebugMessageType("suspendedByClient", 18);
+    public static final DebugMessageType suspendedByClient = new DebugMessageType("suspendedByClient", 21);
-    public static final DebugMessageType suspendedOnBreakpoint = new DebugMessageType("suspendedOnBreakpoint", 19);
+    public static final DebugMessageType suspendedOnBreakpoint = new DebugMessageType("suspendedOnBreakpoint", 22);
-    public static final DebugMessageType suspendedOnWatchpoint = new DebugMessageType("suspendedOnWatchpoint", 20);
+    public static final DebugMessageType suspendedOnWatchpoint = new DebugMessageType("suspendedOnWatchpoint", 23);
-    public static final DebugMessageType suspendedOnStepping = new DebugMessageType("suspendedOnStepping", 21);
+    public static final DebugMessageType suspendedOnStepping = new DebugMessageType("suspendedOnStepping", 24);
-    public static final DebugMessageType suspendedOnError = new DebugMessageType("suspendedOnError", 22);
+    public static final DebugMessageType suspendedOnError = new DebugMessageType("suspendedOnError", 25);
-    public static final DebugMessageType resumedOnSteppingEnd = new DebugMessageType("resumedOnSteppingEnd", 23);
+    public static final DebugMessageType resumedOnSteppingEnd = new DebugMessageType("resumedOnSteppingEnd", 26);
-    public static final DebugMessageType error = new DebugMessageType("error", 24);
+    public static final DebugMessageType outputRedirect = new DebugMessageType("outputRedirect", 27);
-    public static final DebugMessageType terminated = new DebugMessageType("terminated", 25);
+    public static final DebugMessageType terminated = new DebugMessageType("terminated", 28);
-    public static final DebugMessageType clientRequestCallgraphReply = new DebugMessageType("clientRequestCallgraphReply", 26);
+    public static final DebugMessageType disconnected = new DebugMessageType("disconnected", 29);  
-    public static final DebugMessageType clientRequestStackReply = new DebugMessageType("clientRequestStackReply", 27);
-    public static final DebugMessageType clientRequestGlobalReply = new DebugMessageType("clientRequestGlobalReply", 28);
-    public static final DebugMessageType disconnected = new DebugMessageType("disconnected", 29);
-    public static final DebugMessageType sessionId = new DebugMessageType("sessionId", 30);    
-    public static final DebugMessageType debugServiceDown = new DebugMessageType("debugServiceDown", 31);
-    public static final DebugMessageType outputRedirect = new DebugMessageType("outputRedirect", 32);
     
     protected static DebugMessageType[] ENUMS = new DebugMessageType[] {
+        // requests
         start,
         resume,
         suspend,
         exit,
-        lineBreakpointSet,
+        disconnect,
+        lineBreakpointSet, 
         lineBreakpointClear,
         watchpointSet,
         watchpointClear,
@@ -78,25 +79,25 @@ public class DebugMessageType extends EnumType {
         stepOver,
         stepReturn,
         global,
-        disconnect,
         reset,
-        session,
-    	started,
-    	suspendedByClient,
-    	suspendedOnBreakpoint,
-    	suspendedOnWatchpoint,
-    	suspendedOnStepping,
-    	suspendedOnError,
-    	resumedOnSteppingEnd,
-    	error,
-    	terminated,
-    	clientRequestCallgraphReply,
-    	clientRequestStackReply,
-    	clientRequestGlobalReply,
-    	disconnected,
-    	sessionId,
         debugServiceDown,
-        outputRedirect
+
+        // responses
+        clientRequestCallgraphReply,
+        clientRequestStackReply,
+        clientRequestGlobalReply,
+
+        // events
+        started,
+        suspendedByClient,
+        suspendedOnBreakpoint,
+        suspendedOnWatchpoint,
+        suspendedOnStepping,
+        suspendedOnError,
+        resumedOnSteppingEnd,
+        outputRedirect,
+        terminated,
+        disconnected  
     };
 	
     protected DebugMessageType(String name, int ordinal) {

src/debug/org/luaj/debug/SerializationHelper.java

@@ -9,11 +9,9 @@ import java.io.IOException;
 import org.luaj.debug.event.DebugEventBreakpoint;
 import org.luaj.debug.event.DebugEventError;
 import org.luaj.debug.event.DebugEventOutputRedirect;
-import org.luaj.debug.request.DebugRequestDisconnect;
 import org.luaj.debug.request.DebugRequestLineBreakpointToggle;
 import org.luaj.debug.request.DebugRequestStack;
 import org.luaj.debug.response.DebugResponseCallgraph;
-import org.luaj.debug.response.DebugResponseSession;
 import org.luaj.debug.response.DebugResponseStack;
 import org.luaj.debug.response.DebugResponseVariables;
 
@@ -53,14 +51,12 @@ public class SerializationHelper {
     static final int SERIAL_TYPE_DebugMessage                           = 5;
     static final int SERIAL_TYPE_DebugRequestStack                      = 6;
     static final int SERIAL_TYPE_DebugRequestLineBreakpointToggle       = 7;
-    static final int SERIAL_TYPE_DebugRequestDisconnect                 = 8;
+    static final int SERIAL_TYPE_DebugEventBreakpoint                   = 8;
-    static final int SERIAL_TYPE_DebugEventBreakpoint                   = 9;
+    static final int SERIAL_TYPE_DebugEventError                        = 9;
-    static final int SERIAL_TYPE_DebugEventError                        = 10;
+    static final int SERIAL_TYPE_DebugResponseCallgraph                 = 10;
-    static final int SERIAL_TYPE_DebugResponseCallgraph                 = 11;
+    static final int SERIAL_TYPE_DebugResponseVariables                 = 11;
-    static final int SERIAL_TYPE_DebugResponseVariables                 = 12;
+    static final int SERIAL_TYPE_DebugResponseStack                     = 12;   
-    static final int SERIAL_TYPE_DebugResponseStack                     = 13;   
+    static final int SERIAL_TYPE_DebugEventOutputRedirect               = 13;
-    static final int SERIAL_TYPE_DebugResponseSession                   = 14;
-    static final int SERIAL_TYPE_DebugEventOutputRedirect               = 15;
 
     public static void serialize(Serializable object, DataOutputStream dout)
             throws IOException {
@@ -86,9 +82,6 @@ public class SerializationHelper {
             dout.writeInt(SERIAL_TYPE_DebugRequestLineBreakpointToggle);
             DebugRequestLineBreakpointToggle.serialize(dout,
                     (DebugRequestLineBreakpointToggle) object);
-        } else if (object instanceof DebugRequestDisconnect) {
-            dout.writeInt(SERIAL_TYPE_DebugRequestDisconnect);
-            DebugRequestDisconnect.serialize(dout, (DebugRequestDisconnect) object);
         } else if (object instanceof DebugEventBreakpoint) {
             dout.writeInt(SERIAL_TYPE_DebugEventBreakpoint);
             DebugEventBreakpoint.serialize(dout, (DebugEventBreakpoint) object);
@@ -108,9 +101,6 @@ public class SerializationHelper {
             dout.writeInt(SERIAL_TYPE_DebugResponseCallgraph);
             DebugResponseCallgraph.serialize(dout,
                     (DebugResponseCallgraph) object);
-        } else if (object instanceof DebugResponseSession) {
-            dout.writeInt(SERIAL_TYPE_DebugResponseSession);
-            DebugResponseSession.serialize(dout, (DebugResponseSession) object);
         } else if (object instanceof DebugMessage) {
             dout.writeInt(SERIAL_TYPE_DebugMessage);
             DebugMessage.serialize(dout, (DebugMessage) object);
@@ -148,9 +138,6 @@ public class SerializationHelper {
         case SERIAL_TYPE_DebugRequestLineBreakpointToggle:
             object = DebugRequestLineBreakpointToggle.deserialize(din);
             break;
-        case SERIAL_TYPE_DebugRequestDisconnect:
-            object = DebugRequestDisconnect.deserialize(din);
-            break;
         case SERIAL_TYPE_DebugEventBreakpoint:
             object = DebugEventBreakpoint.deserialize(din);
             break;
@@ -169,9 +156,6 @@ public class SerializationHelper {
         case SERIAL_TYPE_DebugResponseVariables:
             object = DebugResponseVariables.deserialize(din);
             break;
-        case SERIAL_TYPE_DebugResponseSession:
-            object = DebugResponseSession.deserialize(din);
-            break;
         case SERIAL_TYPE_DebugMessage:
             object = DebugMessage.deserialize(din);
             break;

src/debug/org/luaj/debug/event/DebugEventError.java

@@ -33,7 +33,7 @@ public class DebugEventError extends DebugMessage {
     protected String trace;
 
     public DebugEventError(String cause, String trace) {
-        super(DebugMessageType.error);
+        super(DebugMessageType.suspendedOnError);
         this.cause = cause;
         this.trace = trace;
     }

src/debug/org/luaj/debug/net/DebugNetSupportBase.java

@@ -29,11 +29,6 @@ public abstract class DebugNetSupportBase implements DebugRequestListener, Debug
      */
     public abstract void disconnect();
     
-    /* (non-Javadoc)
-     * @see org.luaj.debug.net.DebugNetSupport#disconnect(int)
-     */
-    public abstract void disconnect(int id);
-
     protected DebugLuaState vm;
     public void setDebugStackState(DebugLuaState vm) {
         this.vm = vm;

src/debug/org/luaj/debug/net/j2me/ClientConnectionTask.java

@@ -13,7 +13,6 @@ import org.luaj.debug.DebugMessageType;
 import org.luaj.debug.RedirectOutputStream;
 import org.luaj.debug.SerializationHelper;
 import org.luaj.debug.event.DebugEventListener;
-import org.luaj.debug.response.DebugResponseSession;
 import org.luaj.lib.BaseLib;
 
 public class ClientConnectionTask implements Runnable, DebugEventListener {
@@ -92,7 +91,7 @@ public class ClientConnectionTask implements Runnable, DebugEventListener {
             // discard the current connection.
             handleRequest(new DebugMessage(DebugMessageType.reset));
             
-            debugSupport.disconnect(1);
+            debugSupport.disconnect();
         } finally {
             if (redirectOutputStream != null) {
                 try {
@@ -134,11 +133,7 @@ public class ClientConnectionTask implements Runnable, DebugEventListener {
         if ( TRACE )
             System.out.println("SERVER handling request: " + request.toString());
 
-        if (request.getType() == DebugMessageType.session) {
+        debugSupport.handleRequest(request);
-            notifyDebugEvent(new DebugResponseSession(1));
-        } else {
-            debugSupport.handleRequest(request);
-        }
     }
     
     public void notifyDebugEvent(DebugMessage event) {

src/debug/org/luaj/debug/net/j2me/DebugSupportImpl.java

@@ -49,7 +49,7 @@ public class DebugSupportImpl extends DebugNetSupportBase {
     
     public void stop() {
         setState(STOPPED);
-        disconnect(1);        
+        disconnect();        
     }
 
     public void disconnect() {
@@ -60,10 +60,6 @@ public class DebugSupportImpl extends DebugNetSupportBase {
         }        
     }
     
-    public synchronized void disconnect(int id) {
-        disconnect();
-    }
-
     public synchronized void notifyDebugEvent(DebugMessage event) {
         if (clientTask != null) {
             clientTask.notifyDebugEvent(event);

src/debug/org/luaj/debug/net/j2se/ClientConnectionTask.java

@@ -11,7 +11,6 @@ import org.luaj.debug.DebugMessageType;
 import org.luaj.debug.RedirectOutputStream;
 import org.luaj.debug.SerializationHelper;
 import org.luaj.debug.event.DebugEventListener;
-import org.luaj.debug.response.DebugResponseSession;
 import org.luaj.lib.BaseLib;
 
 public class ClientConnectionTask implements Runnable, DebugEventListener {
@@ -92,7 +91,7 @@ public class ClientConnectionTask implements Runnable, DebugEventListener {
             // discard the current connection.
             handleRequest(new DebugMessage(DebugMessageType.reset));
             
-            debugSupport.disconnect(getSessionId());
+            debugSupport.disconnect();
         } finally {
             try {
                 redirectOutputStream.close();
@@ -110,11 +109,7 @@ public class ClientConnectionTask implements Runnable, DebugEventListener {
             System.out.println("SERVER handling request: " + request.toString());
         }
 
-        if (request.getType() == DebugMessageType.session) {
+        debugSupport.handleRequest(request);
-            notifyDebugEvent(new DebugResponseSession(getSessionId()));
-        } else {
-            debugSupport.handleRequest(request);
-        }
     }
     
     public void notifyDebugEvent(DebugMessage event) {

src/debug/org/luaj/debug/net/j2se/DebugSupportImpl.java

@@ -107,7 +107,7 @@ public class DebugSupportImpl extends DebugNetSupportBase {
     public synchronized void stop() {
         setState(STOPPED);
         if (clientConnectionTask != null) {
-            disconnect(clientConnectionTask.getSessionId());
+            disconnect();
         }
         dispose();
     }
@@ -123,18 +123,10 @@ public class DebugSupportImpl extends DebugNetSupportBase {
     }
     
     public synchronized void disconnect() {
-        disconnect(clientConnectionTask.getSessionId());
+        clientConnectionTask.disconnect();
+        clientConnectionTask = null;
     }
     
-    public synchronized void disconnect(int id) {
-        if (clientConnectionTask.getSessionId() == id) {
-            clientConnectionTask.disconnect();
-            clientConnectionTask = null;
-        } else {
-            throw new RuntimeException("Internal Error: mismatching sesion Id");
-        }
-    }        
-    
     public void acceptClientConnection() throws IOException {
         try {
             Socket clientSocket = serverSocket.accept();

src/debug/org/luaj/debug/request/DebugRequestDisconnect.java

@@ -1,37 +0,0 @@
-package org.luaj.debug.request;
-
-import java.io.DataInputStream;
-import java.io.DataOutputStream;
-import java.io.IOException;
-
-import org.luaj.debug.DebugMessage;
-import org.luaj.debug.DebugMessageType;
-
-public class DebugRequestDisconnect extends DebugMessage {
-    protected int sessionId;
-    
-    public DebugRequestDisconnect(int connectionId) {
-        super(DebugMessageType.disconnect);
-        this.sessionId = connectionId;
-    }
-    
-    public int getSessionId() {
-        return this.sessionId;
-    }
-    
-    public String toString() {
-        return super.toString() + " sessionId:" + getSessionId();
-    }
-
-    public static void serialize(DataOutputStream out, DebugRequestDisconnect request)
-            throws IOException {
-        out.writeInt(request.getSessionId());
-    }
-
-    public static DebugMessage deserialize(DataInputStream in)
-            throws IOException {
-        int id = in.readInt();
-
-        return new DebugRequestDisconnect(id);
-    }    
-}

src/debug/org/luaj/debug/response/DebugResponseSession.java

@@ -1,36 +0,0 @@
-package org.luaj.debug.response;
-
-import java.io.DataInputStream;
-import java.io.DataOutputStream;
-import java.io.IOException;
-
-import org.luaj.debug.DebugMessage;
-import org.luaj.debug.DebugMessageType;
-
-public class DebugResponseSession extends DebugMessage {
-    protected int sessionId;
-    
-    public DebugResponseSession(int id) {
-        super(DebugMessageType.session);
-        this.sessionId = id;
-    }
-    
-    public int getSessionId() {
-        return this.sessionId;
-    }
-    
-    public String toString() {
-        return "SessionId: " + getSessionId();
-    }
-    
-    public static void serialize(DataOutputStream out,
-                                 DebugResponseSession response) 
-    throws IOException {
-        out.writeInt(response.getSessionId());
-    }
-    
-    public static DebugMessage deserialize(DataInputStream in) throws IOException {
-        int id = in.readInt();
-        return new DebugResponseSession(id);
-    }
-}

src/test/java/org/luaj/debug/DebugResponseTest.java

@@ -5,7 +5,6 @@ import java.io.IOException;
 import junit.framework.TestCase;
 
 import org.luaj.debug.response.DebugResponseCallgraph;
-import org.luaj.debug.response.DebugResponseSession;
 import org.luaj.debug.response.DebugResponseStack;
 import org.luaj.vm.Lua;
 
@@ -83,17 +82,4 @@ public class DebugResponseTest extends TestCase {
             assertEquals(inFrames[i], outFrames[i]);
         }
     }
-    
-    public void testDebugResponseSession() {
-        try {
-            DebugResponseSession sessionResponse = new DebugResponseSession(100);
-            byte[] data = SerializationHelper.serialize(sessionResponse);
-            DebugResponseSession sessionOut 
-                = (DebugResponseSession) SerializationHelper.deserialize(data);
-            assertNotNull(sessionOut);
-            assertEquals(sessionResponse.getSessionId(), sessionOut.getSessionId());            
-        } catch (IOException e) {
-            fail(e.getMessage());
-        }
-    }
 }

src/test/java/org/luaj/debug/EnumTypeTest.java

@@ -17,7 +17,7 @@ public class EnumTypeTest extends TestCase {
 
     public void testDebugEventTypeSerialization() {
         try {
-            DebugMessageType type = DebugMessageType.error;
+            DebugMessageType type = DebugMessageType.suspendedOnError;
             byte[] data = SerializationHelper.serialize(type);
             DebugMessageType typeOut = (DebugMessageType) SerializationHelper
                     .deserialize(data);