added remote debugging support

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

@@ -279,6 +279,8 @@ public class DebugLuaState extends LuaState implements DebugRequestListener {
             cancelSuspendOnStart();
         } else if (DebugRequestType.exit == requestType) {
             stop();
+        } else if (DebugRequestType.disconnect == requestType) {
+            disconnect();
         } else if (DebugRequestType.suspend == requestType) {
             suspend();
             DebugEvent event = new DebugEvent(DebugEventType.suspendedByClient);
@@ -361,8 +363,10 @@ public class DebugLuaState extends LuaState implements DebugRequestListener {
      */
     public void resume() {
         synchronized (this) {
-            suspended = false;
+            this.suspended = false;
-            stepping = STEP_NONE;
+            this.stepping = STEP_NONE;
+            this.shouldPauseForStepping = false;
+            this.steppingFrame = -1;
             this.notify();
         }
     }
@@ -390,6 +394,27 @@ public class DebugLuaState extends LuaState implements DebugRequestListener {
         exit();
     }
 
+    public void disconnect() {
+        if (this.debugSupport == null) {
+            throw new IllegalStateException(
+                    "DebugStackState is not equiped with DebugSupport.");
+        }
+        
+        reset();
+        debugSupport.disconnect(); 
+        DebugEvent event = new DebugEvent(DebugEventType.disconnected);
+        debugSupport.notifyDebugEvent(event);                   
+    }
+    
+    protected void reset() {
+        synchronized (this) {
+            this.breakpoints.clear();
+            if (this.suspended) {
+                resume();                
+            }
+        }
+    }
+    
     /**
      * terminate the execution
      */

src/debug/org/luaj/debug/DebugSupport.java

@@ -2,7 +2,6 @@ package org.luaj.debug;
 
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
-import java.io.EOFException;
 import java.io.IOException;
 
 import org.luaj.debug.event.DebugEvent;
@@ -21,12 +20,48 @@ public abstract class DebugSupport implements DebugRequestListener, DebugEventLi
 
     protected DebugLuaState vm;
     protected int debugPort;
-    protected Thread requestWatcherThread;
+    protected ClientConnectionTask clientConnectionTask;
     protected int state = UNKNOWN;
     protected DataInputStream requestReader;
     protected DataOutputStream eventWriter;
 
-    public DebugSupport(int debugPort) {
+    class ClientConnectionTask implements Runnable {
+        protected boolean bDisconnected = false;
+                
+        public synchronized void disconnect () {
+            this.bDisconnected = true;
+        }
+        
+        public synchronized boolean isDisconnected() {
+            return this.bDisconnected;
+        }
+        
+        public void run() {
+            try {
+                acceptClientConnection();
+                
+                while (getState() != STOPPED && !isDisconnected()) {
+                    loopForRequest();
+                }
+                
+                if (isDisconnected()) {
+                    releaseClientConnection();
+                } else {
+                    dispose();
+                }
+            } catch (IOException e) {
+                e.printStackTrace();
+                
+                // the connected debugging client aborted abnormally
+                // discard the current connection and start new
+                vm.reset();
+                releaseClientConnection();
+                newClientConnection();
+            }
+        }
+    }
+    
+    public DebugSupport(int debugPort) throws IOException {
         if (debugPort == -1) {
             throw new IllegalArgumentException("requestPort is invalid");
         }
@@ -37,6 +72,8 @@ public abstract class DebugSupport implements DebugRequestListener, DebugEventLi
         this.vm = vm;
     }
     
+    protected abstract void releaseClientConnection();
+    
     protected void dispose() {
         if (DebugUtils.IS_DEBUG)
             DebugUtils.println("releasing the networkig resources...");
@@ -44,6 +81,7 @@ public abstract class DebugSupport implements DebugRequestListener, DebugEventLi
         if (requestReader != null) {
             try {
                 requestReader.close();
+                requestReader = null;
             } catch (IOException e) {
             }
         }
@@ -51,6 +89,7 @@ public abstract class DebugSupport implements DebugRequestListener, DebugEventLi
         if (eventWriter != null) {
             try {
                 eventWriter.close();
+                eventWriter = null;
             } catch (IOException e) {
                 e.printStackTrace();
             }
@@ -67,18 +106,17 @@ public abstract class DebugSupport implements DebugRequestListener, DebugEventLi
                     "DebugLuaState is not set. Please call setDebugStackState first.");
         }
 
-        this.requestWatcherThread = new Thread(new Runnable() {
+        newClientConnection();
-            public void run() {
-                loopForRequests();
-                cleanup();
-            }
-        });
-        this.requestWatcherThread.start();
         this.state = RUNNING;
 
         System.out.println("LuaJ debug server is listening on port: " + debugPort);
     }
 
+    private void newClientConnection() {
+        this.clientConnectionTask = new ClientConnectionTask();
+        new Thread(clientConnectionTask).start();
+    }
+
     protected synchronized int getState() {
         return this.state;
     }
@@ -89,11 +127,9 @@ public abstract class DebugSupport implements DebugRequestListener, DebugEventLi
         this.state = STOPPED;
     }
 
-    public abstract Object getClientConnection();
+    public abstract void acceptClientConnection() throws IOException;
     
-    protected void loopForRequests() {
+    protected void loopForRequest() throws IOException {
-        try {
-            while (getState() != STOPPED) {
         byte[] data = null;
         int size = requestReader.readInt();
         data = new byte[size];
@@ -107,20 +143,6 @@ public abstract class DebugSupport implements DebugRequestListener, DebugEventLi
         
         handleRequest(request);
     }
-        } catch (EOFException e) {
-            // expected. it may occur depending on the timing during the termination
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
-    }
-
-    private void cleanup() {
-        if (DebugUtils.IS_DEBUG)
-            DebugUtils.println("SERVER terminated...");
-
-        dispose();
-        System.exit(0);
-    }
 
     /**
      * This method provides the second communication channel with the debugging
@@ -136,10 +158,12 @@ public abstract class DebugSupport implements DebugRequestListener, DebugEventLi
      * 
      * @param event
      */
-    protected void sendEvent(DebugEvent event) {
+    protected synchronized void sendEvent(DebugEvent event) {
         if (DebugUtils.IS_DEBUG)
             DebugUtils.println("SERVER sending event: " + event.toString());
 
+        if (eventWriter == null) return;
+        
         try {
             byte[] data = SerializationHelper.serialize(event);
             eventWriter.writeInt(data.length);
@@ -171,4 +195,11 @@ public abstract class DebugSupport implements DebugRequestListener, DebugEventLi
 
         vm.handleRequest(request);
     }
+
+    public synchronized void disconnect() {
+        clientConnectionTask.disconnect();
+        clientConnectionTask = null;
+        
+        newClientConnection();
+    }
 }

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

@@ -49,6 +49,8 @@ public class DebugEventType extends EnumType {
         = new DebugEventType("clientRequestStackReply", 15);
     public static DebugEventType clientRequestGlobalReply 
         = new DebugEventType("clientRequestGlobalReply", 16);
+    public static DebugEventType disconnected 
+    = new DebugEventType("disconnected", 17);
     
     protected static DebugEventType[] ENUMS = new DebugEventType[] {
     	started,
@@ -67,7 +69,8 @@ public class DebugEventType extends EnumType {
     	terminated,
     	clientRequestCallgraphReply,
     	clientRequestStackReply,
-    	clientRequestGlobalReply
+    	clientRequestGlobalReply,
+    	disconnected
     };
 	
     protected DebugEventType(String name, int ordinal) {

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

@@ -7,15 +7,17 @@ import javax.microedition.io.ServerSocketConnection;
 import javax.microedition.io.SocketConnection;
 
 import org.luaj.debug.DebugSupport;
-import org.luaj.debug.event.DebugEvent;
 
 public class DebugSupportImpl extends DebugSupport {
     protected ServerSocketConnection serverConnection;
     protected SocketConnection clientDebugConnection;
     protected SocketConnection eventSocketConnection;
 
-    public DebugSupportImpl(int debugPort) {
+    public DebugSupportImpl(int debugPort) throws IOException {
         super(debugPort);
+        this.serverConnection 
+            = (ServerSocketConnection) Connector.open(
+                    "socket://:" + this.debugPort, 1);
     }
 
     /*
@@ -23,12 +25,10 @@ public class DebugSupportImpl extends DebugSupport {
      * 
      * @see lua.debug.j2se.DebugSupport#start()
      */
-    public synchronized void start() throws IOException {
+    public void acceptClientConnection() throws IOException {
         // Set up the request socket and request input + event output streams
-        this.serverConnection = (ServerSocketConnection) Connector
+        this.clientDebugConnection 
-                .open("socket://:" + this.debugPort);
+            = (SocketConnection) serverConnection.acceptAndOpen();
-        this.clientDebugConnection = (SocketConnection) serverConnection
-                .acceptAndOpen();
         clientDebugConnection.setSocketOption(SocketConnection.DELAY, 0);
         clientDebugConnection.setSocketOption(SocketConnection.LINGER, 0);
         clientDebugConnection.setSocketOption(SocketConnection.KEEPALIVE, 1);
@@ -38,34 +38,29 @@ public class DebugSupportImpl extends DebugSupport {
         this.eventWriter = clientDebugConnection.openDataOutputStream();
 
         System.out.println("Lua debug server is started on ports: " + debugPort);
-        super.start();
     }
 
-    protected void dispose() {
+    protected void releaseClientConnection() {
         super.dispose();
 
         if (this.clientDebugConnection != null) {
             try {
                 clientDebugConnection.close();
+                clientDebugConnection = null;
             } catch (IOException e) {
             }
         }        
+    }
+    
+    protected void dispose() {
+        releaseClientConnection();
         
         if (this.serverConnection != null) {
             try {
                 serverConnection.close();
+                serverConnection = null;
             } catch (IOException e) {
             }
         }
     }
-
-    public Object getClientConnection() {
-        return clientDebugConnection;
-    }
-
-    protected void sendEvent(DebugEvent event) {
-        synchronized (eventSocketConnection) {
-            super.sendEvent(event);
-        }
-    }
 }

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

@@ -28,71 +28,44 @@ import java.net.ServerSocket;
 import java.net.Socket;
 
 import org.luaj.debug.DebugSupport;
-import org.luaj.debug.event.DebugEvent;
 
 
 public class DebugSupportImpl extends DebugSupport {	
     protected ServerSocket serverSocket;
     protected Socket clientSocket;
         
-    public DebugSupportImpl(int debugPort) {
+    public DebugSupportImpl(int debugPort) throws IOException {
     	super(debugPort);
+        this.serverSocket = new ServerSocket(debugPort, 1);
     }        
     
-    /* (non-Javadoc)
+    public void acceptClientConnection() throws IOException {
-	 * @see lua.debug.j2se.DebugSupport#start()
-	 */
-    public synchronized void start() throws IOException {
-        this.serverSocket = new ServerSocket(debugPort, 1);
         this.clientSocket = serverSocket.accept();
         this.requestReader 
             = new DataInputStream(clientSocket.getInputStream());
         this.eventWriter 
             = new DataOutputStream(clientSocket.getOutputStream());                 
-        
-        super.start();
     }
      
-    protected void dispose() {
+    protected void releaseClientConnection() {
         super.dispose();
         
         if (this.clientSocket != null) {
             try {
                 clientSocket.close();
+                clientSocket = null;
             } catch (IOException e) {}
         }        
+    }
+    
+    protected void dispose() {        
+        releaseClientConnection();
         
         if (this.serverSocket != null) {
             try {
                 serverSocket.close();
+                serverSocket = null;
             } catch (IOException e) {}
         }        
     }
-    
-    public Object getClientConnection() {        
-        return clientSocket;
-    }
-
-    /**
-     * This method provides the second communication channel with the debugging
-     * client. The server can send events via this channel to notify the client
-     * about debug events (see below) asynchronously.
-     * 
-     * The following events can be fired:
-     * 1. started    -- the vm is started and ready to receive debugging requests
-     *                  (guaranteed to be the first event sent)
-     * 2. terminated -- the vm is terminated (guaranteed to be the last event sent)
-     * 3. suspended client|step|breakpoint N
-     *               -- the vm is suspended by client, due to a stepping request or
-     *                  the breakpoint at line N is hit 
-     * 4. resumed client|step
-     *               -- the vm resumes execution by client or step
-     *              
-     * @param event
-     */
-    protected void sendEvent(DebugEvent event) {
-        synchronized (clientSocket) {
-            super.sendEvent(event);
-        }
-    }
 }

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

@@ -43,6 +43,7 @@ public class DebugRequestType extends EnumType {
     public static final DebugRequestType stepOver = new DebugRequestType("stepOver", 11);
     public static final DebugRequestType stepReturn = new DebugRequestType("stepReturn", 12);
     public static final DebugRequestType global = new DebugRequestType("global", 13);
+    public static final DebugRequestType disconnect = new DebugRequestType("disconnect", 14);
     
     protected static final DebugRequestType[] ENUMS = new DebugRequestType[] {
         start,
@@ -58,7 +59,8 @@ public class DebugRequestType extends EnumType {
         stepInto,
         stepOver,
         stepReturn,
-        global
+        global,
+        disconnect
     };
     
     public DebugRequestType(String name, int ordinal) {