Enable Qute debugger by default

Signed-off-by: azerr <[email protected]>

Author: angelozerr

extensions/qute/runtime/src/main/java/io/quarkus/qute/runtime/debug/DebugQuteEngineObserver.java

@@ -14,7 +14,8 @@
  * Observes the creation of Qute engines and attaches the Qute debugger in development mode.
  *
  * <p>
- * When a new {@link io.quarkus.qute.EngineBuilder} is observed and the application is running in
+ * When a new {@link io.quarkus.qute.EngineBuilder} is observed and the application is started with "-DquteDebugPort"
+ * and running in
  * {@link io.quarkus.runtime.LaunchMode#DEVELOPMENT development mode} with
  * {@code quarkus.qute.debug.enabled=true}, this observer:
  * <ul>
@@ -38,7 +39,11 @@ public class DebugQuteEngineObserver {
      * @param config the Qute configuration
      */
     void configureEngine(@Observes EngineBuilder builder, QuteConfig config) {
-        if (LaunchMode.current() == LaunchMode.DEVELOPMENT && config.debug().enabled()) {
+        if (LaunchMode.current() == LaunchMode.DEVELOPMENT && config.debug().enabled() && registrar.getPort() != null) {
+            // - in dev mode only
+            // - quarkus.qute.debug.enabled=true
+            // - Quarkus application is started with -DquteDebugPort
+            // --> enable the Qute debugger.
             builder.enableTracing(true);
             builder.addEngineListener(registrar);
         }

extensions/qute/runtime/src/main/java/io/quarkus/qute/runtime/debug/QuteDebugConfig.java

@@ -23,19 +23,19 @@ public interface QuteDebugConfig {
      * </p>
      *
      * <p>
-     * <strong>Default value:</strong> {@code false}
+     * <strong>Default value:</strong> {@code true}
      * </p>
      *
      * <p>
      * Example configuration:
      * </p>
      *
      * <pre>
-     * quarkus.qute.debug.enabled = true
+     * quarkus.qute.debug.enabled = false
      * </pre>
      *
      * @return {@code true} if Qute debug mode is active, {@code false} otherwise.
      */
-    @WithDefault("false")
+    @WithDefault("true")
     boolean enabled();
 }

independent-projects/qute/debug/src/main/java/io/quarkus/qute/debug/adapter/RegisterDebugServerAdapter.java

@@ -2,6 +2,7 @@
 
 import java.io.IOException;
 import java.net.ServerSocket;
+import java.net.Socket;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.concurrent.ExecutorService;
@@ -99,7 +100,12 @@ private DebuggeeAgent createAgentIfNeeded() {
         return agent;
     }
 
-    private Integer getPort() {
+    /**
+     * Returns the Qute debugger port defines with "-DquteDebugPort" environment variable and false otherwise.
+     *
+     * @return the Qute debugger port defines with "-DquteDebugPort" environment variable and false otherwise.
+     */
+    public Integer getPort() {
         if (port != null) {
             return port;
         }
@@ -198,7 +204,6 @@ private synchronized void initializeAgentBlocking(int port, boolean suspend) {
                             log("DAP client connected!");
                             setupLauncher(client, false);
                             trackedEngines.forEach(engine -> agent.track(engine));
-                            agent.setEnabled(true);
                         } catch (IOException e) {
                             if (serverSocket != null && !serverSocket.isClosed()) {
                                 e.printStackTrace();
@@ -218,7 +223,7 @@ private synchronized void initializeAgentBlocking(int port, boolean suspend) {
     }
 
     public void dispose() {
-        if (launcherFuture != null) {
+        if (launcherFuture != null && !launcherFuture.isDone()) {
             launcherFuture.cancel(true);
         }
         log("Shutdown hook: closing server socket.");
@@ -249,7 +254,11 @@ public void reset() {
         agent.reset();
         trackedEngines.clear();
         if (!notInitializedEngines.isEmpty()) {
-            notInitializedEngines.forEach(engine -> engine.removeTraceListener(initializeAgentListener));
+            notInitializedEngines.forEach(engine -> {
+                if (engine.getTraceManager() != null) {
+                    engine.removeTraceListener(initializeAgentListener);
+                }
+            });
             notInitializedEngines.clear();
         }
     }
@@ -262,7 +271,7 @@ public void reset() {
      * @param suspend true if suspend mode (used to wait after connection)
      * @throws IOException if socket streams cannot be accessed
      */
-    private void setupLauncher(java.net.Socket client, boolean suspend) throws IOException {
+    private void setupLauncher(Socket client, boolean suspend) throws IOException {
         // Cancel previous launcher if needed
         if (launcherFuture != null && !launcherFuture.isDone()) {
             launcherFuture.cancel(true);
@@ -276,7 +285,11 @@ private void setupLauncher(java.net.Socket client, boolean suspend) throws IOExc
         launcherFuture = launcher.startListening();
 
         if (!notInitializedEngines.isEmpty()) {
-            notInitializedEngines.forEach(engine -> engine.removeTraceListener(initializeAgentListener));
+            notInitializedEngines.forEach(engine -> {
+                if (engine.getTraceManager() != null) {
+                    engine.removeTraceListener(initializeAgentListener);
+                }
+            });
             notInitializedEngines.clear();
         }
 

independent-projects/qute/debug/src/main/java/io/quarkus/qute/debug/agent/DebuggeeAgent.java

@@ -83,6 +83,14 @@ public class DebuggeeAgent implements Debugger {
     /** The set of Qute engines being tracked for debugging. */
     private final Set<Engine> trackedEngine;
 
+    /**
+     * Qute engines that currently have the {@link DebuggerTraceListener} attached.
+     * <p>
+     * Used to prevent adding the same listener multiple times to the same engine.
+     * </p>
+     */
+    private final Set<Engine> enginesWithDebugListener;
+
     /** Indicates whether the debugging agent is enabled. */
     private boolean enabled;
 
@@ -97,6 +105,7 @@ public DebuggeeAgent() {
         this.variablesRegistry = new VariablesRegistry();
         this.sourceTemplateRegistry = new SourceTemplateRegistry();
         this.trackedEngine = new HashSet<>();
+        this.enginesWithDebugListener = new HashSet<>();
         this.evaluationSupport = new EvaluationSupport(this);
         this.completionSupport = new CompletionSupport(this);
     }
@@ -107,8 +116,14 @@ public DebuggeeAgent() {
      * @param engine the engine to track.
      */
     public void track(Engine engine) {
+        // Only track the engine once
         if (!trackedEngine.contains(engine)) {
-            engine.addTraceListener(debugListener);
+            // If the debugger is currently active (DAP client connected),
+            // attach the debug listener immediately so trace events start flowing.
+            if (isEnabled()) {
+                addDebugListener(engine);
+            }
+            // Mark the engine as tracked so we can manage its listener later
             trackedEngine.add(engine);
         }
     }
@@ -336,13 +351,17 @@ void output(OutputEventArguments args) {
      * Unlocks and terminates all debuggee threads, then clears all tracked engines.
      */
     public void unlockAllDebuggeeThreads() {
-        for (RemoteThread thread : debuggees.values()) {
-            thread.terminate();
-            fireThreadEvent(new ThreadEvent(thread.getId(), ThreadStatus.EXITED));
+        if (!debuggees.isEmpty()) {
+            for (RemoteThread thread : debuggees.values()) {
+                thread.terminate();
+                fireThreadEvent(new ThreadEvent(thread.getId(), ThreadStatus.EXITED));
+            }
+            debuggees.clear();
+        }
+        if (!trackedEngine.isEmpty()) {
+            trackedEngine.forEach(this::removeDebugListener);
+            trackedEngine.clear();
         }
-        debuggees.clear();
-        trackedEngine.forEach(engine -> engine.removeTraceListener(debugListener));
-        trackedEngine.clear();
     }
 
     @Override
@@ -462,6 +481,29 @@ public SourceTemplateRegistry getSourceTemplateRegistry() {
     @Override
     public void setEnabled(boolean enabled) {
         this.enabled = enabled;
+        if (enabled) {
+            // A DAP client is now connected → attach the debug listener to all tracked engines
+            trackedEngine.forEach(this::addDebugListener);
+        } else {
+            // The DAP client has disconnected → detach the debug listener from all tracked engines
+            trackedEngine.forEach(this::removeDebugListener);
+        }
+    }
+
+    private void addDebugListener(Engine engine) {
+        // Only attach the listener if the engine supports tracing (has a TraceManager)
+        // and if it has not already been added.
+        if (engine.getTraceManager() != null && !enginesWithDebugListener.contains(engine)) {
+            engine.addTraceListener(debugListener);
+            enginesWithDebugListener.add(engine);
+        }
+    }
+
+    private void removeDebugListener(Engine engine) {
+        if (engine.getTraceManager() != null) {
+            engine.removeTraceListener(debugListener);
+            enginesWithDebugListener.remove(engine);
+        }
     }
 
     @Override