Detach from debugger when front-end disconnects.

Modified session behaviour so that back-end closes session and detaches
from the debugger when front-end web-socked disconnects.

Changed handling of debugger-connection errors so that front-end displays
popup window with error description when back-end cannot connect to debugger.

When a session starts, all previously set breakpoints are removed, since
they were already deactivated by V8 debugger.

front-end/node/Overrides.js

@@ -21,9 +21,7 @@ function onWebSocketConnected() {
 function onWebSocketMessage(message) {
   if (!message || message === 'ping') return;
 
-  if (message === 'debuggerWasDisabled') {
-    WebInspector.debuggerModel.disableDebugger();
-  } else if (message === 'showConsolePanel') {
+  if (message === 'showConsolePanel') {
     InspectorFrontendAPI.showConsole();
   } else {
     InspectorBackend.dispatch(message);

lib/DebuggerAgent.js

@@ -93,8 +93,6 @@ DebuggerAgent.prototype = {
       done);
   },
 
-  // TODO(bajtos) Keep track of breakpoints - see implementation in session.js
-
   setBreakpointByUrl: function(params, done) {
     // TODO(bajtos) - handle params.urlRegex
     var requestParams = {

lib/debug-server.js

@@ -5,10 +5,7 @@ var Http = require('http'),
     Session = require('./session'),
     inherits = require('util').inherits,
     WEBROOT = require('path').join(__dirname, '../front-end'),
-    sessions = {},
-    config = {},
-    connectionTimeout,
-    webPort;
+    config = {};
 
 function serveStaticFiles(req, res) {
   var re = /^\/debug/;
@@ -23,26 +20,16 @@ function getDebuggerPort(url, defaultPort) {
   return parseInt((/\?port=(\d+)/.exec(url) || [null, defaultPort])[1], 10);
 }
 
-function getSession(debuggerPort) {
-  var session = sessions[debuggerPort];
-  if (!session) {
-    session = Session.create(debuggerPort, config);
-    sessions[debuggerPort] = session;
-    session.on('ws_closed', function () {
-      connectionTimeout = setTimeout(function () {
-        session.close();
-      }, 3000);
-    });
-    session.on('close', function () {
-      sessions[debuggerPort] = null;
-    });
-  }
+function createSession(debuggerPort) {
+  var session = Session.create(debuggerPort, config);
+  session.on('ws_closed', function () {
+    session.close();
+  });
   return session;
 }
 
 function handleWebSocketConnection(socket) {
-  clearTimeout(connectionTimeout);
-  getSession(config.debugPort).join(socket);
+  createSession(config.debugPort).join(socket);
 }
 
 function handleServerListening() {

lib/debugger.js

@@ -34,6 +34,9 @@ exports.attachDebugger = function(port) {
         debugBuffer = b.toString('utf8', msg.contentLength, b.length);
         if (msg.body.length > 0) {
           obj = JSON.parse(msg.body);
+          if (typeof obj.running === 'boolean') {
+            debugr.isRunning = obj.running;
+          }
           if (obj.type === 'response' && obj.request_seq > 0) {
             callbackHandler.processResponse(obj.request_seq, [obj]);
           }
@@ -67,6 +70,8 @@ exports.attachDebugger = function(port) {
   }
 
   debugr = Object.create(EventEmitter.prototype, {
+    isRunning: { writable: true, value: true },
+
     send: {
       value: function(data)
       {

lib/session.js

@@ -1,4 +1,5 @@
 var events = require('events'),
+    async = require('async'),
     debugr = require('./debugger'),
     convert = require('./convert.js'),
     ScriptManager = require('./ScriptManager').ScriptManager;
@@ -163,20 +164,60 @@ exports.create = function(debuggerPort, config) {
     }
   }
 
+  function removeAllBreakpoints(done) {
+    debug.sendDebugRequest('listbreakpoints', {}, function(error, response) {
+      if (error) {
+        console.log('Warning: cannot remove old breakpoints. %s', error);
+        done();
+        return;
+      }
+
+      function removeOneBreakpoint(bp, next) {
+        var req = { breakpoint: bp.number };
+        debug.sendDebugRequest('clearbreakpoint', req, function(error) {
+          if (error)
+            console.log(
+              'Warning: cannot remove old breakpoint %d. %s',
+              bp.number,
+              error);
+          next();
+        });
+      }
+
+      async.eachSeries(response.breakpoints, removeOneBreakpoint, done);
+    }.bind(this));
+  }
+
+  function reloadScripts(done) {
+    scriptManager.reset();
+    // TODO(bajtos) use sendDebugRequest and handle errors
+    debug.request(
+      'scripts',
+      { arguments: { includeSource: true, types: 4 }},
+      function(msg) {
+        parsedScripts(msg);
+        done();
+      });
+  }
+
+  function sendBacktraceIfPaused() {
+    if (!debug.isRunning) {
+      sendBacktrace();
+    }
+  }
+
   function browserConnected() { // TODO find a better name
     sendPing();
-    scriptManager.reset();
-    var args = { arguments: { includeSource: true, types: 4 }};
-    debug.request('scripts', args, function(msg) {
-      parsedScripts(msg);
-      // TODO(bajtos) we should probably clear all existing breakpoints here, because:
+
+    async.waterfall([
+      // Remove all existing breakpoints because:
       // 1) front-end inspector cannot restore breakpoints from debugger anyway
-      // 2) all breakpoints are disabled when debugger-client disconnects from
-      // debugged application
-      if (!msg.running) {
-        sendBacktrace();
-      }
-    });
+      // 2) all breakpoints were disabled when the previous debugger-client
+      //    disconnected from the debugged application
+      removeAllBreakpoints,
+      reloadScripts,
+      sendBacktraceIfPaused,
+    ]);
   }
 
   sessionInstance = Object.create(events.EventEmitter.prototype, {
@@ -202,12 +243,7 @@ exports.create = function(debuggerPort, config) {
     attach: {
       value: function(done)
       {
-        if (attachedToDebugger) {
-          // TODO(bajtos) duplicated code - see debug.on('connect')
-          done();
-          browserConnected();
-          return;
-        }
+        var closeReason = 'Debugged process exited.';
         debug = debugr.attachDebugger(debuggerPort);
         debug.on('break', breakEvent);
         debug.on('afterCompile', onAfterCompile)
@@ -216,16 +252,15 @@ exports.create = function(debuggerPort, config) {
           debug = {
             request: function() {
               console.error('debugger not connected');
+            },
+            sendDebugRequest: function(command, args, callback) {
+              callback('debugger not connected');
             }
           };
-          if (conn)
-            conn.send('debuggerWasDisabled');
-          // Do not close the session - keep it for debugee restart
-          // self.close();
-          attachedToDebugger = false;
+          sendEvent('Inspector.detached', { reason: closeReason.replace(/\n/g, '. ') });
+          sessionInstance.close();
         });
         debug.on('connect', function() {
-          // TODO(bajtos) duplicated code - see if (attachedToDebugger)
           done();
           browserConnected();
         });
@@ -236,6 +271,10 @@ exports.create = function(debuggerPort, config) {
           var err = e.toString();
           if (err.match(/ECONNREFUSED/)) {
             err += '\nIs node running with --debug port ' + debuggerPort + '?';
+            closeReason = err;
+          } else if (err.match(/ECONNRESET/)) {
+            err += '\nCheck there is no other debugger client attached to port ' + debuggerPort + '.';
+            closeReason = err;
           }
           sendLogToConsole('error', err);
         });
@@ -253,6 +292,7 @@ exports.create = function(debuggerPort, config) {
       }
     },
     //Controller
+    // TODO(bajtos) move this method to DebuggerAgent.js
     disableDebugger: {
       value: function(done) {
         if (debug && debug.connected) {