add timeout handling for gdb commands

sometimes, commands simply don't return ...

the debug message doesn't say anything which couldn't be found in the
log already, but that way it is more convenient.

and we kill gdb to get creator back to a defined state.

Reviewed-by: hjk

src/plugins/debugger/gdb/gdbengine.cpp

@@ -193,6 +193,11 @@ GdbEngine::GdbEngine(DebuggerManager *manager) :
     m_trkOptions->fromSettings(Core::ICore::instance()->settings());
     m_gdbAdapter = 0;
 
+    m_commandTimer = new QTimer(this);
+    m_commandTimer->setSingleShot(true);
+    m_commandTimer->setInterval(COMMAND_TIMEOUT);
+    connect(m_commandTimer, SIGNAL(timeout()), SLOT(commandTimeout()));
+
     // Needs no resetting in initializeVariables()
     m_busy = false;
 
@@ -606,6 +611,9 @@ void GdbEngine::readGdbStandardError()
 
 void GdbEngine::readGdbStandardOutput()
 {
+    if (m_commandTimer->isActive())
+        m_commandTimer->start(); // Retrigger
+
     int newstart = 0;
     int scan = m_inbuffer.size();
 
@@ -796,10 +804,27 @@ void GdbEngine::flushCommand(const GdbCommand &cmd0)
 
     m_gdbAdapter->write(cmd.command.toLatin1() + "\r\n");
 
+    m_commandTimer->start();
+
     if (cmd.flags & LosesChild)
         setState(InferiorShuttingDown);
 }
 
+void GdbEngine::commandTimeout()
+{
+    // FIXME this needs a proper message box
+    debugMessage(_("TIMED OUT WAITING FOR GDB REPLY. COMMANDS STILL IN PROGRESS:"));
+    QList<int> keys = m_cookieForToken.keys();
+    qSort(keys);
+    foreach (int key, keys) {
+        const GdbCommand &cmd = m_cookieForToken[key];
+        debugMessage(_("  %1: %2 => %3").arg(key).arg(cmd.command).arg(_(cmd.callbackName)));
+    }
+    // This is an entirely undefined state, so we just pull the emergency brake.
+    setState(EngineShuttingDown, true);
+    m_gdbProc.kill();
+}
+
 void GdbEngine::handleResultRecord(GdbResponse *response)
 {
     //qDebug() << "TOKEN:" << response.token
@@ -927,6 +952,9 @@ void GdbEngine::handleResultRecord(GdbResponse *response)
     } else {
         PENDING_DEBUG("MISSING TOKENS: " << m_cookieForToken.keys());
     }
+
+    if (m_cookieForToken.isEmpty())
+        m_commandTimer->stop();
 }
 
 void GdbEngine::executeDebuggerCommand(const QString &command)
@@ -1412,7 +1440,6 @@ void GdbEngine::shutdown()
         m_gdbAdapter->shutdown();
         // fall-through
     case AdapterStartFailed: // Adapter "did something", but it did not help
-        // FIXME set some timeout?
         if (m_gdbProc.state() == QProcess::Running) {
             postCommand(_("-gdb-exit"), GdbEngine::ExitRequest, CB(handleGdbExit));
         } else {
@@ -1423,7 +1450,6 @@ void GdbEngine::shutdown()
     case InferiorRunning:
     case InferiorStopping:
     case InferiorStopped:
-        // FIXME set some timeout?
         postCommand(_(m_gdbAdapter->inferiorShutdownCommand()),
                     NeedsStop | LosesChild, CB(handleInferiorShutdown));
         break;
@@ -1432,7 +1458,6 @@ void GdbEngine::shutdown()
     case InferiorShutDown:
     case InferiorShutdownFailed: // Whatever
     case InferiorUnrunnable:
-        // FIXME set some timeout?
         postCommand(_("-gdb-exit"), GdbEngine::ExitRequest, CB(handleGdbExit));
         setState(EngineShuttingDown); // Do it after posting the command!
         break;

src/plugins/debugger/gdb/gdbengine.h

@@ -49,6 +49,7 @@
 QT_BEGIN_NAMESPACE
 class QAction;
 class QAbstractItemModel;
+class QTimer;
 class QWidget;
 class QMainWindow;
 QT_END_NAMESPACE
@@ -228,9 +229,12 @@ private: ////////// Gdb Command Management //////////
                      const QVariant &cookie = QVariant());
     void postCommandHelper(const GdbCommand &cmd);
     void flushQueuedCommands();
+    Q_SLOT void commandTimeout();
     void setTokenBarrier();
 
     QHash<int, GdbCommand> m_cookieForToken;
+    QTimer *m_commandTimer;
+    enum { COMMAND_TIMEOUT = 20000 };
 
     QByteArray m_pendingConsoleStreamOutput;
     QByteArray m_pendingLogStreamOutput;