Update ProtoTerminal part to use threading and message queues

2 files changed, 281 insertions, 110 deletions

diff --git a/clients/tde/src/part/prototerminal/part.cpp b/clients/tde/src/part/prototerminal/part.cpp
index 7818988..b5e5a1d 100644
--- a/clients/tde/src/part/prototerminal/part.cpp
+++ b/clients/tde/src/part/prototerminal/part.cpp
@@ -15,11 +15,20 @@
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  *
- * (c) 2014 Timothy Pearson
+ * (c) 2014 - 2015 Timothy Pearson
  * Raptor Engineering
  * http://www.raptorengineeringinc.com
  */
 
+/* This part illustrates the correct method of transmitting and receiving
+ * data in a dedicated thread, using two separate message queues to enable
+ * fully non-blocking, event-driven execution.
+ *
+ * NOTE
+ * inboundQueue is filled by the GUI thread with data inbound to the worker thread
+ * outboundQueue is filled by the worker thread with data outbound to the GUI thread
+ */
+
 #include "define.h"
 #include "part.h"
 
@@ -60,6 +69,146 @@ typedef KParts::GenericFactory<RemoteLab::ProtoTerminalPart> Factory;
 #define CLIENT_LIBRARY "libremotelab_prototerminal"
 K_EXPORT_COMPONENT_FACTORY( libremotelab_prototerminal, RemoteLab::Factory )
 
+ProtoTerminalWorker::ProtoTerminalWorker() : TQObject() {
+	m_networkDataMutex = new TQMutex(false);
+	m_outboundQueueMutex = new TQMutex(false);
+	m_inboundQueueMutex = new TQMutex(false);
+	m_newData = false;
+}
+
+ProtoTerminalWorker::~ProtoTerminalWorker() {
+	delete m_networkDataMutex;
+	m_networkDataMutex = NULL;
+	delete m_inboundQueueMutex;
+	m_inboundQueueMutex = NULL;
+	delete m_outboundQueueMutex;
+	m_outboundQueueMutex = NULL;
+}
+
+void ProtoTerminalWorker::run() {
+	TQEventLoop* eventLoop = TQApplication::eventLoop();
+	if (!eventLoop) {
+		return;
+	}
+
+	while (1) {
+		m_instrumentMutex->lock();
+
+		// Handle inbound queue
+		m_inboundQueueMutex->lock();
+		if (m_inboundQueue.count() > 0) {
+			TQDataStream ds(m_socket);
+			ds.setPrintableData(true);
+
+			ProtoTerminalEventQueue::iterator it;
+			for (it = m_inboundQueue.begin(); it != m_inboundQueue.end(); ++it) {
+				if ((*it).first == TxRxSyncPoint) {
+					break;
+				}
+				if ((*it).first == ConsoleTextSend) {
+					ds << (*it).second.toString();
+					m_socket->writeEndOfFrame();
+				}
+				it = m_inboundQueue.erase(it);
+			}
+			m_socket->flush();
+		}
+		m_inboundQueueMutex->unlock();
+
+		// Handle outbound queue
+		if (m_newData) {
+			bool queue_modified = false;
+			m_networkDataMutex->lock();
+			m_newData = false;
+
+			// Receive data
+			if (m_socket->canReadFrame()) {
+				TQDataStream ds(m_socket);
+				ds.setPrintableData(true);
+
+				// Get command status
+				TQString input;
+				while (!ds.atEnd()) {
+					ds >> input;
+					m_outboundQueueMutex->lock();
+					m_outboundQueue.push_back(ProtoTerminalEvent(ConsoleTextReceive, TQVariant(input)));
+					m_outboundQueueMutex->unlock();
+					queue_modified = true;
+				}
+				m_socket->clearFrameTail();
+			}
+			m_networkDataMutex->unlock();
+
+			if (queue_modified) {
+				m_inboundQueueMutex->lock();
+				ProtoTerminalEventQueue::iterator it = m_inboundQueue.begin();
+				if ((it) && (it != m_inboundQueue.end())) {
+					// Remove sync point
+					if ((*it).first == TxRxSyncPoint) {
+						it = m_inboundQueue.erase(it);
+					}
+				}
+				m_inboundQueueMutex->unlock();
+				emit(outboundQueueUpdated());
+			}
+		}
+
+		m_instrumentMutex->unlock();
+
+		// Wait for queue status change or new network activity
+		if (!eventLoop->processEvents(TQEventLoop::ExcludeUserInput)) {
+			eventLoop->processEvents(TQEventLoop::ExcludeUserInput | TQEventLoop::WaitForMore);
+		}
+	}
+
+	eventLoop->exit(0);
+}
+
+void ProtoTerminalWorker::appendItemToInboundQueue(ProtoTerminalEvent item, bool syncPoint) {
+	m_inboundQueueMutex->lock();
+	m_inboundQueue.push_back(item);
+	if (syncPoint) {
+		m_inboundQueue.push_back(ProtoTerminalEvent(TxRxSyncPoint, TQVariant()));
+	}
+	m_inboundQueueMutex->unlock();
+}
+
+bool ProtoTerminalWorker::syncPointActive() {
+	bool active = false;
+
+	m_inboundQueueMutex->lock();
+	ProtoTerminalEventQueue::iterator it = m_inboundQueue.begin();
+	if ((it) && (it != m_inboundQueue.end())) {
+		if ((*it).first == TxRxSyncPoint) {
+			active = true;
+		}
+	}
+	m_inboundQueueMutex->unlock();
+
+	return active;
+}
+
+void ProtoTerminalWorker::wake() {
+	// Do nothing -- the main event loop will wake when this is called
+}
+
+void ProtoTerminalWorker::dataReceived() {
+	m_networkDataMutex->lock();
+	m_newData = true;
+	m_networkDataMutex->unlock();
+}
+
+void ProtoTerminalWorker::lockOutboundQueue() {
+	m_outboundQueueMutex->lock();
+}
+
+void ProtoTerminalWorker::unlockOutboundQueue() {
+	m_outboundQueueMutex->unlock();
+}
+
+ProtoTerminalEventQueue* ProtoTerminalWorker::outboundQueue() {
+	return &m_outboundQueue;
+}
 
 ProtoTerminalPart::ProtoTerminalPart( TQWidget *parentWidget, const char *widgetName, TQObject *parent, const char *name, const TQStringList& )
 	: RemoteInstrumentPart( parent, name ), m_commHandlerState(-1), m_commHandlerMode(0), m_commHandlerCommandState(0), m_connectionActiveAndValid(false), m_base(0)
@@ -74,11 +223,16 @@ ProtoTerminalPart::ProtoTerminalPart( TQWidget *parentWidget, const char *widget
 	setInstance(Factory::instance());
 	setWidget(new TQVBox(parentWidget, widgetName));
 
+	// Set up worker
+	m_worker = new ProtoTerminalWorker();
+	m_workerThread = new TQEventLoopThread();
+	m_worker->moveToThread(m_workerThread);
+	TQObject::connect(this, TQT_SIGNAL(wakeWorkerThread()), m_worker, TQT_SLOT(wake()));
+	TQObject::connect(m_worker, TQT_SIGNAL(outboundQueueUpdated()), this, TQT_SLOT(processOutboundQueue()));
+
 	// Create timers
-	m_forcedUpdateTimer = new TQTimer(this);
-	connect(m_forcedUpdateTimer, SIGNAL(timeout()), this, SLOT(mainEventLoop()));
 	m_updateTimeoutTimer = new TQTimer(this);
-	connect(m_updateTimeoutTimer, SIGNAL(timeout()), this, SLOT(mainEventLoop()));
+	connect(m_updateTimeoutTimer, SIGNAL(timeout()), this, SLOT(networkTimeout()));
 
 	// Create widgets
 	m_base = new ProtoTerminalBase(widget());
@@ -99,6 +253,15 @@ ProtoTerminalPart::~ProtoTerminalPart() {
 
 	disconnectFromServer();
 	delete m_instrumentMutex;
+
+	if (m_workerThread) {
+		m_workerThread->terminate();
+		m_workerThread->wait();
+		delete m_workerThread;
+		m_workerThread = NULL;
+		delete m_worker;
+		m_worker = NULL;
+	}
 }
 
 void ProtoTerminalPart::postInit() {
@@ -129,22 +292,31 @@ void ProtoTerminalPart::processLockouts() {
 }
 
 void ProtoTerminalPart::disconnectFromServerCallback() {
-	m_forcedUpdateTimer->stop();
 	m_updateTimeoutTimer->stop();
 	m_connectionActiveAndValid = false;
 }
 
 void ProtoTerminalPart::connectionFinishedCallback() {
+	// Finish worker setup
+	m_worker->m_socket = m_socket;
+	m_worker->m_instrumentMutex = m_instrumentMutex;
+	m_socket->moveToThread(m_workerThread);
+
 	connect(m_socket, SIGNAL(readyRead()), m_socket, SLOT(processPendingData()));
 	m_socket->processPendingData();
-	connect(m_socket, SIGNAL(newDataReceived()), this, SLOT(mainEventLoop()));
+	connect(m_socket, SIGNAL(newDataReceived()), m_worker, SLOT(dataReceived()));
 	m_tickerState = 0;
 	m_commHandlerState = 0;
 	m_commHandlerMode = 0;
 	m_socket->setDataTimeout(NETWORK_COMM_TIMEOUT_MS);
 	m_updateTimeoutTimer->start(NETWORK_COMM_TIMEOUT_MS, TRUE);
+
+	// Start worker
+	m_workerThread->start();
+	TQTimer::singleShot(0, m_worker, SLOT(run()));
+
 	processLockouts();
-	mainEventLoop();
+	networkTick();
 	return;
 }
 
@@ -176,119 +348,60 @@ void ProtoTerminalPart::setTickerMessage(TQString message) {
 	}
 }
 
-#define UPDATEDISPLAY_TIMEOUT		m_connectionActiveAndValid = false;														\
-					m_tickerState = 0;																\
-					m_commHandlerState = 2;																\
-					m_commHandlerMode = 0;																\
-					m_socket->clearIncomingData();															\
-					setStatusMessage(i18n("Server ping timeout.  Please verify the status of your network connection."));						\
-					m_updateTimeoutTimer->start(NETWORK_COMM_TIMEOUT_MS, TRUE);											\
-					m_instrumentMutex->unlock();															\
-					return;
-
-#define COMMUNICATIONS_FAILED		m_connectionActiveAndValid = false;														\
-					m_tickerState = 0;																\
-					m_commHandlerState = 2;																\
-					m_commHandlerMode = 0;																\
-					m_socket->clearIncomingData();															\
-					setStatusMessage(i18n("Instrument communication failure.  Please verify the status of your network connection."));				\
-					m_updateTimeoutTimer->start(NETWORK_COMM_TIMEOUT_MS, TRUE);											\
-					m_instrumentMutex->unlock();															\
-					return;
-
-#define SET_WATCHDOG_TIMER		if (!m_updateTimeoutTimer->isActive()) m_updateTimeoutTimer->start(NETWORK_COMM_TIMEOUT_MS, TRUE);
-#define PAT_WATCHDOG_TIMER		m_updateTimeoutTimer->stop(); m_updateTimeoutTimer->start(NETWORK_COMM_TIMEOUT_MS, TRUE);							\
-					setTickerMessage(i18n("Connected"));
-
-#define SET_NEXT_STATE(x)		if (m_commHandlerMode == 0) {															\
-						m_commHandlerState = x;															\
-					}																		\
-					else {																		\
-						m_commHandlerState = 255;														\
-					}
-
-#define EXEC_NEXT_STATE_IMMEDIATELY	m_forcedUpdateTimer->start(0, TRUE);
-
-void ProtoTerminalPart::mainEventLoop() {
-	TQDataStream ds(m_socket);
-	ds.setPrintableData(true);
-
-	if (!m_instrumentMutex->tryLock()) {
-		EXEC_NEXT_STATE_IMMEDIATELY
-		return;
-	}
-
-	if (m_socket) {
-		if ((m_commHandlerMode == 0) || (m_commHandlerMode == 1)) {
-			if (m_commHandlerState == 0) {
-				// Setup functions go here
-				setTickerMessage("Connection established");
-
-				m_commHandlerState = 1;
-				EXEC_NEXT_STATE_IMMEDIATELY
-			}
-			else if (m_commHandlerState == 1) {
-				// Receive data
-				if (m_socket->canReadFrame()) {
-					PAT_WATCHDOG_TIMER
-
-					// Get command status
-					TQString input;
-					while (!ds.atEnd()) {
-						ds >> input;
-
-						if (input != "") {
-							input.replace("\r", "\n");
-							m_base->textOutput->append(">>>" + input);
-						}
-					}
-					m_socket->clearFrameTail();
-					EXEC_NEXT_STATE_IMMEDIATELY
-				}
-				else {
-					if (!m_updateTimeoutTimer->isActive()) {
-						UPDATEDISPLAY_TIMEOUT
-					}
-				}
-
-				// Send data
-				if (m_TextToSend != "") {
-					ds << m_TextToSend;
-					m_socket->writeEndOfFrame();
+void ProtoTerminalPart::processOutboundQueue() {
+	bool had_events = false;
 
-					m_base->textOutput->append("<<<" + m_TextToSend);
-					m_TextToSend = "";
+	m_worker->lockOutboundQueue();
 
-					EXEC_NEXT_STATE_IMMEDIATELY
-				}
-
-				// Never time out
-				PAT_WATCHDOG_TIMER
-			}
-			else if (m_commHandlerState == 2) {
-				// Ignore timeouts
-				m_commHandlerState = 1;
-				EXEC_NEXT_STATE_IMMEDIATELY
+	ProtoTerminalEventQueue* eventQueue = m_worker->outboundQueue();
+	ProtoTerminalEventQueue::iterator it;
+	for (it = eventQueue->begin(); it != eventQueue->end(); ++it) {
+		if ((*it).first == ConsoleTextReceive) {
+			TQString input = (*it).second.toString();
+			if (input != "") {
+				input.replace("\r", "\n");
+				m_base->textOutput->append(">>>" + input);
 			}
-			SET_WATCHDOG_TIMER
 		}
+		had_events = true;
 	}
-	else {
-		m_commHandlerState = 0;
-		m_commHandlerCommandState = 0;
+	if (had_events) {
+		networkTick();
+		eventQueue->clear();
 	}
 
+	m_worker->unlockOutboundQueue();
+
 	processLockouts();
+}
 
-	m_instrumentMutex->unlock();
+void ProtoTerminalPart::networkTick() {
+	m_updateTimeoutTimer->stop();
+	setTickerMessage(i18n("Connected"));
+	m_connectionActiveAndValid = true;
+	processLockouts();
+}
+
+void ProtoTerminalPart::networkTimeout() {
+	m_updateTimeoutTimer->stop();
+	m_socket->clearIncomingData();
+	setStatusMessage(i18n("Server ping timeout.  Please verify the status of your network connection."));
+	m_connectionActiveAndValid = false;
+	processLockouts();
 }
 
 void ProtoTerminalPart::sendTextClicked() {
-	m_TextToSend = m_TextToSend + m_base->textInput->text();
-	m_base->textInput->setText("");
+	if (!m_worker->syncPointActive()) {
+		m_TextToSend = m_TextToSend + m_base->textInput->text();
+		m_base->textInput->setText("");
 
-	// Transmit!
-	EXEC_NEXT_STATE_IMMEDIATELY
+		m_worker->appendItemToInboundQueue(ProtoTerminalEvent(ConsoleTextSend, TQVariant(m_TextToSend)), true);
+		m_base->textOutput->append("<<<" + m_TextToSend);
+		m_TextToSend = "";
+
+		emit wakeWorkerThread();
+		m_updateTimeoutTimer->start(NETWORK_COMM_TIMEOUT_MS, TRUE);
+	}
 }
 
 TDEAboutData* ProtoTerminalPart::createAboutData() {
diff --git a/clients/tde/src/part/prototerminal/part.h b/clients/tde/src/part/prototerminal/part.h
index 5bc0a02..a7ad658 100644
--- a/clients/tde/src/part/prototerminal/part.h
+++ b/clients/tde/src/part/prototerminal/part.h
@@ -15,7 +15,7 @@
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  *
- * (c) 2014 Timothy Pearson
+ * (c) 2014 - 2015 Timothy Pearson
  * Raptor Engineering
  * http://www.raptorengineeringinc.com
  */
@@ -23,6 +23,12 @@
 #ifndef REMOTELAB_PROTOTERMINALPART_H
 #define REMOTELAB_PROTOTERMINALPART_H
 
+#include <ntqthread.h>
+#include <ntqeventloop.h>
+
+#include <tqvariant.h>
+#include <tqvaluevector.h>
+
 #include <tdeparts/browserextension.h>
 #include <tdeparts/statusbarextension.h>
 #include <tdeparts/part.h>
@@ -41,6 +47,51 @@ class ProtoTerminalBase;
 
 namespace RemoteLab
 {
+	typedef enum ProtoTerminalEventType {
+		ConsoleTextReceive =	0,
+		ConsoleTextSend =	1,
+		TxRxSyncPoint = 	2
+	} ProtoTerminalEventType;
+
+	typedef TQPair<ProtoTerminalEventType, TQVariant> ProtoTerminalEvent;
+	typedef TQValueVector<ProtoTerminalEvent> ProtoTerminalEventQueue;
+
+	class ProtoTerminalWorker : public TQObject
+	{
+		TQ_OBJECT
+
+		public:
+			ProtoTerminalWorker();
+			~ProtoTerminalWorker();
+
+		signals:
+			void outboundQueueUpdated();
+
+		public slots:
+			void run();
+			void wake();
+			void dataReceived();
+	
+		public:
+			void appendItemToInboundQueue(ProtoTerminalEvent item, bool syncPoint=false);
+			bool syncPointActive();
+			void lockOutboundQueue();
+			void unlockOutboundQueue();
+			ProtoTerminalEventQueue* outboundQueue();
+
+		public:
+			TDEKerberosClientSocket* m_socket;
+			TQMutex* m_instrumentMutex;
+
+		private:
+			ProtoTerminalEventQueue m_outboundQueue;
+			ProtoTerminalEventQueue m_inboundQueue;
+			TQMutex* m_outboundQueueMutex;
+			TQMutex* m_inboundQueueMutex;
+			TQMutex* m_networkDataMutex;
+			bool m_newData;
+	};
+
 	class ProtoTerminalPart : public KParts::RemoteInstrumentPart
 	{
 		Q_OBJECT
@@ -53,8 +104,12 @@ namespace RemoteLab
 			virtual bool closeURL();
 			static TDEAboutData *createAboutData();
 
+		signals:
+			void wakeWorkerThread();
+
 		public slots:
 			virtual bool openURL(const KURL &url);
+			void processOutboundQueue();
 		
 		private slots:
 			void postInit();
@@ -63,20 +118,23 @@ namespace RemoteLab
 			void disconnectFromServerCallback();
 			void connectionStatusChangedCallback();
 			void setTickerMessage(TQString message);
-			void mainEventLoop();
+			void networkTick();
+			void networkTimeout();
 			void sendTextClicked();
 	
 		private:
 			int m_commHandlerState;
 			int m_commHandlerMode;
 			int m_commHandlerCommandState;
-			TQTimer* m_forcedUpdateTimer;
 			TQTimer* m_updateTimeoutTimer;
 			bool m_connectionActiveAndValid;
 			unsigned char m_tickerState;
 			ProtoTerminalBase* m_base;
 			TQMutex* m_instrumentMutex;
 			TQString m_TextToSend;
+
+			ProtoTerminalWorker* m_worker;
+			TQEventLoopThread* m_workerThread;
 	};
 }