implemented unfinished generic signal concept;

implemented example signals for starting, validating, and terminating

src/main/java/teetime/variant/methodcallWithPorts/framework/core/AbstractStage.java

 package teetime.variant.methodcallWithPorts.framework.core;
 
 import java.util.ArrayList;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.UUID;
 
@@ -10,6 +9,8 @@ import org.slf4j.LoggerFactory;
 
 import teetime.variant.methodcallWithPorts.framework.core.pipe.DummyPipe;
 import teetime.variant.methodcallWithPorts.framework.core.pipe.IPipe;
+import teetime.variant.methodcallWithPorts.framework.core.signal.Signal;
+import teetime.variant.methodcallWithPorts.framework.core.validation.InvalidPortConnection;
 
 public abstract class AbstractStage implements StageWithPort {
 
@@ -56,14 +57,6 @@ public abstract class AbstractStage implements StageWithPort {
 		return true;
 	}
 
-	@Override
-	public void onStart() {
-		this.cachedInputPorts = this.inputPortList.toArray(new InputPort<?>[0]);
-		this.cachedOutputPorts = this.outputPortList.toArray(new OutputPort<?>[0]);
-
-		this.connectUnconnectedOutputPorts();
-	}
-
 	@SuppressWarnings("unchecked")
 	private void connectUnconnectedOutputPorts() {
 		for (OutputPort<?> outputPort : this.cachedOutputPorts) {
@@ -74,11 +67,6 @@ public abstract class AbstractStage implements StageWithPort {
 		}
 	}
 
-	protected void onFinished() {
-		// empty default implementation
-		this.onIsPipelineHead();
-	}
-
 	protected InputPort<?>[] getInputPorts() {
 		return this.cachedInputPorts;
 	}
@@ -116,22 +104,31 @@ public abstract class AbstractStage implements StageWithPort {
 	 */
 	@Override
 	public void onSignal(final Signal signal, final InputPort<?> inputPort) {
-		this.logger.debug("Got signal: " + signal + " from input port: " + inputPort);
+		this.logger.trace("Got signal: " + signal + " from input port: " + inputPort);
 
-		switch (signal) {
-		case FINISHED:
-			this.onFinished();
-			break;
-		default:
-			this.logger.warn("Aborted sending signal " + signal + ". Reason: Unknown signal.");
-			break;
-		}
+		signal.trigger(this);
 
 		for (OutputPort<?> outputPort : this.outputPortList) {
 			outputPort.sendSignal(signal);
 		}
 	}
 
+	public void onValidating(final List<InvalidPortConnection> invalidPortConnections) {
+		this.validateOutputPorts(invalidPortConnections);
+	}
+
+	public void onStarting() {
+		this.cachedInputPorts = this.inputPortList.toArray(new InputPort<?>[0]);
+		this.cachedOutputPorts = this.outputPortList.toArray(new OutputPort<?>[0]);
+
+		this.connectUnconnectedOutputPorts();
+	}
+
+	public void onTerminating() {
+		// empty default implementation
+		this.onIsPipelineHead();
+	}
+
 	protected <T> InputPort<T> createInputPort() {
 		InputPort<T> inputPort = new InputPort<T>(this);
 		// inputPort.setType(type); // TODO set type for input port
@@ -146,9 +143,8 @@ public abstract class AbstractStage implements StageWithPort {
 		return outputPort;
 	}
 
-	public List<InvalidPortConnection> validateOutputPorts() {
-		List<InvalidPortConnection> invalidOutputPortMessages = new LinkedList<InvalidPortConnection>();
-
+	@Override
+	public void validateOutputPorts(final List<InvalidPortConnection> invalidPortConnections) {
 		for (OutputPort<?> outputPort : this.getOutputPorts()) {
 			IPipe<?> pipe = outputPort.getPipe();
 			if (null != pipe) { // if output port is connected with another one
@@ -156,12 +152,10 @@ public abstract class AbstractStage implements StageWithPort {
 				Class<?> targetPortType = pipe.getTargetPort().getType();
 				if (null == sourcePortType || !sourcePortType.equals(targetPortType)) {
 					InvalidPortConnection invalidPortConnection = new InvalidPortConnection(outputPort, pipe.getTargetPort());
-					invalidOutputPortMessages.add(invalidPortConnection);
+					invalidPortConnections.add(invalidPortConnection);
 				}
 			}
 		}
-
-		return invalidOutputPortMessages;
 	}
 
 	@Override

src/main/java/teetime/variant/methodcallWithPorts/framework/core/OutputPort.java

 package teetime.variant.methodcallWithPorts.framework.core;
 
+import teetime.variant.methodcallWithPorts.framework.core.signal.Signal;
+
 public class OutputPort<T> extends AbstractPort<T> {
 
 	/**

src/main/java/teetime/variant/methodcallWithPorts/framework/core/Pipeline.java

@@ -5,6 +5,10 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.UUID;
 
+import teetime.variant.methodcallWithPorts.framework.core.signal.Signal;
+import teetime.variant.methodcallWithPorts.framework.core.signal.StartingSignal;
+import teetime.variant.methodcallWithPorts.framework.core.validation.InvalidPortConnection;
+
 import kieker.common.logging.Log;
 import kieker.common.logging.LogFactory;
 
@@ -28,13 +32,7 @@ public class Pipeline<FirstStage extends StageWithPort, LastStage extends StageW
 	private final List<StageWithPort> intermediateStages = new LinkedList<StageWithPort>();
 	private LastStage lastStage;
 
-	// BETTER remove the stage array and use the output ports instead for passing a signal to all stages in the same thread; what about multiple same signals due to
-	// multiple input ports?
-	private StageWithPort[] stages;
 	private StageWithPort parentStage;
-	// private int startIndex;
-
-	private int firstStageIndex;
 
 	// private final Set<StageWithPort<?, ?>> currentHeads = new HashSet<StageWithPort<?, ?>>();
 
@@ -70,7 +68,7 @@ public class Pipeline<FirstStage extends StageWithPort, LastStage extends StageW
 
 	@Override
 	public void executeWithPorts() {
-		StageWithPort headStage = this.stages[this.firstStageIndex];
+		StageWithPort headStage = this.firstStage;
 
 		// do {
 		headStage.executeWithPorts();
@@ -106,16 +104,16 @@ public class Pipeline<FirstStage extends StageWithPort, LastStage extends StageW
 		// do nothing
 	}
 
-	@Override
-	public void onStart() {
+	@Deprecated
+	public void onStarting() {
 		int size = 1 + this.intermediateStages.size() + 1;
-		this.stages = new StageWithPort[size];
-		this.stages[0] = this.firstStage;
+		StageWithPort[] stages = new StageWithPort[size];
+		stages[0] = this.firstStage;
 		for (int i = 0; i < this.intermediateStages.size(); i++) {
 			StageWithPort stage = this.intermediateStages.get(i);
-			this.stages[1 + i] = stage;
+			stages[1 + i] = stage;
 		}
-		this.stages[this.stages.length - 1] = this.lastStage;
+		stages[stages.length - 1] = this.lastStage;
 
 		// for (int i = 0; i < this.stages.length; i++) {
 		// StageWithPort<?, ?> stage = this.stages[i];
@@ -129,8 +127,8 @@ public class Pipeline<FirstStage extends StageWithPort, LastStage extends StageW
 		// }
 		// this.stages[this.stages.length - 1].setSuccessor(new EndStage<Object>());
 
-		for (StageWithPort stage : this.stages) {
-			stage.onStart();
+		for (StageWithPort stage : stages) {
+			stage.onSignal(new StartingSignal(), null);
 		}
 	}
 
@@ -146,14 +144,9 @@ public class Pipeline<FirstStage extends StageWithPort, LastStage extends StageW
 
 	@Override
 	public boolean isReschedulable() {
-		// return this.reschedulable;
 		return this.firstStage.isReschedulable();
 	}
 
-	// public void setReschedulable(final boolean reschedulable) {
-	// this.reschedulable = reschedulable;
-	// }
-
 	@Override
 	public void onSignal(final Signal signal, final InputPort<?> inputPort) {
 		this.firstStage.onSignal(signal, inputPort);
@@ -167,4 +160,9 @@ public class Pipeline<FirstStage extends StageWithPort, LastStage extends StageW
 		return this.lastStage;
 	}
 
+	@Override
+	public void validateOutputPorts(final List<InvalidPortConnection> invalidPortConnections) {
+		// do nothing
+	}
+
 }

src/main/java/teetime/variant/methodcallWithPorts/framework/core/RunnableStage.java

@@ -3,10 +3,15 @@ package teetime.variant.methodcallWithPorts.framework.core;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import teetime.variant.methodcallWithPorts.framework.core.signal.StartingSignal;
+import teetime.variant.methodcallWithPorts.framework.core.signal.TerminatingSignal;
+import teetime.variant.methodcallWithPorts.framework.core.signal.ValidatingSignal;
+
 public class RunnableStage implements Runnable {
 
 	private final StageWithPort stage;
 	private final Logger logger;
+	private boolean validationEnabled;
 
 	public RunnableStage(final StageWithPort stage) {
 		this.stage = stage;
@@ -17,14 +22,25 @@ public class RunnableStage implements Runnable {
 	public void run() {
 		this.logger.debug("Executing runnable stage...");
 
+		if (this.validationEnabled) {
+			ValidatingSignal validatingSignal = new ValidatingSignal();
+			this.stage.onSignal(validatingSignal, null);
+			if (validatingSignal.getInvalidPortConnections().size() > 0) {
+				// throw new RuntimeException(message);
+				// TODO implement what to do on validation messages
+			}
+		}
+
 		try {
-			this.stage.onStart();
+			StartingSignal startingSignal = new StartingSignal();
+			this.stage.onSignal(startingSignal, null);
 
 			do {
 				this.stage.executeWithPorts();
 			} while (this.stage.isReschedulable());
 
-			this.stage.onSignal(Signal.FINISHED, null);
+			TerminatingSignal terminatingSignal = new TerminatingSignal();
+			this.stage.onSignal(terminatingSignal, null);
 
 		} catch (RuntimeException e) {
 			this.logger.error("Terminating thread due to the following exception: ", e);
@@ -33,4 +49,12 @@ public class RunnableStage implements Runnable {
 
 		this.logger.debug("Finished runnable stage. (" + this.stage.getId() + ")");
 	}
+
+	public boolean isValidationEnabled() {
+		return this.validationEnabled;
+	}
+
+	public void setValidationEnabled(final boolean validationEnabled) {
+		this.validationEnabled = validationEnabled;
+	}
 }

src/main/java/teetime/variant/methodcallWithPorts/framework/core/Signal.java

-package teetime.variant.methodcallWithPorts.framework.core;
-
-public enum Signal {
-	FINISHED
-
-}

src/main/java/teetime/variant/methodcallWithPorts/framework/core/StageWithPort.java

 package teetime.variant.methodcallWithPorts.framework.core;
 
+import java.util.List;
+
+import teetime.variant.methodcallWithPorts.framework.core.signal.Signal;
+import teetime.variant.methodcallWithPorts.framework.core.validation.InvalidPortConnection;
+
 public interface StageWithPort {
 
 	String getId();
@@ -20,7 +25,12 @@ public interface StageWithPort {
 
 	void onIsPipelineHead();
 
-	void onStart();
-
 	void onSignal(Signal signal, InputPort<?> inputPort);
+
+	/**
+	 *
+	 * @param invalidPortConnections
+	 *            <i>(Passed as parameter for performance reasons)</i>
+	 */
+	void validateOutputPorts(List<InvalidPortConnection> invalidPortConnections);
 }

src/main/java/teetime/variant/methodcallWithPorts/framework/core/pipe/DummyPipe.java

@@ -2,7 +2,7 @@ package teetime.variant.methodcallWithPorts.framework.core.pipe;
 
 import teetime.variant.methodcallWithPorts.framework.core.InputPort;
 import teetime.variant.methodcallWithPorts.framework.core.OutputPort;
-import teetime.variant.methodcallWithPorts.framework.core.Signal;
+import teetime.variant.methodcallWithPorts.framework.core.signal.Signal;
 
 /**
  * A pipe implementation used to connect unconnected output ports.

src/main/java/teetime/variant/methodcallWithPorts/framework/core/pipe/IPipe.java

@@ -2,7 +2,7 @@ package teetime.variant.methodcallWithPorts.framework.core.pipe;
 
 import teetime.variant.methodcallWithPorts.framework.core.InputPort;
 import teetime.variant.methodcallWithPorts.framework.core.OutputPort;
-import teetime.variant.methodcallWithPorts.framework.core.Signal;
+import teetime.variant.methodcallWithPorts.framework.core.signal.Signal;
 
 public interface IPipe<T> {
 

src/main/java/teetime/variant/methodcallWithPorts/framework/core/pipe/IntraThreadPipe.java

 package teetime.variant.methodcallWithPorts.framework.core.pipe;
 
-import teetime.variant.methodcallWithPorts.framework.core.Signal;
+import teetime.variant.methodcallWithPorts.framework.core.signal.Signal;
 
 public abstract class IntraThreadPipe<T> extends AbstractPipe<T> {
 

src/main/java/teetime/variant/methodcallWithPorts/framework/core/pipe/SpScPipe.java

@@ -10,7 +10,7 @@ import org.jctools.queues.spec.Preference;
 
 import teetime.variant.methodcallWithPorts.framework.core.InputPort;
 import teetime.variant.methodcallWithPorts.framework.core.OutputPort;
-import teetime.variant.methodcallWithPorts.framework.core.Signal;
+import teetime.variant.methodcallWithPorts.framework.core.signal.Signal;
 
 public class SpScPipe<T> extends AbstractPipe<T> {
 

src/main/java/teetime/variant/methodcallWithPorts/framework/core/signal/Signal.java

+package teetime.variant.methodcallWithPorts.framework.core.signal;
+
+import teetime.variant.methodcallWithPorts.framework.core.AbstractStage;
+
+public interface Signal {
+
+	void trigger(AbstractStage stage);
+}

src/main/java/teetime/variant/methodcallWithPorts/framework/core/signal/StartingSignal.java

+package teetime.variant.methodcallWithPorts.framework.core.signal;
+
+import teetime.variant.methodcallWithPorts.framework.core.AbstractStage;
+
+public class StartingSignal implements Signal {
+
+	@Override
+	public void trigger(final AbstractStage stage) {
+		stage.onStarting();
+	}
+
+}

src/main/java/teetime/variant/methodcallWithPorts/framework/core/signal/TerminatingSignal.java

+package teetime.variant.methodcallWithPorts.framework.core.signal;
+
+import teetime.variant.methodcallWithPorts.framework.core.AbstractStage;
+
+public class TerminatingSignal implements Signal {
+
+	@Override
+	public void trigger(final AbstractStage stage) {
+		stage.onTerminating();
+	}
+
+}

src/main/java/teetime/variant/methodcallWithPorts/framework/core/signal/ValidatingSignal.java

+package teetime.variant.methodcallWithPorts.framework.core.signal;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import teetime.variant.methodcallWithPorts.framework.core.AbstractStage;
+import teetime.variant.methodcallWithPorts.framework.core.validation.InvalidPortConnection;
+
+public class ValidatingSignal implements Signal {
+
+	private final List<InvalidPortConnection> invalidPortConnections = new LinkedList<InvalidPortConnection>();
+
+	@Override
+	public void trigger(final AbstractStage stage) {
+		stage.onValidating(this.invalidPortConnections);
+	}
+
+	public List<InvalidPortConnection> getInvalidPortConnections() {
+		return invalidPortConnections;
+	}
+
+}

src/main/java/teetime/variant/methodcallWithPorts/framework/core/InvalidPortConnection.java → src/main/java/teetime/variant/methodcallWithPorts/framework/core/validation/InvalidPortConnection.java

-package teetime.variant.methodcallWithPorts.framework.core;
+package teetime.variant.methodcallWithPorts.framework.core.validation;
+
+import teetime.variant.methodcallWithPorts.framework.core.InputPort;
+import teetime.variant.methodcallWithPorts.framework.core.OutputPort;
 
 public class InvalidPortConnection {
 

src/main/java/teetime/variant/methodcallWithPorts/stage/ElementDelayMeasuringStage.java

@@ -29,9 +29,9 @@ public class ElementDelayMeasuringStage<T> extends ConsumerStage<T> {
 	}
 
 	@Override
-	public void onStart() {
+	public void onStarting() {
 		this.resetTimestamp(System.nanoTime());
-		super.onStart();
+		super.onStarting();
 	}
 
 	private void computeElementDelay(final Long timestampInNs) {

src/main/java/teetime/variant/methodcallWithPorts/stage/ElementThroughputMeasuringStage.java

@@ -30,9 +30,9 @@ public class ElementThroughputMeasuringStage<T> extends ConsumerStage<T> {
 	}
 
 	@Override
-	public void onStart() {
+	public void onStarting() {
 		this.resetTimestamp(System.nanoTime());
-		super.onStart();
+		super.onStarting();
 	}
 
 	private void computeElementThroughput(final Long timestampInNs) {

src/main/java/teetime/variant/methodcallWithPorts/stage/Relay.java

@@ -2,8 +2,8 @@ package teetime.variant.methodcallWithPorts.stage;
 
 import teetime.variant.methodcallWithPorts.framework.core.InputPort;
 import teetime.variant.methodcallWithPorts.framework.core.ProducerStage;
-import teetime.variant.methodcallWithPorts.framework.core.Signal;
 import teetime.variant.methodcallWithPorts.framework.core.pipe.SpScPipe;
+import teetime.variant.methodcallWithPorts.framework.core.signal.TerminatingSignal;
 
 public class Relay<T> extends ProducerStage<T> {
 
@@ -15,8 +15,7 @@ public class Relay<T> extends ProducerStage<T> {
 	public void execute() {
 		T element = this.inputPort.receive();
 		if (null == element) {
-			// if (this.getInputPort().getPipe().isClosed()) {
-			if (this.cachedCastedInputPipe.getSignal() == Signal.FINISHED) {
+			if (this.cachedCastedInputPipe.getSignal() instanceof TerminatingSignal) {
 				this.setReschedulable(false);
 				assert 0 == this.inputPort.getPipe().size();
 			}
@@ -27,16 +26,9 @@ public class Relay<T> extends ProducerStage<T> {
 	}
 
 	@Override
-	public void onStart() {
+	public void onStarting() {
 		this.cachedCastedInputPipe = (SpScPipe<T>) this.inputPort.getPipe();
-		super.onStart();
-	}
-
-	@Override
-	public void onIsPipelineHead() {
-		// if (this.getInputPort().getPipe().isClosed()) {
-		// this.setReschedulable(false);
-		// }
+		super.onStarting();
 	}
 
 	public InputPort<T> getInputPort() {

src/main/java/teetime/variant/methodcallWithPorts/stage/basic/merger/Merger.java

@@ -19,7 +19,7 @@ package teetime.variant.methodcallWithPorts.stage.basic.merger;
 import teetime.variant.methodcallWithPorts.framework.core.AbstractStage;
 import teetime.variant.methodcallWithPorts.framework.core.InputPort;
 import teetime.variant.methodcallWithPorts.framework.core.OutputPort;
-import teetime.variant.methodcallWithPorts.framework.core.Signal;
+import teetime.variant.methodcallWithPorts.framework.core.signal.Signal;
 
 /**
  *
@@ -61,16 +61,9 @@ public class Merger<T> extends AbstractStage {
 
 	@Override
 	public void onSignal(final Signal signal, final InputPort<?> inputPort) {
-		this.logger.debug("Got signal: " + signal + " from input port: " + inputPort);
+		this.logger.trace("Got signal: " + signal + " from input port: " + inputPort);
 
-		switch (signal) {
-		case FINISHED:
-			this.onFinished();
-			break;
-		default:
-			this.logger.warn("Aborted sending signal " + signal + ". Reason: Unknown signal.");
-			break;
-		}
+		signal.trigger(this);
 
 		if (this.finishedInputPorts == this.getInputPorts().length) {
 			this.outputPort.sendSignal(signal);

src/main/java/teetime/variant/methodcallWithPorts/stage/io/DbReader.java

@@ -49,7 +49,7 @@ public class DbReader extends ProducerStage<IMonitoringRecord> {
 	private volatile boolean running = true;
 
 	@Override
-	public void onStart() {
+	public void onStarting() {
 		try {
 			Class.forName(this.driverClassname).newInstance();
 		} catch (final Exception ex) { // NOPMD NOCS (IllegalCatchCheck)