Simulation mit Terminierung

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.4.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.1.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

src/main/java/dev/oxoo2a/sim4da/Message.java

@@ -1,21 +1,42 @@
 package dev.oxoo2a.sim4da;
 
-import java.lang.reflect.Type;
 import java.util.HashMap;
 import java.util.Map;
 
 import com.google.gson.Gson;
-import com.google.gson.reflect.TypeToken;
 
 public class Message {
 
+    private final String time;
+
     public Message () {
-        content = new HashMap<>();
+        this(new HashMap<>(), "");
     }
-
     protected Message ( HashMap<String,String> content ) {
+        this(content, "");
+    }
+    public Message(Time time){
+        this(new HashMap<>(), time.toString());
+    }
+    public Message(Message m, Time time){
+        this(m.content, time);
+    }
+    public Message(HashMap<String,String> content, Time time){
+        this(content, time.toString());
+    }
+    public Message(HashMap<String,String> content, String time){
         this.content = content;
+        this.time = time;
     }
+
+    public boolean hasTime(){
+        return !time.equals("");
+    }
+
+    public String getTime(){
+        return time;
+    }
+
     public Message add ( String key, String value ) {
         content.put(key,value);
         return this;
@@ -24,7 +45,6 @@ public Message add ( String key, String value ) {
     public Message add ( String key, int value ) {
         content.put(key,String.valueOf(value));
         return this;
-
     }
 
     public String query ( String key ) {
@@ -36,18 +56,17 @@ public Map<String,String> getMap () {
     }
 
     public String toJson () {
-        return serialize(content);
+        return serialize(this);
     }
 
     public static Message fromJson ( String s ) {
-        Type contentType = new TypeToken<HashMap<String,String>>() {}.getType();
-        return new Message(serializer.fromJson(s,contentType));
+        return serializer.fromJson(s, Message.class);
     }
 
-    private static synchronized String serialize ( Map<String,String> content ) {
-        return serializer.toJson(content); // Not sure about thread safety of Gson
+    private static synchronized String serialize ( Message m ) {
+        return serializer.toJson(m); // Not sure about thread safety of Gson
     }
 
-    private final HashMap<String,String> content;
-    private static final Gson serializer = new Gson();
+    protected final HashMap<String,String> content;
+    protected static final Gson serializer = new Gson();
 }

src/main/java/dev/oxoo2a/sim4da/NodeWithTime.java

@@ -0,0 +1,63 @@
+package dev.oxoo2a.sim4da;
+
+/***
+ * Node in the network that has a logic clock
+ * @author Tessa Steinigke
+ */
+public abstract class NodeWithTime extends Node {
+
+    protected final Time time; // manages the time according to the rules in the class of the logic clock
+    private final boolean logTime;
+
+    public NodeWithTime(int my_id, Time time) {
+        this(my_id, time, false);
+    }
+    public NodeWithTime(int my_id, Time time, boolean logTime) {
+        super(my_id);
+        this.time = time;
+        this.logTime = logTime;
+    }
+
+    protected void sendUnicast ( int receiver_id, String m ) {
+        time.incrementMyTime();
+        emit("Warning: Can not update time in message!");
+        if(logTime) emit("%d: perform Unicast at %s",myId,time.toString());
+        super.sendUnicast(receiver_id, m); // WARNING: can not update time in message
+    }
+
+    protected void sendUnicast ( int receiver_id, Message m ) {
+        time.incrementMyTime();
+        if(logTime) emit("%d: perform Unicast at %s",myId,time.toString());
+        super.sendUnicast(receiver_id, new Message(m, time));
+    }
+
+    protected void sendBroadcast ( String m ) {
+        time.incrementMyTime();
+        emit("Warning: Can not update time in message!");
+        if(logTime) emit("%d: perform Broadcast at %s",myId,time.toString());
+        super.sendBroadcast(m); // WARNING: can not update time in message
+    }
+
+    protected void sendBroadcast ( Message m ) {
+        time.incrementMyTime();
+        if(logTime) emit("%d: perform Broadcast at %s",myId,time.toString());
+        super.sendBroadcast(new Message(m, time));
+    }
+
+    protected Network.Message receive () {
+        Network.Message m_raw = super.receive();
+        if (m_raw != null) {
+            Message m = Message.fromJson(m_raw.payload);
+            // Update the time with the new time information given in the message
+            if(m.hasTime())
+                time.updateTime(m.getTime());
+
+            if(logTime) {
+                String m_type = m_raw.type == Network.MessageType.BROADCAST ? "Broadcast" : "Unicast";
+                emit("%d: receive %s at %s", myId, m_type,time.toString());
+            }
+        }
+        return m_raw;
+    }
+
+}

src/main/java/dev/oxoo2a/sim4da/Time.java

@@ -0,0 +1,29 @@
+package dev.oxoo2a.sim4da;
+
+public interface Time {
+    /***
+     * Increment the time of the local node
+     */
+    void incrementMyTime();
+
+    /***
+     * String representation of the time
+     * @return - time as string
+     */
+    String toString();
+
+    /***
+     * New time was received by a different node (sender).
+     * Now the time of the local node must be updated.
+     * @param time_sender - time of the sender node in the string representation
+     */
+    void updateTime(String time_sender);
+
+
+    /***
+     * New time was received by a different node (sender).
+     * Now the time of the local node must be updated.
+     * @param time_sender - time of the sender node
+     */
+    void updateTime(Time time_sender);
+}

src/main/java/dev/oxoo2a/sim4da/times/LamportTime.java

@@ -0,0 +1,46 @@
+package dev.oxoo2a.sim4da.times;
+
+import dev.oxoo2a.sim4da.Time;
+
+/***
+ * Implements the rules of the lamport time
+ */
+public class LamportTime implements Time {
+
+    private int time;
+
+    public LamportTime(){
+        time = 0;
+    }
+
+    @Override
+    public void incrementMyTime() {
+        time++;
+    }
+
+    @Override
+    public String toString() {
+        return time+"";
+    }
+
+    @Override
+    public void updateTime(String time_sender) {
+        int time_s_i = Integer.parseInt(time_sender);
+        // max function
+        if(time_s_i > time)
+            time = time_s_i;
+        // increment local time
+        incrementMyTime();
+    }
+
+    @Override
+    public void updateTime(Time time_sender) {
+        if(!( time_sender instanceof LamportTime))
+            throw new IllegalArgumentException("Wrong time format");
+        LamportTime l_time_sender = (LamportTime) time_sender;
+        if(l_time_sender.time > time)
+            time = l_time_sender.time;
+        // increment local time
+        incrementMyTime();
+    }
+}

src/main/java/dev/oxoo2a/sim4da/times/VectorTime.java

@@ -0,0 +1,58 @@
+package dev.oxoo2a.sim4da.times;
+
+import dev.oxoo2a.sim4da.Time;
+
+import java.util.Arrays;
+
+/***
+ * Implements the rules of the vector time
+ */
+public class VectorTime implements Time {
+
+    private int[] time;
+    private final int myId;
+
+    public VectorTime(int myId, int n_nodes){
+        time = new int[n_nodes];
+        for(int i = 0; i < n_nodes; i++){
+            time[i] = 0;
+        }
+        this.myId = myId;
+    }
+
+    @Override
+    public void incrementMyTime() {
+        time[myId]++;
+    }
+
+    @Override
+    public String toString() {
+        return Arrays.toString(time);
+    }
+
+    @Override
+    public void updateTime(String time_sender) {
+        // increment local time
+        incrementMyTime();
+
+        time_sender = time_sender.substring(1, time_sender.length()-1);
+        String[] arr = time_sender.split(", ");
+        // max function
+        for(int i = 0; i < arr.length; i++){
+            int sender_i_int = Integer.parseInt(arr[i]);
+            if(sender_i_int > time[i])
+                time[i] = sender_i_int;
+        }
+    }
+
+    @Override
+    public void updateTime(Time time_sender) {
+        if(!( time_sender instanceof VectorTime))
+            throw new IllegalArgumentException("Wrong time format");
+        VectorTime v_time_sender = (VectorTime) time_sender;
+        for(int i = 0; i < time.length; i++){
+            if(v_time_sender.time[i] > time[i])
+                time[i] = v_time_sender.time[i];
+        }
+    }
+}

src/test/java/dev/oxoo2a/sim4da/NodeWithTimeTest.java

@@ -0,0 +1,53 @@
+package dev.oxoo2a.sim4da;
+
+import dev.oxoo2a.sim4da.nodes.NodeWithTimeRandom;
+import dev.oxoo2a.sim4da.times.LamportTime;
+import dev.oxoo2a.sim4da.times.VectorTime;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.fail;
+
+/***
+ * Test nodes with logic clocks
+ * @author Tessa Steinigke
+ */
+public class NodeWithTimeTest {
+
+    public enum TimeType { LAMPORT, VECTOR }
+
+    private static final int n_nodes = 3;
+
+    /***
+     * Same test for both clocks. Just the Time instances are different.
+     * @param type - Type of logic clock
+     */
+    private static void test(TimeType type){
+        Simulator s = Simulator.createDefaultSimulator(n_nodes);
+        for (int id=0; id<n_nodes; id++) {
+            Time time;
+            if(type == TimeType.LAMPORT)
+                time = new LamportTime();
+            else
+                time = new VectorTime(id, n_nodes);
+            NodeWithTime n = new NodeWithTimeRandom(id, time, n_nodes);
+            s.attachNode(id,n);
+        }
+        try {
+            s.runSimulation(2);
+        }
+        catch (InstantiationException ignored) {
+            fail("Not all nodes instantiated");
+        }
+    }
+
+    @Test
+    public void testLamportTime(){
+        test(TimeType.LAMPORT);
+    }
+
+    @Test
+    public void testVectorTime() {
+        test(TimeType.VECTOR);
+    }
+
+}

src/test/java/dev/oxoo2a/sim4da/SimulatorTest.java

@@ -2,8 +2,7 @@
 
 import static org.junit.jupiter.api.Assertions.*;
 
-import java.beans.Transient;
-
+import dev.oxoo2a.sim4da.nodes.BroadcastNode;
 import org.junit.jupiter.api.Test;
 
 public class SimulatorTest {