Readme

- Refactor simulation handling and improve net iteration methods

src/main/java/net/berack/upo/valpre/sim/Net.java

@@ -7,8 +7,8 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.List;
-import java.util.function.Consumer;
 
 import org.objenesis.strategy.StdInstantiatorStrategy;
 
@@ -25,7 +25,7 @@ import net.berack.upo.valpre.rand.Rng;
  * connections between nodes. In order to start a simulation, at least one node
  * must be a Source or must generate at least one event to be processed.
  */
-public final class Net {
+public final class Net implements Iterable<ServerNode> {
     private final List<ServerNode> servers = new ArrayList<>();
     private final HashMap<ServerNode, Integer> indices = new HashMap<>();
     private final List<List<Connection>> connections = new ArrayList<>();
@@ -220,16 +220,6 @@ public final class Net {
         }
     }
 
-    /**
-     * Apply a consumer to all the nodes. The implementation uses a stream and for
-     * this reason you should consider to make thread safe the consumer.
-     * 
-     * @param consumer a function that takes in input a ServerNode
-     */
-    public void forEachNode(Consumer<ServerNode> consumer) {
-        this.servers.stream().forEach(consumer);
-    }
-
     /**
      * Save the current net to a file.
      * The resulting file is saved with Kryo.
@@ -304,4 +294,9 @@ public final class Net {
             this.weight = weight;
         }
     }
+
+    @Override
+    public Iterator<ServerNode> iterator() {
+        return this.servers.iterator();
+    }
 }

src/main/java/net/berack/upo/valpre/sim/Simulation.java

@@ -40,8 +40,17 @@ public final class Simulation {
         this.rng = rng;
         this.time = 0.0d;
 
+        // check for ending criteria in simulation
+        boolean hasLimit = false;
+        for (var node : net)
+            if (node.spawnArrivals != Integer.MAX_VALUE)
+                hasLimit = true;
+
+        if (!hasLimit && (criterias == null || criterias.length == 0))
+            throw new IllegalArgumentException("At least one end criteria is needed!");
+
         // Initial arrivals (if spawned)
-        net.forEachNode(node -> {
+        net.forEach(node -> {
             this.states.put(node.name, new NodeState());
             if (node.shouldSpawnArrival(0))
                 this.addArrival(node);
@@ -152,7 +161,7 @@ public final class Simulation {
      * on the given node, and the delay is determined by the node's service
      * distribution.
      * 
-     * @param node The node to create the event for.
+     * @param node  The node to create the event for.
      * @param state The current state of the node
      */
     public void addDepartureIfPossible(ServerNode node, NodeState state) {