Merge branch 'unavailable_logic'

src/main/java/net/berack/upo/valpre/Main.java

@@ -29,13 +29,21 @@ public class Main {
             csv = arguments.get("csv");
         var parallel = arguments.containsKey("p");
 
+        // varius distributions
+        var distrExp = new Distribution.Exponential(lambda);
+        var distrNorm = new Distribution.NormalBoxMuller(mu, sigma);
+        var distrUnav = new Distribution.UnavailableTime(0.2, distrNorm);
+
         // Build the network
         var net = new Net();
-        var node1 = ServerNode.createLimitedSource("Source", new Distribution.Exponential(lambda), total);
+        var node1 = ServerNode.createLimitedSource("Source", distrExp, total);
-        var node2 = ServerNode.createQueue("Queue", 1, new Distribution.NormalBoxMuller(mu, sigma));
+        var node2 = ServerNode.createQueue("Queue", 1, distrNorm);
+        var node3 = ServerNode.createQueue("Queue Wait", 1, distrNorm, distrUnav);
         net.addNode(node1);
         net.addNode(node2);
+        net.addNode(node3);
         net.addConnection(node1, node2, 1.0);
+        net.addConnection(node2, node3, 1.0);
         net.normalizeWeights();
 
         /// Run multiple simulations

src/main/java/net/berack/upo/valpre/rand/Distribution.java

@@ -4,8 +4,34 @@ package net.berack.upo.valpre.rand;
  * Represents a probability distribution.
  */
 public interface Distribution {
+    /**
+     * Return a sample from the distribution.
+     * 
+     * @param rng The random number generator to use.
+     * @return A number given from the distribution.
+     */
     public double sample(Rng rng);
 
+    /**
+     * Gets a positive sample from the distribution.
+     * This is useful if you need to generate a positive value from a distribution
+     * that can generate negative values. For example, the normal distribution.
+     * 
+     * @param distribution The distribution to sample
+     * @param rng          The random number generator to use.
+     * @return A positive or 0 value from the distribution.
+     */
+    public static double getPositiveSample(Distribution distribution, Rng rng) {
+        if (distribution == null)
+            return 0;
+
+        double sample;
+        do {
+            sample = distribution.sample(rng);
+        } while (sample < 0);
+        return sample;
+    }
+
     /**
      * Represents an exponential distribution.
      */
@@ -172,4 +198,30 @@ public interface Distribution {
             return -Math.log(rng.random()) / lambdas[i];
         }
     }
+
+    /**
+     * TODO
+     */
+    public static class UnavailableTime implements Distribution {
+        public final double probability;
+        public final Distribution distribution;
+
+        /**
+         * TODO
+         * 
+         * @param probability
+         * @param distribution
+         */
+        public UnavailableTime(double probability, Distribution distribution) {
+            this.probability = probability;
+            this.distribution = distribution;
+        }
+
+        @Override
+        public double sample(Rng rng) {
+            if (rng.random() < this.probability)
+                return Distribution.getPositiveSample(this.distribution, rng);
+            return 0.0;
+        }
+    }
 }

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

@@ -30,19 +30,6 @@ public class Event implements Comparable<Event> {
         return 1;
     }
 
-    /**
-     * Create a new event.
-     * 
-     * @param node The node that the event is associated with.
-     * @param time The time at which the event occurs.
-     * @param type The type of event.
-     * 
-     * @return The new event.
-     */
-    public static Event newType(ServerNode node, double time, Type type) {
-        return new Event(type, node, time);
-    }
-
     /**
      * Create a new arrival event.
      * 
@@ -65,11 +52,23 @@ public class Event implements Comparable<Event> {
         return new Event(Type.DEPARTURE, node, time);
     }
 
+    /**
+     * Create a new available event.
+     * 
+     * @param node The node that the event is associated with.
+     * @param time The time at which the event occurs.
+     * @return The new event.
+     */
+    public static Event newAvailable(ServerNode node, double time) {
+        return new Event(Type.AVAILABLE, node, time);
+    }
+
     /**
      * The type of event.
      */
     public static enum Type {
         ARRIVAL,
         DEPARTURE,
+        AVAILABLE,
     }
 }

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

@@ -11,7 +11,8 @@ public class ServerNode {
     public final String name;
     public final int maxServers;
     public final int spawnArrivals;
-    public final Distribution distribution;
+    public final Distribution service;
+    public final Distribution unavailable;
 
     /**
      * Creates a source node with the given name and distribution.
@@ -23,7 +24,7 @@ public class ServerNode {
      * @return The created source node.
      */
     public static ServerNode createSource(String name, Distribution distribution) {
-        return new ServerNode(name, Integer.MAX_VALUE, distribution, Integer.MAX_VALUE);
+        return new ServerNode(name, Integer.MAX_VALUE, distribution, null, Integer.MAX_VALUE);
     }
 
     /**
@@ -31,25 +32,39 @@ public class ServerNode {
      * arrivals to spawn that are served by infinite servers (Integer.MAX_VALUE).
      * 
      * @param name          The name of the node.
-     * @param distribution  The distribution of the inter-arrival times.
+     * @param service       The distribution of the inter-arrival times.
      * @param spawnArrivals The number of arrivals to spawn.
      * @return The created source node.
      */
-    public static ServerNode createLimitedSource(String name, Distribution distribution, int spawnArrivals) {
+    public static ServerNode createLimitedSource(String name, Distribution service, int spawnArrivals) {
-        return new ServerNode(name, Integer.MAX_VALUE, distribution, spawnArrivals);
+        return new ServerNode(name, Integer.MAX_VALUE, service, null, spawnArrivals);
     }
 
     /**
      * Creates a queue node with the given name, maximum number of servers, and
      * distribution.
      * 
-     * @param name         The name of the node.
+     * @param name       The name of the node.
-     * @param maxServers   The maximum number of servers in the queue.
+     * @param maxServers The maximum number of servers in the queue.
-     * @param distribution The distribution of the service times.
+     * @param service    The distribution of the service times.
      * @return The created queue node.
      */
-    public static ServerNode createQueue(String name, int maxServers, Distribution distribution) {
+    public static ServerNode createQueue(String name, int maxServers, Distribution service) {
-        return new ServerNode(name, maxServers, distribution, 0);
+        return new ServerNode(name, maxServers, service, null, 0);
+    }
+
+    /**
+     * Creates a queue node with the given name, maximum number of servers, and
+     * distribution.
+     * 
+     * @param name        The name of the node.
+     * @param maxServers  The maximum number of servers in the queue.
+     * @param service     The distribution of the service times.
+     * @param unavailable The distribution of the unavailable times after service.
+     * @return The created queue node.
+     */
+    public static ServerNode createQueue(String name, int maxServers, Distribution service, Distribution unavailable) {
+        return new ServerNode(name, maxServers, service, unavailable, 0);
     }
 
     /**
@@ -60,13 +75,14 @@ public class ServerNode {
      * 
      * @param name          The name of the node.
      * @param maxServers    The maximum number of servers in the queue.
-     * @param distribution  The distribution of the service times.
+     * @param service       The distribution of the service times.
+     * @param unavailable   The distribution of the unavailable times after service.
      * @param spawnArrivals The number of arrivals to spawn.
      * @throws NullPointerException if the distribution is null
      */
-    public ServerNode(String name, int maxServers, Distribution distribution, int spawnArrivals) {
+    private ServerNode(String name, int maxServers, Distribution service, Distribution unavailable, int spawnArrivals) {
-        if (distribution == null)
+        if (service == null)
-            throw new NullPointerException("Distribution can't be null");
+            throw new NullPointerException("Service distribution can't be null");
         if (maxServers <= 0)
             maxServers = 1;
         if (spawnArrivals < 0)
@@ -74,8 +90,9 @@ public class ServerNode {
 
         this.name = name;
         this.maxServers = maxServers;
-        this.distribution = distribution;
         this.spawnArrivals = spawnArrivals;
+        this.service = service;
+        this.unavailable = unavailable;
     }
 
     /**
@@ -86,12 +103,18 @@ public class ServerNode {
      * @param rng The random number generator to use.
      * @return A positive sample from the distribution.
      */
-    public double getPositiveSample(Rng rng) {
+    public double getServiceTime(Rng rng) {
-        double sample;
+        return Distribution.getPositiveSample(this.service, rng);
-        do {
+    }
-            sample = this.distribution.sample(rng);
+
-        } while (sample < 0);
+    /**
-        return sample;
+     * Return the unavailable time after a service
+     * 
+     * @param rng The random number generator to use.
+     * @return A positive or 0 value from the distribution.
+     */
+    public double getUnavailableTime(Rng rng) {
+        return Distribution.getPositiveSample(this.unavailable, rng);
     }
 
     /**
@@ -105,6 +128,14 @@ public class ServerNode {
         return this.spawnArrivals > Math.max(0, numArrivals);
     }
 
+    @Override
+    public boolean equals(Object obj) {
+        if (!(obj instanceof ServerNode))
+            return false;
+        var other = (ServerNode) obj;
+        return obj.hashCode() == other.hashCode();
+    }
+
     @Override
     public int hashCode() {
         return this.name.hashCode();

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

@@ -26,7 +26,7 @@ public final class Simulation {
      * Creates a new run of the simulation with the given nodes and random number
      * generator.
      * 
-     * @param states     The nodes in the network.
+     * @param states    The nodes in the network.
      * @param rng       The random number generator to use.
      * @param criterias when the simulation has to end.
      */
@@ -73,32 +73,32 @@ public final class Simulation {
         this.time = event.time;
 
         switch (event.type) {
+            case AVAILABLE -> {
+                state.stats.updateTimes(this.time, state.numServerBusy, state.numServerUnavailable, node.maxServers);
+                state.numServerUnavailable--;
+                this.addDepartureIfPossible(node, state);
+            }
             case ARRIVAL -> {
                 state.queue.add(this.time);
-                state.stats.updateArrival(this.time, state.queue.size(), state.numServerBusy != 0);
+                state.stats.updateArrival(this.time, state.queue.size());
-
+                state.stats.updateTimes(this.time, state.numServerBusy, state.numServerUnavailable, node.maxServers);
-                if (state.numServerBusy < node.maxServers) {
+                this.addDepartureIfPossible(node, state);
-                    state.numServerBusy++;
-                    this.addDeparture(node);
-                }
             }
             case DEPARTURE -> {
-                var startService = state.queue.poll();
+                var arrivalTime = state.queue.poll();
-                state.stats.updateDeparture(this.time, this.time - startService);
+                state.stats.updateDeparture(this.time, arrivalTime);
+                state.stats.updateTimes(this.time, state.numServerBusy, state.numServerUnavailable, node.maxServers);
+                state.numServerBusy--;
 
-                if (state.numServerBusy > state.queue.size()) {
+                this.addUnavailableIfPossible(node, state);
-                    state.numServerBusy--;
+                this.addDepartureIfPossible(node, state);
-                } else {
-                    this.addDeparture(node);
-                }
 
                 var next = this.net.getChildOf(node, this.rng);
-                if (next != null) {
+                if (next != null)
                     this.addArrival(next);
-                }
+
-                if (node.shouldSpawnArrival(state.stats.numArrivals)) {
+                if (node.shouldSpawnArrival(state.stats.numArrivals))
                     this.addArrival(node);
-                }
             }
         }
     }
@@ -149,14 +149,36 @@ public final class Simulation {
 
     /**
      * Adds a departure event to the future event list. The event is created based
-     * on the given node, and the delay is determined by the node's distribution.
+     * on the given node, and the delay is determined by the node's service
+     * distribution.
      * 
      * @param node The node to create the event for.
      */
-    public void addDeparture(ServerNode node) {
+    public void addDepartureIfPossible(ServerNode node, NodeState state) {
-        var delay = node.getPositiveSample(this.rng);
+        var canServe = node.maxServers > state.numServerBusy + state.numServerUnavailable;
-        var event = Event.newDeparture(node, this.time + delay);
+        var hasRequests = state.queue.size() > state.numServerBusy;
-        fel.add(event);
+
+        if (canServe && hasRequests) {
+            state.numServerBusy++;
+            var delay = node.getServiceTime(this.rng);
+            var event = Event.newDeparture(node, this.time + delay);
+            fel.add(event);
+        }
+    }
+
+    /**
+     * TODO
+     * 
+     * @param node
+     * @param state
+     */
+    public void addUnavailableIfPossible(ServerNode node, NodeState state) {
+        var delay = node.getUnavailableTime(rng);
+        if (delay > 0) {
+            state.numServerUnavailable++;
+            var event = Event.newAvailable(node, time + delay);
+            this.fel.add(event);
+        }
     }
 
     /**
@@ -183,7 +205,8 @@ public final class Simulation {
      */
     public static class NodeState {
         public int numServerBusy = 0;
+        public int numServerUnavailable = 0;
         public final Statistics stats = new Statistics();
-        private final ArrayDeque<Double> queue = new ArrayDeque<>();
+        public final ArrayDeque<Double> queue = new ArrayDeque<>();
     }
 }

src/main/java/net/berack/upo/valpre/sim/stats/Result.java

@@ -31,7 +31,7 @@ public class Result {
         this.simulationTime = time;
         this.timeElapsedMS = elapsed;
         this.nodes = nodes;
-        this.size = (int) Math.ceil(Math.log10(this.simulationTime));
+        this.size = (int) Math.ceil(Math.max(Math.log10(this.simulationTime), 1));
         this.iFormat = "%" + this.size + ".0f";
         this.fFormat = "%" + (this.size + 4) + ".3f";
     }
@@ -57,7 +57,7 @@ public class Result {
      */
     public String getSummary() {
         String[] h = { "Node", "Departures", "Avg Queue", "Avg Wait", "Avg Response", "Throughput", "Utilization %",
-                "Last Event" };
+                "Unavailable %", "Last Event" };
         var table = new ConsoleTable(h);
 
         for (var entry : this.nodes.entrySet()) {
@@ -70,6 +70,7 @@ public class Result {
                     fFormat.formatted(stats.avgResponse),
                     fFormat.formatted(stats.troughput),
                     fFormat.formatted(stats.utilization * 100),
+                    fFormat.formatted(stats.unavailable * 100),
                     fFormat.formatted(stats.lastEventTime));
         }
         return table.toString();
@@ -86,7 +87,7 @@ public class Result {
 
         if (tableHeader)
             builder.append(
-                    "Seed,Node,Arrivals,Departures,MaxQueue,AvgQueue,AvgWait,AvgResponse,BusyTime,WaitTime,ResponseTime,LastEventTime,Throughput,Utilization\n");
+                    "Seed,Node,Arrivals,Departures,MaxQueue,AvgQueue,AvgWait,AvgResponse,BusyTime,WaitTime,UnavailableTime,ResponseTime,LastEventTime,Throughput,Utilization,Unavailable\n");
         for (var entry : this.nodes.entrySet()) {
             var stats = entry.getValue();
             builder.append(this.seed);
@@ -109,6 +110,8 @@ public class Result {
             builder.append(',');
             builder.append(stats.waitTime);
             builder.append(',');
+            builder.append(stats.unavailableTime);
+            builder.append(',');
             builder.append(stats.responseTime);
             builder.append(',');
             builder.append(stats.lastEventTime);
@@ -116,6 +119,8 @@ public class Result {
             builder.append(stats.troughput);
             builder.append(',');
             builder.append(stats.utilization);
+            builder.append(',');
+            builder.append(stats.unavailable);
             builder.append('\n');
         }
         return builder.toString();

src/main/java/net/berack/upo/valpre/sim/stats/Statistics.java

@@ -11,6 +11,7 @@ public class Statistics {
     public double numDepartures = 0.0d;
     public double maxQueueLength = 0.0d;
     public double avgQueueLength = 0.0d;
+    public double unavailableTime = 0.0d;
     public double busyTime = 0.0d;
     public double waitTime = 0.0d;
     public double responseTime = 0.0d;
@@ -21,6 +22,7 @@ public class Statistics {
     public double avgResponse = 0.0d;
     public double troughput = 0.0d;
     public double utilization = 0.0d;
+    public double unavailable = 0.0d;
 
     /**
      * TODO
@@ -29,16 +31,12 @@ public class Statistics {
      * @param newQueueSize
      * @param updateBusy
      */
-    public void updateArrival(double time, double newQueueSize, boolean updateBusy) {
+    public void updateArrival(double time, double newQueueSize) {
         var total = this.avgQueueLength * this.numArrivals;
 
         this.numArrivals++;
         this.avgQueueLength = (total + newQueueSize) / this.numArrivals;
         this.maxQueueLength = Math.max(this.maxQueueLength, newQueueSize);
-        if (updateBusy)
-            this.busyTime += time - this.lastEventTime;
-
-        this.lastEventTime = time;
     }
 
     /**
@@ -49,15 +47,30 @@ public class Statistics {
      */
     public void updateDeparture(double time, double response) {
         this.numDepartures++;
-        this.responseTime += response;
+        this.responseTime += time - response;
-        this.busyTime += time - this.lastEventTime;
+    }
-        this.lastEventTime = time;
-        this.waitTime = this.responseTime - this.busyTime;
 
+    /**
+     * TODO
+     * 
+     * @param time
+     * @param serverBusy
+     * @param serverUnavailable
+     */
+    public void updateTimes(double time, int serverBusy, int serverUnavailable, int maxServers) {
+        if (serverBusy > 0)
+            this.busyTime += time - this.lastEventTime;
+        else if (serverUnavailable == maxServers)
+            this.unavailableTime += time - this.lastEventTime;
+
+        this.waitTime = this.responseTime - this.busyTime;
         this.avgWaitTime = this.waitTime / this.numDepartures;
         this.avgResponse = this.responseTime / this.numDepartures;
-        this.troughput = this.numDepartures / this.lastEventTime;
+        this.troughput = this.numDepartures / time;
-        this.utilization = this.busyTime / this.lastEventTime;
+        this.utilization = this.busyTime / time;
+        this.unavailable = this.unavailableTime / time;
+
+        this.lastEventTime = time;
     }
 
     /**
@@ -106,11 +119,13 @@ public class Statistics {
         save.avgQueueLength = func.apply(val1.avgQueueLength, val2.avgQueueLength);
         save.busyTime = func.apply(val1.busyTime, val2.busyTime);
         save.responseTime = func.apply(val1.responseTime, val2.responseTime);
+        save.unavailableTime = func.apply(val1.unavailableTime, val2.unavailableTime);
         save.waitTime = func.apply(val1.waitTime, val2.waitTime);
         save.lastEventTime = func.apply(val1.lastEventTime, val2.lastEventTime);
         // derived stats
         save.avgWaitTime = func.apply(val1.avgWaitTime, val2.avgWaitTime);
         save.avgResponse = func.apply(val1.avgResponse, val2.avgResponse);
+        save.unavailable = func.apply(val1.unavailable, val2.unavailable);
         save.troughput = func.apply(val1.troughput, val2.troughput);
         save.utilization = func.apply(val1.utilization, val2.utilization);
     }

src/test/java/net/berack/upo/valpre/sim/TestSimulation.java

@@ -14,7 +14,7 @@ public class TestSimulation {
     private static double DELTA = 0.0000001;
     private static Rng rigged = new RiggedRng();
     private static Distribution const0 = new Constant(0.0);
-    private static Distribution const1 = new Constant(0.0);
+    private static Distribution const1 = new Constant(1.0);
 
     private final static class RiggedRng extends Rng {
         @Override
@@ -38,7 +38,7 @@ public class TestSimulation {
 
     @Test
     public void serverNode() {
-        var node = new ServerNode("Nodo", 0, const1, 0);
+        var node = ServerNode.createQueue("Nodo", 0, const1);
         assertEquals("Nodo", node.name);
         assertEquals(1, node.maxServers);
         assertFalse(node.shouldSpawnArrival(0));
@@ -46,7 +46,7 @@ public class TestSimulation {
         assertFalse(node.shouldSpawnArrival(1000));
         assertFalse(node.shouldSpawnArrival(Integer.MAX_VALUE));
         assertFalse(node.shouldSpawnArrival(-1));
-        assertEquals(1.0, node.getPositiveSample(null), DELTA);
+        assertEquals(1.0, node.getServiceTime(null), DELTA);
 
         node = ServerNode.createQueue("Queue", 50, const1);
         assertEquals("Queue", node.name);
@@ -56,7 +56,7 @@ public class TestSimulation {
         assertFalse(node.shouldSpawnArrival(1000));
         assertFalse(node.shouldSpawnArrival(Integer.MAX_VALUE));
         assertFalse(node.shouldSpawnArrival(-1));
-        assertEquals(1.0, node.getPositiveSample(null), DELTA);
+        assertEquals(1.0, node.getServiceTime(null), DELTA);
 
         node = ServerNode.createSource("Source", const1);
         assertEquals("Source", node.name);
@@ -67,7 +67,7 @@ public class TestSimulation {
         assertTrue(node.shouldSpawnArrival(Integer.MAX_VALUE - 1));
         assertFalse(node.shouldSpawnArrival(Integer.MAX_VALUE));
         assertTrue(node.shouldSpawnArrival(-1));
-        assertEquals(1.0, node.getPositiveSample(null), DELTA);
+        assertEquals(1.0, node.getServiceTime(null), DELTA);
 
         node = ServerNode.createLimitedSource("Source", const1, 50);
         assertEquals("Source", node.name);
@@ -78,25 +78,25 @@ public class TestSimulation {
         assertFalse(node.shouldSpawnArrival(1000));
         assertFalse(node.shouldSpawnArrival(Integer.MAX_VALUE));
         assertTrue(node.shouldSpawnArrival(-1));
-        assertEquals(1.0, node.getPositiveSample(null), DELTA);
+        assertEquals(1.0, node.getServiceTime(null), DELTA);
     }
 
     @Test
     public void event() {
         var node = ServerNode.createSource("Source", const0);
-        var event = Event.newType(node, 0, Event.Type.ARRIVAL);
+        var event = Event.newAvailable(node, 1.0);
         assertEquals(node, event.node);
-        assertEquals(0.0, event.time, 0.000000000001);
+        assertEquals(1.0, event.time, 0.000000000001);
-        assertEquals(Event.Type.ARRIVAL, event.type);
+        assertEquals(Event.Type.AVAILABLE, event.type);
 
-        var event2 = Event.newArrival(node, 1.0);
+        var event2 = Event.newArrival(node, 5.0);
         assertEquals(node, event2.node);
-        assertEquals(1.0, event2.time, 0.000000000001);
+        assertEquals(5.0, event2.time, 0.000000000001);
         assertEquals(Event.Type.ARRIVAL, event2.type);
 
-        var event3 = Event.newDeparture(node, 5.0);
+        var event3 = Event.newDeparture(node, 8.0);
         assertEquals(node, event3.node);
-        assertEquals(5.0, event3.time, 0.000000000001);
+        assertEquals(8.0, event3.time, 0.000000000001);
         assertEquals(Event.Type.DEPARTURE, event3.type);
 
         assertEquals(0, event2.compareTo(event2));