refactor(#18): Redesign core simulation API

This change contains the redesign of the core simulation API and
provides a cleaner interface for developing simulation models for the
users.

22 files changed, 488 insertions, 873 deletions

diff --git a/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/AdjacencyList.kt b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/AdjacencyList.kt
new file mode 100644
index 00000000..c042a2d5
--- /dev/null
+++ b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/AdjacencyList.kt
@@ -0,0 +1,260 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.model.topology
+
+import com.atlarge.opendc.simulator.Entity
+import com.atlarge.opendc.model.topology.Edge as BaseEdge
+import java.util.concurrent.atomic.AtomicInteger
+
+/**
+ * This module provides a [Topology] implementation backed internally by an adjacency list.
+ *
+ * This implementation is best suited for sparse graphs, where an adjacency matrix would take up too much space with
+ * empty cells.
+ *
+ * *Note that this implementation is not synchronized.*
+ */
+object AdjacencyList {
+	/**
+	 * Return a [TopologyBuilder] that constructs the topology represents as an adjacency list.
+	 *
+	 * @return A [TopologyBuilder] instance.
+	 */
+	fun builder(): TopologyBuilder = AdjacencyListTopologyBuilder()
+}
+
+/**
+ * A builder for [Topology] instances, which is backed by an adjacency list.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+internal class AdjacencyListTopologyBuilder : TopologyBuilder {
+	/**
+	 * Build a [Topology] instance from the current state of this builder.
+	 *
+	 * @return The graph built from this builder.
+	 */
+	override fun create(): MutableTopology = AdjacencyListTopology()
+}
+
+/**
+ * A [Topology] whose graph is represented as adjacency list.
+ */
+internal class AdjacencyListTopology : MutableTopology {
+	/**
+	 * The identifier for the next node in the graph.
+	 */
+	private var nextId: AtomicInteger = AtomicInteger(0)
+
+	/**
+	 * A mapping of nodes to their internal representation with the edges of the nodes.
+	 */
+	private var nodes: MutableMap<Entity<*, Topology>, Node> = HashMap()
+
+	// Topology
+
+	/**
+	 * The listeners of this topology.
+	 */
+	override val listeners: MutableSet<TopologyListener> = HashSet()
+
+	/**
+	 * A unique identifier of this node within the topology.
+	 */
+	override val Entity<*, Topology>.id: Int
+		get() = nodes[this]!!.id
+
+	/**
+	 * The set of ingoing edges of this node.
+	 */
+	override val Entity<*, Topology>.ingoingEdges: MutableSet<BaseEdge<*>>
+		get() = nodes[this]!!.ingoingEdges
+
+	/**
+	 * The set of outgoing edges of this node.
+	 */
+	override val Entity<*, Topology>.outgoingEdges: MutableSet<BaseEdge<*>>
+		get() = nodes[this]!!.outgoingEdges
+
+	// MutableTopology
+
+	/**
+	 * Create a directed edge between two [Node]s in the topology.
+	 *
+	 * @param from The source of the edge.
+	 * @param to The destination of the edge.
+	 * @param label The label of the edge.
+	 * @param tag The tag of the edge that uniquely identifies the relationship the edge represents.
+	 * @return The edge that has been created.
+	 */
+	override fun <T> connect(from: Entity<*, Topology>, to: Entity<*, Topology>, label: T, tag: String?): BaseEdge<T> {
+		if (!contains(from) || !contains(to))
+			throw IllegalArgumentException("One of the entities is not part of the topology")
+		val edge = Edge(label, tag, from, to)
+		from.outgoingEdges.add(edge)
+		to.ingoingEdges.add(edge)
+		listeners.forEach { it.run { this@AdjacencyListTopology.onEdgeAdded(edge) } }
+		return edge
+	}
+
+	// Cloneable
+
+	/**
+	 * Create a copy of the graph.
+	 *
+	 * @return A new [Topology] instance with a copy of the graph.
+	 */
+	override fun clone(): Topology {
+		val copy = AdjacencyListTopology()
+		copy.nextId = AtomicInteger(nextId.get())
+		copy.nodes = HashMap(nodes)
+		return copy
+	}
+
+	// Set
+
+	/**
+	 * Returns the size of the collection.
+	 */
+	override val size: Int = nodes.size
+
+	/**
+	 * Checks if the specified element is contained in this collection.
+	 */
+	override fun contains(element: Entity<*, Topology>): Boolean = nodes.contains(element)
+
+	/**
+	 * Checks if all elements in the specified collection are contained in this collection.
+	 */
+	override fun containsAll(elements: Collection<Entity<*, Topology>>): Boolean =
+		elements.all { nodes.containsKey(it) }
+
+	/**
+	 * Returns `true` if the collection is empty (contains no elements), `false` otherwise.
+	 */
+	override fun isEmpty(): Boolean = nodes.isEmpty()
+
+	// MutableSet
+
+	/**
+	 * Add a node to the graph.
+	 *
+	 * @param element The element to add to this graph.
+	 * @return `true` if the graph has changed, `false` otherwise.
+	 */
+	override fun add(element: Entity<*, Topology>): Boolean {
+		if (nodes.putIfAbsent(element, Node(nextId.getAndIncrement())) == null) {
+			listeners.forEach { it.run { this@AdjacencyListTopology.onNodeAdded(element) } }
+			return true
+		}
+		return false
+	}
+
+	/**
+	 * Add all nodes in the specified collection to the graph.
+	 *
+	 * @param elements The nodes to add to this graph.
+	 * @return `true` if the graph has changed, `false` otherwise.
+	 */
+	override fun addAll(elements: Collection<Entity<*, Topology>>): Boolean = elements.any { add(it) }
+
+	/**
+	 * Remove all nodes and their respective edges from the graph.
+	 */
+	override fun clear() = nodes.clear()
+
+	/**
+	 * Remove the given node and its edges from the graph.
+	 *
+	 * @param element The element to remove from the graph.
+	 * @return `true` if the graph has changed, `false` otherwise.
+	 */
+	override fun remove(element: Entity<*, Topology>): Boolean {
+		nodes[element]?.ingoingEdges?.forEach {
+			it.from.outgoingEdges.remove(it)
+		}
+		nodes[element]?.outgoingEdges?.forEach {
+			it.to.ingoingEdges.remove(it)
+		}
+		if (nodes.keys.remove(element)) {
+			listeners.forEach { it.run { this@AdjacencyListTopology.onNodeRemoved(element) } }
+			return true
+		}
+		return false
+	}
+
+
+	/**
+	 * Remove all nodes in the given collection from the graph.
+	 *
+	 * @param elements The elements to remove from the graph.
+	 * @return `true` if the graph has changed, `false` otherwise.
+	 */
+	override fun removeAll(elements: Collection<Entity<*, Topology>>): Boolean = elements.any(this::remove)
+
+	/**
+	 * Remove all nodes in the graph, except those in the specified collection.
+	 *
+	 * Take note that this method currently only guarantees a maximum runtime complexity of O(n^2).
+	 *
+	 * @param elements The elements to retain in the graph.
+	 */
+	override fun retainAll(elements: Collection<Entity<*, Topology>>): Boolean {
+		val iterator = nodes.keys.iterator()
+		var changed = false
+		while (iterator.hasNext()) {
+			val entity = iterator.next()
+
+			if (entity !in elements) {
+				iterator.remove()
+				changed = true
+			}
+		}
+		return changed
+	}
+
+	/**
+	 * Return a mutable iterator over the nodes of the graph.
+	 *
+	 * @return A [MutableIterator] over the nodes of the graph.
+	 */
+	override fun iterator(): MutableIterator<Entity<*, Topology>> = nodes.keys.iterator()
+
+	/**
+	 * The internal representation of a node within the graph.
+	 */
+	internal data class Node(val id: Int) {
+		val ingoingEdges: MutableSet<BaseEdge<*>> = HashSet()
+		val outgoingEdges: MutableSet<BaseEdge<*>> = HashSet()
+	}
+
+	/**
+	 * The internal representation of an edge within the graph.
+	 */
+	internal class Edge<out T>(override val label: T,
+							   override val tag: String?,
+							   override val from: Entity<*, Topology>,
+							   override val to: Entity<*, Topology>) : BaseEdge<T>
+}
diff --git a/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/Bootstrap.kt b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/Bootstrap.kt
new file mode 100644
index 00000000..de9a41d5
--- /dev/null
+++ b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/Bootstrap.kt
@@ -0,0 +1,23 @@
+package com.atlarge.opendc.model.topology
+
+import com.atlarge.opendc.simulator.Bootstrap
+import com.atlarge.opendc.simulator.Entity
+
+/**
+ * Create a [Bootstrap] procedure for the given [Topology].
+ *
+ * @return A bootstrap procedure for the topology.
+ */
+fun <T: Topology> T.bootstrap(): Bootstrap<T> = Bootstrap.create { ctx ->
+	forEach { ctx.register(it) }
+	listeners += object : TopologyListener {
+		override fun Topology.onNodeAdded(node: Entity<*, Topology>) {
+			ctx.register(node)
+		}
+
+		override fun Topology.onNodeRemoved(node: Entity<*, Topology>) {
+			ctx.deregister(node)
+		}
+	}
+	this
+}
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Trace.kt b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/Component.kt
index 6dd2efb8..5e8611a0 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Trace.kt
+++ b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/Component.kt
@@ -22,16 +22,12 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.platform.workload
+package com.atlarge.opendc.model.topology
 
 /**
- * A timestamped sequence of jobs received in a cloud network.
- *
+ * A component within a [Topology], which is either a node or an [Edge] representing the relationship between
+ * entities within a logical topology of a cloud network.
+ **
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-interface Trace {
-	/**
-	 * The [Job]s in the trace.
-	 */
-	val jobs: Set<Job>
-}
+interface Component
diff --git a/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/Edge.kt b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/Edge.kt
new file mode 100644
index 00000000..3e507887
--- /dev/null
+++ b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/Edge.kt
@@ -0,0 +1,61 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.model.topology
+
+import com.atlarge.opendc.simulator.Entity
+
+/**
+ * An edge that represents a directed relationship between exactly two nodes in a logical topology of a cloud network.
+ *
+ * @param T The relationship type the edge represents within a logical topology.
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface Edge<out T> : Component {
+	/**
+	 * The label of this edge.
+	 */
+	val label: T
+
+	/**
+	 * A tag to uniquely identify the relationship this edge represents.
+	 */
+	val tag: String?
+
+	/**
+	 * The source of the edge.
+	 *
+	 * This property is not guaranteed to have a runtime complexity of <code>O(1)</code>, but must be at least
+	 * <code>O(n)</code>, with respect to the size of the topology.
+	 */
+	val from: Entity<*, Topology>
+
+	/**
+	 * The destination of the edge.
+	 *
+	 * This property is not guaranteed to have a runtime complexity of <code>O(1)</code>, but must be at least
+	 * <code>O(n)</code>, with respect to the size of the topology.
+	 */
+	val to: Entity<*, Topology>
+}
diff --git a/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/MutableTopology.kt b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/MutableTopology.kt
new file mode 100644
index 00000000..ac1b4ba5
--- /dev/null
+++ b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/MutableTopology.kt
@@ -0,0 +1,65 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.model.topology
+
+import com.atlarge.opendc.simulator.Entity
+
+/**
+ * A subinterface of [Topology] which adds mutation methods. When mutation is not required, users
+ * should prefer the [Topology] interface.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface MutableTopology : Topology, MutableSet<Entity<*, Topology>> {
+	/**
+	 * Create a directed, labeled edge between two nodes in the topology.
+	 *
+	 * @param from The source of the edge.
+	 * @param to The destination of the edge.
+	 * @param label The label of the edge.
+	 * @param tag The tag of the edge that uniquely identifies the relationship the edge represents.
+	 * @return The edge that has been created.
+	 */
+	fun <T> connect(from: Entity<*, Topology>, to: Entity<*, Topology>, label: T, tag: String? = null): Edge<T>
+
+	/**
+	 * Create a directed, unlabeled edge between two nodes in the topology.
+	 *
+	 * @param from The source of the edge.
+	 * @param to The destination of the edge.
+	 * @param tag The tag of the edge that uniquely identifies the relationship the edge represents.
+	 * @return The edge that has been created.
+	 */
+	fun connect(from: Entity<*, Topology>, to: Entity<*, Topology>, tag: String? = null): Edge<Unit> =
+		connect(from, to, Unit, tag)
+
+	/**
+	 * Create a directed, unlabeled edge between two nodes in the topology.
+	 *
+	 * @param dest The destination of the edge.
+	 * @return The edge that has been created.
+	 */
+	infix fun Entity<*, Topology>.to(dest: Entity<*, Topology>): Edge<Unit> = connect(this, dest)
+}
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Job.kt b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/Topology.kt
index df2f2b6a..1e5a404f 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Job.kt
+++ b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/Topology.kt
@@ -22,32 +22,29 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.platform.workload
+package com.atlarge.opendc.model.topology
+
+import com.atlarge.opendc.simulator.Entity
 
 /**
- * A bag of tasks which are submitted by a [User] to the cloud network.
+ * A graph data structure which represents the logical topology of a cloud network consisting of one or more
+ * datacenters.
+ *
+ * A topology is [Iterable] and allows implementation-dependent iteration of the nodes in the topology.
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-interface Job {
-	/**
-	 * A unique identifier of the job.
-	 */
-	val id: Int
-
+interface Topology : TopologyContext, Cloneable, Set<Entity<*, Topology>> {
 	/**
-	 * The owner of this job.
+	 * The listeners of this topology.
 	 */
-	val owner: User
+	val listeners: MutableSet<TopologyListener>
 
 	/**
-	 * The tasks this job consists of.
+	 * Create a copy of the topology.
+	 *
+	 * @return A new [Topology] with a copy of the graph.
 	 */
-	val tasks: Set<Task>
-
-	/**
-	 * A flag to indicate the job has finished.
-	 */
-	val finished: Boolean
-		get() = !tasks.any { !it.finished }
+	public override fun clone(): Topology
 }
+
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/User.kt b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/TopologyBuilder.kt
index d827fee5..44b1cb4e 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/User.kt
+++ b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/TopologyBuilder.kt
@@ -22,24 +22,19 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.platform.workload
+package com.atlarge.opendc.model.topology
 
 /**
- * A user of a cloud network that provides [Job]s for the simulation.
- *
- * Each user in a simulation has its own logical view of the cloud network which is used to route its jobs in the
- * physical network.
+ * A builder for [Topology] instances.
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-interface User {
-	/**
-	 * The unique identifier of the user.
-	 */
-	val id: Int
-
+interface TopologyBuilder : TopologyFactory {
 	/**
-	 * The name of this user.
+	 * Construct a [Topology] from the given block and return it.
+	 *
+	 * @param block The block to construct the topology.
+	 * @return The topology that has been built.
 	 */
-	val name: String
+	fun construct(block: MutableTopology.() -> Unit): MutableTopology = create().apply(block)
 }
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/ProcessingUnit.kt b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/TopologyContext.kt
index abc8608b..2bf87a39 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/ProcessingUnit.kt
+++ b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/TopologyContext.kt
@@ -22,28 +22,29 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.topology.machine
+package com.atlarge.opendc.model.topology
 
-import nl.atlarge.opendc.topology.Entity
+import com.atlarge.opendc.simulator.Entity
 
 /**
- * An interface representing a generic processing unit which is placed into a [Machine].
+ * A [TopologyContext] represents the context for entities in a specific topology, providing access to the identifier
+ * and ingoing and outgoing edges of the [Entity] within a [Topology].
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-interface ProcessingUnit : Entity<Unit> {
+interface TopologyContext {
 	/**
-	 * The speed of this [ProcessingUnit] per core in MHz.
+	 * A unique identifier of an [Entity] within the topology.
 	 */
-	val clockRate: Int
+	val Entity<*, Topology>.id: Int
 
 	/**
-	 * The amount of cores within this [ProcessingUnit].
+	 * The set of ingoing edges of an [Entity].
 	 */
-	val cores: Int
+	val Entity<*, Topology>.ingoingEdges: Set<Edge<*>>
 
 	/**
-	 * The energy consumption of this [ProcessingUnit] in Watt.
+	 * The set of outgoing edges of an [Entity].
 	 */
-	val energyConsumption: Double
+	val Entity<*, Topology>.outgoingEdges: Set<Edge<*>>
 }
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Rack.kt b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/TopologyFactory.kt
index 25429f71..35cfa97a 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Rack.kt
+++ b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/TopologyFactory.kt
@@ -22,14 +22,19 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.topology.container
-
-import nl.atlarge.opendc.topology.Entity
+package com.atlarge.opendc.model.topology
 
 /**
- * A type of physical steel and electronic framework that is designed to house servers, networking devices, cables and
- * other datacenter computing equipment.
+ * An interface for producing [Topology] instances. Implementors of this interface provide a way of generating a
+ * topology based on the state of the factory.
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-interface Rack : Entity<Unit>
+interface TopologyFactory {
+	/**
+	 * Create a [MutableTopology] instance.
+	 *
+	 * @return A mutable topology.
+	 */
+	fun create(): MutableTopology
+}
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/Scheduler.kt b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/TopologyListener.kt
index 578bef9c..93108cc0 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/Scheduler.kt
+++ b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/TopologyListener.kt
@@ -22,50 +22,42 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.platform.scheduler
+package com.atlarge.opendc.model.topology;
 
-import nl.atlarge.opendc.kernel.Context
-import nl.atlarge.opendc.platform.workload.Task
-import nl.atlarge.opendc.topology.Entity
-import nl.atlarge.opendc.topology.machine.Machine
+import com.atlarge.opendc.simulator.Entity
 
 /**
- * A task scheduler that is coupled to an [Entity] in the topology of the cloud network.
+ * A listener interface for [Topology] instances. The methods of this interface are invoked on
+ * mutation of the topology the listener is listening to.
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-interface Scheduler {
+interface TopologyListener {
 	/**
-	 * The name of this scheduler.
-	 */
-	val name: String
-
-	/**
-	 * (Re)schedule the tasks submitted to the scheduler over the specified set of machines.
+	 * This method is invoked when an [Entity] is added to the [Topology].
 	 *
-	 * This method should be invoked at some interval to allow the scheduler to reschedule existing tasks and schedule
-	 * new tasks.
+	 * @param node The entity that has been added to the [Topology].
 	 */
-	suspend fun <E: Entity<*>> Context<E>.schedule()
+	fun Topology.onNodeAdded(node: Entity<*, Topology>) {}
 
 	/**
-	 * Submit a [Task] to this scheduler.
+	 * This method is invoked when an [Entity] is removed from the [Topology].
 	 *
-	 * @param task The task to submit to the scheduler.
+	 * @param node The entity that has been removed from the [Topology].
 	 */
-	fun submit(task: Task)
+	fun Topology.onNodeRemoved(node: Entity<*, Topology>) {}
 
 	/**
-	 * Register a [Machine] to this scheduler.
+	 * This method is invoked when an [Edge] is added to the [Topology].
 	 *
-	 * @param machine The machine to register.
+	 * @param edge The edge that has been added to the [Topology].
 	 */
-	fun register(machine: Machine)
+	fun Topology.onEdgeAdded(edge: Edge<*>) {}
 
 	/**
-	 * Deregister a [Machine] from this scheduler.
+	 * This method is invoked when an [Edge] is removed from the [Topology].
 	 *
-	 * @param machine The machine to deregister.
+	 * @param edge The entity that has been removed from the [Topology].
 	 */
-	fun deregister(machine: Machine)
+	fun Topology.onEdgeRemoved(edge: Edge<*>) {}
 }
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Room.kt b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/Traversable.kt
index 3b338899..23720c46 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Room.kt
+++ b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/model/topology/Traversable.kt
@@ -22,13 +22,20 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.topology.container
+package com.atlarge.opendc.model.topology
 
-import nl.atlarge.opendc.topology.Entity
+/**
+ * Filter a [Set] of [Edge]s based on the tag of the edges and return the origin nodes casted to type `T`.
+ *
+ * @param tag The tag of the edges to get.
+ * @return An [Iterable] of the specified type `T` with the given tag.
+ */
+inline fun <reified T> Set<Edge<*>>.origins(tag: String) = filter { it.tag == tag }.map { it.from as T }
 
 /**
- * A physical room in a datacenter with relationships to the entities within the room.
+ * Filter a [Set] of [Edge]s based on the tag of the edges and return the destination nodes casted to type `T`.
  *
- * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ * @param tag The tag of the edges to get.
+ * @return An [Iterable] of the specified type `T` with the given tag.
  */
-interface Room : Entity<Unit>
+inline fun <reified T> Set<Edge<*>>.destinations(tag: String) = filter { it.tag == tag }.map { it.to as T }
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/FifoScheduler.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/FifoScheduler.kt
deleted file mode 100644
index 6f5db211..00000000
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/FifoScheduler.kt
+++ /dev/null
@@ -1,120 +0,0 @@
-/*
- * MIT License
- *
- * Copyright (c) 2017 atlarge-research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package nl.atlarge.opendc.platform.scheduler
-
-import nl.atlarge.opendc.kernel.Context
-import nl.atlarge.opendc.platform.workload.Job
-import nl.atlarge.opendc.topology.Entity
-import nl.atlarge.opendc.topology.machine.Machine
-import nl.atlarge.opendc.platform.workload.Task
-import java.util.*
-
-/**
- * A [Scheduler] that distributes work according to the first-in-first-out principle.
- *
- * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
- */
-class FifoScheduler : Scheduler {
-	/**
-	 * The name of this scheduler.
-	 */
-	override val name: String = "FIFO"
-
-	/**
-	 * The set of machines the scheduler knows of.
-	 */
-	val machines: MutableSet<Machine> = HashSet()
-
-	/**
-	 * The queue of [Task]s that need to be scheduled.
-	 */
-	val queue: Queue<Task> = ArrayDeque()
-
-	/**
-	 * (Re)schedule the tasks submitted to the scheduler over the specified set of machines.
-	 */
-	override suspend fun <E : Entity<*>> Context<E>.schedule() {
-		if (queue.isEmpty()) {
-			return
-		}
-
-		// The tasks that need to be rescheduled
-		val rescheduled = ArrayDeque<Task>()
-		val iterator = queue.iterator()
-
-		machines
-			.filter { it.state.status != Machine.Status.HALT }
-			.forEach { machine ->
-				while (iterator.hasNext()) {
-					val task = iterator.next()
-
-					// TODO What to do with tasks that are not ready yet to be processed
-					if (!task.ready) {
-						iterator.remove()
-						rescheduled.add(task)
-						continue
-					} else if (task.finished) {
-						iterator.remove()
-						continue
-					}
-
-					machine.send(task)
-					break
-				}
-			}
-
-		// Reschedule all tasks that are not ready yet
-		while (!rescheduled.isEmpty()) {
-			queue.add(rescheduled.poll())
-		}
-	}
-
-	/**
-	 * Submit a [Task] to this scheduler.
-	 *
-	 * @param task The task to submit to the scheduler.
-	 */
-	override fun submit(task: Task) {
-		queue.add(task)
-	}
-
-	/**
-	 * Register a [Machine] to this scheduler.
-	 *
-	 * @param machine The machine to register.
-	 */
-	override fun register(machine: Machine) {
-		machines.add(machine)
-	}
-
-	/**
-	 * Deregister a [Machine] from this scheduler.
-	 *
-	 * @param machine The machine to deregister.
-	 */
-	override fun deregister(machine: Machine) {
-		machines.remove(machine)
-	}
-}
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/SrtfScheduler.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/SrtfScheduler.kt
deleted file mode 100644
index 1fbf8c04..00000000
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/SrtfScheduler.kt
+++ /dev/null
@@ -1,111 +0,0 @@
-/*
- * MIT License
- *
- * Copyright (c) 2017 atlarge-research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package nl.atlarge.opendc.platform.scheduler
-
-import nl.atlarge.opendc.kernel.Context
-import nl.atlarge.opendc.platform.workload.Task
-import nl.atlarge.opendc.topology.Entity
-import nl.atlarge.opendc.topology.machine.Machine
-import java.util.*
-
-/**
- * A [Scheduler] that distributes work according to the shortest job first policy.
- *
- * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
- */
-class SrtfScheduler : Scheduler {
-	/**
-	 * The name of this scheduler.
-	 */
-	override val name: String = "SRTF"
-
-	/**
-	 * The set of machines the scheduler knows of.
-	 */
-	val machines: MutableSet<Machine> = HashSet()
-
-	/**
-	 * The set of [Task]s that need to be scheduled.
-	 */
-	val tasks: MutableSet<Task> = HashSet()
-
-	/**
-	 * (Re)schedule the tasks submitted to the scheduler over the specified set of machines.
-	 */
-	override suspend fun <E : Entity<*>> Context<E>.schedule() {
-		if (tasks.isEmpty()) {
-			return
-		}
-
-		val iterator = tasks.sortedBy { it.remaining }.iterator()
-
-		machines
-			.filter { it.state.status != Machine.Status.HALT }
-			.forEach { machine ->
-				while (iterator.hasNext()) {
-					val task = iterator.next()
-
-					// TODO What to do with tasks that are not ready yet to be processed
-					if (!task.ready) {
-						tasks.add(task)
-						continue
-					} else if (task.finished) {
-						tasks.remove(task)
-						continue
-					}
-
-					machine.send(task)
-					break
-				}
-			}
-	}
-
-	/**
-	 * Submit a [Task] to this scheduler.
-	 *
-	 * @param task The task to submit to the scheduler.
-	 */
-	override fun submit(task: Task) {
-		tasks.add(task)
-	}
-
-	/**
-	 * Register a [Machine] to this scheduler.
-	 *
-	 * @param machine The machine to register.
-	 */
-	override fun register(machine: Machine) {
-		machines.add(machine)
-	}
-
-	/**
-	 * Deregister a [Machine] from this scheduler.
-	 *
-	 * @param machine The machine to deregister.
-	 */
-	override fun deregister(machine: Machine) {
-		machines.remove(machine)
-	}
-}
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Task.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Task.kt
deleted file mode 100644
index e740cdd8..00000000
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Task.kt
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * MIT License
- *
- * Copyright (c) 2017 atlarge-research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package nl.atlarge.opendc.platform.workload
-
-import nl.atlarge.opendc.kernel.time.Instant
-import nl.atlarge.opendc.topology.machine.Machine
-
-/**
- * A task that runs as part of a [Job] on a [Machine].
- *
- * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
- */
-interface Task {
-	/**
-	 * The unique identifier of the task.
-	 */
-	val id: Int
-
-	/**
-	 * The amount of flops for this task.
-	 */
-	val flops: Long
-
-	/**
-	 * The dependencies of the task.
-	 */
-	val dependencies: Set<Task>
-
-	/**
-	 * A flag to indicate the task is parallelizable.
-	 */
-	val parallelizable: Boolean
-
-	/**
-	 * The remaining flops for this task.
-	 */
-	val remaining: Long
-
-	/**
-	 * The state of the task.
-	 */
-	val state: TaskState
-
-	/**
-	 * A flag to indicate whether the task is ready to be started.
-	 */
-	val ready: Boolean
-		get() = !dependencies.any { !it.finished }
-
-	/**
-	 * A flag to indicate whether the task has finished.
-	 */
-	val finished: Boolean
-		get() = state is TaskState.Finished
-
-	/**
-	 * This method is invoked when a task has arrived at a datacenter.
-	 *
-	 * @param time The moment in time the task has arrived at the datacenter.
-	 */
-	fun arrive(time: Instant)
-
-	/**
-	 * Consume the given amount of flops of this task.
-	 *
-	 * @param time The current moment in time of the consumption.
-	 * @param flops The total amount of flops to consume.
-	 */
-	fun consume(time: Instant, flops: Long)
-}
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/TaskState.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/TaskState.kt
deleted file mode 100644
index d1f908af..00000000
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/TaskState.kt
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * MIT License
- *
- * Copyright (c) 2017 atlarge-research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package nl.atlarge.opendc.platform.workload
-
-import nl.atlarge.opendc.kernel.time.Instant
-
-
-/**
- * This class hierarchy describes the states of a [Task].
- *
- * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
- */
-sealed class TaskState {
-	/**
-	 * A state to indicate the task has not yet arrived at the [Datacenter].
-	 */
-	object Underway : TaskState()
-
-	/**
-	 * A state to indicate the task has arrived at the [Datacenter].
-	 *
-	 * @property at The moment in time the task has arrived.
-	 */
-	data class Queued(val at: Instant) : TaskState()
-
-	/**
-	 * A state to indicate the task has started running on a machine.
-	 *
-	 * @property previous The previous state of the task.
-	 * @property at The moment in time the task started.
-	 */
-	data class Running(val previous: Queued, val at: Instant) : TaskState()
-
-	/**
-	 * A state to indicate the task has finished.
-	 *
-	 * @property previous The previous state of the task.
-	 * @property at The moment in time the task finished.
-	 */
-	data class Finished(val previous: Running, val at: Instant) : TaskState()
-
-	/**
-	 * A state to indicate the task has failed.
-	 *
-	 * @property previous The previous state of the task.
-	 * @property at The moment in time the task failed.
-	 * @property reason The reason of the failure.
-	 */
-	data class Failed(val previous: Running, val at: Instant, val reason: String) : TaskState()
-}
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Datacenter.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Datacenter.kt
deleted file mode 100644
index f7eb29d8..00000000
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Datacenter.kt
+++ /dev/null
@@ -1,102 +0,0 @@
-/*
- * MIT License
- *
- * Copyright (c) 2017 atlarge-research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package nl.atlarge.opendc.topology.container
-
-import mu.KotlinLogging
-import nl.atlarge.opendc.topology.destinations
-import nl.atlarge.opendc.kernel.Context
-import nl.atlarge.opendc.kernel.Process
-import nl.atlarge.opendc.kernel.time.Duration
-import nl.atlarge.opendc.platform.scheduler.Scheduler
-import nl.atlarge.opendc.platform.workload.Task
-import nl.atlarge.opendc.topology.Entity
-import nl.atlarge.opendc.topology.machine.Machine
-import java.util.*
-
-/**
- * A representation of a facility used to house computer systems and associated components.
- *
- * @property scheduler The tasks scheduler the datacenter uses.
- * @property interval The interval at which task will be (re)scheduled.
- * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
- */
-interface Datacenter : Entity<Unit>, Process<Datacenter> {
-	/**
-	 * The task scheduler the datacenter uses.
-	 */
-	val scheduler: Scheduler
-
-	/**
-	 * The interval at which task will be (re)scheduled.
-	 */
-	val interval: Duration
-
-	/**
-	 * This method is invoked to start the simulation an [Entity] associated with this [Process].
-	 *
-	 * This method is assumed to be running during a simulation, but should hand back control to the simulator at
-	 * some point by suspending the process. This allows other processes to do work in the current tick of the
-	 * simulation.
-	 * Suspending the process can be achieved by calling suspending method in the context:
-	 * 	- [Context.tick]	- Wait for the next tick to occur
-	 * 	- [Context.wait]	- Wait for `n` amount of ticks before resuming execution.
-	 * 	- [Context.receive]	- Wait for a message to be received in the mailbox of the [Entity] before resuming
-	 * 	execution.
-	 *
-	 * If this method exits early, before the simulation has finished, the entity is assumed to be shutdown and its
-	 * simulation will not run any further.
-	 */
-	suspend override fun Context<Datacenter>.run() {
-		val logger = KotlinLogging.logger {}
-
-		// The queue of messages to be processed after a cycle
-		val queue: Queue<Any> = ArrayDeque()
-		// Find all machines in the datacenter
-		val machines = outgoingEdges.destinations<Room>("room").asSequence()
-			.flatMap { it.outgoingEdges.destinations<Rack>("rack").asSequence() }
-			.flatMap { it.outgoingEdges.destinations<Machine>("machine").asSequence() }.toList()
-
-		logger.info { "Initialising datacenter with ${machines.size} machines" }
-
-		// Register all machines to the scheduler
-		machines.forEach(scheduler::register)
-
-		while (true) {
-			// Process all messages in the queue
-			while (queue.isNotEmpty()) {
-				val msg = queue.poll()
-				if (msg is Task) {
-					msg.arrive(time)
-					scheduler.submit(msg)
-				}
-			}
-			// (Re)schedule the tasks
-			scheduler.run { schedule() }
-
-			// Sleep a time quantum
-			wait(interval, queue)
-		}
-	}
-}
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/Cpu.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/Cpu.kt
deleted file mode 100644
index f97e73e9..00000000
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/Cpu.kt
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * MIT License
- *
- * Copyright (c) 2017 atlarge-research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package nl.atlarge.opendc.topology.machine
-
-/**
- * A central processing unit.
- *
- * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
- */
-interface Cpu : ProcessingUnit
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/Gpu.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/Gpu.kt
deleted file mode 100644
index 15c5263f..00000000
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/Gpu.kt
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * MIT License
- *
- * Copyright (c) 2017 atlarge-research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package nl.atlarge.opendc.topology.machine
-
-/**
- * A graphics processing unit.
- *
- * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
- */
-interface Gpu : ProcessingUnit
-
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/Machine.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/Machine.kt
deleted file mode 100644
index b5016adb..00000000
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/Machine.kt
+++ /dev/null
@@ -1,123 +0,0 @@
-/*
- * MIT License
- *
- * Copyright (c) 2017 atlarge-research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package nl.atlarge.opendc.topology.machine
-
-import mu.KotlinLogging
-import nl.atlarge.opendc.topology.destinations
-import nl.atlarge.opendc.platform.workload.Task
-import nl.atlarge.opendc.kernel.Context
-import nl.atlarge.opendc.kernel.Process
-import nl.atlarge.opendc.kernel.time.Duration
-import nl.atlarge.opendc.topology.Entity
-
-/**
- * A Physical Machine (PM) inside a rack of a datacenter. It has a speed, and can be given a workload on which it will
- * work until finished or interrupted.
- *
- * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
- */
-open class Machine : Entity<Machine.State>, Process<Machine> {
-	/**
-	 * The logger instance to use for the simulator.
-	 */
-	private val logger = KotlinLogging.logger {}
-
-	/**
-	 * The status of a machine.
-	 */
-	enum class Status {
-		HALT, IDLE, RUNNING
-	}
-
-	/**
-	 * The shape of the state of a [Machine] entity.
-	 *
-	 * @property status The status of the machine.
-	 * @property task The task assign to the machine.
-	 * @property memory The memory usage of the machine (defaults to 50mb for the kernel)
-	 * @property load The load on the machine (defaults to 0.0)
-	 * @property temperature The temperature of the machine (defaults to 23 degrees Celcius)
-	 */
-	data class State(val status: Status,
-					 val task: Task? = null,
-					 val memory: Int = 50,
-					 val load: Double = 0.0,
-					 val temperature: Double = 23.0)
-
-	/**
-	 * The initial state of a [Machine] entity.
-	 */
-	override val initialState = State(Status.HALT)
-
-	/**
-	 * Run the simulation kernel for this entity.
-	 */
-	override suspend fun Context<Machine>.run() {
-		update(State(Status.IDLE))
-
-		val interval: Duration = 10
-		val cpus = outgoingEdges.destinations<Cpu>("cpu")
-		val speed = cpus.fold(0, { acc, cpu -> acc + cpu.clockRate * cpu.cores })
-
-		// Halt the machine if it has not processing units (see bug #4)
-		if (cpus.isEmpty()) {
-			update(State(Status.HALT))
-			return
-		}
-
-		var task: Task = receiveTask()
-		update(State(Status.RUNNING, task, load = 1.0, memory = state.memory + 50, temperature = 30.0))
-
-		while (true) {
-			if (task.finished) {
-				logger.info { "${entity.id}: Task ${task.id} finished. Machine idle at $time" }
-				update(State(Status.IDLE))
-				task = receiveTask()
-			} else {
-				task.consume(time, speed * delta)
-			}
-
-			// Check if we have received a new order in the meantime.
-			val msg = receive(interval)
-			if (msg is Task) {
-				task = msg
-				update(State(Status.RUNNING, task, load = 1.0, memory = state.memory + 50, temperature = 30.0))
-			}
-		}
-	}
-
-	/**
-	 * Wait for a [Task] to be received by the [Process] and discard all other messages received in the meantime.
-	 *
-	 * @return The task that has been received.
-	 */
-	private suspend fun Context<Machine>.receiveTask(): Task {
-		while (true) {
-			val msg = receive()
-			if (msg is Task)
-				return msg
-		}
-	}
-}
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/network/NetworkUnit.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/network/NetworkUnit.kt
deleted file mode 100644
index d3a9eefe..00000000
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/network/NetworkUnit.kt
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * MIT License
- *
- * Copyright (c) 2017 atlarge-research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package nl.atlarge.opendc.topology.network
-
-import nl.atlarge.opendc.topology.Entity
-
-/**
- * A generic interface for a network unit in a cloud network.
- *
- * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
- */
-interface NetworkUnit : Entity<Unit>
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/power/PowerUnit.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/power/PowerUnit.kt
deleted file mode 100644
index b9602e55..00000000
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/power/PowerUnit.kt
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * MIT License
- *
- * Copyright (c) 2017 atlarge-research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package nl.atlarge.opendc.topology.power
-
-import nl.atlarge.opendc.topology.Entity
-
-/**
- * An [Entity] which provides power for other entities a cloud network to run.
- *
- * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
- */
-interface PowerUnit : Entity<Unit>
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/storage/StorageUnit.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/storage/StorageUnit.kt
deleted file mode 100644
index f719f152..00000000
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/storage/StorageUnit.kt
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * MIT License
- *
- * Copyright (c) 2017 atlarge-research
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package nl.atlarge.opendc.topology.storage
-
-import nl.atlarge.opendc.topology.Entity
-
-/**
- * A generic interface for a storage unit in a cloud network.
- *
- * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
- */
-interface StorageUnit : Entity<Unit>