Add notion of initial states of entities

This change adds a notion of entities having an initial state specified
in the topology.

9 files changed, 46 insertions, 12 deletions

diff --git a/opendc-core/src/main/kotlin/nl/atlarge/opendc/kernel/Simulator.kt b/opendc-core/src/main/kotlin/nl/atlarge/opendc/kernel/Simulator.kt
index ee8d5072..3ad16da5 100644
--- a/opendc-core/src/main/kotlin/nl/atlarge/opendc/kernel/Simulator.kt
+++ b/opendc-core/src/main/kotlin/nl/atlarge/opendc/kernel/Simulator.kt
@@ -148,13 +148,12 @@ class Simulator(val topology: Topology, private val mapping: Map<Component<*>, C
          */
 		suspend override fun <T> receive(block: Envelope<*>.(Any?) -> T): T = suspendCoroutine {}
 
-
 		/**
-         * The observable state of an [Entity] within the simulation is provided by context.
-         */
+		 * The observable state of an [Entity] within the simulation is provided by context.
+		 */
 		@Suppress("UNCHECKED_CAST")
 		override val <S> Entity<S>.state: S
-			get() = states[this] as S
+			get() = states.computeIfAbsent(this, { initialState }) as S
 
 		/**
          * Update the state of the entity being simulated.
@@ -201,7 +200,7 @@ class Simulator(val topology: Topology, private val mapping: Map<Component<*>, C
 		 */
 		@Suppress("UNCHECKED_CAST")
 		override val <S> Entity<S>.state: S
-			get() = states[this] as S
+			get() = states.computeIfAbsent(this, { initialState }) as S
 
 		/**
 		 * Suspend the simulation kernel for <code>n</code> ticks before resuming the execution.
diff --git a/opendc-core/src/main/kotlin/nl/atlarge/opendc/kernel/impl/MachineKernel.kt b/opendc-core/src/main/kotlin/nl/atlarge/opendc/kernel/impl/MachineKernel.kt
index e34c7060..f81014e0 100644
--- a/opendc-core/src/main/kotlin/nl/atlarge/opendc/kernel/impl/MachineKernel.kt
+++ b/opendc-core/src/main/kotlin/nl/atlarge/opendc/kernel/impl/MachineKernel.kt
@@ -34,6 +34,9 @@ class MachineKernel(ctx: EntityContext<Machine>): AbstractEntityKernel<Machine>(
 
 	suspend override fun EntityContext<Machine>.run() {
 		println("${this}: Initialising!")
+		println("${this}: ${component.entity.state}")
+		update(Machine.State(Machine.Status.IDLE))
+		println("${this}: ${component.entity.state}")
 
 		val cpus = component.outgoingEdges().filter { it.tag == "cpu" }.map { it.to.entity as Cpu }
 		val speed = cpus.fold(0, { acc, (speed, cores) -> acc + speed * cores })
diff --git a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/Entity.kt b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/Entity.kt
index 44264a35..e6f37cf6 100644
--- a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/Entity.kt
+++ b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/Entity.kt
@@ -36,4 +36,9 @@ package nl.atlarge.opendc.topology
  * a simulation.
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-interface Entity<out S>
+interface Entity<out S> {
+	/**
+	 * The initial state of the entity.
+	 */
+	val initialState: S
+}
diff --git a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/container/Datacenter.kt b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/container/Datacenter.kt
index 2b464f15..b484f70e 100644
--- a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/container/Datacenter.kt
+++ b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/container/Datacenter.kt
@@ -31,4 +31,6 @@ import nl.atlarge.opendc.topology.Entity
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-class Datacenter: Entity<Unit>
+class Datacenter: Entity<Unit> {
+	override val initialState = Unit
+}
diff --git a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/container/Rack.kt b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/container/Rack.kt
index 043ad31a..f9595adc 100644
--- a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/container/Rack.kt
+++ b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/container/Rack.kt
@@ -32,4 +32,6 @@ import nl.atlarge.opendc.topology.Entity
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-class Rack: Entity<Unit>
+class Rack: Entity<Unit> {
+	override val initialState = Unit
+}
diff --git a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/machine/Cpu.kt b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/machine/Cpu.kt
index e06ad00c..1e2135e8 100644
--- a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/machine/Cpu.kt
+++ b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/machine/Cpu.kt
@@ -33,4 +33,6 @@ data class Cpu(
 	override val speed: Int,
 	override val cores: Int,
 	override val energyConsumption: Int
-): ProcessingUnit
+): ProcessingUnit {
+	override val initialState = Unit
+}
diff --git a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/machine/Gpu.kt b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/machine/Gpu.kt
index f15847e4..a294db38 100644
--- a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/machine/Gpu.kt
+++ b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/machine/Gpu.kt
@@ -33,5 +33,7 @@ class Gpu(
 	override val speed: Int,
 	override val cores: Int,
 	override val energyConsumption: Int
-): ProcessingUnit
+): ProcessingUnit {
+	override val initialState = Unit
+}
 
diff --git a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/machine/Machine.kt b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/machine/Machine.kt
index 396339a2..138abee7 100644
--- a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/machine/Machine.kt
+++ b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/machine/Machine.kt
@@ -32,4 +32,21 @@ import nl.atlarge.opendc.topology.Entity
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-class Machine: Entity<Unit>
+class Machine: Entity<Machine.State> {
+	/**
+	 * The status of a machine.
+	 */
+	enum class Status {
+		HALT, IDLE, RUNNING
+	}
+
+	/**
+	 * The shape of the state of a [Machine] entity.
+	 */
+	data class State(val status: Status)
+
+	/**
+	 * The initial state of a [Machine] entity.
+	 */
+	override val initialState = State(Status.HALT)
+}
diff --git a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/power/PowerUnit.kt b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/power/PowerUnit.kt
index e016a12b..2938e530 100644
--- a/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/power/PowerUnit.kt
+++ b/opendc-core/src/main/kotlin/nl/atlarge/opendc/topology/power/PowerUnit.kt
@@ -32,4 +32,6 @@ import nl.atlarge.opendc.topology.Entity
  * @param output The power output of the power unit in Watt.
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-class PowerUnit(val output: Double): Entity<Unit>
+class PowerUnit(val output: Double): Entity<Unit> {
+	override val initialState = Unit
+}