Implement JPA integration

15 files changed, 196 insertions, 89 deletions

diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/scheduler/FifoScheduler.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/FifoScheduler.kt
index 5382e48b..1c3dc869 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/scheduler/FifoScheduler.kt
+++ b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/FifoScheduler.kt
@@ -22,12 +22,12 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.scheduler
+package nl.atlarge.opendc.platform.scheduler
 
 import nl.atlarge.opendc.kernel.Context
 import nl.atlarge.opendc.topology.Entity
 import nl.atlarge.opendc.topology.machine.Machine
-import nl.atlarge.opendc.workload.Task
+import nl.atlarge.opendc.platform.workload.Task
 import java.util.*
 
 /**
@@ -37,6 +37,11 @@ import java.util.*
  */
 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()
@@ -54,6 +59,8 @@ class FifoScheduler : Scheduler {
 			return
 		}
 
+		// The tasks that need to be rescheduled
+		val rescheduled = ArrayDeque<Task>()
 		val iterator = queue.iterator()
 
 		machines
@@ -64,7 +71,7 @@ class FifoScheduler : Scheduler {
 					// TODO What to do with tasks that are not ready yet to be processed
 					if (!task.isReady()) {
 						iterator.remove()
-						submit(task)
+						rescheduled.add(task)
 						continue
 					} else if (task.finished) {
 						iterator.remove()
@@ -75,6 +82,11 @@ class FifoScheduler : Scheduler {
 					break
 				}
 			}
+
+		// Reschedule all tasks that are not ready yet
+		while (!rescheduled.isEmpty()) {
+			submit(rescheduled.poll())
+		}
 	}
 
 	/**
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/scheduler/Scheduler.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/Scheduler.kt
index 8c96341a..bf988802 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/scheduler/Scheduler.kt
+++ b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/Scheduler.kt
@@ -22,12 +22,12 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.scheduler
+package nl.atlarge.opendc.platform.scheduler
 
 import nl.atlarge.opendc.kernel.Context
 import nl.atlarge.opendc.topology.Entity
 import nl.atlarge.opendc.topology.machine.Machine
-import nl.atlarge.opendc.workload.Task
+import nl.atlarge.opendc.platform.workload.Task
 
 /**
  * A task scheduler that is coupled to an [Entity] in the topology of the cloud network.
@@ -36,6 +36,11 @@ import nl.atlarge.opendc.workload.Task
  */
 interface Scheduler {
 	/**
+	 * The name of this scheduler.
+	 */
+	val name: String
+
+	/**
 	 * (Re)schedule the tasks submitted to the scheduler over the specified set of machines.
 	 *
 	 * This method should be invoked at some interval to allow the scheduler to reschedule existing tasks and schedule
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/scheduler/SrtfScheduler.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/SrtfScheduler.kt
index 0e94f81a..b2660964 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/scheduler/SrtfScheduler.kt
+++ b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/scheduler/SrtfScheduler.kt
@@ -22,12 +22,12 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.scheduler
+package nl.atlarge.opendc.platform.scheduler
 
 import nl.atlarge.opendc.kernel.Context
 import nl.atlarge.opendc.topology.Entity
 import nl.atlarge.opendc.topology.machine.Machine
-import nl.atlarge.opendc.workload.Task
+import nl.atlarge.opendc.platform.workload.Task
 import java.util.*
 
 /**
@@ -37,6 +37,11 @@ import java.util.*
  */
 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()
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/workload/Job.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Job.kt
index 6dbbf327..eb173229 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/workload/Job.kt
+++ b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Job.kt
@@ -22,15 +22,32 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.workload
+package nl.atlarge.opendc.platform.workload
 
 /**
  * A job that is submitted to a cloud network, which consists of one or multiple [Task]s.
  *
- * @param id The unique identifier of this job.
- * @param name The name of this job.
- * @param owner The user to which the job belongs.
- * @param tasks The tasks of which the job consists.
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-data class Job(val id: Int, val name: String, val owner: User, val tasks: Collection<Task>)
+interface Job {
+	/**
+	 * A unique identifier of the job.
+	 */
+	val id: Int
+
+	/**
+	 * The owner of this job.
+	 */
+	val owner: User
+
+	/**
+	 * The tasks this job consists of.
+	 */
+	val tasks: Set<Task>
+
+	/**
+	 * A flag to indicate the job has finished.
+	 */
+	val finished: Boolean
+		get() = !tasks.any { !it.finished }
+}
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/workload/Task.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Task.kt
index bd2b0604..140a5d5d 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/workload/Task.kt
+++ b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Task.kt
@@ -22,31 +22,57 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.workload
+package nl.atlarge.opendc.platform.workload
 
-import nl.atlarge.opendc.kernel.time.Instant
+import nl.atlarge.opendc.kernel.Context
+import nl.atlarge.opendc.topology.container.Datacenter
+import nl.atlarge.opendc.topology.machine.Machine
 
 /**
  * A task represents some computation that is part of a [Job].
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-data class Task(
-	val id: Int,
-	val dependencies: Set<Task>,
+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 amount of flops to compute.
 	 */
-	var remaining: Long = flops
-		private set
+	val remaining: Long
+
+	/**
+	 * A flag to indicate the task has been accepted by the datacenter.
+	 */
+	val accepted: Boolean
+
+	/**
+	 * A flag to indicate the task has been started.
+	 */
+	val started: Boolean
 
 	/**
 	 * A flag to indicate whether the task is finished.
 	 */
-	var finished: Boolean = false
-		private set
+	val finished: Boolean
 
 	/**
 	 * Determine whether the task is ready to be processed.
@@ -56,18 +82,24 @@ data class Task(
 	fun isReady() = dependencies.all { it.finished }
 
 	/**
+	 * Accept the task into the scheduling queue.
+	 */
+	fun Context<Datacenter>.accept()
+
+	/**
+	 * Start a task.
+	 */
+	fun Context<Machine>.start()
+
+	/**
 	 * Consume the given amount of flops of this task.
 	 *
 	 * @param flops The total amount of flops to consume.
 	 */
-	fun consume(flops: Long) {
-		if (finished)
-			return
-		if (remaining <= flops) {
-			finished = true
-			remaining = 0
-		} else {
-			remaining -= flops
-		}
-	}
+	fun Context<Machine>.consume(flops: Long)
+
+	/**
+	 * Finalise the task.
+	 */
+	fun Context<Machine>.finalize()
 }
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Trace.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Trace.kt
new file mode 100644
index 00000000..6dd2efb8
--- /dev/null
+++ b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/Trace.kt
@@ -0,0 +1,37 @@
+/*
+ * 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
+
+/**
+ * A timestamped sequence of jobs received in a cloud network.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface Trace {
+	/**
+	 * The [Job]s in the trace.
+	 */
+	val jobs: Set<Job>
+}
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/workload/User.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/User.kt
index d0e90851..d827fee5 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/workload/User.kt
+++ b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/platform/workload/User.kt
@@ -22,19 +22,24 @@
  * SOFTWARE.
  */
 
-package nl.atlarge.opendc.workload
-
-import nl.atlarge.opendc.topology.Topology
+package nl.atlarge.opendc.platform.workload
 
 /**
  * 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
+ * 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.
  *
- * @param id The unique identifier of the user.
- * @param name The name of the user.
- * @param view The view of the user on the topology.
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-data class User(val id: Int, val name: String, val view: Topology)
+interface User {
+	/**
+	 * The unique identifier of the user.
+	 */
+	val id: Int
+
+	/**
+	 * The name of this user.
+	 */
+	val name: String
+}
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
index f8954527..333609bb 100644
--- 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
@@ -25,14 +25,14 @@
 package nl.atlarge.opendc.topology.container
 
 import mu.KotlinLogging
-import nl.atlarge.opendc.extension.topology.destinations
+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.scheduler.Scheduler
+import nl.atlarge.opendc.platform.scheduler.Scheduler
 import nl.atlarge.opendc.topology.Entity
 import nl.atlarge.opendc.topology.machine.Machine
-import nl.atlarge.opendc.workload.Task
+import nl.atlarge.opendc.platform.workload.Task
 import java.util.*
 
 /**
@@ -42,16 +42,16 @@ import java.util.*
  * @property interval The interval at which task will be (re)scheduled.
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-class Datacenter(val scheduler: Scheduler, val interval: Duration) : Entity<Unit>, Process<Datacenter> {
+interface Datacenter : Entity<Unit>, Process<Datacenter> {
 	/**
-	 * The logger instance to use for the simulator.
+	 * The task scheduler the datacenter uses.
 	 */
-	private val logger = KotlinLogging.logger {}
+	val scheduler: Scheduler
 
 	/**
-	 * The initial state of the entity.
+	 * The interval at which task will be (re)scheduled.
 	 */
-	override val initialState = Unit
+	val interval: Duration
 
 	/**
 	 * This method is invoked to start the simulation an [Entity] associated with this [Process].
@@ -69,6 +69,8 @@ class Datacenter(val scheduler: Scheduler, val interval: Duration) : Entity<Unit
 	 * 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
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Rack.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Rack.kt
index 27207d4c..25429f71 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Rack.kt
+++ b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Rack.kt
@@ -32,6 +32,4 @@ import nl.atlarge.opendc.topology.Entity
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-class Rack : Entity<Unit> {
-	override val initialState = Unit
-}
+interface Rack : Entity<Unit>
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Room.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Room.kt
index 109a5629..3b338899 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Room.kt
+++ b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/container/Room.kt
@@ -31,9 +31,4 @@ import nl.atlarge.opendc.topology.Entity
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-class Room : Entity<Unit> {
-	/**
-	 * The initial state of the entity.
-	 */
-	override val initialState = Unit
-}
+interface Room : Entity<Unit>
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
index 78e2eaaa..f97e73e9 100644
--- 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
@@ -29,10 +29,4 @@ package nl.atlarge.opendc.topology.machine
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-data class Cpu(
-	override val speed: Int,
-	override val cores: Int,
-	override val energyConsumption: Int
-) : ProcessingUnit {
-	override val initialState = Unit
-}
+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
index 09179c94..15c5263f 100644
--- 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
@@ -29,11 +29,5 @@ package nl.atlarge.opendc.topology.machine
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-class Gpu(
-	override val speed: Int,
-	override val cores: Int,
-	override val energyConsumption: Int
-) : ProcessingUnit {
-	override val initialState = Unit
-}
+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
index 3305581a..4338ae04 100644
--- 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
@@ -25,8 +25,8 @@
 package nl.atlarge.opendc.topology.machine
 
 import mu.KotlinLogging
-import nl.atlarge.opendc.extension.topology.destinations
-import nl.atlarge.opendc.workload.Task
+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
@@ -38,7 +38,7 @@ import nl.atlarge.opendc.topology.Entity
  *
  * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
  */
-class Machine : Entity<Machine.State>, Process<Machine> {
+open class Machine : Entity<Machine.State>, Process<Machine> {
 	/**
 	 * The logger instance to use for the simulator.
 	 */
@@ -53,8 +53,18 @@ class Machine : Entity<Machine.State>, Process<Machine> {
 
 	/**
 	 * 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)
+	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.
@@ -69,24 +79,28 @@ class Machine : Entity<Machine.State>, Process<Machine> {
 
 		val interval: Duration = 10
 		val cpus = outgoingEdges.destinations<Cpu>("cpu")
-		val speed = cpus.fold(0, { acc, (speed, cores) -> acc + speed * cores })
+		val speed = cpus.fold(0, { acc, cpu -> acc + cpu.clockRate * cpu.cores }) / 10
+
 		var task: Task = receiveTask()
-		update(State(Status.RUNNING, task))
+		update(State(Status.RUNNING, task, load = 1.0, memory = state.memory + 50, temperature = 30.0))
+		task.run { start() }
 
 		while (true) {
-			if (task.finished) {
+			if (task.remaining <= 0) {
+				task.run { finalize() }
 				logger.info { "${entity.id}: Task ${task.id} finished. Machine idle at $time" }
 				update(State(Status.IDLE))
 				task = receiveTask()
 			} else {
-				task.consume(speed * delta)
+				task.run { consume(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))
+				update(State(Status.RUNNING, task, load = 1.0, memory = state.memory + 50, temperature = 30.0))
+				task.run { start() }
 			}
 		}
 	}
diff --git a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/ProcessingUnit.kt b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/ProcessingUnit.kt
index 31bfbcd6..abc8608b 100644
--- a/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/ProcessingUnit.kt
+++ b/opendc-stdlib/src/main/kotlin/nl/atlarge/opendc/topology/machine/ProcessingUnit.kt
@@ -33,9 +33,9 @@ import nl.atlarge.opendc.topology.Entity
  */
 interface ProcessingUnit : Entity<Unit> {
 	/**
-	 * The speed of this [ProcessingUnit] per core.
+	 * The speed of this [ProcessingUnit] per core in MHz.
 	 */
-	val speed: Int
+	val clockRate: Int
 
 	/**
 	 * The amount of cores within this [ProcessingUnit].
@@ -43,7 +43,7 @@ interface ProcessingUnit : Entity<Unit> {
 	val cores: Int
 
 	/**
-	 * The energy consumption of this [ProcessingUnit] in Kj/s.
+	 * The energy consumption of this [ProcessingUnit] in Watt.
 	 */
-	val energyConsumption: Int
+	val energyConsumption: Double
 }
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
index aac4ce03..b9602e55 100644
--- 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
@@ -29,9 +29,6 @@ import nl.atlarge.opendc.topology.Entity
 /**
  * An [Entity] which provides power for other entities a cloud network to run.
  *
- * @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> {
-	override val initialState = Unit
-}
+interface PowerUnit : Entity<Unit>