simulator: Add energy modelling subsystem to OpenDC

This pull request adds a subsystem to OpenDC for modelling power components in datacenters, 
such as UPSes, PDUs and PSUs. 
These components also take into account electrical losses that occur in real-world scenarios.

- Add module for datacenter power components (UPS, PDU)
- Integrate power subsystem with compute subsystem (PSU)
- Model power loss in power components

**Breaking API Changes**

1. `SimBareMetalMachine.powerDraw` is replaced by `SimBareMetalMachine.psu.powerDraw`

2 files changed, 109 insertions, 2 deletions

diff --git a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimMachineTest.kt b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimMachineTest.kt
index 0c686aa0..b9cfb06b 100644
--- a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimMachineTest.kt
+++ b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimMachineTest.kt
@@ -40,6 +40,7 @@ import org.opendc.simulator.compute.util.SimWorkloadLifecycle
 import org.opendc.simulator.compute.workload.SimFlopsWorkload
 import org.opendc.simulator.compute.workload.SimWorkload
 import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.power.SimPowerSource
 import org.opendc.simulator.resources.SimResourceInterpreter
 import org.opendc.simulator.resources.consumer.SimWorkConsumer
 
@@ -142,16 +143,20 @@ class SimMachineTest {
 
     @Test
     fun testPower() = runBlockingSimulation {
+        val interpreter = SimResourceInterpreter(coroutineContext, clock)
         val machine = SimBareMetalMachine(
-            SimResourceInterpreter(coroutineContext, clock),
+            interpreter,
             machineModel,
             SimplePowerDriver(LinearPowerModel(100.0, 50.0))
         )
+        val source = SimPowerSource(interpreter, capacity = 1000.0)
+        source.connect(machine.psu)
 
         try {
             coroutineScope {
                 launch { machine.run(SimFlopsWorkload(2_000, utilization = 1.0)) }
-                assertEquals(100.0, machine.powerDraw)
+                assertEquals(100.0, machine.psu.powerDraw)
+                assertEquals(100.0, source.powerDraw)
             }
         } finally {
             machine.close()
diff --git a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimPsuTest.kt b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimPsuTest.kt
new file mode 100644
index 00000000..e0ebdb73
--- /dev/null
+++ b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimPsuTest.kt
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2021 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 org.opendc.simulator.compute
+
+import io.mockk.every
+import io.mockk.mockk
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertThrows
+import org.opendc.simulator.compute.power.PowerDriver
+import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.power.SimPowerSource
+import org.opendc.simulator.resources.SimResourceInterpreter
+
+/**
+ * Test suite for [SimPsu]
+ */
+internal class SimPsuTest {
+
+    @Test
+    fun testInvalidInput() {
+        assertThrows<IllegalArgumentException> { SimPsu(1.0, emptyMap()) }
+    }
+
+    @Test
+    fun testDoubleConnect() {
+        val psu = SimPsu(1.0, mapOf(0.0 to 1.0))
+        val cpuLogic = mockk<PowerDriver.Logic>()
+        psu.connect(cpuLogic)
+        assertThrows<IllegalStateException> { psu.connect(mockk()) }
+    }
+
+    @Test
+    fun testPsuIdle() = runBlockingSimulation {
+        val ratedOutputPower = 240.0
+        val energyEfficiency = mapOf(0.0 to 1.0)
+
+        val interpreter = SimResourceInterpreter(coroutineContext, clock)
+        val source = SimPowerSource(interpreter, capacity = ratedOutputPower)
+
+        val cpuLogic = mockk<PowerDriver.Logic>()
+        every { cpuLogic.computePower() } returns 0.0
+
+        val psu = SimPsu(ratedOutputPower, energyEfficiency)
+        psu.connect(cpuLogic)
+        source.connect(psu)
+
+        assertEquals(0.0, source.powerDraw, 0.01)
+    }
+
+    @Test
+    fun testPsuPowerLoss() = runBlockingSimulation {
+        val ratedOutputPower = 240.0
+        // Efficiency of 80 Plus Titanium PSU
+        val energyEfficiency = sortedMapOf(
+            0.3 to 0.9,
+            0.7 to 0.92,
+            1.0 to 0.94,
+        )
+
+        val interpreter = SimResourceInterpreter(coroutineContext, clock)
+        val source = SimPowerSource(interpreter, capacity = ratedOutputPower)
+
+        val cpuLogic = mockk<PowerDriver.Logic>()
+        every { cpuLogic.computePower() } returnsMany listOf(50.0, 100.0, 150.0, 200.0)
+
+        val psu = SimPsu(ratedOutputPower, energyEfficiency)
+        psu.connect(cpuLogic)
+        source.connect(psu)
+
+        assertEquals(55.55, source.powerDraw, 0.01)
+
+        psu.update()
+        assertEquals(108.695, source.powerDraw, 0.01)
+
+        psu.update()
+        assertEquals(163.043, source.powerDraw, 0.01)
+
+        psu.update()
+        assertEquals(212.765, source.powerDraw, 0.01)
+    }
+}