simulator: Add support for emitting VM usage metrics

This change re-enables support for VM usage metrics by adding an adapter
for SimResourceConsumer instances that can export the consumer speed.

4 files changed, 80 insertions, 6 deletions

diff --git a/simulator/opendc-simulator/opendc-simulator-compute/src/main/kotlin/org/opendc/simulator/compute/SimAbstractMachine.kt b/simulator/opendc-simulator/opendc-simulator-compute/src/main/kotlin/org/opendc/simulator/compute/SimAbstractMachine.kt
index 52945354..1c0f94fd 100644
--- a/simulator/opendc-simulator/opendc-simulator-compute/src/main/kotlin/org/opendc/simulator/compute/SimAbstractMachine.kt
+++ b/simulator/opendc-simulator/opendc-simulator-compute/src/main/kotlin/org/opendc/simulator/compute/SimAbstractMachine.kt
@@ -102,7 +102,7 @@ public abstract class SimAbstractMachine(private val clock: Clock) : SimMachine
             val consumer = workload.getConsumer(ctx, cpu)
             val job = source.speed
                 .onEach {
-                    _speed[cpu.id] = source.speed.value
+                    _speed[cpu.id] = it
                     _usage.value = _speed.sum() / totalCapacity
                 }
                 .launchIn(this)
@@ -116,9 +116,8 @@ public abstract class SimAbstractMachine(private val clock: Clock) : SimMachine
 
     override fun close() {
         if (!isTerminated) {
-            resources.forEach { (_, provider) -> provider.close() }
-        } else {
             isTerminated = true
+            resources.forEach { (_, provider) -> provider.close() }
         }
     }
 }
diff --git a/simulator/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimHypervisorTest.kt b/simulator/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimHypervisorTest.kt
index 0149024f..5773b325 100644
--- a/simulator/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimHypervisorTest.kt
+++ b/simulator/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimHypervisorTest.kt
@@ -24,6 +24,7 @@ package org.opendc.simulator.compute
 
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.flow.toList
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.test.runBlockingTest
 import kotlinx.coroutines.yield
@@ -98,15 +99,21 @@ internal class SimHypervisorTest {
             println("Hypervisor finished")
         }
         yield()
-        hypervisor.createMachine(model).run(workloadA)
+        val vm = hypervisor.createMachine(model)
+        val res = mutableListOf<Double>()
+        val job = launch { machine.usage.toList(res) }
+
+        vm.run(workloadA)
         yield()
+        job.cancel()
         machine.close()
 
         assertAll(
             { assertEquals(1113300, listener.totalRequestedWork, "Requested Burst does not match") },
             { assertEquals(1023300, listener.totalGrantedWork, "Granted Burst does not match") },
             { assertEquals(90000, listener.totalOvercommittedWork, "Overcommissioned Burst does not match") },
-            { assertEquals(1200000, currentTime) }
+            { assertEquals(listOf(0.0, 0.00875, 1.0, 0.0, 0.0571875, 0.0), res) { "VM usage is correct" } },
+            { assertEquals(1200000, currentTime) { "Current time is correct" } }
         )
     }
 
diff --git a/simulator/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimMachineTest.kt b/simulator/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimMachineTest.kt
index 7e014245..071bdf77 100644
--- a/simulator/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimMachineTest.kt
+++ b/simulator/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimMachineTest.kt
@@ -76,7 +76,7 @@ class SimMachineTest {
 
         try {
             machine.run(SimFlopsWorkload(2_000, utilization = 1.0))
-
+            yield()
             job.cancel()
             assertEquals(listOf(0.0, 0.5, 1.0, 0.5, 0.0), res) { "Machine is fully utilized" }
         } finally {
diff --git a/simulator/opendc-simulator/opendc-simulator-resources/src/main/kotlin/org/opendc/simulator/resources/consumer/SimSpeedConsumerAdapter.kt b/simulator/opendc-simulator/opendc-simulator-resources/src/main/kotlin/org/opendc/simulator/resources/consumer/SimSpeedConsumerAdapter.kt
new file mode 100644
index 00000000..fd4a9ed5
--- /dev/null
+++ b/simulator/opendc-simulator/opendc-simulator-resources/src/main/kotlin/org/opendc/simulator/resources/consumer/SimSpeedConsumerAdapter.kt
@@ -0,0 +1,68 @@
+/*
+ * 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.resources.consumer
+
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import org.opendc.simulator.resources.SimResourceCommand
+import org.opendc.simulator.resources.SimResourceConsumer
+import org.opendc.simulator.resources.SimResourceContext
+import kotlin.math.min
+
+/**
+ * Helper class to expose an observable [speed] field describing the speed of the consumer.
+ */
+public class SimSpeedConsumerAdapter(private val delegate: SimResourceConsumer) : SimResourceConsumer by delegate {
+    /**
+     * The resource processing speed over time.
+     */
+    public val speed: StateFlow<Double>
+        get() = _speed
+    private val _speed = MutableStateFlow(0.0)
+
+    override fun onNext(ctx: SimResourceContext): SimResourceCommand {
+        val command = delegate.onNext(ctx)
+
+        when (command) {
+            is SimResourceCommand.Idle -> _speed.value = 0.0
+            is SimResourceCommand.Consume -> _speed.value = min(ctx.capacity, command.limit)
+            is SimResourceCommand.Exit -> _speed.value = 0.0
+        }
+
+        return command
+    }
+
+    override fun onCapacityChanged(ctx: SimResourceContext, isThrottled: Boolean) {
+        val oldSpeed = _speed.value
+
+        delegate.onCapacityChanged(ctx, isThrottled)
+
+        // Check if the consumer interrupted the consumer and updated the resource consumption. If not, we might
+        // need to update the current speed.
+        if (oldSpeed == _speed.value) {
+            _speed.value = min(ctx.capacity, _speed.value)
+        }
+    }
+
+    override fun toString(): String = "SimSpeedConsumerAdapter[delegate=$delegate]"
+}