fix the can VM fit on Host check, added Unit tests for the SimHost

.github/workflows/build.yml

@@ -61,10 +61,10 @@ jobs:
             ./**/build/distributions/**/*.zip
           retention-days: 5
       - name: Upload code coverage
+        if: matrix.os == 'ubuntu-22.04'
         uses: codecov/codecov-action@v5
         with:
-          token: ${{ secrets.CODECOV_TOKEN }}
-          files: ./build/reports/jacoco/codeCoverageReport/codeCoverageReport.xml
+          files: /home/runner/work/opendc/opendc/build/reports/jacoco/codeCoverageReport/codeCoverageReport.xml
   build-docker:
     name: Build Docker Images
     runs-on: ubuntu-22.04

opendc-compute/opendc-compute-simulator/src/main/java/org/opendc/compute/simulator/service/ServiceFlavor.java

@@ -40,7 +40,8 @@ public final class ServiceFlavor implements Flavor {
     private final long memorySize;
     private final Map<String, ?> meta;
 
-    ServiceFlavor(ComputeService service, UUID uid, String name, int coreCount, long memorySize, Map<String, ?> meta) {
+    public ServiceFlavor(
+            ComputeService service, UUID uid, String name, int coreCount, long memorySize, Map<String, ?> meta) {
         this.service = service;
         this.uid = uid;
         this.name = name;

opendc-compute/opendc-compute-simulator/src/main/java/org/opendc/compute/simulator/service/ServiceTask.java

@@ -64,7 +64,7 @@ public class ServiceTask {
 
     private int numFailures = 0;
 
-    ServiceTask(
+    public ServiceTask(
             ComputeService service,
             UUID uid,
             String name,

opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/host/SimHost.kt

@@ -42,15 +42,18 @@ import java.time.Instant
 import java.time.InstantSource
 
 /**
- * A [SimHost] implementation that simulates virtual machines on a physical machine.
+ * The `SimHost` class represents a simulated host that operates as a hypervisor for running virtualized tasks.
+ * It manages its state, running tasks, associated virtual machines, and system metrics, while providing host
+ * lifecycle management and resource usage computation.
  *
- * @param name The name of the host.
- * @param clock The (virtual) clock used to track time.
- * @param graph The Flow Graph that the Host is part of
- * @param machineModel The static model of the host
- * @param cpuPowerModel The power model of the host
- * @param powerDistributor The power distributor to which the host is connected
- * @constructor Create empty Sim host
+ * @constructor Initializes the SimHost with required parameters.
+ * @param name The unique name of the simulated host.
+ * @param clusterName The cluster name to which this host belongs.
+ * @param clock The clock source to simulate time within the system.
+ * @param graph The data-flow graph used by the simulation for task operations.
+ * @param machineModel The hardware model attributes of the host.
+ * @param cpuPowerModel The CPU power characteristics of the host.
+ * @param powerDistributor The power distributor managing system energy allocations.
  */
 public class SimHost(
     private val name: String,
@@ -191,8 +194,32 @@ public class SimHost(
         return this.guests
     }
 
+    /**
+     * Calculates the total memory used by the currently running tasks on the host.
+     *
+     * Iterates through the tasks mapped to guests in `taskToGuestMap`. For tasks that are in the
+     * `TaskState.RUNNING` state, their memory consumption is summed up.
+     *
+     * @return Total memory used by tasks currently in the RUNNING state, in bytes.
+     */
+    private fun usedMemoryByRunningTasks(): Long {
+        var usedMemory: Long = 0
+        for (vm in this.taskToGuestMap) {
+            if (vm.value.state == TaskState.RUNNING) {
+                usedMemory += vm.key.flavor.memorySize
+            }
+        }
+        return usedMemory
+    }
+
+    /**
+     * Determines if the given task can fit on this host based on its resource requirements.
+     *
+     * @param task The task to be checked. It includes the resource requirements such as memory size and core count.
+     * @return True if the task can fit on this host considering available memory, CPU cores, and machine model compatibility; false otherwise.
+     */
     public fun canFit(task: ServiceTask): Boolean {
-        val sufficientMemory = model.memoryCapacity >= task.flavor.memorySize
+        val sufficientMemory = (model.memoryCapacity - this.usedMemoryByRunningTasks()) >= task.flavor.memorySize
         val enoughCpus = model.coreCount >= task.flavor.coreCount
         val canFit = simMachine!!.canFit(task.flavor.toMachineModel())
 

opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/provisioner/ComputeMonitorProvisioningStep.kt

@@ -25,6 +25,7 @@ package org.opendc.compute.simulator.provisioner
 import org.opendc.compute.simulator.service.ComputeService
 import org.opendc.compute.simulator.telemetry.ComputeMetricReader
 import org.opendc.compute.simulator.telemetry.ComputeMonitor
+import org.opendc.compute.simulator.telemetry.OutputFiles
 import java.time.Duration
 
 /**
@@ -36,6 +37,14 @@ public class ComputeMonitorProvisioningStep(
     private val monitor: ComputeMonitor,
     private val exportInterval: Duration,
     private val startTime: Duration = Duration.ofMillis(0),
+    private val filesToExport: Map<OutputFiles, Boolean> =
+        mapOf(
+            OutputFiles.HOST to true,
+            OutputFiles.TASK to true,
+            OutputFiles.SERVICE to true,
+            OutputFiles.POWER_SOURCE to true,
+            OutputFiles.BATTERY to true,
+        ),
 ) : ProvisioningStep {
     override fun apply(ctx: ProvisioningContext): AutoCloseable {
         val service =
@@ -49,6 +58,7 @@ public class ComputeMonitorProvisioningStep(
                 monitor,
                 exportInterval,
                 startTime,
+                filesToExport,
             )
         return metricReader
     }

opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/provisioner/ComputeSteps.kt

@@ -26,6 +26,7 @@ package org.opendc.compute.simulator.provisioner
 
 import org.opendc.compute.simulator.scheduler.ComputeScheduler
 import org.opendc.compute.simulator.telemetry.ComputeMonitor
+import org.opendc.compute.simulator.telemetry.OutputFiles
 import org.opendc.compute.topology.specs.ClusterSpec
 import org.opendc.compute.topology.specs.HostSpec
 import java.time.Duration
@@ -59,8 +60,16 @@ public fun registerComputeMonitor(
     monitor: ComputeMonitor,
     exportInterval: Duration = Duration.ofMinutes(5),
     startTime: Duration = Duration.ofMillis(0),
+    filesToExport: Map<OutputFiles, Boolean> =
+        mapOf(
+            OutputFiles.HOST to true,
+            OutputFiles.TASK to true,
+            OutputFiles.SERVICE to true,
+            OutputFiles.POWER_SOURCE to true,
+            OutputFiles.BATTERY to true,
+        ),
 ): ProvisioningStep {
-    return ComputeMonitorProvisioningStep(serviceDomain, monitor, exportInterval, startTime)
+    return ComputeMonitorProvisioningStep(serviceDomain, monitor, exportInterval, startTime, filesToExport)
 }
 
 /**

opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/telemetry/ComputeMetricReader.kt

@@ -56,6 +56,14 @@ public class ComputeMetricReader(
     private val monitor: ComputeMonitor,
     private val exportInterval: Duration = Duration.ofMinutes(5),
     private val startTime: Duration = Duration.ofMillis(0),
+    private val toMonitor: Map<OutputFiles, Boolean> =
+        mapOf(
+            OutputFiles.HOST to true,
+            OutputFiles.TASK to true,
+            OutputFiles.POWER_SOURCE to true,
+            OutputFiles.BATTERY to true,
+            OutputFiles.SERVICE to true,
+        ),
 ) : AutoCloseable {
     private val logger = KotlinLogging.logger {}
     private val scope = CoroutineScope(dispatcher.asCoroutineDispatcher())
@@ -116,68 +124,78 @@ public class ComputeMetricReader(
         try {
             val now = this.clock.instant()
 
-            for (host in this.service.hosts) {
-                val reader =
-                    this.hostTableReaders.computeIfAbsent(host) {
-                        HostTableReaderImpl(
-                            it,
-                            startTime,
-                        )
-                    }
-                reader.record(now)
-                this.monitor.record(reader.copy())
-                reader.reset()
+            if (toMonitor[OutputFiles.HOST] == true) {
+                for (host in this.service.hosts) {
+                    val reader =
+                        this.hostTableReaders.computeIfAbsent(host) {
+                            HostTableReaderImpl(
+                                it,
+                                startTime,
+                            )
+                        }
+                    reader.record(now)
+                    this.monitor.record(reader.copy())
+                    reader.reset()
+                }
             }
 
-            for (task in this.service.tasks) {
-                val reader =
-                    this.taskTableReaders.computeIfAbsent(task) {
-                        TaskTableReaderImpl(
-                            service,
-                            it,
-                            startTime,
-                        )
-                    }
-                reader.record(now)
-                this.monitor.record(reader.copy())
-                reader.reset()
+            if (toMonitor[OutputFiles.TASK] == true) {
+                for (task in this.service.tasks) {
+                    val reader =
+                        this.taskTableReaders.computeIfAbsent(task) {
+                            TaskTableReaderImpl(
+                                service,
+                                it,
+                                startTime,
+                            )
+                        }
+                    reader.record(now)
+                    this.monitor.record(reader.copy())
+                    reader.reset()
+                }
             }
 
             for (task in this.service.tasksToRemove) {
                 task.delete()
             }
             this.service.clearTasksToRemove()
 
-            for (simPowerSource in this.service.powerSources) {
-                val reader =
-                    this.powerSourceTableReaders.computeIfAbsent(simPowerSource) {
-                        PowerSourceTableReaderImpl(
-                            it,
-                            startTime,
-                        )
-                    }
-
-                reader.record(now)
-                this.monitor.record(reader.copy())
-                reader.reset()
+            if (toMonitor[OutputFiles.POWER_SOURCE] == true) {
+                for (simPowerSource in this.service.powerSources) {
+                    val reader =
+                        this.powerSourceTableReaders.computeIfAbsent(simPowerSource) {
+                            PowerSourceTableReaderImpl(
+                                it,
+                                startTime,
+                            )
+                        }
+
+                    reader.record(now)
+                    this.monitor.record(reader.copy())
+                    reader.reset()
+                }
             }
 
-            for (simBattery in this.service.batteries) {
-                val reader =
-                    this.batteryTableReaders.computeIfAbsent(simBattery) {
-                        BatteryTableReaderImpl(
-                            it,
-                            startTime,
-                        )
-                    }
-
-                reader.record(now)
-                this.monitor.record(reader.copy())
-                reader.reset()
+            if (toMonitor[OutputFiles.BATTERY] == true) {
+                for (simBattery in this.service.batteries) {
+                    val reader =
+                        this.batteryTableReaders.computeIfAbsent(simBattery) {
+                            BatteryTableReaderImpl(
+                                it,
+                                startTime,
+                            )
+                        }
+
+                    reader.record(now)
+                    this.monitor.record(reader.copy())
+                    reader.reset()
+                }
             }
 
-            this.serviceTableReader.record(now)
-            monitor.record(this.serviceTableReader.copy())
+            if (toMonitor[OutputFiles.SERVICE] == true) {
+                this.serviceTableReader.record(now)
+                monitor.record(this.serviceTableReader.copy())
+            }
 
             if (loggCounter >= 100) {
                 var loggString = "\n\t\t\t\t\tMetrics after ${now.toEpochMilli() / 1000 / 60 / 60} hours:\n"

opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/telemetry/OutputFiles.kt

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2025 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.compute.simulator.telemetry
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+public enum class OutputFiles {
+    @SerialName("host")
+    HOST,
+
+    @SerialName("task")
+    TASK,
+
+    @SerialName("powerSource")
+    POWER_SOURCE,
+
+    @SerialName("battery")
+    BATTERY,
+
+    @SerialName("service")
+    SERVICE,
+}