refactor: Use InstantSource as time source

This change updates the modules of OpenDC to always accept
the `InstantSource` interface as source of time. Previously we used
`java.time.Clock`, but this class is bound to a time zone which does not
make sense for our use-cases.

Since `java.time.Clock` implements `java.time.InstantSource`, it can be
used in places that require an `InstantSource` as parameter. Conversion
from `InstantSource` to `Clock` is also possible by invoking
`InstantSource#withZone`.

10 files changed, 24 insertions, 24 deletions

diff --git a/opendc-experiments/opendc-experiments-base/src/main/kotlin/org/opendc/experiments/provisioner/Provisioner.kt b/opendc-experiments/opendc-experiments-base/src/main/kotlin/org/opendc/experiments/provisioner/Provisioner.kt
index 7fe3a2eb..66fcca22 100644
--- a/opendc-experiments/opendc-experiments-base/src/main/kotlin/org/opendc/experiments/provisioner/Provisioner.kt
+++ b/opendc-experiments/opendc-experiments-base/src/main/kotlin/org/opendc/experiments/provisioner/Provisioner.kt
@@ -25,7 +25,7 @@ package org.opendc.experiments.provisioner
 import org.opendc.experiments.MutableServiceRegistry
 import org.opendc.experiments.ServiceRegistry
 import org.opendc.experiments.internal.ServiceRegistryImpl
-import java.time.Clock
+import java.time.InstantSource
 import java.util.ArrayDeque
 import java.util.SplittableRandom
 import kotlin.coroutines.CoroutineContext
@@ -38,15 +38,15 @@ import kotlin.coroutines.CoroutineContext
  * down after the simulation completes.
  *
  * @param coroutineContext The [CoroutineContext] in which the environment is set up.
- * @param clock The simulation [Clock].
+ * @param clock The simulation clock represented as [InstantSource].
  * @param seed A seed for initializing the randomness of the environment.
  */
-public class Provisioner(coroutineContext: CoroutineContext, clock: Clock, seed: Long) : AutoCloseable {
+public class Provisioner(coroutineContext: CoroutineContext, clock: InstantSource, seed: Long) : AutoCloseable {
     /**
      * Implementation of [ProvisioningContext].
      */
     private val context = object : ProvisioningContext {
-        override val clock: Clock = clock
+        override val clock: InstantSource = clock
         override val coroutineContext: CoroutineContext = coroutineContext
         override val seeder: SplittableRandom = SplittableRandom(seed)
         override val registry: MutableServiceRegistry = ServiceRegistryImpl()
diff --git a/opendc-experiments/opendc-experiments-base/src/main/kotlin/org/opendc/experiments/provisioner/ProvisioningContext.kt b/opendc-experiments/opendc-experiments-base/src/main/kotlin/org/opendc/experiments/provisioner/ProvisioningContext.kt
index b8679872..7eec6fa4 100644
--- a/opendc-experiments/opendc-experiments-base/src/main/kotlin/org/opendc/experiments/provisioner/ProvisioningContext.kt
+++ b/opendc-experiments/opendc-experiments-base/src/main/kotlin/org/opendc/experiments/provisioner/ProvisioningContext.kt
@@ -23,7 +23,7 @@
 package org.opendc.experiments.provisioner
 
 import org.opendc.experiments.MutableServiceRegistry
-import java.time.Clock
+import java.time.InstantSource
 import java.util.SplittableRandom
 import java.util.random.RandomGenerator
 import kotlin.coroutines.CoroutineContext
@@ -40,9 +40,9 @@ public interface ProvisioningContext {
     public val coroutineContext: CoroutineContext
 
     /**
-     * The [Clock] tracking the virtual simulation time.
+     * The [InstantSource] tracking the virtual simulation time.
      */
-    public val clock: Clock
+    public val clock: InstantSource
 
     /**
      * A [SplittableRandom] instance used to seed the provisioners.
diff --git a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/FailureModel.kt b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/FailureModel.kt
index de2447c6..eb85dbb8 100644
--- a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/FailureModel.kt
+++ b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/FailureModel.kt
@@ -24,7 +24,7 @@ package org.opendc.experiments.compute
 
 import org.opendc.compute.service.ComputeService
 import org.opendc.compute.simulator.failure.HostFaultInjector
-import java.time.Clock
+import java.time.InstantSource
 import java.util.random.RandomGenerator
 import kotlin.coroutines.CoroutineContext
 
@@ -37,7 +37,7 @@ public interface FailureModel {
      */
     public fun createInjector(
         context: CoroutineContext,
-        clock: Clock,
+        clock: InstantSource,
         service: ComputeService,
         random: RandomGenerator
     ): HostFaultInjector
diff --git a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/FailureModels.kt b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/FailureModels.kt
index a77047b0..679e370a 100644
--- a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/FailureModels.kt
+++ b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/FailureModels.kt
@@ -31,8 +31,8 @@ import org.opendc.compute.simulator.SimHost
 import org.opendc.compute.simulator.failure.HostFaultInjector
 import org.opendc.compute.simulator.failure.StartStopHostFault
 import org.opendc.compute.simulator.failure.StochasticVictimSelector
-import java.time.Clock
 import java.time.Duration
+import java.time.InstantSource
 import java.util.random.RandomGenerator
 import kotlin.coroutines.CoroutineContext
 import kotlin.math.ln
@@ -47,7 +47,7 @@ public fun grid5000(failureInterval: Duration): FailureModel {
     return object : FailureModel {
         override fun createInjector(
             context: CoroutineContext,
-            clock: Clock,
+            clock: InstantSource,
             service: ComputeService,
             random: RandomGenerator
         ): HostFaultInjector {
diff --git a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/TraceHelpers.kt b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/TraceHelpers.kt
index f0e31932..16d28edb 100644
--- a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/TraceHelpers.kt
+++ b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/TraceHelpers.kt
@@ -29,7 +29,7 @@ import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.yield
 import org.opendc.compute.service.ComputeService
-import java.time.Clock
+import java.time.InstantSource
 import java.util.Random
 import kotlin.coroutines.coroutineContext
 import kotlin.math.max
@@ -45,7 +45,7 @@ import kotlin.math.max
  * @param interference A flag to indicate that VM interference needs to be enabled.
  */
 public suspend fun ComputeService.replay(
-    clock: Clock,
+    clock: InstantSource,
     trace: List<VirtualMachine>,
     seed: Long,
     submitImmediately: Boolean = false,
diff --git a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/telemetry/ComputeMetricReader.kt b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/telemetry/ComputeMetricReader.kt
index ac058171..f39f74bc 100644
--- a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/telemetry/ComputeMetricReader.kt
+++ b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/telemetry/ComputeMetricReader.kt
@@ -35,9 +35,9 @@ import org.opendc.experiments.compute.telemetry.table.HostTableReader
 import org.opendc.experiments.compute.telemetry.table.ServerInfo
 import org.opendc.experiments.compute.telemetry.table.ServerTableReader
 import org.opendc.experiments.compute.telemetry.table.ServiceTableReader
-import java.time.Clock
 import java.time.Duration
 import java.time.Instant
+import java.time.InstantSource
 
 /**
  * A helper class to collect metrics from a [ComputeService] instance and automatically export the metrics every
@@ -51,7 +51,7 @@ import java.time.Instant
  */
 public class ComputeMetricReader(
     scope: CoroutineScope,
-    clock: Clock,
+    clock: InstantSource,
     private val service: ComputeService,
     private val monitor: ComputeMonitor,
     private val exportInterval: Duration = Duration.ofMinutes(5)
diff --git a/opendc-experiments/opendc-experiments-faas/src/main/kotlin/org/opendc/experiments/faas/TraceHelpers.kt b/opendc-experiments/opendc-experiments-faas/src/main/kotlin/org/opendc/experiments/faas/TraceHelpers.kt
index c4001e2e..7a354d69 100644
--- a/opendc-experiments/opendc-experiments-faas/src/main/kotlin/org/opendc/experiments/faas/TraceHelpers.kt
+++ b/opendc-experiments/opendc-experiments-faas/src/main/kotlin/org/opendc/experiments/faas/TraceHelpers.kt
@@ -28,16 +28,16 @@ import kotlinx.coroutines.coroutineScope
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import org.opendc.faas.service.FaaSService
-import java.time.Clock
+import java.time.InstantSource
 import kotlin.math.max
 
 /**
  * Run a simulation of the [FaaSService] by replaying the workload trace given by [trace].
  *
- * @param clock A [Clock] instance tracking simulation time.
+ * @param clock An [InstantSource] instance tracking simulation time.
  * @param trace The trace to simulate.
  */
-public suspend fun FaaSService.replay(clock: Clock, trace: List<FunctionTrace>) {
+public suspend fun FaaSService.replay(clock: InstantSource, trace: List<FunctionTrace>) {
     val client = newClient()
     try {
         coroutineScope {
diff --git a/opendc-experiments/opendc-experiments-tf20/src/main/kotlin/org/opendc/experiments/tf20/core/SimTFDevice.kt b/opendc-experiments/opendc-experiments-tf20/src/main/kotlin/org/opendc/experiments/tf20/core/SimTFDevice.kt
index eb308970..51f6e763 100644
--- a/opendc-experiments/opendc-experiments-tf20/src/main/kotlin/org/opendc/experiments/tf20/core/SimTFDevice.kt
+++ b/opendc-experiments/opendc-experiments-tf20/src/main/kotlin/org/opendc/experiments/tf20/core/SimTFDevice.kt
@@ -42,7 +42,7 @@ import org.opendc.simulator.flow2.FlowEngine
 import org.opendc.simulator.flow2.FlowStage
 import org.opendc.simulator.flow2.FlowStageLogic
 import org.opendc.simulator.flow2.OutPort
-import java.time.Clock
+import java.time.InstantSource
 import java.util.ArrayDeque
 import java.util.UUID
 import kotlin.coroutines.Continuation
@@ -58,7 +58,7 @@ public class SimTFDevice(
     override val uid: UUID,
     override val isGpu: Boolean,
     context: CoroutineContext,
-    clock: Clock,
+    clock: InstantSource,
     pu: ProcessingUnit,
     private val memory: MemoryUnit,
     powerModel: CpuPowerModel
diff --git a/opendc-experiments/opendc-experiments-tf20/src/main/kotlin/org/opendc/experiments/tf20/network/NetworkController.kt b/opendc-experiments/opendc-experiments-tf20/src/main/kotlin/org/opendc/experiments/tf20/network/NetworkController.kt
index 7d65a674..6fcdf513 100644
--- a/opendc-experiments/opendc-experiments-tf20/src/main/kotlin/org/opendc/experiments/tf20/network/NetworkController.kt
+++ b/opendc-experiments/opendc-experiments-tf20/src/main/kotlin/org/opendc/experiments/tf20/network/NetworkController.kt
@@ -24,14 +24,14 @@ package org.opendc.experiments.tf20.network
 
 import kotlinx.coroutines.channels.Channel
 import org.opendc.common.util.TimerScheduler
-import java.time.Clock
+import java.time.InstantSource
 import kotlin.coroutines.CoroutineContext
 
 /**
  * The network controller represents a simple network model between the worker and master nodes during
  * TensorFlow execution.
  */
-public class NetworkController(context: CoroutineContext, clock: Clock) : AutoCloseable {
+public class NetworkController(context: CoroutineContext, clock: InstantSource) : AutoCloseable {
     /**
      * The scheduler for the message.
      */
diff --git a/opendc-experiments/opendc-experiments-workflow/src/main/kotlin/org/opendc/experiments/workflow/TraceHelpers.kt b/opendc-experiments/opendc-experiments-workflow/src/main/kotlin/org/opendc/experiments/workflow/TraceHelpers.kt
index b622362a..2037dad4 100644
--- a/opendc-experiments/opendc-experiments-workflow/src/main/kotlin/org/opendc/experiments/workflow/TraceHelpers.kt
+++ b/opendc-experiments/opendc-experiments-workflow/src/main/kotlin/org/opendc/experiments/workflow/TraceHelpers.kt
@@ -42,7 +42,7 @@ import org.opendc.workflow.api.Task
 import org.opendc.workflow.api.WORKFLOW_TASK_CORES
 import org.opendc.workflow.api.WORKFLOW_TASK_DEADLINE
 import org.opendc.workflow.service.WorkflowService
-import java.time.Clock
+import java.time.InstantSource
 import java.util.UUID
 import kotlin.collections.HashMap
 import kotlin.collections.HashSet
@@ -110,7 +110,7 @@ public fun Trace.toJobs(): List<Job> {
 /**
  * Helper method to replay the specified list of [jobs] and suspend execution util all jobs have finished.
  */
-public suspend fun WorkflowService.replay(clock: Clock, jobs: List<Job>) {
+public suspend fun WorkflowService.replay(clock: InstantSource, jobs: List<Job>) {
     // Sort jobs by their arrival time
     val orderedJobs = jobs.sortedBy { it.metadata.getOrDefault("WORKFLOW_SUBMIT_TIME", Long.MAX_VALUE) as Long }
     if (orderedJobs.isEmpty()) {