refactor: Use RandomGenerator as randomness source

This change updates the modules of OpenDC to always accept
the `RandomGenerator` interface as source of randomness. This interface
is implemented by the slower `java.util.Random` class, but also by the
faster `java.util.SplittableRandom` class

8 files changed, 18 insertions, 19 deletions

diff --git a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/ComputeSchedulers.kt b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/ComputeSchedulers.kt
index bbc70489..125ba6ef 100644
--- a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/ComputeSchedulers.kt
+++ b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/ComputeSchedulers.kt
@@ -34,12 +34,13 @@ import org.opendc.compute.service.scheduler.weights.CoreRamWeigher
 import org.opendc.compute.service.scheduler.weights.InstanceCountWeigher
 import org.opendc.compute.service.scheduler.weights.RamWeigher
 import org.opendc.compute.service.scheduler.weights.VCpuWeigher
-import java.util.Random
+import java.util.SplittableRandom
+import java.util.random.RandomGenerator
 
 /**
  * Create a [ComputeScheduler] for the experiment.
  */
-public fun createComputeScheduler(name: String, seeder: Random, placements: Map<String, String> = emptyMap()): ComputeScheduler {
+public fun createComputeScheduler(name: String, seeder: RandomGenerator, placements: Map<String, String> = emptyMap()): ComputeScheduler {
     val cpuAllocationRatio = 16.0
     val ramAllocationRatio = 1.5
     return when (name) {
@@ -79,7 +80,7 @@ public fun createComputeScheduler(name: String, seeder: Random, placements: Map<
             filters = listOf(ComputeFilter(), VCpuFilter(cpuAllocationRatio), RamFilter(ramAllocationRatio)),
             weighers = emptyList(),
             subsetSize = Int.MAX_VALUE,
-            random = Random(seeder.nextLong())
+            random = SplittableRandom(seeder.nextLong())
         )
         "replay" -> ReplayScheduler(placements)
         else -> throw IllegalArgumentException("Unknown policy $name")
diff --git a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/ComputeWorkload.kt b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/ComputeWorkload.kt
index 2200880d..b7884293 100644
--- a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/ComputeWorkload.kt
+++ b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/ComputeWorkload.kt
@@ -22,7 +22,7 @@
 
 package org.opendc.experiments.compute
 
-import java.util.Random
+import java.util.random.RandomGenerator
 
 /**
  * An interface that describes how a workload is resolved.
@@ -31,5 +31,5 @@ public interface ComputeWorkload {
     /**
      * Resolve the workload into a list of [VirtualMachine]s to simulate.
      */
-    public fun resolve(loader: ComputeWorkloadLoader, random: Random): List<VirtualMachine>
+    public fun resolve(loader: ComputeWorkloadLoader, random: RandomGenerator): List<VirtualMachine>
 }
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 81a5cf33..de2447c6 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
@@ -25,7 +25,7 @@ package org.opendc.experiments.compute
 import org.opendc.compute.service.ComputeService
 import org.opendc.compute.simulator.failure.HostFaultInjector
 import java.time.Clock
-import java.util.Random
+import java.util.random.RandomGenerator
 import kotlin.coroutines.CoroutineContext
 
 /**
@@ -39,6 +39,6 @@ public interface FailureModel {
         context: CoroutineContext,
         clock: Clock,
         service: ComputeService,
-        random: Random
+        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 ff747066..a77047b0 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
@@ -33,7 +33,7 @@ import org.opendc.compute.simulator.failure.StartStopHostFault
 import org.opendc.compute.simulator.failure.StochasticVictimSelector
 import java.time.Clock
 import java.time.Duration
-import java.util.Random
+import java.util.random.RandomGenerator
 import kotlin.coroutines.CoroutineContext
 import kotlin.math.ln
 
@@ -49,7 +49,7 @@ public fun grid5000(failureInterval: Duration): FailureModel {
             context: CoroutineContext,
             clock: Clock,
             service: ComputeService,
-            random: Random
+            random: RandomGenerator
         ): HostFaultInjector {
             val rng = Well19937c(random.nextLong())
             val hosts = service.hosts.map { it as SimHost }.toSet()
diff --git a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/CompositeComputeWorkload.kt b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/CompositeComputeWorkload.kt
index 3a7a51f2..ca23a7c5 100644
--- a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/CompositeComputeWorkload.kt
+++ b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/CompositeComputeWorkload.kt
@@ -26,7 +26,7 @@ import mu.KotlinLogging
 import org.opendc.experiments.compute.ComputeWorkload
 import org.opendc.experiments.compute.ComputeWorkloadLoader
 import org.opendc.experiments.compute.VirtualMachine
-import java.util.Random
+import java.util.random.RandomGenerator
 
 /**
  * A [ComputeWorkload] that samples multiple workloads based on the total load of all workloads.
@@ -37,7 +37,7 @@ internal class CompositeComputeWorkload(val sources: Map<ComputeWorkload, Double
      */
     private val logger = KotlinLogging.logger {}
 
-    override fun resolve(loader: ComputeWorkloadLoader, random: Random): List<VirtualMachine> {
+    override fun resolve(loader: ComputeWorkloadLoader, random: RandomGenerator): List<VirtualMachine> {
         val traces = sources.map { (source, fraction) -> fraction to source.resolve(loader, random) }
 
         val totalLoad = traces.sumOf { (_, vms) -> vms.sumOf { it.totalLoad } }
diff --git a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/HpcSampledComputeWorkload.kt b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/HpcSampledComputeWorkload.kt
index a6055762..583405da 100644
--- a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/HpcSampledComputeWorkload.kt
+++ b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/HpcSampledComputeWorkload.kt
@@ -26,8 +26,8 @@ import mu.KotlinLogging
 import org.opendc.experiments.compute.ComputeWorkload
 import org.opendc.experiments.compute.ComputeWorkloadLoader
 import org.opendc.experiments.compute.VirtualMachine
-import java.util.Random
 import java.util.UUID
+import java.util.random.RandomGenerator
 
 /**
  * A [ComputeWorkload] that samples HPC VMs in the workload.
@@ -46,7 +46,7 @@ internal class HpcSampledComputeWorkload(val source: ComputeWorkload, val fracti
      */
     private val pattern = Regex("^(ComputeNode|cn).*")
 
-    override fun resolve(loader: ComputeWorkloadLoader, random: Random): List<VirtualMachine> {
+    override fun resolve(loader: ComputeWorkloadLoader, random: RandomGenerator): List<VirtualMachine> {
         val vms = source.resolve(loader, random)
 
         val (hpc, nonHpc) = vms.partition { entry ->
@@ -58,7 +58,6 @@ internal class HpcSampledComputeWorkload(val source: ComputeWorkload, val fracti
             .map { index ->
                 val res = mutableListOf<VirtualMachine>()
                 hpc.mapTo(res) { sample(it, index) }
-                res.shuffle(random)
                 res
             }
             .flatten()
@@ -67,7 +66,6 @@ internal class HpcSampledComputeWorkload(val source: ComputeWorkload, val fracti
             .map { index ->
                 val res = mutableListOf<VirtualMachine>()
                 nonHpc.mapTo(res) { sample(it, index) }
-                res.shuffle(random)
                 res
             }
             .flatten()
diff --git a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/LoadSampledComputeWorkload.kt b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/LoadSampledComputeWorkload.kt
index 793f1de9..ffb7e0c6 100644
--- a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/LoadSampledComputeWorkload.kt
+++ b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/LoadSampledComputeWorkload.kt
@@ -26,7 +26,7 @@ import mu.KotlinLogging
 import org.opendc.experiments.compute.ComputeWorkload
 import org.opendc.experiments.compute.ComputeWorkloadLoader
 import org.opendc.experiments.compute.VirtualMachine
-import java.util.Random
+import java.util.random.RandomGenerator
 
 /**
  * A [ComputeWorkload] that is sampled based on total load.
@@ -37,7 +37,7 @@ internal class LoadSampledComputeWorkload(val source: ComputeWorkload, val fract
      */
     private val logger = KotlinLogging.logger {}
 
-    override fun resolve(loader: ComputeWorkloadLoader, random: Random): List<VirtualMachine> {
+    override fun resolve(loader: ComputeWorkloadLoader, random: RandomGenerator): List<VirtualMachine> {
         val vms = source.resolve(loader, random)
         val res = mutableListOf<VirtualMachine>()
 
diff --git a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/TraceComputeWorkload.kt b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/TraceComputeWorkload.kt
index b4e9005f..d9e311cd 100644
--- a/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/TraceComputeWorkload.kt
+++ b/opendc-experiments/opendc-experiments-compute/src/main/kotlin/org/opendc/experiments/compute/internal/TraceComputeWorkload.kt
@@ -25,13 +25,13 @@ package org.opendc.experiments.compute.internal
 import org.opendc.experiments.compute.ComputeWorkload
 import org.opendc.experiments.compute.ComputeWorkloadLoader
 import org.opendc.experiments.compute.VirtualMachine
-import java.util.Random
+import java.util.random.RandomGenerator
 
 /**
  * A [ComputeWorkload] from a trace.
  */
 internal class TraceComputeWorkload(val name: String, val format: String) : ComputeWorkload {
-    override fun resolve(loader: ComputeWorkloadLoader, random: Random): List<VirtualMachine> {
+    override fun resolve(loader: ComputeWorkloadLoader, random: RandomGenerator): List<VirtualMachine> {
         return loader.get(name, format)
     }
 }