merge: Increase minimum Java version to 17 (#115)

This pull request increases the minimum version of Java required by OpenDC to 17.
This new version of Java introduces several new features compared to our old minimum 
version (11), which we attempt to apply in this conversion.

## Implementation Notes :hammer_and_pick:

* Increase minimum Java version to Java 17 
* Use RandomGenerator as randomness source 
* Add common dispatcher interface 
* Add compatibility with Kotlin coroutines
* Use InstantSource as time source
* Re-implement SimulationScheduler as Dispatcher 
* Replace use of CoroutineContext by Dispatcher 

## External Dependencies :four_leaf_clover:

* Java 17

## Breaking API Changes :warning:

* The use of `CoroutineContext` and `Clock` as parameters of classes has been replaced 
  by the `Dispatcher` interface.
* The use of `Clock` has been replaced by `InstantSource` which does not carry time
   zone info.
* The use of `Random` and `SplittableRandom` as parameter type has been replaced 
   by `RandomGenerator`

3 files changed, 8 insertions, 9 deletions

diff --git a/opendc-experiments/opendc-experiments-faas/src/main/kotlin/org/opendc/experiments/faas/FaaSServiceProvisioningStep.kt b/opendc-experiments/opendc-experiments-faas/src/main/kotlin/org/opendc/experiments/faas/FaaSServiceProvisioningStep.kt
index 3b4200c8..e5c2f86a 100644
--- a/opendc-experiments/opendc-experiments-faas/src/main/kotlin/org/opendc/experiments/faas/FaaSServiceProvisioningStep.kt
+++ b/opendc-experiments/opendc-experiments-faas/src/main/kotlin/org/opendc/experiments/faas/FaaSServiceProvisioningStep.kt
@@ -56,10 +56,9 @@ public class FaaSServiceProvisioningStep internal constructor(
         } else {
             ZeroDelayInjector
         }
-        val deployer = SimFunctionDeployer(ctx.coroutineContext, ctx.clock, machineModel, delayInjector)
+        val deployer = SimFunctionDeployer(ctx.dispatcher, machineModel, delayInjector)
         val service = FaaSService(
-            ctx.coroutineContext,
-            ctx.clock,
+            ctx.dispatcher,
             deployer,
             routingPolicy(ctx),
             terminationPolicy(ctx)
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-faas/src/test/kotlin/org/opendc/experiments/faas/FaaSExperiment.kt b/opendc-experiments/opendc-experiments-faas/src/test/kotlin/org/opendc/experiments/faas/FaaSExperiment.kt
index 1ad9c57f..4a4d9ae0 100644
--- a/opendc-experiments/opendc-experiments-faas/src/test/kotlin/org/opendc/experiments/faas/FaaSExperiment.kt
+++ b/opendc-experiments/opendc-experiments-faas/src/test/kotlin/org/opendc/experiments/faas/FaaSExperiment.kt
@@ -49,12 +49,12 @@ class FaaSExperiment {
     fun testSmoke() = runSimulation {
         val faasService = "faas.opendc.org"
 
-        Provisioner(coroutineContext, clock, seed = 0L).use { provisioner ->
+        Provisioner(dispatcher, seed = 0L).use { provisioner ->
             provisioner.runStep(
                 setupFaaSService(
                     faasService,
                     { RandomRoutingPolicy() },
-                    { FunctionTerminationPolicyFixed(it.coroutineContext, it.clock, timeout = Duration.ofMinutes(10)) },
+                    { FunctionTerminationPolicyFixed(it.dispatcher, timeout = Duration.ofMinutes(10)) },
                     createMachineModel(),
                     coldStartModel = ColdStartModel.GOOGLE
                 )
@@ -63,7 +63,7 @@ class FaaSExperiment {
             val service = provisioner.registry.resolve(faasService, FaaSService::class.java)!!
 
             val trace = ServerlessTraceReader().parse(File("src/test/resources/trace"))
-            service.replay(clock, trace)
+            service.replay(timeSource, trace)
 
             val stats = service.getSchedulerStats()