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* The use of `CoroutineContext` and `Clock` as parameters of classes has been replaced 
  by the `Dispatcher` interface.
* The use of `Clock` has been replaced by `InstantSource` which does not carry time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* The use of `Random` and `SplittableRandom` as parameter type has been replaced 
   by `RandomGenerator`

2 files changed, 3 insertions, 4 deletions

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()) {
diff --git a/opendc-experiments/opendc-experiments-workflow/src/main/kotlin/org/opendc/experiments/workflow/WorkflowServiceProvisioningStep.kt b/opendc-experiments/opendc-experiments-workflow/src/main/kotlin/org/opendc/experiments/workflow/WorkflowServiceProvisioningStep.kt
index 5cee9abf..fe4fde17 100644
--- a/opendc-experiments/opendc-experiments-workflow/src/main/kotlin/org/opendc/experiments/workflow/WorkflowServiceProvisioningStep.kt
+++ b/opendc-experiments/opendc-experiments-workflow/src/main/kotlin/org/opendc/experiments/workflow/WorkflowServiceProvisioningStep.kt
@@ -47,8 +47,7 @@ public class WorkflowServiceProvisioningStep internal constructor(
 
         val client = computeService.newClient()
         val service = WorkflowService(
-            ctx.coroutineContext,
-            ctx.clock,
+            ctx.dispatcher,
             client,
             scheduler.schedulingQuantum,
             jobAdmissionPolicy = scheduler.jobAdmissionPolicy,