Eliminate use of Domain and simulationContext in OpenDC

This change takes the first step in eliminating the explict use of
Domain and simulationContext from OpenDC. In this way, we decouple the
logic of various datacenter services from simulation logic, which should
promote re-use.

3 files changed, 20 insertions, 24 deletions

diff --git a/simulator/opendc/opendc-workflows/src/main/kotlin/com/atlarge/opendc/workflows/service/StageWorkflowService.kt b/simulator/opendc/opendc-workflows/src/main/kotlin/com/atlarge/opendc/workflows/service/StageWorkflowService.kt
index 1193f7b2..aea27972 100644
--- a/simulator/opendc/opendc-workflows/src/main/kotlin/com/atlarge/opendc/workflows/service/StageWorkflowService.kt
+++ b/simulator/opendc/opendc-workflows/src/main/kotlin/com/atlarge/opendc/workflows/service/StageWorkflowService.kt
@@ -24,9 +24,7 @@
 
 package com.atlarge.opendc.workflows.service
 
-import com.atlarge.odcsim.Domain
 import com.atlarge.odcsim.flow.EventFlow
-import com.atlarge.odcsim.simulationContext
 import com.atlarge.opendc.compute.core.Server
 import com.atlarge.opendc.compute.core.ServerEvent
 import com.atlarge.opendc.compute.core.ServerState
@@ -39,22 +37,23 @@ import com.atlarge.opendc.workflows.service.stage.resource.ResourceSelectionPoli
 import com.atlarge.opendc.workflows.service.stage.task.TaskEligibilityPolicy
 import com.atlarge.opendc.workflows.service.stage.task.TaskOrderPolicy
 import com.atlarge.opendc.workflows.workload.Job
-import java.util.PriorityQueue
-import java.util.Queue
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.launch
-import kotlinx.coroutines.withContext
+import java.time.Clock
+import java.util.PriorityQueue
+import java.util.Queue
 
 /**
  * A [WorkflowService] that distributes work through a multi-stage process based on the Reference Architecture for
  * Topology Scheduling.
  */
 class StageWorkflowService(
-    private val domain: Domain,
+    internal val coroutineScope: CoroutineScope,
+    internal val clock: Clock,
     private val provisioningService: ProvisioningService,
     mode: WorkflowSchedulerMode,
     jobAdmissionPolicy: JobAdmissionPolicy,
@@ -63,7 +62,7 @@ class StageWorkflowService(
     taskOrderPolicy: TaskOrderPolicy,
     resourceFilterPolicy: ResourceFilterPolicy,
     resourceSelectionPolicy: ResourceSelectionPolicy
-) : WorkflowService, CoroutineScope by domain {
+) : WorkflowService {
 
     /**
      * The incoming jobs ready to be processed by the scheduler.
@@ -175,7 +174,7 @@ class StageWorkflowService(
     private val eventFlow = EventFlow<WorkflowEvent>()
 
     init {
-        domain.launch {
+        coroutineScope.launch {
             nodes = provisioningService.nodes().toList()
             available.addAll(nodes)
         }
@@ -191,9 +190,9 @@ class StageWorkflowService(
 
     override val events: Flow<WorkflowEvent> = eventFlow
 
-    override suspend fun submit(job: Job) = withContext(domain.coroutineContext) {
+    override suspend fun submit(job: Job) {
         // J1 Incoming Jobs
-        val jobInstance = JobState(job, simulationContext.clock.millis())
+        val jobInstance = JobState(job, clock.millis())
         val instances = job.tasks.associateWith {
             TaskState(jobInstance, it)
         }
@@ -241,7 +240,7 @@ class StageWorkflowService(
             iterator.remove()
             jobQueue.add(jobInstance)
             activeJobs += jobInstance
-            eventFlow.emit(WorkflowEvent.JobStarted(this, jobInstance.job, simulationContext.clock.millis()))
+            eventFlow.emit(WorkflowEvent.JobStarted(this, jobInstance.job, clock.millis()))
             rootListener.jobStarted(jobInstance)
         }
 
@@ -295,7 +294,7 @@ class StageWorkflowService(
                 taskByServer[server] = instance
                 server.events
                     .onEach { event -> if (event is ServerEvent.StateChanged) stateChanged(event.server) }
-                    .launchIn(this)
+                    .launchIn(coroutineScope)
 
                 activeTasks += instance
                 taskQueue.poll()
@@ -310,19 +309,19 @@ class StageWorkflowService(
         when (server.state) {
             ServerState.ACTIVE -> {
                 val task = taskByServer.getValue(server)
-                task.startedAt = simulationContext.clock.millis()
-                eventFlow.emit(WorkflowEvent.TaskStarted(this@StageWorkflowService, task.job.job, task.task, simulationContext.clock.millis()))
+                task.startedAt = clock.millis()
+                eventFlow.emit(WorkflowEvent.TaskStarted(this@StageWorkflowService, task.job.job, task.task, clock.millis()))
                 rootListener.taskStarted(task)
             }
             ServerState.SHUTOFF, ServerState.ERROR -> {
                 val task = taskByServer.remove(server) ?: throw IllegalStateException()
                 val job = task.job
                 task.state = TaskStatus.FINISHED
-                task.finishedAt = simulationContext.clock.millis()
+                task.finishedAt = clock.millis()
                 job.tasks.remove(task)
                 available += task.host!!
                 activeTasks -= task
-                eventFlow.emit(WorkflowEvent.TaskFinished(this@StageWorkflowService, task.job.job, task.task, simulationContext.clock.millis()))
+                eventFlow.emit(WorkflowEvent.TaskFinished(this@StageWorkflowService, task.job.job, task.task, clock.millis()))
                 rootListener.taskFinished(task)
 
                 // Add job roots to the scheduling queue
@@ -347,7 +346,7 @@ class StageWorkflowService(
 
     private suspend fun finishJob(job: JobState) {
         activeJobs -= job
-        eventFlow.emit(WorkflowEvent.JobFinished(this, job.job, simulationContext.clock.millis()))
+        eventFlow.emit(WorkflowEvent.JobFinished(this, job.job, clock.millis()))
         rootListener.jobFinished(job)
     }
 
diff --git a/simulator/opendc/opendc-workflows/src/main/kotlin/com/atlarge/opendc/workflows/service/WorkflowSchedulerMode.kt b/simulator/opendc/opendc-workflows/src/main/kotlin/com/atlarge/opendc/workflows/service/WorkflowSchedulerMode.kt
index 776f0b07..cb075b18 100644
--- a/simulator/opendc/opendc-workflows/src/main/kotlin/com/atlarge/opendc/workflows/service/WorkflowSchedulerMode.kt
+++ b/simulator/opendc/opendc-workflows/src/main/kotlin/com/atlarge/opendc/workflows/service/WorkflowSchedulerMode.kt
@@ -24,7 +24,6 @@
 
 package com.atlarge.opendc.workflows.service
 
-import com.atlarge.odcsim.simulationContext
 import com.atlarge.opendc.workflows.service.stage.StagePolicy
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
@@ -66,13 +65,12 @@ sealed class WorkflowSchedulerMode : StagePolicy<WorkflowSchedulerMode.Logic> {
 
         override fun invoke(scheduler: StageWorkflowService): Logic = object : Logic {
             override suspend fun requestCycle() {
-                val ctx = simulationContext
                 if (next == null) {
                     // In batch mode, we assume that the scheduler runs at a fixed slot every time
                     // quantum (e.g t=0, t=60, t=120). We calculate here the delay until the next scheduling slot.
-                    val delay = quantum - (ctx.clock.millis() % quantum)
+                    val delay = quantum - (scheduler.clock.millis() % quantum)
 
-                    val job = ctx.domain.launch {
+                    val job = scheduler.coroutineScope.launch {
                         delay(delay)
                         next = null
                         scheduler.schedule()
@@ -93,11 +91,10 @@ sealed class WorkflowSchedulerMode : StagePolicy<WorkflowSchedulerMode.Logic> {
 
         override fun invoke(scheduler: StageWorkflowService): Logic = object : Logic {
             override suspend fun requestCycle() {
-                val ctx = simulationContext
                 if (next == null) {
                     val delay = random.nextInt(200).toLong()
 
-                    val job = ctx.domain.launch {
+                    val job = scheduler.coroutineScope.launch {
                         delay(delay)
                         next = null
                         scheduler.schedule()
diff --git a/simulator/opendc/opendc-workflows/src/main/kotlin/com/atlarge/opendc/workflows/service/WorkflowService.kt b/simulator/opendc/opendc-workflows/src/main/kotlin/com/atlarge/opendc/workflows/service/WorkflowService.kt
index a60ba0e2..ad818dde 100644
--- a/simulator/opendc/opendc-workflows/src/main/kotlin/com/atlarge/opendc/workflows/service/WorkflowService.kt
+++ b/simulator/opendc/opendc-workflows/src/main/kotlin/com/atlarge/opendc/workflows/service/WorkflowService.kt
@@ -26,8 +26,8 @@ package com.atlarge.opendc.workflows.service
 
 import com.atlarge.opendc.core.services.AbstractServiceKey
 import com.atlarge.opendc.workflows.workload.Job
-import java.util.UUID
 import kotlinx.coroutines.flow.Flow
+import java.util.UUID
 
 /**
  * A service for cloud workflow management.