refactor: Replace use of CoroutineContext by Dispatcher

This change replaces the use of `CoroutineContext` for passing the
`SimulationDispatcher` across the different modules of OpenDC by the
lightweight `Dispatcher` interface of the OpenDC common module.

3 files changed, 10 insertions, 16 deletions

diff --git a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/ComputeService.kt b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/ComputeService.kt
index 4ced9569..9d7dcba6 100644
--- a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/ComputeService.kt
+++ b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/ComputeService.kt
@@ -22,6 +22,7 @@
 
 package org.opendc.compute.service
 
+import org.opendc.common.Dispatcher
 import org.opendc.compute.api.ComputeClient
 import org.opendc.compute.api.Server
 import org.opendc.compute.service.driver.Host
@@ -29,8 +30,6 @@ import org.opendc.compute.service.internal.ComputeServiceImpl
 import org.opendc.compute.service.scheduler.ComputeScheduler
 import org.opendc.compute.service.telemetry.SchedulerStats
 import java.time.Duration
-import java.time.InstantSource
-import kotlin.coroutines.CoroutineContext
 
 /**
  * The [ComputeService] hosts the API implementation of the OpenDC Compute service.
@@ -80,18 +79,16 @@ public interface ComputeService : AutoCloseable {
         /**
          * Construct a new [ComputeService] implementation.
          *
-         * @param context The [CoroutineContext] to use in the service.
-         * @param clock The clock instance to use.
+         * @param dispatcher The [Dispatcher] for scheduling future events.
          * @param scheduler The scheduler implementation to use.
          * @param schedulingQuantum The interval between scheduling cycles.
          */
         public operator fun invoke(
-            context: CoroutineContext,
-            clock: InstantSource,
+            dispatcher: Dispatcher,
             scheduler: ComputeScheduler,
             schedulingQuantum: Duration = Duration.ofMinutes(5)
         ): ComputeService {
-            return ComputeServiceImpl(context, clock, scheduler, schedulingQuantum)
+            return ComputeServiceImpl(dispatcher, scheduler, schedulingQuantum)
         }
     }
 }
diff --git a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/internal/ComputeServiceImpl.kt b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/internal/ComputeServiceImpl.kt
index 2b755988..77932545 100644
--- a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/internal/ComputeServiceImpl.kt
+++ b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/internal/ComputeServiceImpl.kt
@@ -23,6 +23,7 @@
 package org.opendc.compute.service.internal
 
 import mu.KotlinLogging
+import org.opendc.common.Dispatcher
 import org.opendc.common.util.Pacer
 import org.opendc.compute.api.ComputeClient
 import org.opendc.compute.api.Flavor
@@ -37,25 +38,21 @@ import org.opendc.compute.service.scheduler.ComputeScheduler
 import org.opendc.compute.service.telemetry.SchedulerStats
 import java.time.Duration
 import java.time.Instant
-import java.time.InstantSource
 import java.util.ArrayDeque
 import java.util.Deque
 import java.util.Random
 import java.util.UUID
-import kotlin.coroutines.CoroutineContext
 import kotlin.math.max
 
 /**
  * Internal implementation of the OpenDC Compute service.
  *
- * @param coroutineContext The [CoroutineContext] to use in the service.
- * @param clock The clock instance to use.
+ * @param dispatcher The [Dispatcher] for scheduling future events.
  * @param scheduler The scheduler implementation to use.
  * @param schedulingQuantum The interval between scheduling cycles.
  */
 internal class ComputeServiceImpl(
-    coroutineContext: CoroutineContext,
-    private val clock: InstantSource,
+    private val dispatcher: Dispatcher,
     private val scheduler: ComputeScheduler,
     schedulingQuantum: Duration
 ) : ComputeService, HostListener {
@@ -108,6 +105,7 @@ internal class ComputeServiceImpl(
     override val hosts: Set<Host>
         get() = hostToView.keys
 
+    private val clock = dispatcher.timeSource
     private var maxCores = 0
     private var maxMemory = 0L
     private var _attemptsSuccess = 0L
@@ -120,7 +118,7 @@ internal class ComputeServiceImpl(
     /**
      * The [Pacer] to use for scheduling the scheduler cycles.
      */
-    private val pacer = Pacer(coroutineContext, clock, schedulingQuantum.toMillis()) { doSchedule() }
+    private val pacer = Pacer(dispatcher, schedulingQuantum.toMillis()) { doSchedule() }
 
     override fun newClient(): ComputeClient {
         check(!isClosed) { "Service is already closed" }
diff --git a/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/ComputeServiceTest.kt b/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/ComputeServiceTest.kt
index b790d36f..b5685aba 100644
--- a/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/ComputeServiceTest.kt
+++ b/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/ComputeServiceTest.kt
@@ -62,12 +62,11 @@ internal class ComputeServiceTest {
     @BeforeEach
     fun setUp() {
         scope = SimulationCoroutineScope()
-        val clock = scope.timeSource
         val computeScheduler = FilterScheduler(
             filters = listOf(ComputeFilter(), VCpuFilter(allocationRatio = 1.0), RamFilter(allocationRatio = 1.0)),
             weighers = listOf(RamWeigher())
         )
-        service = ComputeService(scope.coroutineContext, clock, computeScheduler)
+        service = ComputeService(scope.dispatcher, computeScheduler)
     }
 
     @Test