simulator: Introduce SimulationCoroutineDispatcher

This change introduces the SimulationCoroutineDispatcher implementation
which replaces the TestCoroutineDispatcher for running single-threaded
simulations.

Previously, we used the TestCoroutineDispatcher from the
kotlinx-coroutines-test modules for running simulations. However, this
module is aimed at coroutine tests and not at simulations.

In particular, having to construct a Clock object each time for the
TestCoroutineDispatcher caused a lot of unnecessary lines. With the new
approach, the SimulationCoroutineDispatcher automatically exposes a
usable Clock object.

In addition to ergonomic benefits, the SimulationCoroutineDispatcher is
much faster than the TestCoroutineDispatcher due to the assumption that
simulations run in only a single thread. As a result, the dispatcher
does not need to perform synchronization and can use the fast
PriorityQueue implementation.

1 files changed, 3 insertions, 8 deletions

diff --git a/simulator/opendc-experiments/opendc-experiments-capelin/src/test/kotlin/org/opendc/experiments/capelin/CapelinIntegrationTest.kt b/simulator/opendc-experiments/opendc-experiments-capelin/src/test/kotlin/org/opendc/experiments/capelin/CapelinIntegrationTest.kt
index 4a47922d..4cb50ab9 100644
--- a/simulator/opendc-experiments/opendc-experiments-capelin/src/test/kotlin/org/opendc/experiments/capelin/CapelinIntegrationTest.kt
+++ b/simulator/opendc-experiments/opendc-experiments-capelin/src/test/kotlin/org/opendc/experiments/capelin/CapelinIntegrationTest.kt
@@ -25,10 +25,8 @@ package org.opendc.experiments.capelin
 import io.opentelemetry.api.metrics.MeterProvider
 import io.opentelemetry.sdk.metrics.SdkMeterProvider
 import io.opentelemetry.sdk.metrics.export.MetricProducer
-import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.cancel
 import kotlinx.coroutines.channels.Channel
-import kotlinx.coroutines.test.runBlockingTest
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.Test
@@ -46,14 +44,13 @@ import org.opendc.format.environment.EnvironmentReader
 import org.opendc.format.environment.sc20.Sc20ClusterEnvironmentReader
 import org.opendc.format.trace.TraceReader
 import org.opendc.simulator.compute.workload.SimWorkload
-import org.opendc.simulator.utils.DelayControllerClockAdapter
+import org.opendc.simulator.core.runBlockingSimulation
 import org.opendc.telemetry.sdk.toOtelClock
 import java.io.File
 
 /**
  * An integration test suite for the SC20 experiments.
  */
-@OptIn(ExperimentalCoroutinesApi::class)
 class CapelinIntegrationTest {
     /**
      * The monitor used to keep track of the metrics.
@@ -69,8 +66,7 @@ class CapelinIntegrationTest {
     }
 
     @Test
-    fun testLarge() = runBlockingTest {
-        val clock = DelayControllerClockAdapter(this)
+    fun testLarge() = runBlockingSimulation {
         val failures = false
         val seed = 0
         val chan = Channel<Unit>(Channel.CONFLATED)
@@ -132,8 +128,7 @@ class CapelinIntegrationTest {
     }
 
     @Test
-    fun testSmall() = runBlockingTest {
-        val clock = DelayControllerClockAdapter(this)
+    fun testSmall() = runBlockingSimulation {
         val seed = 1
         val chan = Channel<Unit>(Channel.CONFLATED)
         val allocationPolicy = FilterScheduler(