merge: Extract scheduler from simulation coroutine dispatcher (#106)

This pull request extracts the scheduler from the `SimulationCoroutineDispatcher` into 
a separate `SimulationScheduler` class which allows users to re-use the scheduler 
between different coroutine dispatchers.

We implement the `SimulationScheduler` in Java, removing the explicit dependency on 
Kotlin or `kotlinx-coroutines`. The scheduler uses a separate specialized priority queue 
implementation that eliminates allocation in the hot path of the simulator.

## Implementation Notes :hammer_and_pick:

* Add Java-based simulator core
* Use SimulationScheduler in coroutine dispatcher
* Rename runBlockingSimulation to runSimulation

## External Dependencies :four_leaf_clover:

* N/A 

## Breaking API Changes :warning:

* The Kotlin API for simulation has been moved to `org.opendc.simulator.kotlin`.
* `runBlockingSImulation` renamed to `runSimulation`

3 files changed, 9 insertions, 9 deletions

diff --git a/opendc-experiments/opendc-experiments-capelin/src/jmh/kotlin/org/opendc/experiments/capelin/CapelinBenchmarks.kt b/opendc-experiments/opendc-experiments-capelin/src/jmh/kotlin/org/opendc/experiments/capelin/CapelinBenchmarks.kt
index f021e223..ef3deeb2 100644
--- a/opendc-experiments/opendc-experiments-capelin/src/jmh/kotlin/org/opendc/experiments/capelin/CapelinBenchmarks.kt
+++ b/opendc-experiments/opendc-experiments-capelin/src/jmh/kotlin/org/opendc/experiments/capelin/CapelinBenchmarks.kt
@@ -32,7 +32,7 @@ import org.opendc.experiments.capelin.topology.clusterTopology
 import org.opendc.experiments.compute.*
 import org.opendc.experiments.compute.topology.HostSpec
 import org.opendc.experiments.provisioner.Provisioner
-import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.kotlin.runSimulation
 import org.openjdk.jmh.annotations.*
 import java.io.File
 import java.util.*
@@ -60,7 +60,7 @@ class CapelinBenchmarks {
     }
 
     @Benchmark
-    fun benchmarkCapelin() = runBlockingSimulation {
+    fun benchmarkCapelin() = runSimulation {
         val serviceDomain = "compute.opendc.org"
 
         Provisioner(coroutineContext, clock, seed = 0).use { provisioner ->
diff --git a/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/CapelinRunner.kt b/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/CapelinRunner.kt
index f1214b08..7461038d 100644
--- a/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/CapelinRunner.kt
+++ b/opendc-experiments/opendc-experiments-capelin/src/main/kotlin/org/opendc/experiments/capelin/CapelinRunner.kt
@@ -28,7 +28,7 @@ import org.opendc.experiments.capelin.topology.clusterTopology
 import org.opendc.experiments.compute.*
 import org.opendc.experiments.compute.export.parquet.ParquetComputeMonitor
 import org.opendc.experiments.provisioner.Provisioner
-import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.kotlin.runSimulation
 import java.io.File
 import java.time.Duration
 import java.util.*
@@ -54,7 +54,7 @@ public class CapelinRunner(
     /**
      * Run a single [scenario] with the specified seed.
      */
-    fun runScenario(scenario: Scenario, seed: Long) = runBlockingSimulation {
+    fun runScenario(scenario: Scenario, seed: Long) = runSimulation {
         val serviceDomain = "compute.opendc.org"
         val topology = clusterTopology(File(envPath, "${scenario.topology.name}.txt"))
 
diff --git a/opendc-experiments/opendc-experiments-capelin/src/test/kotlin/org/opendc/experiments/capelin/CapelinIntegrationTest.kt b/opendc-experiments/opendc-experiments-capelin/src/test/kotlin/org/opendc/experiments/capelin/CapelinIntegrationTest.kt
index 9be2d522..238a5f87 100644
--- a/opendc-experiments/opendc-experiments-capelin/src/test/kotlin/org/opendc/experiments/capelin/CapelinIntegrationTest.kt
+++ b/opendc-experiments/opendc-experiments-capelin/src/test/kotlin/org/opendc/experiments/capelin/CapelinIntegrationTest.kt
@@ -39,7 +39,7 @@ import org.opendc.experiments.compute.telemetry.table.HostTableReader
 import org.opendc.experiments.compute.telemetry.table.ServiceTableReader
 import org.opendc.experiments.compute.topology.HostSpec
 import org.opendc.experiments.provisioner.Provisioner
-import org.opendc.simulator.core.runBlockingSimulation
+import org.opendc.simulator.kotlin.runSimulation
 import java.io.File
 import java.time.Duration
 import java.util.*
@@ -80,7 +80,7 @@ class CapelinIntegrationTest {
      * Test a large simulation setup.
      */
     @Test
-    fun testLarge() = runBlockingSimulation {
+    fun testLarge() = runSimulation {
         val seed = 0L
         val workload = createTestWorkload(1.0, seed)
         val topology = createTopology()
@@ -124,7 +124,7 @@ class CapelinIntegrationTest {
      * Test a small simulation setup.
      */
     @Test
-    fun testSmall() = runBlockingSimulation {
+    fun testSmall() = runSimulation {
         val seed = 1L
         val workload = createTestWorkload(0.25, seed)
         val topology = createTopology("single")
@@ -164,7 +164,7 @@ class CapelinIntegrationTest {
      * Test a small simulation setup with interference.
      */
     @Test
-    fun testInterference() = runBlockingSimulation {
+    fun testInterference() = runSimulation {
         val seed = 0L
         val workload = createTestWorkload(1.0, seed)
         val topology = createTopology("single")
@@ -202,7 +202,7 @@ class CapelinIntegrationTest {
      * Test a small simulation setup with failures.
      */
     @Test
-    fun testFailures() = runBlockingSimulation {
+    fun testFailures() = runSimulation {
         val seed = 0L
         val topology = createTopology("single")
         val workload = createTestWorkload(0.25, seed)