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`

5 files changed, 32 insertions, 32 deletions

diff --git a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimMachineTest.kt b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimMachineTest.kt
index 644eb497..b7af6803 100644
--- a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimMachineTest.kt
+++ b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimMachineTest.kt
@@ -33,9 +33,9 @@ import org.opendc.simulator.compute.power.SimplePowerDriver
 import org.opendc.simulator.compute.workload.SimFlopsWorkload
 import org.opendc.simulator.compute.workload.SimWorkload
 import org.opendc.simulator.compute.workload.SimWorkloadLifecycle
-import org.opendc.simulator.core.runBlockingSimulation
 import org.opendc.simulator.flow.FlowEngine
 import org.opendc.simulator.flow.source.FixedFlowSource
+import org.opendc.simulator.kotlin.runSimulation
 import org.opendc.simulator.network.SimNetworkSink
 import org.opendc.simulator.power.SimPowerSource
 
@@ -58,7 +58,7 @@ class SimMachineTest {
     }
 
     @Test
-    fun testFlopsWorkload() = runBlockingSimulation {
+    fun testFlopsWorkload() = runSimulation {
         val machine = SimBareMetalMachine(
             FlowEngine(coroutineContext, clock),
             machineModel,
@@ -72,7 +72,7 @@ class SimMachineTest {
     }
 
     @Test
-    fun testDualSocketMachine() = runBlockingSimulation {
+    fun testDualSocketMachine() = runSimulation {
         val cpuNode = machineModel.cpus[0].node
         val machineModel = MachineModel(
             cpus = List(cpuNode.coreCount * 2) { ProcessingUnit(cpuNode, it % 2, 1000.0) },
@@ -91,7 +91,7 @@ class SimMachineTest {
     }
 
     @Test
-    fun testPower() = runBlockingSimulation {
+    fun testPower() = runSimulation {
         val engine = FlowEngine(coroutineContext, clock)
         val machine = SimBareMetalMachine(
             engine,
@@ -111,7 +111,7 @@ class SimMachineTest {
     }
 
     @Test
-    fun testCapacityClamp() = runBlockingSimulation {
+    fun testCapacityClamp() = runSimulation {
         val machine = SimBareMetalMachine(
             FlowEngine(coroutineContext, clock),
             machineModel,
@@ -135,7 +135,7 @@ class SimMachineTest {
     }
 
     @Test
-    fun testMemory() = runBlockingSimulation {
+    fun testMemory() = runSimulation {
         val machine = SimBareMetalMachine(
             FlowEngine(coroutineContext, clock),
             machineModel,
@@ -153,7 +153,7 @@ class SimMachineTest {
     }
 
     @Test
-    fun testMemoryUsage() = runBlockingSimulation {
+    fun testMemoryUsage() = runSimulation {
         val machine = SimBareMetalMachine(
             FlowEngine(coroutineContext, clock),
             machineModel,
@@ -173,7 +173,7 @@ class SimMachineTest {
     }
 
     @Test
-    fun testNetUsage() = runBlockingSimulation {
+    fun testNetUsage() = runSimulation {
         val engine = FlowEngine(coroutineContext, clock)
         val machine = SimBareMetalMachine(
             engine,
@@ -198,7 +198,7 @@ class SimMachineTest {
     }
 
     @Test
-    fun testDiskReadUsage() = runBlockingSimulation {
+    fun testDiskReadUsage() = runSimulation {
         val engine = FlowEngine(coroutineContext, clock)
         val machine = SimBareMetalMachine(
             engine,
@@ -220,7 +220,7 @@ class SimMachineTest {
     }
 
     @Test
-    fun testDiskWriteUsage() = runBlockingSimulation {
+    fun testDiskWriteUsage() = runSimulation {
         val engine = FlowEngine(coroutineContext, clock)
         val machine = SimBareMetalMachine(
             engine,
@@ -242,7 +242,7 @@ class SimMachineTest {
     }
 
     @Test
-    fun testCancellation() = runBlockingSimulation {
+    fun testCancellation() = runSimulation {
         val machine = SimBareMetalMachine(
             FlowEngine(coroutineContext, clock),
             machineModel,
@@ -262,7 +262,7 @@ class SimMachineTest {
     }
 
     @Test
-    fun testConcurrentRuns() = runBlockingSimulation {
+    fun testConcurrentRuns() = runSimulation {
         val machine = SimBareMetalMachine(
             FlowEngine(coroutineContext, clock),
             machineModel,
diff --git a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/device/SimPsuTest.kt b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/device/SimPsuTest.kt
index e5b509f0..5481cad2 100644
--- a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/device/SimPsuTest.kt
+++ b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/device/SimPsuTest.kt
@@ -28,8 +28,8 @@ import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.assertThrows
 import org.opendc.simulator.compute.power.PowerDriver
-import org.opendc.simulator.core.runBlockingSimulation
 import org.opendc.simulator.flow.FlowEngine
+import org.opendc.simulator.kotlin.runSimulation
 import org.opendc.simulator.power.SimPowerSource
 
 /**
@@ -51,7 +51,7 @@ internal class SimPsuTest {
     }
 
     @Test
-    fun testPsuIdle() = runBlockingSimulation {
+    fun testPsuIdle() = runSimulation {
         val ratedOutputPower = 240.0
         val energyEfficiency = mapOf(0.0 to 1.0)
 
@@ -69,7 +69,7 @@ internal class SimPsuTest {
     }
 
     @Test
-    fun testPsuPowerLoss() = runBlockingSimulation {
+    fun testPsuPowerLoss() = runSimulation {
         val ratedOutputPower = 240.0
         // Efficiency of 80 Plus Titanium PSU
         val energyEfficiency = sortedMapOf(
diff --git a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/kernel/SimFairShareHypervisorTest.kt b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/kernel/SimFairShareHypervisorTest.kt
index ddf8cf14..aae8d139 100644
--- a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/kernel/SimFairShareHypervisorTest.kt
+++ b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/kernel/SimFairShareHypervisorTest.kt
@@ -41,9 +41,9 @@ import org.opendc.simulator.compute.runWorkload
 import org.opendc.simulator.compute.workload.SimTrace
 import org.opendc.simulator.compute.workload.SimTraceFragment
 import org.opendc.simulator.compute.workload.SimTraceWorkload
-import org.opendc.simulator.core.runBlockingSimulation
 import org.opendc.simulator.flow.FlowEngine
 import org.opendc.simulator.flow.mux.FlowMultiplexerFactory
+import org.opendc.simulator.kotlin.runSimulation
 import java.util.*
 
 /**
@@ -65,7 +65,7 @@ internal class SimFairShareHypervisorTest {
      * Test overcommitting of resources via the hypervisor with a single VM.
      */
     @Test
-    fun testOvercommittedSingle() = runBlockingSimulation {
+    fun testOvercommittedSingle() = runSimulation {
         val duration = 5 * 60L
         val workloadA =
             SimTraceWorkload(
@@ -105,7 +105,7 @@ internal class SimFairShareHypervisorTest {
      * Test overcommitting of resources via the hypervisor with two VMs.
      */
     @Test
-    fun testOvercommittedDual() = runBlockingSimulation {
+    fun testOvercommittedDual() = runSimulation {
         val duration = 5 * 60L
         val workloadA =
             SimTraceWorkload(
@@ -158,7 +158,7 @@ internal class SimFairShareHypervisorTest {
     }
 
     @Test
-    fun testMultipleCPUs() = runBlockingSimulation {
+    fun testMultipleCPUs() = runSimulation {
         val cpuNode = ProcessingNode("Intel", "Xeon", "amd64", 2)
         val model = MachineModel(
             cpus = List(cpuNode.coreCount) { ProcessingUnit(cpuNode, it, 3200.0) },
@@ -179,7 +179,7 @@ internal class SimFairShareHypervisorTest {
     }
 
     @Test
-    fun testInterference() = runBlockingSimulation {
+    fun testInterference() = runSimulation {
         val cpuNode = ProcessingNode("Intel", "Xeon", "amd64", 2)
         val model = MachineModel(
             cpus = List(cpuNode.coreCount) { ProcessingUnit(cpuNode, it, 3200.0) },
diff --git a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/kernel/SimSpaceSharedHypervisorTest.kt b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/kernel/SimSpaceSharedHypervisorTest.kt
index df6755f1..664bb2da 100644
--- a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/kernel/SimSpaceSharedHypervisorTest.kt
+++ b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/kernel/SimSpaceSharedHypervisorTest.kt
@@ -37,9 +37,9 @@ import org.opendc.simulator.compute.power.ConstantPowerModel
 import org.opendc.simulator.compute.power.SimplePowerDriver
 import org.opendc.simulator.compute.runWorkload
 import org.opendc.simulator.compute.workload.*
-import org.opendc.simulator.core.runBlockingSimulation
 import org.opendc.simulator.flow.FlowEngine
 import org.opendc.simulator.flow.mux.FlowMultiplexerFactory
+import org.opendc.simulator.kotlin.runSimulation
 import java.util.*
 
 /**
@@ -61,7 +61,7 @@ internal class SimSpaceSharedHypervisorTest {
      * Test a trace workload.
      */
     @Test
-    fun testTrace() = runBlockingSimulation {
+    fun testTrace() = runSimulation {
         val duration = 5 * 60L
         val workloadA =
             SimTraceWorkload(
@@ -92,7 +92,7 @@ internal class SimSpaceSharedHypervisorTest {
      * Test runtime workload on hypervisor.
      */
     @Test
-    fun testRuntimeWorkload() = runBlockingSimulation {
+    fun testRuntimeWorkload() = runSimulation {
         val duration = 5 * 60L * 1000
         val workload = SimRuntimeWorkload(duration)
         val engine = FlowEngine(coroutineContext, clock)
@@ -114,7 +114,7 @@ internal class SimSpaceSharedHypervisorTest {
      * Test FLOPs workload on hypervisor.
      */
     @Test
-    fun testFlopsWorkload() = runBlockingSimulation {
+    fun testFlopsWorkload() = runSimulation {
         val duration = 5 * 60L * 1000
         val workload = SimFlopsWorkload((duration * 3.2).toLong(), 1.0)
         val engine = FlowEngine(coroutineContext, clock)
@@ -134,7 +134,7 @@ internal class SimSpaceSharedHypervisorTest {
      * Test two workloads running sequentially.
      */
     @Test
-    fun testTwoWorkloads() = runBlockingSimulation {
+    fun testTwoWorkloads() = runSimulation {
         val duration = 5 * 60L * 1000
         val engine = FlowEngine(coroutineContext, clock)
         val machine = SimBareMetalMachine(engine, machineModel, SimplePowerDriver(ConstantPowerModel(0.0)))
@@ -162,7 +162,7 @@ internal class SimSpaceSharedHypervisorTest {
      * Test concurrent workloads on the machine.
      */
     @Test
-    fun testConcurrentWorkloadFails() = runBlockingSimulation {
+    fun testConcurrentWorkloadFails() = runSimulation {
         val engine = FlowEngine(coroutineContext, clock)
         val machine = SimBareMetalMachine(engine, machineModel, SimplePowerDriver(ConstantPowerModel(0.0)))
         val hypervisor = SimHypervisor(engine, FlowMultiplexerFactory.forwardingMultiplexer(), SplittableRandom(1), null)
@@ -184,7 +184,7 @@ internal class SimSpaceSharedHypervisorTest {
      * Test concurrent workloads on the machine.
      */
     @Test
-    fun testConcurrentWorkloadSucceeds() = runBlockingSimulation {
+    fun testConcurrentWorkloadSucceeds() = runSimulation {
         val engine = FlowEngine(coroutineContext, clock)
         val machine = SimBareMetalMachine(engine, machineModel, SimplePowerDriver(ConstantPowerModel(0.0)))
         val hypervisor = SimHypervisor(engine, FlowMultiplexerFactory.forwardingMultiplexer(), SplittableRandom(1), null)
diff --git a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/workload/SimTraceWorkloadTest.kt b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/workload/SimTraceWorkloadTest.kt
index aa91984a..70aea3f4 100644
--- a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/workload/SimTraceWorkloadTest.kt
+++ b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/workload/SimTraceWorkloadTest.kt
@@ -31,8 +31,8 @@ import org.opendc.simulator.compute.model.*
 import org.opendc.simulator.compute.power.ConstantPowerModel
 import org.opendc.simulator.compute.power.SimplePowerDriver
 import org.opendc.simulator.compute.runWorkload
-import org.opendc.simulator.core.runBlockingSimulation
 import org.opendc.simulator.flow.FlowEngine
+import org.opendc.simulator.kotlin.runSimulation
 
 /**
  * Test suite for the [SimTraceWorkloadTest] class.
@@ -51,7 +51,7 @@ class SimTraceWorkloadTest {
     }
 
     @Test
-    fun testSmoke() = runBlockingSimulation {
+    fun testSmoke() = runSimulation {
         val machine = SimBareMetalMachine(
             FlowEngine(coroutineContext, clock),
             machineModel,
@@ -74,7 +74,7 @@ class SimTraceWorkloadTest {
     }
 
     @Test
-    fun testOffset() = runBlockingSimulation {
+    fun testOffset() = runSimulation {
         val machine = SimBareMetalMachine(
             FlowEngine(coroutineContext, clock),
             machineModel,
@@ -97,7 +97,7 @@ class SimTraceWorkloadTest {
     }
 
     @Test
-    fun testSkipFragment() = runBlockingSimulation {
+    fun testSkipFragment() = runSimulation {
         val machine = SimBareMetalMachine(
             FlowEngine(coroutineContext, clock),
             machineModel,
@@ -121,7 +121,7 @@ class SimTraceWorkloadTest {
     }
 
     @Test
-    fun testZeroCores() = runBlockingSimulation {
+    fun testZeroCores() = runSimulation {
         val machine = SimBareMetalMachine(
             FlowEngine(coroutineContext, clock),
             machineModel,