merge: Increase minimum Java version to 17 (#115)

This pull request increases the minimum version of Java required by OpenDC to 17.
This new version of Java introduces several new features compared to our old minimum 
version (11), which we attempt to apply in this conversion.

## Implementation Notes :hammer_and_pick:

* Increase minimum Java version to Java 17 
* Use RandomGenerator as randomness source 
* Add common dispatcher interface 
* Add compatibility with Kotlin coroutines
* Use InstantSource as time source
* Re-implement SimulationScheduler as Dispatcher 
* Replace use of CoroutineContext by Dispatcher 

## External Dependencies :four_leaf_clover:

* Java 17

## Breaking API Changes :warning:

* The use of `CoroutineContext` and `Clock` as parameters of classes has been replaced 
  by the `Dispatcher` interface.
* The use of `Clock` has been replaced by `InstantSource` which does not carry time
   zone info.
* The use of `Random` and `SplittableRandom` as parameter type has been replaced 
   by `RandomGenerator`

2 files changed, 10 insertions, 15 deletions

diff --git a/opendc-experiments/opendc-experiments-tf20/src/test/kotlin/org/opendc/experiments/tf20/TensorFlowTest.kt b/opendc-experiments/opendc-experiments-tf20/src/test/kotlin/org/opendc/experiments/tf20/TensorFlowTest.kt
index 32f72686..899aafc0 100644
--- a/opendc-experiments/opendc-experiments-tf20/src/test/kotlin/org/opendc/experiments/tf20/TensorFlowTest.kt
+++ b/opendc-experiments/opendc-experiments-tf20/src/test/kotlin/org/opendc/experiments/tf20/TensorFlowTest.kt
@@ -48,8 +48,7 @@ class TensorFlowTest {
         val device = SimTFDevice(
             def.uid,
             def.meta["gpu"] as Boolean,
-            coroutineContext,
-            clock,
+            dispatcher,
             def.model.cpus[0],
             def.model.memory[0],
             CpuPowerModels.linear(250.0, 60.0)
@@ -67,7 +66,7 @@ class TensorFlowTest {
 
         val stats = device.getDeviceStats()
         assertAll(
-            { assertEquals(3309694252, clock.millis()) },
+            { assertEquals(3309694252, timeSource.millis()) },
             { assertEquals(8.27423563E8, stats.energyUsage) }
         )
     }
@@ -83,8 +82,7 @@ class TensorFlowTest {
         val device = SimTFDevice(
             def.uid,
             def.meta["gpu"] as Boolean,
-            coroutineContext,
-            clock,
+            dispatcher,
             def.model.cpus[0],
             def.model.memory[0],
             CpuPowerModels.linear(250.0, 60.0)
@@ -102,7 +100,7 @@ class TensorFlowTest {
 
         val stats = device.getDeviceStats()
         assertAll(
-            { assertEquals(176230328513, clock.millis()) },
+            { assertEquals(176230328513, timeSource.millis()) },
             { assertEquals(4.405758212825E10, stats.energyUsage) }
         )
     }
@@ -118,8 +116,7 @@ class TensorFlowTest {
         val deviceA = SimTFDevice(
             def.uid,
             def.meta["gpu"] as Boolean,
-            coroutineContext,
-            clock,
+            dispatcher,
             def.model.cpus[0],
             def.model.memory[0],
             CpuPowerModels.linear(250.0, 60.0)
@@ -128,8 +125,7 @@ class TensorFlowTest {
         val deviceB = SimTFDevice(
             UUID.randomUUID(),
             def.meta["gpu"] as Boolean,
-            coroutineContext,
-            clock,
+            dispatcher,
             def.model.cpus[0],
             def.model.memory[0],
             CpuPowerModels.linear(250.0, 60.0)
@@ -150,7 +146,7 @@ class TensorFlowTest {
         val statsA = deviceA.getDeviceStats()
         val statsB = deviceB.getDeviceStats()
         assertAll(
-            { assertEquals(1704994000, clock.millis()) },
+            { assertEquals(1704994000, timeSource.millis()) },
             { assertEquals(4.262485E8, statsA.energyUsage) },
             { assertEquals(4.262485E8, statsB.energyUsage) }
         )
diff --git a/opendc-experiments/opendc-experiments-tf20/src/test/kotlin/org/opendc/experiments/tf20/core/SimTFDeviceTest.kt b/opendc-experiments/opendc-experiments-tf20/src/test/kotlin/org/opendc/experiments/tf20/core/SimTFDeviceTest.kt
index 910cbcc9..549c6f3e 100644
--- a/opendc-experiments/opendc-experiments-tf20/src/test/kotlin/org/opendc/experiments/tf20/core/SimTFDeviceTest.kt
+++ b/opendc-experiments/opendc-experiments-tf20/src/test/kotlin/org/opendc/experiments/tf20/core/SimTFDeviceTest.kt
@@ -47,8 +47,7 @@ internal class SimTFDeviceTest {
         val device = SimTFDevice(
             UUID.randomUUID(),
             isGpu = true,
-            coroutineContext,
-            clock,
+            dispatcher,
             pu,
             memory,
             CpuPowerModels.linear(250.0, 100.0)
@@ -56,7 +55,7 @@ internal class SimTFDeviceTest {
 
         // Load 1 GiB into GPU memory
         device.load(1000)
-        assertEquals(1140, clock.millis())
+        assertEquals(1140, timeSource.millis())
 
         coroutineScope {
             launch { device.compute(1e6) }
@@ -68,7 +67,7 @@ internal class SimTFDeviceTest {
         val stats = device.getDeviceStats()
 
         assertAll(
-            { assertEquals(3681, clock.millis()) },
+            { assertEquals(3681, timeSource.millis()) },
             { assertEquals(749.25, stats.energyUsage) }
         )
     }