simulator: Improve simulator resource model (#142)

This pull request improves the existing simulator resource model
that is at the core of all simulation models in OpenDC. 
Most importantly, we have changed the way of how metrics are reported by this layer.

* Add `SimResourceInterpreter` which is responsible for efficiently scheduling 
  communication between resources in OpenDC. The performance gain is in the 2x-5x range.
* Add uniform interface for exposing resource metrics (using `SimResourceCounters`).
* Split the CPUFreq subsystem in the compute simulator as it mixed responsibilities of 
  different layers.

**Breaking API Changes**

* Resource providers now accept a `SimResourceInterpreter` which is
   responsible for coordinating the communication between resources.
* `ScalingGovernor` is not part of the machine layer anymore. Instead, it should 
   move in the OS/Hypervisor layer.
* Workloads should now start CPU consumers using `cpu.startConsumer`.

1 files changed, 19 insertions, 19 deletions

diff --git a/opendc-simulator/opendc-simulator-resources/src/jmh/kotlin/org/opendc/simulator/resources/SimResourceBenchmarks.kt b/opendc-simulator/opendc-simulator-resources/src/jmh/kotlin/org/opendc/simulator/resources/SimResourceBenchmarks.kt
index cd5f33bd..b45b2a2f 100644
--- a/opendc-simulator/opendc-simulator-resources/src/jmh/kotlin/org/opendc/simulator/resources/SimResourceBenchmarks.kt
+++ b/opendc-simulator/opendc-simulator-resources/src/jmh/kotlin/org/opendc/simulator/resources/SimResourceBenchmarks.kt
@@ -37,12 +37,12 @@ import java.util.concurrent.TimeUnit
 @OptIn(ExperimentalCoroutinesApi::class)
 class SimResourceBenchmarks {
     private lateinit var scope: SimulationCoroutineScope
-    private lateinit var scheduler: SimResourceScheduler
+    private lateinit var interpreter: SimResourceInterpreter
 
     @Setup
     fun setUp() {
         scope = SimulationCoroutineScope()
-        scheduler = SimResourceSchedulerTrampoline(scope.coroutineContext, scope.clock)
+        interpreter = SimResourceInterpreter(scope.coroutineContext, scope.clock)
     }
 
     @State(Scope.Thread)
@@ -67,7 +67,7 @@ class SimResourceBenchmarks {
     @Benchmark
     fun benchmarkSource(state: Workload) {
         return scope.runBlockingSimulation {
-            val provider = SimResourceSource(4200.0, scheduler)
+            val provider = SimResourceSource(4200.0, interpreter)
             return@runBlockingSimulation provider.consume(SimTraceConsumer(state.trace))
         }
     }
@@ -75,7 +75,7 @@ class SimResourceBenchmarks {
     @Benchmark
     fun benchmarkForwardOverhead(state: Workload) {
         return scope.runBlockingSimulation {
-            val provider = SimResourceSource(4200.0, scheduler)
+            val provider = SimResourceSource(4200.0, interpreter)
             val forwarder = SimResourceForwarder()
             provider.startConsumer(forwarder)
             return@runBlockingSimulation forwarder.consume(SimTraceConsumer(state.trace))
@@ -85,12 +85,12 @@ class SimResourceBenchmarks {
     @Benchmark
     fun benchmarkSwitchMaxMinSingleConsumer(state: Workload) {
         return scope.runBlockingSimulation {
-            val switch = SimResourceSwitchMaxMin(scheduler)
+            val switch = SimResourceSwitchMaxMin(interpreter)
 
-            switch.addInput(SimResourceSource(3000.0, scheduler))
-            switch.addInput(SimResourceSource(3000.0, scheduler))
+            switch.addInput(SimResourceSource(3000.0, interpreter))
+            switch.addInput(SimResourceSource(3000.0, interpreter))
 
-            val provider = switch.addOutput(3500.0)
+            val provider = switch.newOutput()
             return@runBlockingSimulation provider.consume(SimTraceConsumer(state.trace))
         }
     }
@@ -98,14 +98,14 @@ class SimResourceBenchmarks {
     @Benchmark
     fun benchmarkSwitchMaxMinTripleConsumer(state: Workload) {
         return scope.runBlockingSimulation {
-            val switch = SimResourceSwitchMaxMin(scheduler)
+            val switch = SimResourceSwitchMaxMin(interpreter)
 
-            switch.addInput(SimResourceSource(3000.0, scheduler))
-            switch.addInput(SimResourceSource(3000.0, scheduler))
+            switch.addInput(SimResourceSource(3000.0, interpreter))
+            switch.addInput(SimResourceSource(3000.0, interpreter))
 
-            repeat(3) { i ->
+            repeat(3) {
                 launch {
-                    val provider = switch.addOutput(3500.0)
+                    val provider = switch.newOutput()
                     provider.consume(SimTraceConsumer(state.trace))
                 }
             }
@@ -117,10 +117,10 @@ class SimResourceBenchmarks {
         return scope.runBlockingSimulation {
             val switch = SimResourceSwitchExclusive()
 
-            switch.addInput(SimResourceSource(3000.0, scheduler))
-            switch.addInput(SimResourceSource(3000.0, scheduler))
+            switch.addInput(SimResourceSource(3000.0, interpreter))
+            switch.addInput(SimResourceSource(3000.0, interpreter))
 
-            val provider = switch.addOutput(3500.0)
+            val provider = switch.newOutput()
             return@runBlockingSimulation provider.consume(SimTraceConsumer(state.trace))
         }
     }
@@ -130,12 +130,12 @@ class SimResourceBenchmarks {
         return scope.runBlockingSimulation {
             val switch = SimResourceSwitchExclusive()
 
-            switch.addInput(SimResourceSource(3000.0, scheduler))
-            switch.addInput(SimResourceSource(3000.0, scheduler))
+            switch.addInput(SimResourceSource(3000.0, interpreter))
+            switch.addInput(SimResourceSource(3000.0, interpreter))
 
             repeat(2) {
                 launch {
-                    val provider = switch.addOutput(3500.0)
+                    val provider = switch.newOutput()
                     provider.consume(SimTraceConsumer(state.trace))
                 }
             }