merge: Improve the OpenDC compute model (#37)

This pull request contains various improvements to the OpenDC compute simulation model.

- Support filtering hosts based on CPU capacity
- Do not allocate lambda in fast-path
- Redesign VM interference algorithm
- Report provisioning time of virtual machines
- Prevent allocations during collection cycle 
- Use correct flow input capacity for counters
- Support running workloads without coroutines

**Breaking API Changes**

- `VirtualMachine` now requires `cpuCapacity` parameter.
- `VmInterferenceModel` needs to be constructed using `VmInterferenceModel.Builder` and can't be passed a list of groups anymore.
- Scheduling latency is not collected anymore. Instead, use the boot time and provisioning time to derive the scheduling latency.
- Telemetry data is recorded using `*TableReader` interfaces as opposed to the `*Data` classes. These classes are re-used per row and should not be shared with other threads, since the underlying data may change.
- `SimMachine` does not implement `AutoCloseable` anymore. Machines can be removed from a `SimHypervisor` using the `removeMachine` method.
- `SimMachine.run` is moved to an extension method called `runWorkload`. Users can now also choose to run a workload using the asynchronous `SimMachine.startWorkload`.

3 files changed, 28 insertions, 4 deletions

diff --git a/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/mux/FlowMultiplexer.kt b/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/mux/FlowMultiplexer.kt
index 04ba7f21..a7877546 100644
--- a/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/mux/FlowMultiplexer.kt
+++ b/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/mux/FlowMultiplexer.kt
@@ -62,13 +62,21 @@ public interface FlowMultiplexer {
     public val counters: FlowCounters
 
     /**
-     * Create a new input on this multiplexer.
+     * Create a new input on this multiplexer with a coupled capacity.
      *
      * @param key The key of the interference member to which the input belongs.
      */
     public fun newInput(key: InterferenceKey? = null): FlowConsumer
 
     /**
+     * Create a new input on this multiplexer with the specified [capacity].
+     *
+     * @param capacity The capacity of the input.
+     * @param key The key of the interference member to which the input belongs.
+     */
+    public fun newInput(capacity: Double, key: InterferenceKey? = null): FlowConsumer
+
+    /**
      * Remove [input] from this multiplexer.
      */
     public fun removeInput(input: FlowConsumer)
diff --git a/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/mux/ForwardingFlowMultiplexer.kt b/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/mux/ForwardingFlowMultiplexer.kt
index 125d10fe..b68a8baa 100644
--- a/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/mux/ForwardingFlowMultiplexer.kt
+++ b/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/mux/ForwardingFlowMultiplexer.kt
@@ -78,6 +78,8 @@ public class ForwardingFlowMultiplexer(private val engine: FlowEngine) : FlowMul
         return input
     }
 
+    override fun newInput(capacity: Double, key: InterferenceKey?): FlowConsumer = newInput(key)
+
     override fun removeInput(input: FlowConsumer) {
         if (!_inputs.remove(input)) {
             return
diff --git a/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/mux/MaxMinFlowMultiplexer.kt b/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/mux/MaxMinFlowMultiplexer.kt
index a0fb8a4e..3d26efda 100644
--- a/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/mux/MaxMinFlowMultiplexer.kt
+++ b/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/mux/MaxMinFlowMultiplexer.kt
@@ -86,7 +86,15 @@ public class MaxMinFlowMultiplexer(
     private val scheduler = Scheduler(engine, parent)
 
     override fun newInput(key: InterferenceKey?): FlowConsumer {
-        val provider = Input(engine, scheduler, interferenceDomain, key, scheduler.capacity)
+        return newInput(isCoupled = true, Double.POSITIVE_INFINITY, key)
+    }
+
+    override fun newInput(capacity: Double, key: InterferenceKey?): FlowConsumer {
+        return newInput(isCoupled = false, capacity, key)
+    }
+
+    private fun newInput(isCoupled: Boolean, initialCapacity: Double, key: InterferenceKey?): FlowConsumer {
+        val provider = Input(engine, scheduler, interferenceDomain, key, isCoupled, initialCapacity)
         _inputs.add(provider)
         return provider
     }
@@ -206,7 +214,10 @@ public class MaxMinFlowMultiplexer(
             // Disable timers and convergence of the source if one of the output manages it
             input.shouldConsumerConverge = !hasActivationOutput
             input.enableTimers = !hasActivationOutput
-            input.capacity = capacity
+
+            if (input.isCoupled) {
+                input.capacity = capacity
+            }
 
             trigger(_clock.millis())
         }
@@ -340,7 +351,9 @@ public class MaxMinFlowMultiplexer(
             capacity = newCapacity
 
             for (input in _activeInputs) {
-                input.capacity = newCapacity
+                if (input.isCoupled) {
+                    input.capacity = newCapacity
+                }
             }
 
             // Sort outputs by their capacity
@@ -495,6 +508,7 @@ public class MaxMinFlowMultiplexer(
         private val scheduler: Scheduler,
         private val interferenceDomain: InterferenceDomain?,
         @JvmField val key: InterferenceKey?,
+        @JvmField val isCoupled: Boolean,
         initialCapacity: Double,
     ) : FlowConsumer, FlowConsumerLogic, Comparable<Input> {
         /**