refactor(simulator): Remove capacity event

This change removes the Capacity entry from FlowEvent. Since the source
is always pulled on a capacity change, we do not need a separate event
for this.

8 files changed, 21 insertions, 45 deletions

diff --git a/opendc-experiments/opendc-experiments-tf20/src/main/kotlin/org/opendc/experiments/tf20/core/SimTFDevice.kt b/opendc-experiments/opendc-experiments-tf20/src/main/kotlin/org/opendc/experiments/tf20/core/SimTFDevice.kt
index 2ba65e90..6f460ef7 100644
--- a/opendc-experiments/opendc-experiments-tf20/src/main/kotlin/org/opendc/experiments/tf20/core/SimTFDevice.kt
+++ b/opendc-experiments/opendc-experiments-tf20/src/main/kotlin/org/opendc/experiments/tf20/core/SimTFDevice.kt
@@ -131,6 +131,8 @@ public class SimTFDevice(
         override fun onPull(conn: FlowConnection, now: Long, delta: Long): Long {
             val consumedWork = conn.rate * delta / 1000.0
 
+            capacity = conn.capacity
+
             val activeWork = activeWork
             if (activeWork != null) {
                 if (activeWork.consume(consumedWork)) {
@@ -158,12 +160,8 @@ public class SimTFDevice(
         override fun onEvent(conn: FlowConnection, now: Long, event: FlowEvent) {
             when (event) {
                 FlowEvent.Start -> {
-                    this.ctx = conn
-                    this.capacity = conn.capacity
-                }
-                FlowEvent.Capacity -> {
-                    this.capacity = conn.capacity
-                    conn.pull()
+                    ctx = conn
+                    capacity = conn.capacity
                 }
                 FlowEvent.Converge -> {
                     _usage.record(conn.rate)
diff --git a/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/FlowEvent.kt b/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/FlowEvent.kt
index 14c85183..bb6f25b1 100644
--- a/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/FlowEvent.kt
+++ b/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/FlowEvent.kt
@@ -40,9 +40,4 @@ public enum class FlowEvent {
      * This event is emitted to the source when the system has converged into a steady state.
      */
     Converge,
-
-    /**
-     * This event is emitted to the source when the capacity of the consumer has changed.
-     */
-    Capacity,
 }
diff --git a/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/internal/FlowConsumerContextImpl.kt b/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/internal/FlowConsumerContextImpl.kt
index a74f89b4..a86ed6ea 100644
--- a/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/internal/FlowConsumerContextImpl.kt
+++ b/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/internal/FlowConsumerContextImpl.kt
@@ -51,7 +51,11 @@ internal class FlowConsumerContextImpl(
             // Only changes will be propagated
             if (value != oldValue) {
                 field = value
-                onCapacityChange()
+
+                // Do not pull the source if it has not been started yet
+                if (_state == State.Active) {
+                    pull()
+                }
             }
         }
 
@@ -328,23 +332,6 @@ internal class FlowConsumerContextImpl(
     }
 
     /**
-     * Indicate that the capacity of the resource has changed.
-     */
-    private fun onCapacityChange() {
-        // Do not inform the consumer if it has not been started yet
-        if (_state != State.Active) {
-            return
-        }
-
-        engine.batch {
-            // Inform the consumer of the capacity change. This might already trigger an interrupt.
-            source.onEvent(this, _clock.millis(), FlowEvent.Capacity)
-
-            pull()
-        }
-    }
-
-    /**
      * Schedule an immediate update for this connection.
      */
     private fun scheduleImmediate() {
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 a3e108f6..b98cf2f1 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
@@ -356,8 +356,7 @@ public class MaxMinFlowMultiplexer(
         /**
          * The capacity of this output.
          */
-        val capacity: Double
-            get() = _ctx?.capacity ?: 0.0
+        @JvmField var capacity: Double = 0.0
 
         /**
          * Push the specified rate to the consumer.
@@ -374,6 +373,12 @@ public class MaxMinFlowMultiplexer(
         }
 
         override fun onPull(conn: FlowConnection, now: Long, delta: Long): Long {
+            val capacity = capacity
+            if (capacity != conn.capacity) {
+                this.capacity = capacity
+                updateCapacity()
+            }
+
             runScheduler(now)
             return Long.MAX_VALUE
         }
@@ -383,13 +388,14 @@ public class MaxMinFlowMultiplexer(
                 FlowEvent.Start -> {
                     assert(_ctx == null) { "Source running concurrently" }
                     _ctx = conn
+                    capacity = conn.capacity
                     updateCapacity()
                 }
                 FlowEvent.Exit -> {
                     _ctx = null
+                    capacity = 0.0
                     updateCapacity()
                 }
-                FlowEvent.Capacity -> updateCapacity()
                 else -> {}
             }
         }
diff --git a/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/source/FlowSourceRateAdapter.kt b/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/source/FlowSourceRateAdapter.kt
index fcee3906..24ae64cb 100644
--- a/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/source/FlowSourceRateAdapter.kt
+++ b/opendc-simulator/opendc-simulator-flow/src/main/kotlin/org/opendc/simulator/flow/source/FlowSourceRateAdapter.kt
@@ -25,7 +25,6 @@ package org.opendc.simulator.flow.source
 import org.opendc.simulator.flow.FlowConnection
 import org.opendc.simulator.flow.FlowEvent
 import org.opendc.simulator.flow.FlowSource
-import kotlin.math.min
 
 /**
  * Helper class to expose an observable [rate] field describing the flow rate of the source.
@@ -59,20 +58,11 @@ public class FlowSourceRateAdapter(
     }
 
     override fun onEvent(conn: FlowConnection, now: Long, event: FlowEvent) {
-        val oldSpeed = rate
-
         try {
             delegate.onEvent(conn, now, event)
 
             when (event) {
                 FlowEvent.Converge -> rate = conn.rate
-                FlowEvent.Capacity -> {
-                    // Check if the consumer interrupted the consumer and updated the resource consumption. If not, we might
-                    // need to update the current speed.
-                    if (oldSpeed == rate) {
-                        rate = min(conn.capacity, rate)
-                    }
-                }
                 FlowEvent.Exit -> rate = 0.0
                 else -> {}
             }
diff --git a/opendc-simulator/opendc-simulator-flow/src/test/kotlin/org/opendc/simulator/flow/FlowConsumerContextTest.kt b/opendc-simulator/opendc-simulator-flow/src/test/kotlin/org/opendc/simulator/flow/FlowConsumerContextTest.kt
index f1a5cbe4..fe39eb2c 100644
--- a/opendc-simulator/opendc-simulator-flow/src/test/kotlin/org/opendc/simulator/flow/FlowConsumerContextTest.kt
+++ b/opendc-simulator/opendc-simulator-flow/src/test/kotlin/org/opendc/simulator/flow/FlowConsumerContextTest.kt
@@ -99,6 +99,6 @@ class FlowConsumerContextTest {
         context.start()
         context.capacity = 4200.0
 
-        verify(exactly = 0) { consumer.onEvent(any(), any(), FlowEvent.Capacity) }
+        verify(exactly = 1) { consumer.onPull(any(), any(), any()) }
     }
 }
diff --git a/opendc-simulator/opendc-simulator-flow/src/test/kotlin/org/opendc/simulator/flow/FlowForwarderTest.kt b/opendc-simulator/opendc-simulator-flow/src/test/kotlin/org/opendc/simulator/flow/FlowForwarderTest.kt
index d125c638..7fae918a 100644
--- a/opendc-simulator/opendc-simulator-flow/src/test/kotlin/org/opendc/simulator/flow/FlowForwarderTest.kt
+++ b/opendc-simulator/opendc-simulator-flow/src/test/kotlin/org/opendc/simulator/flow/FlowForwarderTest.kt
@@ -197,7 +197,7 @@ internal class FlowForwarderTest {
         }
 
         assertEquals(3000, clock.millis())
-        verify(exactly = 1) { consumer.onEvent(any(), any(), FlowEvent.Capacity) }
+        verify(exactly = 1) { consumer.onPull(any(), any(), any()) }
     }
 
     @Test
diff --git a/opendc-simulator/opendc-simulator-flow/src/test/kotlin/org/opendc/simulator/flow/FlowSinkTest.kt b/opendc-simulator/opendc-simulator-flow/src/test/kotlin/org/opendc/simulator/flow/FlowSinkTest.kt
index 010a985e..5d579e5d 100644
--- a/opendc-simulator/opendc-simulator-flow/src/test/kotlin/org/opendc/simulator/flow/FlowSinkTest.kt
+++ b/opendc-simulator/opendc-simulator-flow/src/test/kotlin/org/opendc/simulator/flow/FlowSinkTest.kt
@@ -67,7 +67,7 @@ internal class FlowSinkTest {
             provider.capacity = 0.5
         }
         assertEquals(3000, clock.millis())
-        verify(exactly = 1) { consumer.onEvent(any(), any(), FlowEvent.Capacity) }
+        verify(exactly = 1) { consumer.onPull(any(), any(), any()) }
     }
 
     @Test