Convert train-movement event detection to kDisco waitCrossing state events (Issue #750, step 1)

CLAUDE.md

@@ -202,7 +202,7 @@ For complete navigation services architecture, Koin DI integration patterns, and
 - `objects/paths/` - Route management
 
 **Simulation engine:**
-- Built on kDisco library (`cz.hovorka.kdisco:kdisco-core-jvm:0.6.0`) — replaces jDisco entirely (Phase 1 migration complete 2026-03-20)
+- Built on kDisco library (`cz.ksimulantenbande.kdisco:kdisco-core-jvm:0.6.1-SNAPSHOT`) — replaces jDisco entirely (Phase 1 migration complete 2026-03-20)
 - kDisco repo: https://github.com/bedaHovorka/kdisco
 - `sim/` package contains simulation processes (e.g., `ShuntingLoop`)
 

TEAM.md

@@ -29,7 +29,7 @@ This file defines specialized agent roles for the interlockSim project. When Cla
 
 **Focus Areas:**
 1. **Simulation Engine**
-   - kDisco 0.6.0 (Phase 1 migration complete 2026-03-20; Koin injection now allowed in sim/)
+   - kDisco 0.6.1-SNAPSHOT (Phase 1 migration complete 2026-03-20; Koin injection now allowed in sim/)
    - Kalasim migration planning (Goal 10, Phase 2, future)
    - `:fast-sim` native CLI subproject (linuxX64, PR #421)
    - Discrete-event simulation patterns

build.gradle.kts

@@ -50,7 +50,7 @@ val checkKdisco by tasks.registering {
     doLast {
         val kdiscoJar =
             file(
-                "${System.getProperty("user.home")}/.m2/repository/cz/hovorka/kdisco/kdisco-core-jvm/$kdiscoVersion/kdisco-core-jvm-$kdiscoVersion.jar",
+                "${System.getProperty("user.home")}/.m2/repository/cz/ksimulantenbande/kdisco/kdisco-core-jvm/$kdiscoVersion/kdisco-core-jvm-$kdiscoVersion.jar",
             )
 
         if (kdiscoJar.exists()) {

core/build.gradle.kts

@@ -21,7 +21,7 @@
  *     which benefits from commonMain staying free of JVM-only APIs.
  *  3. kDisco 0.4.0 ships multiplatform artifacts (jvm + linuxX64
  *     klibs) and this module consumes the multiplatform coordinate
- *     (`cz.hovorka.kdisco:kdisco-core`; see commonMain dependencies
+ *     (`cz.ksimulantenbande.kdisco:kdisco-core`; see commonMain dependencies
  *     below). Remaining blockers for fully portable common code are
  *     test infrastructure (MockK/JUnit5 are JVM-only; commonTest is
  *     restricted to kotlin.test) and a Koin/xmlutil native audit on
@@ -129,7 +129,7 @@ kotlin {
         val commonMain by getting {
             dependencies {
                 // KMP multiplatform artifacts (jvm + linuxX64 klibsavailable in mavenLocal)
-                implementation("cz.hovorka.kdisco:kdisco-core:$kdiscoVersion")
+                implementation("cz.ksimulantenbande.kdisco:kdisco-core:$kdiscoVersion")
                 implementation("io.insert-koin:koin-core:$koinVersion")
                 implementation("io.github.oshai:kotlin-logging:$kotlinLoggingVersion")
                 implementation("org.jetbrains.kotlin:kotlin-stdlib:$kotlinVersion")

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/context/DefaultSimulationContext.kt

@@ -9,10 +9,10 @@
  */
 package cz.vutbr.fit.interlockSim.context
 
-import cz.hovorka.kdisco.DiscoException
-import cz.hovorka.kdisco.Process
-import cz.hovorka.kdisco.Random
-import cz.hovorka.kdisco.Simulation
+import cz.ksimulantenbande.kdisco.DiscoException
+import cz.ksimulantenbande.kdisco.Process
+import cz.ksimulantenbande.kdisco.Random
+import cz.ksimulantenbande.kdisco.Simulation
 import cz.vutbr.fit.interlockSim.context.SimulationContext.ReportType
 import cz.vutbr.fit.interlockSim.context.navigation.BlockEvent
 import cz.vutbr.fit.interlockSim.context.navigation.PathReservationService
@@ -61,6 +61,7 @@ import cz.vutbr.fit.interlockSim.util.Util
 import cz.vutbr.fit.interlockSim.util.platformIdentityCode
 import io.github.oshai.kotlinlogging.KotlinLogging
 import kotlinx.coroutines.runBlocking
+import cz.ksimulantenbande.kdisco.SimulationEvent as KDiscoSimulationEvent
 import cz.vutbr.fit.interlockSim.sim.events.BlockEvent as AnimBlockEvent
 
 /**
@@ -206,7 +207,7 @@ open class DefaultSimulationContext(
 	private val pendingBlockEventListeners: MutableList<(BlockEvent) -> Unit> = mutableListOf()
 
 	/** Raw kdisco event listeners registered before run(); wired into kdisco at run() time. */
-	private val pendingSimEventListeners: MutableList<(cz.hovorka.kdisco.SimulationEvent) -> Unit> = mutableListOf()
+	private val pendingSimEventListeners: MutableList<(KDiscoSimulationEvent) -> Unit> = mutableListOf()
 
 	/** Spatial-conflict event listeners registered before run(); wired into kdisco at run() time. */
 	private val pendingConflictEventListeners: MutableList<(ConflictDetectedEvent) -> Unit> = mutableListOf()
@@ -1227,7 +1228,7 @@ open class DefaultSimulationContext(
 		pendingBlockEventListeners += listener
 	}
 
-	override fun onSimulationEvent(listener: (cz.hovorka.kdisco.SimulationEvent) -> Unit) {
+	override fun onSimulationEvent(listener: (KDiscoSimulationEvent) -> Unit) {
 		if (simulationHasStarted) return
 		pendingSimEventListeners += listener
 	}
@@ -1410,7 +1411,7 @@ open class DefaultSimulationContext(
 		if (listeners.isEmpty()) return
 		val snapshot = listeners.toList()
 		sim.onEvent { event ->
-			if (event is cz.hovorka.kdisco.SimulationEvent.Custom) {
+			if (event is KDiscoSimulationEvent.Custom) {
 				val payload = event.payload
 				if (payload is T) {
 					snapshot.forEach { it(payload) }

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/context/SimulationEnvironment.kt

@@ -9,7 +9,7 @@
  */
 package cz.vutbr.fit.interlockSim.context
 
-import cz.hovorka.kdisco.Condition
+import cz.ksimulantenbande.kdisco.Condition
 import cz.vutbr.fit.interlockSim.context.navigation.BlockEvent
 import cz.vutbr.fit.interlockSim.context.navigation.PathResult
 import cz.vutbr.fit.interlockSim.context.navigation.RoutingServices
@@ -29,7 +29,7 @@ import cz.vutbr.fit.interlockSim.sim.conflict.TemporalConflictDetector
 import cz.vutbr.fit.interlockSim.sim.conflict.TemporalConflictEvent
 import cz.vutbr.fit.interlockSim.sim.events.BlockEventListener
 import cz.vutbr.fit.interlockSim.sim.metrics.MetricsServices
-import cz.hovorka.kdisco.SimulationEvent as KDiscoSimulationEvent
+import cz.ksimulantenbande.kdisco.SimulationEvent as KDiscoSimulationEvent
 import cz.vutbr.fit.interlockSim.sim.events.BlockEvent as AnimBlockEvent
 
 /**
@@ -150,7 +150,7 @@ interface SimulationEnvironment : NetworkState {
 	 * Create a kDisco [Condition] that becomes true when the path starting at
 	 * [separator] is reserved for [trainId].
 	 *
-	 * This lets a train process suspend with [cz.hovorka.kdisco.Process.waitUntil]
+	 * This lets a train process suspend with [cz.ksimulantenbande.kdisco.Process.waitUntil]
 	 * and resume deterministically as soon as the dispatcher reserves the path
 	 * (or as soon as a conflicting train releases the required blocks).
 	 *

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/context/navigation/BlockEvent.kt

@@ -6,7 +6,7 @@ import cz.vutbr.fit.interlockSim.objects.tracks.DynamicTrackBlock
 /**
  * Domain events emitted when block reservation or occupancy state changes.
  *
- * Delivered via kdisco's event bus as [cz.hovorka.kdisco.SimulationEvent.Custom] payloads.
+ * Delivered via kdisco's event bus as [cz.ksimulantenbande.kdisco.SimulationEvent.Custom] payloads.
  * Subscribe via [cz.vutbr.fit.interlockSim.context.SimulationEnvironment.onBlockEvent].
  *
  * All fields are captured at emission time (simulation-thread values).

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/context/navigation/DefaultPathReservationService.kt

@@ -9,8 +9,8 @@
  */
 package cz.vutbr.fit.interlockSim.context.navigation
 
-import cz.hovorka.kdisco.Process
-import cz.hovorka.kdisco.emitCustom
+import cz.ksimulantenbande.kdisco.Process
+import cz.ksimulantenbande.kdisco.emitCustom
 import cz.vutbr.fit.interlockSim.context.RouteFinder
 import cz.vutbr.fit.interlockSim.context.SimulationEnvironment
 import cz.vutbr.fit.interlockSim.exceptions.PathSeparatorChangeException

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/context/navigation/PathReservationRegistry.kt

@@ -9,7 +9,7 @@
  */
 package cz.vutbr.fit.interlockSim.context.navigation
 
-import cz.hovorka.kdisco.Condition
+import cz.ksimulantenbande.kdisco.Condition
 import cz.vutbr.fit.interlockSim.context.SimulationContext
 import cz.vutbr.fit.interlockSim.exceptions.requireValidState
 import cz.vutbr.fit.interlockSim.objects.cells.DynamicRailSwitch
@@ -506,7 +506,7 @@ class PathReservationRegistry(
 	 * The condition is deterministic: kDisco re-evaluates all wait notices after
 	 * every discrete event (including the block-release event that happens when
 	 * [unregister] or [unregisterBlock] removes the owner). A process can suspend
-	 * with [cz.hovorka.kdisco.Process.waitUntil] and resume without busy-polling.
+	 * with [cz.ksimulantenbande.kdisco.Process.waitUntil] and resume without busy-polling.
 	 *
 	 * @param block The block to wait for
 	 * @return A condition evaluating to true once the block is free

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/exceptions/SimulationException.kt

@@ -9,7 +9,7 @@
  */
 package cz.vutbr.fit.interlockSim.exceptions
 
-import cz.hovorka.kdisco.Process
+import cz.ksimulantenbande.kdisco.Process
 
 /**
  * Exception thrown during simulation - at start, between start and end of simulation.

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/objects/cells/DynamicRailSemaphore.kt

@@ -9,7 +9,7 @@
  */
 package cz.vutbr.fit.interlockSim.objects.cells
 
-import cz.hovorka.kdisco.Process
+import cz.ksimulantenbande.kdisco.Process
 import cz.vutbr.fit.interlockSim.exceptions.PathSeparatorChangeException
 import cz.vutbr.fit.interlockSim.exceptions.requireSimulation
 import cz.vutbr.fit.interlockSim.objects.core.Cell

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/objects/cells/DynamicRailSwitch.kt

@@ -9,7 +9,7 @@
  */
 package cz.vutbr.fit.interlockSim.objects.cells
 
-import cz.hovorka.kdisco.Process
+import cz.ksimulantenbande.kdisco.Process
 import cz.vutbr.fit.interlockSim.exceptions.PathSeparatorChangeException
 import cz.vutbr.fit.interlockSim.exceptions.requireSimulationNotNull
 import cz.vutbr.fit.interlockSim.objects.cells.RailSwitch.Conf

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/objects/paths/AbstractPath.kt

@@ -9,7 +9,7 @@
  */
 package cz.vutbr.fit.interlockSim.objects.paths
 
-import cz.hovorka.kdisco.Process
+import cz.ksimulantenbande.kdisco.Process
 import cz.vutbr.fit.interlockSim.context.SimulationContext
 import cz.vutbr.fit.interlockSim.context.SimulationContext.ReportType
 import cz.vutbr.fit.interlockSim.domain.ABSOLUTE_MAX_SPEED

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/objects/tracks/DynamicTrack.kt

@@ -9,7 +9,7 @@
  */
 package cz.vutbr.fit.interlockSim.objects.tracks
 
-import cz.hovorka.kdisco.Process
+import cz.ksimulantenbande.kdisco.Process
 import cz.vutbr.fit.interlockSim.exceptions.TrackOperationException
 import cz.vutbr.fit.interlockSim.exceptions.requireSimulation
 import cz.vutbr.fit.interlockSim.exceptions.requireSimulationNotNull

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/objects/tracks/DynamicTrackBlock.kt

@@ -9,8 +9,8 @@
  */
 package cz.vutbr.fit.interlockSim.objects.tracks
 
-import cz.hovorka.kdisco.Process
-import cz.hovorka.kdisco.emitCustom
+import cz.ksimulantenbande.kdisco.Process
+import cz.ksimulantenbande.kdisco.emitCustom
 import cz.vutbr.fit.interlockSim.context.navigation.BlockEvent
 import cz.vutbr.fit.interlockSim.exceptions.TrackOperationException
 import cz.vutbr.fit.interlockSim.exceptions.requireSimulation

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/ports/DefaultNetworkPerceptionPort.kt

@@ -9,8 +9,8 @@
  */
 package cz.vutbr.fit.interlockSim.ports
 
-import cz.hovorka.kdisco.DiscoException
-import cz.hovorka.kdisco.Process
+import cz.ksimulantenbande.kdisco.DiscoException
+import cz.ksimulantenbande.kdisco.Process
 import cz.vutbr.fit.interlockSim.context.SimulationEnvironment
 import cz.vutbr.fit.interlockSim.objects.cells.DynamicRailSemaphore
 import cz.vutbr.fit.interlockSim.objects.cells.NodeCell

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/sim/BlockResourceRegistry.kt

@@ -9,7 +9,7 @@
  */
 package cz.vutbr.fit.interlockSim.sim
 
-import cz.hovorka.kdisco.Resource
+import cz.ksimulantenbande.kdisco.Resource
 import cz.vutbr.fit.interlockSim.context.SimulationContext
 import cz.vutbr.fit.interlockSim.objects.core.TrackFacility
 import cz.vutbr.fit.interlockSim.objects.tracks.DynamicTrackBlock

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/sim/ContinuousInvariantChecker.kt

@@ -9,8 +9,8 @@
  */
 package cz.vutbr.fit.interlockSim.sim
 
-import cz.hovorka.kdisco.Continuous
-import cz.hovorka.kdisco.Process
+import cz.ksimulantenbande.kdisco.Continuous
+import cz.ksimulantenbande.kdisco.Process
 import cz.vutbr.fit.interlockSim.exceptions.requireSimulation
 
 /**

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/sim/DispatchObservation.kt

@@ -82,6 +82,22 @@ data class QueuedTrainObservation(
  *   [ShuntingLoop]). `null` when no FREE next separator exists, in which case the
  *   dispatcher emits [DispatchDecision.NoAction] for this input (the train waits
  *   and is reconsidered next tick).
+ *
+ *   **Populated only where a forward reservation is possible** (Issue #749). The shell
+ *   resolves it exclusively for inputs satisfying
+ *   `!pathAlreadyExtendedBeyond && (isApproachingThisInput || pathSetUpTowardThisInput)`;
+ *   for every other input — FREE, not approaching this input, or already extended beyond
+ *   it — this is `null` **without the search having been run**. Resolving it means a BFS
+ *   plus a per-candidate topological-path enumeration
+ *   ([PathReservationService.findNextReservationTarget][cz.vutbr.fit.interlockSim.context.navigation.PathReservationService.findNextReservationTarget]);
+ *   running it for the ~98% of inputs whose value is then discarded cost ~9% of fast-sim
+ *   wall time.
+ *
+ *   A `null` here therefore means *"no forward-reservation target applies"*, not
+ *   *"the search found nothing"* — the two are indistinguishable to a dispatcher, and
+ *   both call for the same response (no reservation for this input on this tick).
+ *   Dispatcher implementations — including future LLM-backed ones — must not read
+ *   `toSeparatorName == null` as evidence that the track ahead is occupied.
  * @property state Occupancy state of the block.
  * @property ownerTrainId Name of the train associated with this block: the
  *   occupant's name when OCCUPIED, [cz.vutbr.fit.interlockSim.objects.tracks.DynamicTrackBlock.trainName]

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/sim/Generator.kt

@@ -9,12 +9,12 @@
  */
 package cz.vutbr.fit.interlockSim.sim
 
-import cz.hovorka.kdisco.Process
-import cz.hovorka.kdisco.Random
-import cz.hovorka.kdisco.dtMax
-import cz.hovorka.kdisco.dtMin
-import cz.hovorka.kdisco.maxAbsError
-import cz.hovorka.kdisco.maxRelError
+import cz.ksimulantenbande.kdisco.Process
+import cz.ksimulantenbande.kdisco.Random
+import cz.ksimulantenbande.kdisco.dtMax
+import cz.ksimulantenbande.kdisco.dtMin
+import cz.ksimulantenbande.kdisco.maxAbsError
+import cz.ksimulantenbande.kdisco.maxRelError
 import cz.vutbr.fit.interlockSim.context.SimulationEnvironment
 import io.github.oshai.kotlinlogging.KotlinLogging
 
@@ -31,6 +31,13 @@ open class Generator(
 
 	override suspend fun startAction() {
 		dtMin = 1e-6
+		// Block-boundary and tail-entry events are now located by kDisco root-finding
+		// (`Process.waitCrossing`, see Train.kt) rather than by step granularity, so `dtMax` no
+		// longer has to be tiny to keep *those* events' overshoot negligible. Motor's
+		// AccelerationStopCondition (velocity-target detection, Train.kt) is NOT yet converted —
+		// it still relies on step granularity via plain `waitUntil` — so `dtMax` is deliberately
+		// left unchanged here rather than raised further; converting Motor and re-tuning dtMax
+		// is tracked separately (Issue #760, follow-up to #750).
 		dtMax = 1e-3
 		maxRelError = 1e-2
 		maxAbsError = 1e-2

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/sim/InOutWorker.kt

@@ -9,10 +9,10 @@
  */
 package cz.vutbr.fit.interlockSim.sim
 
-import cz.hovorka.kdisco.Condition
-import cz.hovorka.kdisco.Head
-import cz.hovorka.kdisco.Link
-import cz.hovorka.kdisco.Process
+import cz.ksimulantenbande.kdisco.Condition
+import cz.ksimulantenbande.kdisco.Head
+import cz.ksimulantenbande.kdisco.Link
+import cz.ksimulantenbande.kdisco.Process
 import cz.vutbr.fit.interlockSim.context.SimulationContext.ReportType
 import cz.vutbr.fit.interlockSim.context.SimulationEnvironment
 import cz.vutbr.fit.interlockSim.context.navigation.PathReservationService

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/sim/LoopProcess.kt

@@ -9,8 +9,8 @@
  */
 package cz.vutbr.fit.interlockSim.sim
 
-import cz.hovorka.kdisco.DiscoException
-import cz.hovorka.kdisco.Process
+import cz.ksimulantenbande.kdisco.DiscoException
+import cz.ksimulantenbande.kdisco.Process
 import io.github.oshai.kotlinlogging.KotlinLogging
 
 /**

core/src/commonMain/kotlin/cz/vutbr/fit/interlockSim/sim/MultiTrainLoop.kt

@@ -9,8 +9,8 @@
  */
 package cz.vutbr.fit.interlockSim.sim
 
-import cz.hovorka.kdisco.Process
-import cz.hovorka.kdisco.Resource
+import cz.ksimulantenbande.kdisco.Process
+import cz.ksimulantenbande.kdisco.Resource
 import cz.vutbr.fit.interlockSim.context.SimulationContext
 import cz.vutbr.fit.interlockSim.context.SimulationContext.ReportType
 import cz.vutbr.fit.interlockSim.context.SimulationEnvironment
@@ -52,7 +52,7 @@ import io.github.oshai.kotlinlogging.KotlinLogging
  * ## Determinism
  *
  * Train injection times come from caller-supplied specs, so runs are repeatable
- * when paired with a fixed kDisco seed. No standalone [cz.hovorka.kdisco.Random]
+ * when paired with a fixed kDisco seed. No standalone [cz.ksimulantenbande.kdisco.Random]
  * generator is required.
  *
  * ## Scope limitations (documented)