SimulationReset.kt

src/jvmMain/kotlin/afield/runtime/lifecycle/SimulationReset.kt · 74 lines

package afield.runtime.lifecycle

import afield.data.table.div
import afield.data.table.minus
import afield.data.table.plus
import afield.data.table.rem
import afield.data.table.times
import afield.document.graph.box
import afield.runtime.execution.plus
import afield.ui.output.history

import afield.audio.synth.*
import afield.data.table.get
import afield.graphics.vulkan.*
import afield.media.stream.*
import afield.media.video.*
import java.util.concurrent.atomic.AtomicLong

SimulationReset, a way for UI or agent threads to ask a running simulation to reset at its next frame boundary, with several requests before that boundary coalesced into one reset.

class SimulationReset

Coalesced reset requests, consumed explicitly at an application's frame boundary. This is not a launcher: create it in normal box setup and consume it inside the existing frames/loop coroutine. Requests can arrive from UI/agent threads.

The reset callback runs on the consuming thread. Keep GPU/audio allocations outside it; reset their contents/history explicitly on their owning threads.

class SimulationReset {
    private val requested = AtomicLong()
    @Volatile private var consumed = 0L
    private var lastFrame: Long? = null
    private var owner: Thread? = null

@Volatile var completed: Long

    @Volatile var completed: Long = 0
        private set

@Volatile var failure: String?

    @Volatile var failure: String? = null
        private set

@Volatile var epoch: Any

    @Volatile var epoch: Any = Any()
        private set

val pending: Boolean get() = requested.get() > consumed

fun request(): Long = requested.updateAndGet { check(it < Long.MAX_VALUE); it + 1 }

Returns a ticket. Multiple requests before the next boundary share one reset.

fun atFrame(frame: Long, reset: () -> Unit): Boolean {

At most once per frame id. A failed callback is reported and is not retried silently; request again after repairing it. No state rollback is implied. A request arriving during the callback remains pending for the next frame.

    fun atFrame(frame: Long, reset: () -> Unit): Boolean {
        val thread = Thread.currentThread()
        check(owner == null || owner === thread) { "Consume resets on one owner thread" }
        owner = thread
        if (lastFrame == frame) return false
        lastFrame = frame
        val ticket = requested.get()
        if (ticket == consumed) return false
        consumed = ticket
        try {
            reset()
            epoch = Any()
            completed = ticket
            failure = null
            return true
        } catch (t: Throwable) {
            failure = t.message ?: t.javaClass.name
            throw t
        }
    }
}