test to reproduce dynamic graph crash

Package.swift

@@ -7,7 +7,7 @@ let package = Package(
     name: "AudioKitEX",
     platforms: [.macOS(.v12), .iOS(.v13), .tvOS(.v13)],
     products: [.library(name: "AudioKitEX", targets: ["AudioKitEX"])],
-    dependencies: [.package(url: "https://github.com/AudioKit/AudioKit", from: "5.5.0")],
+    dependencies: [.package(url: "https://github.com/AudioKit/AudioKit", branch: "dynamic_graph_crash")],
     targets: [
         .target(name: "AudioKitEX", dependencies: ["AudioKit", "CAudioKitEX"]),
         .target(name: "CAudioKitEX", cxxSettings: [.headerSearchPath(".")]),

Tests/AudioKitEXTests/DynamicGraphTests.swift

@@ -0,0 +1,327 @@
+//
+//  DynamicGraphTests.swift
+//  AudioKitEX
+//
+//  Created by Taylor Holliday on 3/23/26.
+//
+
+import Testing
+import AudioKit
+import AudioKitEX
+import AVFoundation
+import Accelerate
+import CAudioKitEX
+
+/// Manages local audio file playback using `AudioKit` with `AudioKitEX` fades.
+@MainActor
+final class AudioKitFilePlayer {
+    private struct ActivePlaybackNode {
+        let player: AudioPlayer
+        let fader: Fader
+        let panMixer: Mixer
+        let instrument: Instrument
+
+        var id: ObjectIdentifier {
+            ObjectIdentifier(player.playerNode)
+        }
+    }
+
+    let levelsHolder = LevelsHolder()
+
+    private let audioEngine = AudioEngine()
+    private let masterMixer = Mixer(name: "AudioKitFilePlayer Master")
+    private let instrumentMixers = Dictionary(
+        uniqueKeysWithValues: Instrument.allCases.map { instrument in
+            (instrument, Mixer(name: "\(instrument.rawValue) Mixer"))
+        }
+    )
+    private var levelsTap: RawBufferTap?
+
+    private var activePlaybackNodes: [ObjectIdentifier: ActivePlaybackNode] = [:]
+    private var engineIsRunning = false
+
+    var isRunning: Bool {
+        engineIsRunning
+    }
+
+    init() {
+        setupInstrumentMixers()
+        audioEngine.output = masterMixer
+        let levelsTap = RawBufferTap(
+            masterMixer,
+            bufferSize: 1024,
+            callbackQueue: .global(qos: .userInitiated),
+            handler: Self.makeLevelsTap(holder: levelsHolder)
+        )
+        self.levelsTap = levelsTap
+        levelsTap.start()
+    }
+
+    func startPlayback() {
+        do {
+            if !engineIsRunning {
+                try audioEngine.start()
+                engineIsRunning = true
+                Self.log("AudioEngine started")
+            }
+        } catch {
+            Self.log("Error starting AudioEngine: \(error)")
+        }
+    }
+
+    func stopPlayback() {
+        stopAllRunningPlayers()
+    }
+
+    func pausePlayback() {
+        stopAllRunningPlayers()
+        audioEngine.pause()
+        engineIsRunning = false
+    }
+
+    func reset() {
+        stopAllRunningPlayers()
+        audioEngine.stop()
+        levelsTap?.stop()
+        engineIsRunning = false
+    }
+
+    func setOutputVolume(_ outputVolume: Float) {
+        masterMixer.volume = outputVolume
+    }
+
+    func updateActiveInstruments(_ activeInstruments: Set<Instrument>) {
+        for (instrument, mixer) in instrumentMixers {
+            mixer.volume = activeInstruments.contains(instrument) ? 1.0 : 0.0
+        }
+    }
+
+    func scheduleFilePlayback(
+        _ audioFile: AVAudioFile,
+        fileName: String,
+        instrument: Instrument,
+        gain: Float,
+        startTime: Double,
+        endTime: Double,
+        fileOffset: Double,
+        fadeInDuration: Double,
+        fadeOutDuration: Double,
+        pan: Float
+    ) {
+        guard isRunning else { return }
+
+        guard let instrumentMixer = instrumentMixers[instrument] else {
+            Self.log("Missing mixer for instrument \(instrument.rawValue)")
+            return
+        }
+
+        let player = AudioPlayer()
+        let fader = Fader(player, gain: gain)
+        let panMixer = Mixer(fader, name: "\(fileName) Pan")
+        let activeNode = ActivePlaybackNode(
+            player: player,
+            fader: fader,
+            panMixer: panMixer,
+            instrument: instrument
+        )
+
+        do {
+            try player.load(file: audioFile, buffered: false)
+        } catch {
+            Self.log("Could not load audio file for \(fileName): \(error)")
+            return
+        }
+
+        panMixer.pan = AUValue(pan)
+        instrumentMixer.addInput(panMixer)
+        activePlaybackNodes[activeNode.id] = activeNode
+
+        let playDuration = max(0, endTime - startTime)
+        let effectiveGain = AUValue(max(0, gain))
+
+        if fadeInDuration > 0 {
+            fader.gain = 0
+        } else {
+            fader.gain = effectiveGain
+        }
+
+        let automationEvents = makeGainAutomationEvents(
+            targetGain: effectiveGain,
+            playDuration: playDuration,
+            fadeInDuration: fadeInDuration,
+            fadeOutDuration: fadeOutDuration
+        )
+
+        if !automationEvents.isEmpty {
+            fader.automateGain(events: automationEvents)
+        }
+
+        player.completionHandler = { [weak self] in
+            Task { @MainActor [weak self] in
+                self?.cleanupPlaybackNode(id: activeNode.id, fileName: fileName)
+            }
+        }
+
+        player.play(from: fileOffset, to: fileOffset + playDuration)
+    }
+
+    private func makeGainAutomationEvents(
+        targetGain: AUValue,
+        playDuration: Double,
+        fadeInDuration: Double,
+        fadeOutDuration: Double
+    ) -> [AutomationEvent] {
+        var events: [AutomationEvent] = []
+
+        if fadeInDuration > 0 {
+            events.append(
+                AutomationEvent(
+                    targetValue: targetGain,
+                    startTime: 0,
+                    rampDuration: Float(fadeInDuration)
+                )
+            )
+        }
+
+        if fadeOutDuration > 0 {
+            let fadeOutDelay = playDuration - fadeOutDuration
+
+            if fadeOutDelay > 0 {
+                events.append(
+                    AutomationEvent(
+                        targetValue: 0,
+                        startTime: Float(fadeOutDelay),
+                        rampDuration: Float(fadeOutDuration)
+                    )
+                )
+            }
+        }
+
+        return events
+    }
+
+    private func setupInstrumentMixers() {
+        for mixer in instrumentMixers.values {
+            masterMixer.addInput(mixer)
+        }
+    }
+
+    private func stopAllRunningPlayers() {
+        let activeNodes = Array(activePlaybackNodes.values)
+
+        for activeNode in activeNodes {
+            cleanupPlaybackNode(id: activeNode.id)
+        }
+    }
+
+    private func cleanupPlaybackNode(id: ObjectIdentifier, fileName: String? = nil) {
+        guard let activeNode = activePlaybackNodes.removeValue(forKey: id) else {
+            return
+        }
+
+        activeNode.player.stop()
+        activeNode.fader.stopAutomation()
+        activeNode.panMixer.volume = 0
+        instrumentMixers[activeNode.instrument]?.removeInput(activeNode.panMixer)
+
+        if let fileName {
+            Self.log("Detaching AudioKit player node for \(fileName)")
+        }
+    }
+
+    nonisolated private static func makeLevelsTap(holder: LevelsHolder) -> AVAudioNodeTapBlock {
+        return { buffer, _ in
+            guard let floatData = buffer.floatChannelData else {
+                log("Tap received nil floatChannelData")
+                return
+            }
+
+            let channelCount = Int(buffer.format.channelCount)
+            let length = UInt(buffer.frameLength)
+
+            for channelIndex in 0..<channelCount {
+                let data = floatData[channelIndex]
+
+                var rms: Float = 0
+                vDSP_rmsqv(data, 1, &rms, length)
+
+                holder.setLevel(rms, channel: channelIndex)
+            }
+        }
+    }
+}
+
+extension AudioKitFilePlayer {
+    nonisolated private static func log(_ message: @autoclosure () -> String) {
+        print("[AudioKitFilePlayer] \(message())")
+    }
+}
+
+enum Instrument: String, CaseIterable, Hashable {
+    case waves
+}
+
+final class LevelsHolder: @unchecked Sendable {
+    private let lock = NSLock()
+    private var levels: [Int: Float] = [:]
+
+    func setLevel(_ level: Float, channel: Int) {
+        lock.lock()
+        levels[channel] = level
+        lock.unlock()
+    }
+}
+
+
+/// Minimal repro: dynamically adding a player to a running engine and calling play() crashes
+/// with "player started when in a disconnected state".
+@MainActor
+@Test
+func testDynamicPlayerCrash() throws {
+    let engine = AudioEngine()
+    let masterMixer = Mixer(name: "Master")
+    engine.output = masterMixer
+    try engine.start()
+
+    let testFileURL = Bundle.module.url(forResource: "12345", withExtension: "wav", subdirectory: "TestResources")!
+    let audioFile = try AVAudioFile(forReading: testFileURL)
+
+    // Pre-connect an intermediate mixer (like an instrument bus)
+    let instrumentMixer = Mixer(name: "Instrument")
+    masterMixer.addInput(instrumentMixer)
+
+    let player = AudioPlayer()
+    try player.load(file: audioFile, buffered: false)
+
+    let fader = Fader(player)
+    let panMixer = Mixer(fader, name: "Pan")
+    instrumentMixer.addInput(panMixer)
+
+    player.play()
+}
+
+@MainActor
+@Test
+func testAudioKitFilePlayerCanScheduleLocalMP3() throws {
+    let testFileURL = Bundle.module.url(forResource: "12345", withExtension: "wav", subdirectory: "TestResources")!
+    let audioFile = try AVAudioFile(forReading: testFileURL)
+
+    let player = AudioKitFilePlayer()
+    player.startPlayback()
+
+    #expect(player.isRunning)
+
+    player.scheduleFilePlayback(
+        audioFile,
+        fileName: testFileURL.lastPathComponent,
+        instrument: .waves,
+        gain: 1.0,
+        startTime: 0,
+        endTime: min(audioFile.duration, 0.25),
+        fileOffset: 0,
+        fadeInDuration: 0.05,
+        fadeOutDuration: 0.05,
+        pan: 0
+    )
+}
+