Incremental migration to strict concurrency checking #1

Package@swift-5.9.swift

@@ -41,6 +41,7 @@ let package = Package(
             ],
             swiftSettings: [
                 .enableExperimentalFeature("AccessLevelOnImport"),
+                .enableExperimentalFeature("StrictConcurrency"),
             ]
         ),
         .testTarget(

Sources/LiveKit/Broadcast/Uploader/DarwinNotificationCenter.swift

@@ -21,20 +21,16 @@ enum DarwinNotification: String {
     case broadcastStopped = "iOS_BroadcastStopped"
 }
 
-class DarwinNotificationCenter {
-    #if compiler(>=6.0)
-    public nonisolated(unsafe) static let shared = DarwinNotificationCenter()
-    #else
+final class DarwinNotificationCenter: @unchecked Sendable {
     public static let shared = DarwinNotificationCenter()
-    #endif
 
-    private let notificationCenter: CFNotificationCenter
-
-    init() {
-        notificationCenter = CFNotificationCenterGetDarwinNotifyCenter()
-    }
+    private let notificationCenter = CFNotificationCenterGetDarwinNotifyCenter()
 
     func postNotification(_ name: DarwinNotification) {
-        CFNotificationCenterPostNotification(notificationCenter, CFNotificationName(rawValue: name.rawValue as CFString), nil, nil, true)
+        CFNotificationCenterPostNotification(notificationCenter,
+                                             CFNotificationName(rawValue: name.rawValue as CFString),
+                                             nil,
+                                             nil,
+                                             true)
     }
 }

Sources/LiveKit/Core/Room+Debug.swift

@@ -16,7 +16,7 @@
 
 import Foundation
 
-public enum SimulateScenario {
+public enum SimulateScenario: Sendable {
     // Client
     case quickReconnect
     case fullReconnect

Sources/LiveKit/Core/Room+Engine.swift

@@ -221,7 +221,7 @@ extension Room {
 
 // MARK: - Connection / Reconnection logic
 
-public enum StartReconnectReason {
+public enum StartReconnectReason: Sendable {
     case websocket
     case transport
     case networkSwitch

Sources/LiveKit/Core/Room+SignalClientDelegate.swift

@@ -301,7 +301,7 @@ extension Room: SignalClientDelegate {
         }
     }
 
-    func signalClient(_: SignalClient, didReceiveIceCandidate iceCandidate: LKRTCIceCandidate, target: Livekit_SignalTarget) async {
+    func signalClient(_: SignalClient, didReceiveIceCandidate iceCandidate: IceCandidate, target: Livekit_SignalTarget) async {
         guard let transport = target == .subscriber ? _state.subscriber : _state.publisher else {
             log("Failed to add ice candidate, transport is nil for target: \(target)", .error)
             return

Sources/LiveKit/Core/Room+TransportDelegate.swift

@@ -68,7 +68,7 @@ extension Room: TransportDelegate {
         }
     }
 
-    func transport(_ transport: Transport, didGenerateIceCandidate iceCandidate: LKRTCIceCandidate) {
+    func transport(_ transport: Transport, didGenerateIceCandidate iceCandidate: IceCandidate) {
         Task {
             do {
                 log("sending iceCandidate")

Sources/LiveKit/Core/Room.swift

@@ -205,7 +205,7 @@ public class Room: NSObject, ObservableObject, Loggable {
         }
 
         // listen to app states
-        AppStateListener.shared.add(delegate: self)
+        AppStateListener.shared.delegates.add(delegate: self)
 
         // trigger events when state mutates
         _state.onDidMutate = { [weak self] newState, oldState in

Sources/LiveKit/Core/SignalClient.swift

@@ -28,7 +28,7 @@ actor SignalClient: Loggable {
     typealias AddTrackRequestPopulator<R> = (inout Livekit_AddTrackRequest) throws -> R
     typealias AddTrackResult<R> = (result: R, trackInfo: Livekit_TrackInfo)
 
-    public enum ConnectResponse {
+    public enum ConnectResponse: Sendable {
         case join(Livekit_JoinResponse)
         case reconnect(Livekit_ReconnectResponse)
 
@@ -289,7 +289,7 @@ private extension SignalClient {
                 return
             }
 
-            _delegate.notifyDetached { await $0.signalClient(self, didReceiveIceCandidate: rtcCandidate, target: trickle.target) }
+            _delegate.notifyDetached { await $0.signalClient(self, didReceiveIceCandidate: rtcCandidate.toLKType(), target: trickle.target) }
 
         case let .update(update):
             _delegate.notifyDetached { await $0.signalClient(self, didUpdateParticipants: update.participants) }
@@ -377,11 +377,11 @@ extension SignalClient {
         try await _sendRequest(r)
     }
 
-    func sendCandidate(candidate: LKRTCIceCandidate, target: Livekit_SignalTarget) async throws {
+    func sendCandidate(candidate: IceCandidate, target: Livekit_SignalTarget) async throws {
         let r = try Livekit_SignalRequest.with {
             $0.trickle = try Livekit_TrickleRequest.with {
                 $0.target = target
-                $0.candidateInit = try candidate.toLKType().toJsonString()
+                $0.candidateInit = try candidate.toJsonString()
             }
         }
 

Sources/LiveKit/Core/Transport.swift

@@ -64,11 +64,11 @@ actor Transport: NSObject, Loggable {
     // forbid direct access to PeerConnection
     private let _pc: LKRTCPeerConnection
 
-    private lazy var _iceCandidatesQueue = QueueActor<LKRTCIceCandidate>(onProcess: { [weak self] iceCandidate in
+    private lazy var _iceCandidatesQueue = QueueActor<IceCandidate>(onProcess: { [weak self] iceCandidate in
         guard let self else { return }
 
         do {
-            try await self._pc.add(iceCandidate)
+            try await self._pc.add(iceCandidate.toRTCType())
         } catch {
             self.log("Failed to add(iceCandidate:) with error: \(error)", .error)
         }
@@ -114,7 +114,7 @@ actor Transport: NSObject, Loggable {
         _isRestartingIce = true
     }
 
-    func add(iceCandidate candidate: LKRTCIceCandidate) async throws {
+    func add(iceCandidate candidate: IceCandidate) async throws {
         await _iceCandidatesQueue.process(candidate, if: remoteDescription != nil && !_isRestartingIce)
     }
 
@@ -222,7 +222,7 @@ extension Transport: LKRTCPeerConnectionDelegate {
     }
 
     nonisolated func peerConnection(_: LKRTCPeerConnection, didGenerate candidate: LKRTCIceCandidate) {
-        _delegate.notify { $0.transport(self, didGenerateIceCandidate: candidate) }
+        _delegate.notify { $0.transport(self, didGenerateIceCandidate: candidate.toLKType()) }
     }
 
     nonisolated func peerConnectionShouldNegotiate(_: LKRTCPeerConnection) {

Sources/LiveKit/E2EE/KeyProvider.swift

@@ -28,7 +28,7 @@ public let defaultRatchetWindowSize: Int32 = 0
 public let defaultFailureTolerance: Int32 = -1
 
 @objc
-public class KeyProviderOptions: NSObject {
+public final class KeyProviderOptions: NSObject, Sendable {
     @objc
     public let sharedKey: Bool
 
@@ -80,7 +80,7 @@ public class KeyProviderOptions: NSObject {
 }
 
 @objc
-public class BaseKeyProvider: NSObject, Loggable {
+public final class BaseKeyProvider: NSObject, Loggable, Sendable {
     @objc
     public let options: KeyProviderOptions
 

Sources/LiveKit/E2EE/Options.swift

@@ -17,7 +17,7 @@
 import Foundation
 
 @objc
-public enum EncryptionType: Int {
+public enum EncryptionType: Int, Sendable {
     case none
     case gcm
     case custom
@@ -46,7 +46,7 @@ extension Livekit_Encryption.TypeEnum {
 }
 
 @objc
-public class E2EEOptions: NSObject {
+public final class E2EEOptions: NSObject, Sendable {
     @objc
     public let keyProvider: BaseKeyProvider
 

Sources/LiveKit/E2EE/State.swift

@@ -23,7 +23,7 @@ internal import LiveKitWebRTC
 #endif
 
 @objc
-public enum E2EEState: Int {
+public enum E2EEState: Int, Sendable {
     case new
     case ok
     case key_ratcheted

Sources/LiveKit/Errors.swift

@@ -22,7 +22,7 @@ internal import LiveKitWebRTC
 @_implementationOnly import LiveKitWebRTC
 #endif
 
-public enum LiveKitErrorType: Int {
+public enum LiveKitErrorType: Int, Sendable {
     case unknown = 0
     case cancelled = 100
     case timedOut = 101
@@ -98,7 +98,7 @@ extension LiveKitErrorType: CustomStringConvertible {
 }
 
 @objc
-public class LiveKitError: NSError {
+public class LiveKitError: NSError, @unchecked Sendable {
     public let type: LiveKitErrorType
     public let message: String?
     public let underlyingError: Error?

Sources/LiveKit/Extensions/RTCMediaConstraints.swift

@@ -23,16 +23,8 @@ internal import LiveKitWebRTC
 #endif
 
 extension LKRTCMediaConstraints {
-    //    static let defaultOfferConstraints = RTCMediaConstraints(
-    //        mandatoryConstraints: [
-    //            kRTCMediaConstraintsOfferToReceiveAudio: kRTCMediaConstraintsValueFalse,
-    //            kRTCMediaConstraintsOfferToReceiveVideo: kRTCMediaConstraintsValueFalse,
-    //        ],
-    //        optionalConstraints: nil
-    //    )
-
-    static let defaultPCConstraints = DispatchQueue.liveKitWebRTC.sync { LKRTCMediaConstraints(
+    static let defaultPCConstraints = LKRTCMediaConstraints(
         mandatoryConstraints: nil,
         optionalConstraints: ["DtlsSrtpKeyAgreement": kRTCMediaConstraintsValueTrue]
-    ) }
+    )
 }

Sources/LiveKit/Extensions/Sendable.swift

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2024 LiveKit
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import Foundation
+
+#if swift(>=5.9)
+internal import LiveKitWebRTC
+#else
+@_implementationOnly import LiveKitWebRTC
+#endif
+
+// Immutable classes.
+extension LKRTCMediaConstraints: @unchecked Sendable {}
+extension LKRTCSessionDescription: @unchecked Sendable {}

Sources/LiveKit/Protocols/SignalClientDelegate.swift

@@ -27,7 +27,7 @@ protocol SignalClientDelegate: AnyObject {
     func signalClient(_ signalClient: SignalClient, didReceiveConnectResponse connectResponse: SignalClient.ConnectResponse) async
     func signalClient(_ signalClient: SignalClient, didReceiveAnswer answer: LKRTCSessionDescription) async
     func signalClient(_ signalClient: SignalClient, didReceiveOffer offer: LKRTCSessionDescription) async
-    func signalClient(_ signalClient: SignalClient, didReceiveIceCandidate iceCandidate: LKRTCIceCandidate, target: Livekit_SignalTarget) async
+    func signalClient(_ signalClient: SignalClient, didReceiveIceCandidate iceCandidate: IceCandidate, target: Livekit_SignalTarget) async
     func signalClient(_ signalClient: SignalClient, didUnpublishLocalTrack localTrack: Livekit_TrackUnpublishedResponse) async
     func signalClient(_ signalClient: SignalClient, didUpdateParticipants participants: [Livekit_ParticipantInfo]) async
     func signalClient(_ signalClient: SignalClient, didUpdateRoom room: Livekit_Room) async

Sources/LiveKit/Protocols/TransportDelegate.swift

@@ -22,7 +22,7 @@ internal import LiveKitWebRTC
 
 protocol TransportDelegate: AnyObject {
     func transport(_ transport: Transport, didUpdateState state: RTCPeerConnectionState)
-    func transport(_ transport: Transport, didGenerateIceCandidate iceCandidate: LKRTCIceCandidate)
+    func transport(_ transport: Transport, didGenerateIceCandidate iceCandidate: IceCandidate)
     func transport(_ transport: Transport, didOpenDataChannel dataChannel: LKRTCDataChannel)
     func transport(_ transport: Transport, didAddTrack track: LKRTCMediaStreamTrack, rtpReceiver: LKRTCRtpReceiver, streams: [LKRTCMediaStream])
     func transport(_ transport: Transport, didRemoveTrack track: LKRTCMediaStreamTrack)

Sources/LiveKit/Support/AppStateListener.swift

@@ -35,57 +35,56 @@ protocol AppStateDelegate: AnyObject {
     func appDidWake()
 }
 
-class AppStateListener: MulticastDelegate<AppStateDelegate> {
+class AppStateListener: Loggable {
     static let shared = AppStateListener()
 
-    private let queue = OperationQueue()
+    private let _queue = OperationQueue()
+    let delegates = MulticastDelegate<AppStateDelegate>(label: "AppStateDelegate")
 
     private init() {
-        super.init(label: "AppStateDelegate")
-
         let defaultCenter = NotificationCenter.default
 
         #if os(iOS) || os(visionOS) || os(tvOS)
         defaultCenter.addObserver(forName: UIApplication.didEnterBackgroundNotification,
                                   object: nil,
-                                  queue: queue)
+                                  queue: _queue)
         { _ in
             self.log("UIApplication.didEnterBackground")
-            self.notify { $0.appDidEnterBackground() }
+            self.delegates.notify { $0.appDidEnterBackground() }
         }
 
         defaultCenter.addObserver(forName: UIApplication.willEnterForegroundNotification,
                                   object: nil,
-                                  queue: queue)
+                                  queue: _queue)
         { _ in
             self.log("UIApplication.willEnterForeground")
-            self.notify { $0.appWillEnterForeground() }
+            self.delegates.notify { $0.appWillEnterForeground() }
         }
 
         defaultCenter.addObserver(forName: UIApplication.willTerminateNotification,
                                   object: nil,
-                                  queue: queue)
+                                  queue: _queue)
         { _ in
             self.log("UIApplication.willTerminate")
-            self.notify { $0.appWillTerminate() }
+            self.delegates.notify { $0.appWillTerminate() }
         }
         #elseif os(macOS)
         let workspaceCenter = NSWorkspace.shared.notificationCenter
 
         workspaceCenter.addObserver(forName: NSWorkspace.willSleepNotification,
                                     object: nil,
-                                    queue: queue)
+                                    _queue: _queue)
         { _ in
             self.log("NSWorkspace.willSleepNotification")
-            self.notify { $0.appWillSleep() }
+            self.delegates.notify { $0.appWillSleep() }
         }
 
         workspaceCenter.addObserver(forName: NSWorkspace.didWakeNotification,
                                     object: nil,
-                                    queue: queue)
+                                    _queue: _queue)
         { _ in
             self.log("NSWorkspace.didWakeNotification")
-            self.notify { $0.appDidWake() }
+            self.delegates.notify { $0.appDidWake() }
         }
         #endif
     }

Sources/LiveKit/Support/QueueActor.swift

@@ -21,7 +21,7 @@ actor QueueActor<T>: Loggable {
 
     // MARK: - Public
 
-    public enum State {
+    public enum State: Sendable {
         case resumed
         case suspended
     }

Sources/LiveKit/Support/ValueOrAbsent.swift

@@ -15,7 +15,7 @@
  */
 
 /// Allows distinguishing between setting nil and no-op in copyWith operations.
-public enum ValueOrAbsent<T> {
+public enum ValueOrAbsent<T: Sendable>: Sendable {
     case value(T)
     case absent
 

Sources/LiveKit/Track/Capturers/MacOSScreenCapturer.swift

@@ -269,7 +269,7 @@ public extension LocalVideoTrack {
 }
 
 @objc
-public enum MacOSScreenShareSourceType: Int {
+public enum MacOSScreenShareSourceType: Int, Sendable {
     case any
     case display
     case window

Sources/LiveKit/Track/Capturers/VideoCapturer.swift

@@ -61,7 +61,7 @@ public class VideoCapturer: NSObject, Loggable, VideoCapturerProtocol {
     }
 
     @objc
-    public enum CapturerState: Int {
+    public enum CapturerState: Int, Sendable {
         case stopped
         case started
     }