Add tests

NWParameters is a class, so we don't need it to be inout when passing it to the configurator closure

Sources/NIOTransportServices/Datagram/NIOTSDatagramBootstrap.swift

@@ -47,7 +47,7 @@ public final class NIOTSDatagramBootstrap {
     private var qos: DispatchQoS?
     private var udpOptions: NWProtocolUDP.Options = .init()
     private var tlsOptions: NWProtocolTLS.Options?
-    private var nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+    private var nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?
 
     /// Create a `NIOTSDatagramConnectionBootstrap` on the `EventLoopGroup` `group`.
     ///
@@ -136,7 +136,7 @@ public final class NIOTSDatagramBootstrap {
 
     /// Customise the `NWParameters` to be used when creating the connection.
     public func configureNWParameters(
-        _ configurator: @Sendable @escaping (inout NWParameters) -> Void
+        _ configurator: @Sendable @escaping (NWParameters) -> Void
     ) -> Self {
         self.nwParametersConfigurator = configurator
         return self

Sources/NIOTransportServices/Datagram/NIOTSDatagramChannel.swift

@@ -140,11 +140,11 @@ internal final class NIOTSDatagramChannel: StateManagedNWConnectionChannel {
     internal var allowLocalEndpointReuse = false
     internal var multipathServiceType: NWParameters.MultipathServiceType = .disabled
 
-    private let nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+    private let nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?
 
     var parameters: NWParameters {
-        var parameters = NWParameters(dtls: self.tlsOptions, udp: self.udpOptions)
-        self.nwParametersConfigurator?(&parameters)
+        let parameters = NWParameters(dtls: self.tlsOptions, udp: self.udpOptions)
+        self.nwParametersConfigurator?(parameters)
         return parameters
     }
 
@@ -187,7 +187,7 @@ internal final class NIOTSDatagramChannel: StateManagedNWConnectionChannel {
         maximumReceiveLength: Int = 8192,
         udpOptions: NWProtocolUDP.Options,
         tlsOptions: NWProtocolTLS.Options?,
-        nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+        nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?
     ) {
         self.tsEventLoop = eventLoop
         self.closePromise = eventLoop.makePromise()
@@ -213,7 +213,7 @@ internal final class NIOTSDatagramChannel: StateManagedNWConnectionChannel {
         maximumReceiveLength: Int = 8192,
         udpOptions: NWProtocolUDP.Options,
         tlsOptions: NWProtocolTLS.Options?,
-        nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+        nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?
     ) {
         self.init(
             eventLoop: eventLoop,

Sources/NIOTransportServices/Datagram/NIOTSDatagramListener.swift

@@ -66,7 +66,7 @@ public final class NIOTSDatagramListenerBootstrap {
     private var udpOptions: NWProtocolUDP.Options = .init()
     private var tlsOptions: NWProtocolTLS.Options?
     private var bindTimeout: TimeAmount?
-    private var nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+    private var nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?
 
     /// Create a ``NIOTSListenerBootstrap`` for the `EventLoopGroup` `group`.
     ///
@@ -239,7 +239,7 @@ public final class NIOTSDatagramListenerBootstrap {
 
     /// Customise the `NWParameters` to be used when creating the connection.
     public func configureNWParameters(
-        _ configurator: @Sendable @escaping (inout NWParameters) -> Void
+        _ configurator: @Sendable @escaping (NWParameters) -> Void
     ) -> Self {
         self.nwParametersConfigurator = configurator
         return self

Sources/NIOTransportServices/Datagram/NIOTSDatagramListenerChannel.swift

@@ -81,12 +81,12 @@ internal final class NIOTSDatagramListenerChannel: StateManagedListenerChannel<N
         qos: DispatchQoS? = nil,
         udpOptions: NWProtocolUDP.Options,
         tlsOptions: NWProtocolTLS.Options?,
-        nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?,
+        nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?,
         childLoopGroup: EventLoopGroup,
         childChannelQoS: DispatchQoS?,
         childUDPOptions: NWProtocolUDP.Options,
         childTLSOptions: NWProtocolTLS.Options?,
-        childNWParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+        childNWParametersConfigurator: (@Sendable (NWParameters) -> Void)?
     ) {
         self.init(
             eventLoop: eventLoop,
@@ -108,12 +108,12 @@ internal final class NIOTSDatagramListenerChannel: StateManagedListenerChannel<N
         qos: DispatchQoS? = nil,
         udpOptions: NWProtocolUDP.Options,
         tlsOptions: NWProtocolTLS.Options?,
-        nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?,
+        nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?,
         childLoopGroup: EventLoopGroup,
         childChannelQoS: DispatchQoS?,
         childUDPOptions: NWProtocolUDP.Options,
         childTLSOptions: NWProtocolTLS.Options?,
-        childNWParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+        childNWParametersConfigurator: (@Sendable (NWParameters) -> Void)?
     ) {
         self.init(
             wrapping: listener,

Sources/NIOTransportServices/NIOTSConnectionBootstrap.swift

@@ -62,7 +62,7 @@ public final class NIOTSConnectionBootstrap {
     private var tcpOptions: NWProtocolTCP.Options = .init()
     private var tlsOptions: NWProtocolTLS.Options?
     private var protocolHandlers: (@Sendable () -> [ChannelHandler])? = nil
-    private var nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+    private var nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?
 
     /// Create a `NIOTSConnectionBootstrap` on the `EventLoopGroup` `group`.
     ///
@@ -168,7 +168,7 @@ public final class NIOTSConnectionBootstrap {
 
     /// Customise the `NWParameters` to be used when creating the connection.
     public func configureNWParameters(
-        _ configurator: @Sendable @escaping (inout NWParameters) -> Void
+        _ configurator: @Sendable @escaping (NWParameters) -> Void
     ) -> Self {
         self.nwParametersConfigurator = configurator
         return self

Sources/NIOTransportServices/NIOTSConnectionChannel.swift

@@ -164,11 +164,11 @@ internal final class NIOTSConnectionChannel: StateManagedNWConnectionChannel {
     /// An `EventLoopPromise` that will be succeeded or failed when a connection attempt succeeds or fails.
     internal var connectPromise: EventLoopPromise<Void>?
 
-    private let nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+    private let nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?
 
     internal var parameters: NWParameters {
-        var parameters = NWParameters(tls: self.tlsOptions, tcp: self.tcpOptions)
-        self.nwParametersConfigurator?(&parameters)
+        let parameters = NWParameters(tls: self.tlsOptions, tcp: self.tcpOptions)
+        self.nwParametersConfigurator?(parameters)
         return parameters
     }
 
@@ -247,7 +247,7 @@ internal final class NIOTSConnectionChannel: StateManagedNWConnectionChannel {
         maximumReceiveLength: Int = 8192,
         tcpOptions: NWProtocolTCP.Options,
         tlsOptions: NWProtocolTLS.Options?,
-        nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+        nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?
     ) {
         self.tsEventLoop = eventLoop
         self.closePromise = eventLoop.makePromise()
@@ -273,7 +273,7 @@ internal final class NIOTSConnectionChannel: StateManagedNWConnectionChannel {
         maximumReceiveLength: Int = 8192,
         tcpOptions: NWProtocolTCP.Options,
         tlsOptions: NWProtocolTLS.Options?,
-        nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+        nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?
     ) {
         self.init(
             eventLoop: eventLoop,

Sources/NIOTransportServices/NIOTSListenerBootstrap.swift

@@ -66,7 +66,7 @@ public final class NIOTSListenerBootstrap {
     private var tcpOptions: NWProtocolTCP.Options = .init()
     private var tlsOptions: NWProtocolTLS.Options?
     private var bindTimeout: TimeAmount?
-    private var nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+    private var nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?
 
     /// Create a ``NIOTSListenerBootstrap`` for the `EventLoopGroup` `group`.
     ///
@@ -240,6 +240,14 @@ public final class NIOTSListenerBootstrap {
         return self
     }
 
+    /// Customise the `NWParameters` to be used when creating the connection.
+    public func configureNWParameters(
+        _ configurator: @Sendable @escaping (NWParameters) -> Void
+    ) -> Self {
+        self.nwParametersConfigurator = configurator
+        return self
+    }
+
     /// Specifies a type of Multipath service to use for this listener, instead of the default
     /// service type for the event loop.
     ///

Sources/NIOTransportServices/NIOTSListenerChannel.swift

@@ -81,12 +81,12 @@ internal final class NIOTSListenerChannel: StateManagedListenerChannel<NIOTSConn
         qos: DispatchQoS? = nil,
         tcpOptions: NWProtocolTCP.Options,
         tlsOptions: NWProtocolTLS.Options?,
-        nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?,
+        nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?,
         childLoopGroup: EventLoopGroup,
         childChannelQoS: DispatchQoS?,
         childTCPOptions: NWProtocolTCP.Options,
         childTLSOptions: NWProtocolTLS.Options?,
-        childNWParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+        childNWParametersConfigurator: (@Sendable (NWParameters) -> Void)?
     ) {
         self.init(
             eventLoop: eventLoop,
@@ -108,12 +108,12 @@ internal final class NIOTSListenerChannel: StateManagedListenerChannel<NIOTSConn
         qos: DispatchQoS? = nil,
         tcpOptions: NWProtocolTCP.Options,
         tlsOptions: NWProtocolTLS.Options?,
-        nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?,
+        nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?,
         childLoopGroup: EventLoopGroup,
         childChannelQoS: DispatchQoS?,
         childTCPOptions: NWProtocolTCP.Options,
         childTLSOptions: NWProtocolTLS.Options?,
-        childNWParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+        childNWParametersConfigurator: (@Sendable (NWParameters) -> Void)?
     ) {
         self.init(
             wrapping: listener,

Sources/NIOTransportServices/StateManagedListenerChannel.swift

@@ -67,7 +67,7 @@ internal class StateManagedListenerChannel<ChildChannel: StateManagedChannel>: S
     /// The TLS options for this listener.
     internal let tlsOptions: NWProtocolTLS.Options?
 
-    internal var nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+    internal var nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?
 
     /// The `DispatchQueue` that socket events for this connection will be dispatched onto.
     internal let connectionQueue: DispatchQueue
@@ -115,7 +115,7 @@ internal class StateManagedListenerChannel<ChildChannel: StateManagedChannel>: S
     /// The TLS options to use for child channels.
     internal let childTLSOptions: NWProtocolTLS.Options?
 
-    internal var childNWParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+    internal var childNWParametersConfigurator: (@Sendable (NWParameters) -> Void)?
 
     /// The cache of the local and remote socket addresses. Must be accessed using _addressCacheLock.
     internal var addressCache = AddressCache(local: nil, remote: nil)
@@ -134,22 +134,24 @@ internal class StateManagedListenerChannel<ChildChannel: StateManagedChannel>: S
         qos: DispatchQoS? = nil,
         protocolOptions: ProtocolOptions,
         tlsOptions: NWProtocolTLS.Options?,
-        nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?,
+        nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?,
         childLoopGroup: EventLoopGroup,
         childChannelQoS: DispatchQoS?,
         childProtocolOptions: ProtocolOptions,
         childTLSOptions: NWProtocolTLS.Options?,
-        childNWParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+        childNWParametersConfigurator: (@Sendable (NWParameters) -> Void)?
     ) {
         self.tsEventLoop = eventLoop
         self.closePromise = eventLoop.makePromise()
         self.connectionQueue = eventLoop.channelQueue(label: "nio.transportservices.listenerchannel", qos: qos)
         self.protocolOptions = protocolOptions
         self.tlsOptions = tlsOptions
+        self.nwParametersConfigurator = nwParametersConfigurator
         self.childLoopGroup = childLoopGroup
         self.childChannelQoS = childChannelQoS
         self.childProtocolOptions = childProtocolOptions
         self.childTLSOptions = childTLSOptions
+        self.childNWParametersConfigurator = childNWParametersConfigurator
 
         // Must come last, as it requires self to be completely initialized.
         self._pipeline = ChannelPipeline(channel: self)
@@ -161,12 +163,12 @@ internal class StateManagedListenerChannel<ChildChannel: StateManagedChannel>: S
         qos: DispatchQoS? = nil,
         protocolOptions: ProtocolOptions,
         tlsOptions: NWProtocolTLS.Options?,
-        nwParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?,
+        nwParametersConfigurator: (@Sendable (NWParameters) -> Void)?,
         childLoopGroup: EventLoopGroup,
         childChannelQoS: DispatchQoS?,
         childProtocolOptions: ProtocolOptions,
         childTLSOptions: NWProtocolTLS.Options?,
-        childNWParametersConfigurator: (@Sendable (inout NWParameters) -> Void)?
+        childNWParametersConfigurator: (@Sendable (NWParameters) -> Void)?
     ) {
         self.init(
             eventLoop: eventLoop,
@@ -408,6 +410,8 @@ extension StateManagedListenerChannel {
 
         parameters.multipathServiceType = self.multipathServiceType
 
+        self.nwParametersConfigurator?(parameters)
+
         let listener: NWListener
         do {
             listener = try NWListener(using: parameters)

Tests/NIOTransportServicesTests/NIOTSBootstrapTests.swift

@@ -371,6 +371,36 @@ final class NIOTSBootstrapTests: XCTestCase {
         XCTAssertEqual(try listenerChannel.getOption(NIOTSChannelOptions.multipathServiceType).wait(), .handover)
         XCTAssertEqual(try connectionChannel.getOption(NIOTSChannelOptions.multipathServiceType).wait(), .handover)
     }
+
+    func testNWParametersConfigurator() throws {
+        let group = NIOTSEventLoopGroup()
+        defer {
+            try! group.syncShutdownGracefully()
+        }
+
+        let configuratorListenerCounter = NIOLockedValueBox(0)
+        let configuratorConnectionCounter = NIOLockedValueBox(0)
+
+        let listenerChannel = try NIOTSListenerBootstrap(group: group)
+            .configureNWParameters { _ in
+                configuratorListenerCounter.withLockedValue { $0 += 1 }
+            }
+            .bind(host: "localhost", port: 0)
+            .wait()
+
+        let connectionChannel: Channel = try NIOTSConnectionBootstrap(group: group)
+            .configureNWParameters { _ in
+                configuratorConnectionCounter.withLockedValue { $0 += 1 }
+            }
+            .connect(to: listenerChannel.localAddress!)
+            .wait()
+
+        try listenerChannel.close().wait()
+        try connectionChannel.close().wait()
+
+        XCTAssertEqual(1, configuratorListenerCounter.withLockedValue { $0 })
+        XCTAssertEqual(1, configuratorConnectionCounter.withLockedValue { $0 })
+    }
 }
 
 extension Channel {

Tests/NIOTransportServicesTests/NIOTSDatagramConnectionChannelTests.swift

@@ -18,6 +18,7 @@ import Network
 import NIOCore
 import NIOTransportServices
 import Foundation
+import NIOConcurrencyHelpers
 
 extension Channel {
     func wait<T: Sendable>(for type: T.Type, count: Int) throws -> [T] {
@@ -232,6 +233,36 @@ final class NIOTSDatagramConnectionChannelTests: XCTestCase {
         XCTAssertNoThrow(try connection.close().wait())
     }
 
+    func testNWParametersConfigurator() throws {
+        let group = NIOTSEventLoopGroup()
+        defer {
+            try! group.syncShutdownGracefully()
+        }
+
+        let configuratorListenerCounter = NIOLockedValueBox(0)
+        let configuratorConnectionCounter = NIOLockedValueBox(0)
+
+        let listenerChannel = try NIOTSDatagramListenerBootstrap(group: group)
+            .configureNWParameters { _ in
+                configuratorListenerCounter.withLockedValue { $0 += 1 }
+            }
+            .bind(host: "localhost", port: 0)
+            .wait()
+
+        let connectionChannel: Channel = try NIOTSDatagramBootstrap(group: group)
+            .configureNWParameters { _ in
+                configuratorConnectionCounter.withLockedValue { $0 += 1 }
+            }
+            .connect(to: listenerChannel.localAddress!)
+            .wait()
+
+        try listenerChannel.close().wait()
+        try connectionChannel.close().wait()
+
+        XCTAssertEqual(1, configuratorListenerCounter.withLockedValue { $0 })
+        XCTAssertEqual(1, configuratorConnectionCounter.withLockedValue { $0 })
+    }
+
     func testCanExtractTheConnection() throws {
         guard #available(macOS 14.0, iOS 17.0, watchOS 10.0, tvOS 17.0, *) else {
             throw XCTSkip("Option not available")