Adopt NonisolatedNonsendingByDefault

Package.swift

@@ -2,7 +2,9 @@
 import PackageDescription
 
 #if compiler(>=6.1)
-let swiftSettings: [SwiftSetting] = []
+let swiftSettings: [SwiftSetting] = [
+    .enableUpcomingFeature("NonisolatedNonsendingByDefault")
+]
 #else
 let swiftSettings: [SwiftSetting] = [
     // Sadly the 6.0 compiler concurrency checker finds false positives.

Sources/ConnectionPoolModule/ConnectionPool.swift

@@ -578,20 +578,20 @@ protocol TaskGroupProtocol {
     // We need to call this `addTask_` because some Swift versions define this
     // under exactly this name and others have different attributes. So let's pick
     // a name that doesn't clash anywhere and implement it using the standard `addTask`.
-    mutating func addTask_(operation: @escaping @Sendable () async -> Void)
+    mutating func addTask_(operation: @isolated(any) @escaping @Sendable () async -> Void)
 }
 
 @available(macOS 14.0, iOS 17.0, tvOS 17.0, watchOS 10.0, *)
 extension DiscardingTaskGroup: TaskGroupProtocol {
     @inlinable
-    mutating func addTask_(operation: @escaping @Sendable () async -> Void) {
+    mutating func addTask_(operation: @isolated(any) @escaping @Sendable () async -> Void) {
         self.addTask(priority: nil, operation: operation)
     }
 }
 
 extension TaskGroup<Void>: TaskGroupProtocol {
     @inlinable
-    mutating func addTask_(operation: @escaping @Sendable () async -> Void) {
+    mutating func addTask_(operation: @isolated(any) @escaping @Sendable () async -> Void) {
         self.addTask(priority: nil, operation: operation)
     }
 }

Sources/PostgresNIO/New/PostgresNotificationSequence.swift

@@ -6,18 +6,30 @@ public struct PostgresNotification: Sendable {
 public struct PostgresNotificationSequence: AsyncSequence, Sendable {
     public typealias Element = PostgresNotification
 
-    let base: AsyncThrowingStream<PostgresNotification, Error>
+    let base: AsyncThrowingStream<PostgresNotification, any Error>
 
     public func makeAsyncIterator() -> AsyncIterator {
         AsyncIterator(base: self.base.makeAsyncIterator())
     }
 
     public struct AsyncIterator: AsyncIteratorProtocol {
-        var base: AsyncThrowingStream<PostgresNotification, Error>.AsyncIterator
+        var base: AsyncThrowingStream<PostgresNotification, any Error>.AsyncIterator
 
+        #if compiler(>=6.2)
+        @concurrent
         public mutating func next() async throws -> Element? {
             try await self.base.next()
         }
+        #else
+        public mutating func next() async throws -> Element? {
+            try await self.base.next()
+        }
+        #endif
+
+        @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
+        public mutating func next(isolation actor: isolated (any Actor)?) async throws(Self.Failure) -> Element? {
+            try await self.base.next(isolation: actor)
+        }
     }
 }
 

Sources/PostgresNIO/New/PostgresRowSequence.swift

@@ -31,6 +31,7 @@ public struct PostgresRowSequence: AsyncSequence, Sendable {
 extension PostgresRowSequence {
     public struct AsyncIterator: AsyncIteratorProtocol {
         public typealias Element = PostgresRow
+        public typealias Failure = any Error
 
         let backing: BackingSequence.AsyncIterator
 
@@ -43,7 +44,9 @@ extension PostgresRowSequence {
             self.columns = columns
         }
 
-        public mutating func next() async throws -> PostgresRow? {
+        #if compiler(>=6.2)
+        @concurrent
+        public mutating func next() async throws -> Element? {
             if let dataRow = try await self.backing.next() {
                 return PostgresRow(
                     data: dataRow,
@@ -53,6 +56,36 @@ extension PostgresRowSequence {
             }
             return nil
         }
+        #else
+        public mutating func next() async throws -> Element? {
+            if let dataRow = try await self.backing.next() {
+                return PostgresRow(
+                    data: dataRow,
+                    lookupTable: self.lookupTable,
+                    columns: self.columns
+                )
+            }
+            return nil
+        }
+        #endif
+
+        @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
+        public mutating func next(isolation actor: isolated (any Actor)?) async throws(Self.Failure) -> PostgresRow? {
+            // Since the underlying NIOThrowingAsyncSequenceProducer<DataRow, Error, AdaptiveRowBuffer, PSQLRowStream>.AsyncIterator
+            // does not supported the next(isolation:) call yet, we will hop here back and forth.
+            struct UnsafeTransfer: @unchecked Sendable {
+                var backing: BackingSequence.AsyncIterator
+            }
+            let unsafeTransfer = UnsafeTransfer(backing: self.backing)
+            if let dataRow = try await unsafeTransfer.backing.next() {
+                return PostgresRow(
+                    data: dataRow,
+                    lookupTable: self.lookupTable,
+                    columns: self.columns
+                )
+            }
+            return nil
+        }
     }
 }