Merge pull request #74151 from gottesmm/pr-89c1f2ab73ad928c312b9bdddb9e2c5cb550439c

[concurrency] Update withUnsafe{,Throwing}Continuation to have a sending result.

Author: gottesmm

stdlib/public/Concurrency/PartialAsyncTask.swift

@@ -505,7 +505,7 @@ public struct UnsafeContinuation<T, E: Error>: Sendable {
   /// The task continues executing
   /// when its executor schedules it.
   @_alwaysEmitIntoClient
-  public func resume(returning value: __owned T) where E == Never {
+  public func resume(returning value: sending T) where E == Never {
     #if compiler(>=5.5) && $BuiltinContinuation
     Builtin.resumeNonThrowingContinuationReturning(context, value)
     #else
@@ -527,7 +527,7 @@ public struct UnsafeContinuation<T, E: Error>: Sendable {
   /// The task continues executing
   /// when its executor schedules it.
   @_alwaysEmitIntoClient
-  public func resume(returning value: __owned T) {
+  public func resume(returning value: sending T) {
     #if compiler(>=5.5) && $BuiltinContinuation
     Builtin.resumeThrowingContinuationReturning(context, value)
     #else
@@ -549,7 +549,7 @@ public struct UnsafeContinuation<T, E: Error>: Sendable {
   /// The task continues executing
   /// when its executor schedules it.
   @_alwaysEmitIntoClient
-  public func resume(throwing error: __owned E) {
+  public func resume(throwing error: consuming E) {
     #if compiler(>=5.5) && $BuiltinContinuation
     Builtin.resumeThrowingContinuationThrowing(context, error)
     #else
@@ -577,7 +577,7 @@ extension UnsafeContinuation {
   /// The task continues executing
   /// when its executor schedules it.
   @_alwaysEmitIntoClient
-  public func resume<Er: Error>(with result: Result<T, Er>) where E == Error {
+  public func resume<Er: Error>(with result: __shared sending Result<T, Er>) where E == Error {
     switch result {
       case .success(let val):
         self.resume(returning: val)
@@ -603,7 +603,7 @@ extension UnsafeContinuation {
   /// The task continues executing
   /// when its executor schedules it.
   @_alwaysEmitIntoClient
-  public func resume(with result: Result<T, E>) {
+  public func resume(with result: __shared sending Result<T, E>) {
     switch result {
       case .success(let val):
         self.resume(returning: val)
@@ -635,7 +635,7 @@ extension UnsafeContinuation {
 @_alwaysEmitIntoClient
 internal func _resumeUnsafeContinuation<T>(
   _ continuation: UnsafeContinuation<T, Never>,
-  _ value: __owned T
+  _ value: sending T
 ) {
   continuation.resume(returning: value)
 }
@@ -644,7 +644,7 @@ internal func _resumeUnsafeContinuation<T>(
 @_alwaysEmitIntoClient
 internal func _resumeUnsafeThrowingContinuation<T>(
   _ continuation: UnsafeContinuation<T, Error>,
-  _ value: __owned T
+  _ value: sending T
 ) {
   continuation.resume(returning: value)
 }
@@ -653,7 +653,7 @@ internal func _resumeUnsafeThrowingContinuation<T>(
 @_alwaysEmitIntoClient
 internal func _resumeUnsafeThrowingContinuationWithError<T>(
   _ continuation: UnsafeContinuation<T, Error>,
-  _ error: __owned Error
+  _ error: consuming Error
 ) {
   continuation.resume(throwing: error)
 }
@@ -689,7 +689,7 @@ internal func _resumeUnsafeThrowingContinuationWithError<T>(
 public func withUnsafeContinuation<T>(
   isolation: isolated (any Actor)? = #isolation,
   _ fn: (UnsafeContinuation<T, Never>) -> Void
-) async -> T {
+) async -> sending T {
   return await Builtin.withUnsafeContinuation {
     fn(UnsafeContinuation<T, Never>($0))
   }
@@ -725,7 +725,7 @@ public func withUnsafeContinuation<T>(
 public func withUnsafeThrowingContinuation<T>(
   isolation: isolated (any Actor)? = #isolation,
   _ fn: (UnsafeContinuation<T, Error>) -> Void
-) async throws -> T {
+) async throws -> sending T {
   return try await Builtin.withUnsafeThrowingContinuation {
     fn(UnsafeContinuation<T, Error>($0))
   }

test/Concurrency/sending_continuation.swift

@@ -23,6 +23,12 @@ func withCheckedContinuation_1() async -> NonSendableKlass {
   }
 }
 
+func withCheckedContinuation_1a() async -> NonSendableKlass {
+  await withCheckedContinuation { continuation in
+    continuation.resume(returning: NonSendableKlass())
+  }
+}
+
 @MainActor
 func withCheckedContinuation_2() async -> NonSendableKlass {
   await withCheckedContinuation { continuation in
@@ -34,6 +40,16 @@ func withCheckedContinuation_2() async -> NonSendableKlass {
   }
 }
 
+func withCheckedContinuation_2a() async -> NonSendableKlass {
+  await withCheckedContinuation { continuation in
+    let x = NonSendableKlass()
+    continuation.resume(returning: x)
+    // expected-error @-1 {{sending 'x' risks causing data races}}
+    // expected-note @-2 {{'x' used after being passed as a 'sending' parameter}}
+    useValue(x) // expected-note {{access can happen concurrently}}
+  }
+}
+
 @MainActor
 func withCheckedContinuation_3() async {
   // x is main actor isolated since withCheckedContinuation is #isolated.
@@ -49,6 +65,19 @@ func withCheckedContinuation_3() async {
   // expected-note @-2 {{sending main actor-isolated 'x' to nonisolated global function 'useValueAsync' risks causing data races between nonisolated and main actor-isolated uses}}
 }
 
+func withCheckedContinuation_3a() async {
+  let x = await withCheckedContinuation { continuation in
+    let x = NonSendableKlass()
+    continuation.resume(returning: x)
+    // expected-error @-1 {{sending 'x' risks causing data races}}
+    // expected-note @-2 {{'x' used after being passed as a 'sending' parameter}}
+    useValue(x) // expected-note {{access can happen concurrently}}
+  }
+
+  // This is ok since x is disconnected.
+  await useValueAsync(x)
+}
+
 @MainActor
 func withCheckedContinuation_4() async {
   // x is main actor isolated since withCheckedContinuation is #isolated.
@@ -64,6 +93,18 @@ func withCheckedContinuation_4() async {
   // expected-note @-2 {{sending main actor-isolated 'x' to nonisolated global function 'useValueAsync' risks causing data races between nonisolated and main actor-isolated uses}}
 }
 
+func withCheckedContinuation_4a() async {
+  // x is main actor isolated since withCheckedContinuation is #isolated.
+  let y = NonSendableKlass()
+  let x = await withCheckedContinuation { continuation in
+    continuation.resume(returning: y)
+    // expected-error @-1 {{sending 'y' risks causing data races}}
+    // expected-note @-2 {{task-isolated 'y' is passed as a 'sending' parameter}}
+    useValue(y)
+  }
+  await useValueAsync(x)
+}
+
 @MainActor func testAsyncStream() {
   let (_, continuation) = AsyncStream.makeStream(of: NonSendableKlass.self)
 
@@ -103,3 +144,90 @@ func withCheckedContinuation_4() async {
     useValue(x) // expected-note {{access can happen concurrently}}
   }
 }
+
+@MainActor
+func withUnsafeContinuation_1() async -> NonSendableKlass {
+  await withUnsafeContinuation { continuation in
+    continuation.resume(returning: NonSendableKlass())
+  }
+}
+
+func withUnsafeContinuation_1a() async -> NonSendableKlass {
+  await withUnsafeContinuation { continuation in
+    continuation.resume(returning: NonSendableKlass())
+  }
+}
+
+@MainActor
+func withUnsafeContinuation_2() async -> NonSendableKlass {
+  await withUnsafeContinuation { continuation in
+    let x = NonSendableKlass()
+    continuation.resume(returning: x)
+    // expected-error @-1 {{sending 'x' risks causing data races}}
+    // expected-note @-2 {{'x' used after being passed as a 'sending' parameter}}
+    useValue(x) // expected-note {{access can happen concurrently}}
+  }
+}
+
+func withUnsafeContinuation_2a() async -> NonSendableKlass {
+  await withUnsafeContinuation { continuation in
+    let x = NonSendableKlass()
+    continuation.resume(returning: x)
+    // expected-error @-1 {{sending 'x' risks causing data races}}
+    // expected-note @-2 {{'x' used after being passed as a 'sending' parameter}}
+    useValue(x) // expected-note {{access can happen concurrently}}
+  }
+}
+
+@MainActor
+func withUnsafeContinuation_3() async {
+  // x is main actor isolated since withUnsafeContinuation is #isolated.
+  let x = await withUnsafeContinuation { continuation in
+    let x = NonSendableKlass()
+    continuation.resume(returning: x)
+    // expected-error @-1 {{sending 'x' risks causing data races}}
+    // expected-note @-2 {{'x' used after being passed as a 'sending' parameter}}
+    useValue(x) // expected-note {{access can happen concurrently}}
+  }
+  await useValueAsync(x)
+  // expected-error @-1 {{sending 'x' risks causing data races}}
+  // expected-note @-2 {{sending main actor-isolated 'x' to nonisolated global function 'useValueAsync' risks causing data races between nonisolated and main actor-isolated uses}}
+}
+
+func withUnsafeContinuation_3a() async {
+  let x = await withUnsafeContinuation { continuation in
+    let x = NonSendableKlass()
+    continuation.resume(returning: x)
+    // expected-error @-1 {{sending 'x' risks causing data races}}
+    // expected-note @-2 {{'x' used after being passed as a 'sending' parameter}}
+    useValue(x) // expected-note {{access can happen concurrently}}
+  }
+  await useValueAsync(x)
+}
+
+@MainActor
+func withUnsafeContinuation_4() async {
+  // x is main actor isolated since withUnsafeContinuation is #isolated.
+  let y = NonSendableKlass()
+  let x = await withUnsafeContinuation { continuation in
+    continuation.resume(returning: y)
+    // expected-error @-1 {{sending 'y' risks causing data races}}
+    // expected-note @-2 {{main actor-isolated 'y' is passed as a 'sending' parameter}}
+    useValue(y)
+  }
+  await useValueAsync(x)
+  // expected-error @-1 {{sending 'x' risks causing data races}}
+  // expected-note @-2 {{sending main actor-isolated 'x' to nonisolated global function 'useValueAsync' risks causing data races between nonisolated and main actor-isolated uses}}
+}
+
+func withUnsafeContinuation_4a() async {
+  // x is main actor isolated since withUnsafeContinuation is #isolated.
+  let y = NonSendableKlass()
+  let x = await withUnsafeContinuation { continuation in
+    continuation.resume(returning: y)
+    // expected-error @-1 {{sending 'y' risks causing data races}}
+    // expected-note @-2 {{task-isolated 'y' is passed as a 'sending' parameter}}
+    useValue(y)
+  }
+  await useValueAsync(x)
+}