[Concurrency] Remove last usages of @_unsafeInheritExecutor

stdlib/public/Concurrency/Clock.swift

@@ -77,7 +77,7 @@ extension Clock {
   }
 
   @available(SwiftStdlib 5.7, *)
-  @_unsafeInheritExecutor
+  @_unsafeInheritExecutor // for ABI compatibility
   @usableFromInline
   internal func measure(
     _ work: () async throws -> Void

stdlib/public/Concurrency/DiscardingTaskGroup.swift

@@ -68,9 +68,37 @@ import Swift
 ///
 /// - SeeAlso: ``withThrowingDiscardingTaskGroup(returning:body:)
 @available(SwiftStdlib 5.9, *)
+@backDeployed(before: SwiftStdlib 6.0)
 @inlinable
-@_unsafeInheritExecutor
 public func withDiscardingTaskGroup<GroupResult>(
+  returning returnType: GroupResult.Type = GroupResult.self,
+  isolation: isolated (any Actor)? = #isolation,
+  body: (inout DiscardingTaskGroup) async -> GroupResult
+) async -> GroupResult {
+  #if compiler(>=5.5) && $BuiltinCreateTaskGroupWithFlags
+  let flags = taskGroupCreateFlags(
+    discardResults: true
+  )
+
+  let _group = Builtin.createTaskGroupWithFlags(flags, GroupResult.self)
+  var group = DiscardingTaskGroup(group: _group)
+  defer { Builtin.destroyTaskGroup(_group) }
+
+  let result = await body(&group)
+
+  try! await group.awaitAllRemainingTasks() // try!-safe, cannot throw since this is a non throwing group
+
+  return result
+  #else
+  fatalError("Swift compiler is incompatible with this SDK version")
+  #endif
+}
+
+@available(SwiftStdlib 5.9, *)
+@usableFromInline
+@_unsafeInheritExecutor // for ABI compatibility
+@_silgen_name("$ss23withDiscardingTaskGroup9returning4bodyxxm_xs0bcD0VzYaXEtYalF")
+internal func __abi_withDiscardingTaskGroup<GroupResult>(
   returning returnType: GroupResult.Type = GroupResult.self,
   body: (inout DiscardingTaskGroup) async -> GroupResult
 ) async -> GroupResult {
@@ -709,9 +737,46 @@ extension DiscardingTaskGroup: Sendable { }
 /// }
 /// ```
 @available(SwiftStdlib 5.9, *)
+@backDeployed(before: SwiftStdlib 6.0)
 @inlinable
-@_unsafeInheritExecutor
 public func withThrowingDiscardingTaskGroup<GroupResult>(
+    returning returnType: GroupResult.Type = GroupResult.self,
+    isolation: isolated (any Actor)? = #isolation,
+    body: (inout ThrowingDiscardingTaskGroup<Error>) async throws -> GroupResult
+) async throws -> GroupResult {
+  #if compiler(>=5.5) && $BuiltinCreateTaskGroupWithFlags
+  let flags = taskGroupCreateFlags(
+      discardResults: true
+  )
+
+  let _group = Builtin.createTaskGroupWithFlags(flags, GroupResult.self)
+  var group = ThrowingDiscardingTaskGroup<Error>(group: _group)
+  defer { Builtin.destroyTaskGroup(_group) }
+
+  let result: GroupResult
+  do {
+    result = try await body(&group)
+  } catch {
+    group.cancelAll()
+
+    try await group.awaitAllRemainingTasks(bodyError: error)
+
+    throw error
+  }
+
+  try await group.awaitAllRemainingTasks(bodyError: nil)
+
+  return result
+  #else
+  fatalError("Swift compiler is incompatible with this SDK version")
+  #endif
+}
+
+@available(SwiftStdlib 5.9, *)
+@usableFromInline
+@_unsafeInheritExecutor // for ABI compatibility
+@_silgen_name("$ss31withThrowingDiscardingTaskGroup9returning4bodyxxm_xs0bcdE0Vys5Error_pGzYaKXEtYaKlF")
+internal func __abi_withThrowingDiscardingTaskGroup<GroupResult>(
     returning returnType: GroupResult.Type = GroupResult.self,
     body: (inout ThrowingDiscardingTaskGroup<Error>) async throws -> GroupResult
 ) async throws -> GroupResult {

stdlib/public/Concurrency/Task+TaskExecutor.swift

@@ -161,7 +161,7 @@ public func withTaskExecutorPreference<T, Failure>(
 
 @_unavailableInEmbedded
 @available(SwiftStdlib 6.0, *)
-@_unsafeInheritExecutor // calling withTaskExecutor MUST NOT perform the "usual" hop to global
+@_unsafeInheritExecutor // for ABI compatibility
 @_silgen_name("$ss26withTaskExecutorPreference_9operationxSch_pSg_xyYaYbKXEtYaKs8SendableRzlF")
 public func __abi__withTaskExecutorPreference<T: Sendable>(
   _ taskExecutor: (any TaskExecutor)?,

stdlib/public/Concurrency/TaskCancellation.swift

@@ -67,10 +67,26 @@ import Swift
 /// as resuming a continuation, may acquire these same internal locks.
 /// Therefore, if a cancellation handler must acquire a lock, other code should
 /// not cancel tasks or resume continuations while holding that lock.
-@_unsafeInheritExecutor // the operation runs on the same executor as we start out with
 @available(SwiftStdlib 5.1, *)
-@backDeployed(before: SwiftStdlib 5.8)
+@backDeployed(before: SwiftStdlib 6.0)
 public func withTaskCancellationHandler<T>(
+  operation: () async throws -> T,
+  onCancel handler: @Sendable () -> Void,
+  isolation: isolated (any Actor)? = #isolation
+) async rethrows -> T {
+  // unconditionally add the cancellation record to the task.
+  // if the task was already cancelled, it will be executed right away.
+  let record = _taskAddCancellationHandler(handler: handler)
+  defer { _taskRemoveCancellationHandler(record: record) }
+
+  return try await operation()
+}
+
+@_unsafeInheritExecutor // ABI compatibility with Swift 5.1
+@available(SwiftStdlib 5.1, *)
+@usableFromInline
+@_silgen_name("$ss27withTaskCancellationHandler9operation8onCancelxxyYaKXE_yyYbXEtYaKlF")
+internal func __abi_withTaskCancellationHandler<T>(
   operation: () async throws -> T,
   onCancel handler: @Sendable () -> Void
 ) async rethrows -> T {

stdlib/public/Concurrency/TaskGroup.swift

@@ -63,9 +63,36 @@ import Swift
 /// such as returning the work completed so far, returning an empty result, or returning `nil`.
 /// For tasks that need to handle cancellation by throwing an error,
 /// use the `withThrowingTaskGroup(of:returning:body:)` method instead.
+@available(SwiftStdlib 5.1, *)
+@backDeployed(before: SwiftStdlib 6.0, *)
+@inlinable
+public func withTaskGroup<ChildTaskResult, GroupResult>(
+  of childTaskResultType: ChildTaskResult.Type,
+  returning returnType: GroupResult.Type = GroupResult.self,
+  isolation: isolated (any Actor)? = #isolation,
+  body: (inout TaskGroup<ChildTaskResult>) async -> GroupResult
+) async -> GroupResult {
+  #if compiler(>=5.5) && $BuiltinTaskGroupWithArgument
+
+  let _group = Builtin.createTaskGroup(ChildTaskResult.self)
+  var group = TaskGroup<ChildTaskResult>(group: _group)
+
+  // Run the withTaskGroup body.
+  let result = await body(&group)
+
+  await group.awaitAllRemainingTasks()
+
+  Builtin.destroyTaskGroup(_group)
+  return result
+
+  #else
+  fatalError("Swift compiler is incompatible with this SDK version")
+  #endif
+}
+
 @available(SwiftStdlib 5.1, *)
 @_silgen_name("$ss13withTaskGroup2of9returning4bodyq_xm_q_mq_ScGyxGzYaXEtYar0_lF")
-@_unsafeInheritExecutor
+@_unsafeInheritExecutor // for ABI compatibility
 @inlinable
 public func withTaskGroup<ChildTaskResult, GroupResult>(
   of childTaskResultType: ChildTaskResult.Type,
@@ -80,7 +107,6 @@ public func withTaskGroup<ChildTaskResult, GroupResult>(
   // Run the withTaskGroup body.
   let result = await body(&group)
 
-  // TODO(concurrency): should get isolation from param from withThrowingTaskGroup
   await group.awaitAllRemainingTasks()
 
   Builtin.destroyTaskGroup(_group)
@@ -167,10 +193,46 @@ public func withTaskGroup<ChildTaskResult, GroupResult>(
 /// which gives you a chance to handle the individual error
 /// or to let the group rethrow the error.
 @available(SwiftStdlib 5.1, *)
-@_silgen_name("$ss21withThrowingTaskGroup2of9returning4bodyq_xm_q_mq_Scgyxs5Error_pGzYaKXEtYaKr0_lF")
-@_unsafeInheritExecutor
+@backDeployed(before: SwiftStdlib 6.0)
 @inlinable
 public func withThrowingTaskGroup<ChildTaskResult, GroupResult>(
+  of childTaskResultType: ChildTaskResult.Type,
+  returning returnType: GroupResult.Type = GroupResult.self,
+  isolation: isolated (any Actor)? = #isolation,
+  body: (inout ThrowingTaskGroup<ChildTaskResult, Error>) async throws -> GroupResult
+) async rethrows -> GroupResult {
+  #if compiler(>=5.5) && $BuiltinTaskGroupWithArgument
+
+  let _group = Builtin.createTaskGroup(ChildTaskResult.self)
+  var group = ThrowingTaskGroup<ChildTaskResult, Error>(group: _group)
+
+  do {
+    // Run the withTaskGroup body.
+    let result = try await body(&group)
+
+    await group.awaitAllRemainingTasks()
+    Builtin.destroyTaskGroup(_group)
+
+    return result
+  } catch {
+    group.cancelAll()
+
+    await group.awaitAllRemainingTasks()
+    Builtin.destroyTaskGroup(_group)
+
+    throw error
+  }
+
+  #else
+  fatalError("Swift compiler is incompatible with this SDK version")
+  #endif
+}
+
+@available(SwiftStdlib 5.1, *)
+@_silgen_name("$ss21withThrowingTaskGroup2of9returning4bodyq_xm_q_mq_Scgyxs5Error_pGzYaKXEtYaKr0_lF")
+@_unsafeInheritExecutor // for ABI compatibility
+@usableFromInline
+internal func withThrowingTaskGroup<ChildTaskResult, GroupResult>(
   of childTaskResultType: ChildTaskResult.Type,
   returning returnType: GroupResult.Type = GroupResult.self,
   body: (inout ThrowingTaskGroup<ChildTaskResult, Error>) async throws -> GroupResult
@@ -184,15 +246,13 @@ public func withThrowingTaskGroup<ChildTaskResult, GroupResult>(
     // Run the withTaskGroup body.
     let result = try await body(&group)
 
-    // TODO(concurrency): should get isolation from param from withThrowingTaskGroup
     await group.awaitAllRemainingTasks()
     Builtin.destroyTaskGroup(_group)
 
     return result
   } catch {
     group.cancelAll()
 
-    // TODO(concurrency): should get isolation from param from withThrowingTaskGroup
     await group.awaitAllRemainingTasks()
     Builtin.destroyTaskGroup(_group)
 

stdlib/public/Concurrency/TaskLocal.swift

@@ -260,7 +260,7 @@ public final class TaskLocal<Value: Sendable>: Sendable, CustomStringConvertible
 
   @inlinable
   @discardableResult
-  @_unsafeInheritExecutor
+  @_unsafeInheritExecutor // internal for backwards compatibility; though may be able to be removed safely?
   @available(SwiftStdlib 5.1, *)
   @backDeployed(before: SwiftStdlib 5.9)
   internal func withValueImpl<R>(_ valueDuringOperation: __owned Value,

test/Concurrency/actor_withCancellationHandler.swift

@@ -7,7 +7,7 @@
 // REQUIRES: concurrency
 // REQUIRES: asserts
 
-actor foo {
+actor Foo {
   var t: Task<Void, Error>?
 
   func access() {}
@@ -22,3 +22,25 @@ actor foo {
     }
   }
 }
+
+actor Container {
+  var num: Int = 0 // expected-note{{mutation of this property is only permitted within the actor}}
+  func test() async {
+
+    // no warnings:
+    await withTaskCancellationHandler {
+      num += 1
+    } onCancel: {
+      // nothing
+    }
+  }
+
+  func errors() async {
+    await withTaskCancellationHandler {
+      num += 1 // no error, this runs synchronously on caller context
+    } onCancel: {
+      // this should error because cancellation is invoked concurrently
+      num += 10 // expected-error{{actor-isolated property 'num' can not be mutated from a Sendable closure}}
+    }
+  }
+}

test/Concurrency/async_task_group_body_inherit_isolation.swift

@@ -0,0 +1,27 @@
+// RUN: %target-swift-frontend -emit-sil -verify -o /dev/null -disable-availability-checking %s -swift-version 6 -strict-concurrency=complete
+
+// REQUIRES: concurrency
+// REQUIRES: asserts
+
+actor A {
+  func g() { }
+  func h() throws { }
+
+  func f() async throws {
+    await withTaskGroup(of: Int.self, returning: Void.self) { group in
+      self.g()
+    }
+
+    try await withThrowingTaskGroup(of: String.self, returning: Void.self) { group in
+      try self.h()
+    }
+
+    await withDiscardingTaskGroup(returning: Void.self) { group in
+      self.g()
+    }
+
+    try await withThrowingDiscardingTaskGroup(returning: Void.self) { group in
+      try self.h()
+    }
+  }
+}

test/abi/macOS/arm64/concurrency.swift

@@ -316,7 +316,19 @@ Added: _$sScf13checkIsolatedyyFTj
 // method descriptor for Swift.SerialExecutor.checkIsolated() -> ()
 Added: _$sScf13checkIsolatedyyFTq
 
-// #isolated adoption in TaskLocal.withValue
+// #isolated adoption in multiple APIs
+// withTaskCancellationHandler gains #isolated
+Added: _$ss27withTaskCancellationHandler9operation8onCancel9isolationxxyYaKXE_yyYbXEScA_pSgYitYaKlF
+Added: _$ss27withTaskCancellationHandler9operation8onCancel9isolationxxyYaKXE_yyYbXEScA_pSgYitYaKlFTu
+// TaskGroup.with... APIs gain #isolated
+Added: _$ss23withDiscardingTaskGroup9returning9isolation4bodyxxm_ScA_pSgYixs0bcD0VzYaXEtYalF
+Added: _$ss23withDiscardingTaskGroup9returning9isolation4bodyxxm_ScA_pSgYixs0bcD0VzYaXEtYalFTu
+Added: _$ss13withTaskGroup2of9returning9isolation4bodyq_xm_q_mScA_pSgYiq_ScGyxGzYaXEtYas8SendableRzr0_lF
+Added: _$ss13withTaskGroup2of9returning9isolation4bodyq_xm_q_mScA_pSgYiq_ScGyxGzYaXEtYas8SendableRzr0_lFTu
+Added: _$ss31withThrowingDiscardingTaskGroup9returning9isolation4bodyxxm_ScA_pSgYixs0bcdE0Vys5Error_pGzYaKXEtYaKlF
+Added: _$ss31withThrowingDiscardingTaskGroup9returning9isolation4bodyxxm_ScA_pSgYixs0bcdE0Vys5Error_pGzYaKXEtYaKlFTu
+Added: _$ss21withThrowingTaskGroup2of9returning9isolation4bodyq_xm_q_mScA_pSgYiq_Scgyxs5Error_pGzYaKXEtYaKs8SendableRzr0_lF
+Added: _$ss21withThrowingTaskGroup2of9returning9isolation4bodyq_xm_q_mScA_pSgYiq_Scgyxs5Error_pGzYaKXEtYaKs8SendableRzr0_lFTu
 // Swift.TaskLocal.withValueImpl<A>(_: __owned A, operation: () async throws -> A1, isolation: isolated Swift.Actor?, file: Swift.String, line: Swift.UInt) async throws -> A1
 Added: _$ss9TaskLocalC13withValueImpl_9operation9isolation4file4lineqd__xn_qd__yYaKXEScA_pSgYiSSSutYaKlF
 Added: _$ss9TaskLocalC13withValueImpl_9operation9isolation4file4lineqd__xn_qd__yYaKXEScA_pSgYiSSSutYaKlFTu

test/abi/macOS/x86_64/concurrency.swift

@@ -316,7 +316,19 @@ Added: _$sScf13checkIsolatedyyFTj
 // method descriptor for Swift.SerialExecutor.checkIsolated() -> ()
 Added: _$sScf13checkIsolatedyyFTq
 
-// #isolated adoption in TaskLocal.withValue
+// #isolated adoption in multiple APis
+// withTaskCancellationHandler gains #isolated
+Added: _$ss27withTaskCancellationHandler9operation8onCancel9isolationxxyYaKXE_yyYbXEScA_pSgYitYaKlF
+Added: _$ss27withTaskCancellationHandler9operation8onCancel9isolationxxyYaKXE_yyYbXEScA_pSgYitYaKlFTu
+// TaskGroup.with... APIs gain #isolated
+Added: _$ss23withDiscardingTaskGroup9returning9isolation4bodyxxm_ScA_pSgYixs0bcD0VzYaXEtYalF
+Added: _$ss23withDiscardingTaskGroup9returning9isolation4bodyxxm_ScA_pSgYixs0bcD0VzYaXEtYalFTu
+Added: _$ss13withTaskGroup2of9returning9isolation4bodyq_xm_q_mScA_pSgYiq_ScGyxGzYaXEtYas8SendableRzr0_lF
+Added: _$ss13withTaskGroup2of9returning9isolation4bodyq_xm_q_mScA_pSgYiq_ScGyxGzYaXEtYas8SendableRzr0_lFTu
+Added: _$ss31withThrowingDiscardingTaskGroup9returning9isolation4bodyxxm_ScA_pSgYixs0bcdE0Vys5Error_pGzYaKXEtYaKlF
+Added: _$ss31withThrowingDiscardingTaskGroup9returning9isolation4bodyxxm_ScA_pSgYixs0bcdE0Vys5Error_pGzYaKXEtYaKlFTu
+Added: _$ss21withThrowingTaskGroup2of9returning9isolation4bodyq_xm_q_mScA_pSgYiq_Scgyxs5Error_pGzYaKXEtYaKs8SendableRzr0_lF
+Added: _$ss21withThrowingTaskGroup2of9returning9isolation4bodyq_xm_q_mScA_pSgYiq_Scgyxs5Error_pGzYaKXEtYaKs8SendableRzr0_lFTu
 // Swift.TaskLocal.withValueImpl<A>(_: __owned A, operation: () async throws -> A1, isolation: isolated Swift.Actor?, file: Swift.String, line: Swift.UInt) async throws -> A1
 Added: _$ss9TaskLocalC13withValueImpl_9operation9isolation4file4lineqd__xn_qd__yYaKXEScA_pSgYiSSSutYaKlF
 Added: _$ss9TaskLocalC13withValueImpl_9operation9isolation4file4lineqd__xn_qd__yYaKXEScA_pSgYiSSSutYaKlFTu

test/api-digester/stability-concurrency-abi.test

@@ -85,6 +85,10 @@ Func withCheckedThrowingContinuation(function:_:) has mangled name changing from
 Func withCheckedThrowingContinuation(function:_:) has parameter 0 type change from Swift.String to (any _Concurrency.Actor)?
 Func withCheckedThrowingContinuation(function:_:) has parameter 1 type change from (_Concurrency.CheckedContinuation<τ_0_0, any Swift.Error>) -> () to Swift.String
 
+// #isolation adoption for cancellation handlers; old APIs are kept ABI compatible
+Func withTaskCancellationHandler(operation:onCancel:) has been renamed to Func withTaskCancellationHandler(operation:onCancel:isolation:)
+Func withTaskCancellationHandler(operation:onCancel:) has mangled name changing from '_Concurrency.withTaskCancellationHandler<A>(operation: () async throws -> A, onCancel: @Sendable () -> ()) async throws -> A' to '_Concurrency.withTaskCancellationHandler<A>(operation: () async throws -> A, onCancel: @Sendable () -> (), isolation: isolated Swift.Optional<Swift.Actor>) async throws -> A'
+
 // #isolated was adopted and the old methods kept: $ss31withCheckedThrowingContinuation8function_xSS_yScCyxs5Error_pGXEtYaKlF
 Func withCheckedContinuation(function:_:) has been renamed to Func withCheckedContinuation(isolation:function:_:)
 Func withCheckedContinuation(function:_:) has mangled name changing from '_Concurrency.withCheckedContinuation<A>(function: Swift.String, _: (Swift.CheckedContinuation<A, Swift.Never>) -> ()) async -> A' to '_Concurrency.withCheckedContinuation<A>(isolation: isolated Swift.Optional<Swift.Actor>, function: Swift.String, _: (Swift.CheckedContinuation<A, Swift.Never>) -> ()) async -> A'