diff --git a/stdlib/public/Concurrency/CFExecutor.swift b/stdlib/public/Concurrency/CFExecutor.swift
index bc78d3175c60a..d115dc009e4c5 100644
--- a/stdlib/public/Concurrency/CFExecutor.swift
+++ b/stdlib/public/Concurrency/CFExecutor.swift
@@ -39,23 +39,41 @@ enum CoreFoundation {
 
   static let CFRunLoopRun: @convention(c) () -> () =
     symbol("CFRunLoopRun")
+  static let CFRunLoopRunInMode:
+    @convention(c) (AnyObject, Double, CBool) -> Int32 =
+    symbol("CFRunLoopRunInMode")
   static let CFRunLoopGetMain: @convention(c) () -> OpaquePointer =
     unsafe symbol("CFRunLoopGetMain")
   static let CFRunLoopStop: @convention(c) (OpaquePointer) -> () =
     unsafe symbol("CFRunLoopStop")
+
+  private static let _kCFRunLoopCommonModes: UnsafePointer<AnyObject> =
+    unsafe symbol("kCFRunLoopCommonModes")
+  static var kCFRunLoopCommonModes: AnyObject {
+    return unsafe _kCFRunLoopCommonModes.pointee
+  }
 }
 
 // .. Main Executor ............................................................
 
 /// A CFRunLoop-based main executor (Apple platforms only)
 @available(StdlibDeploymentTarget 6.2, *)
-final class CFMainExecutor: DispatchMainExecutor, @unchecked Sendable {
+final class CFMainExecutor: DispatchMainExecutor, RunLoopExecutor,
+                            @unchecked Sendable {
 
   override public func run() throws {
     CoreFoundation.CFRunLoopRun()
   }
 
-  override public func stop() {
+  public func runUntil(_ condition: () -> Bool) throws {
+    while !condition() {
+      CoreFoundation.CFRunLoopRunInMode(CoreFoundation.kCFRunLoopCommonModes,
+                                        0,
+                                        false)
+    }
+  }
+
+  public func stop() {
     unsafe CoreFoundation.CFRunLoopStop(CoreFoundation.CFRunLoopGetMain())
   }
 
diff --git a/stdlib/public/Concurrency/DispatchExecutor.swift b/stdlib/public/Concurrency/DispatchExecutor.swift
index 0910848ccd96b..ee8f600528d4b 100644
--- a/stdlib/public/Concurrency/DispatchExecutor.swift
+++ b/stdlib/public/Concurrency/DispatchExecutor.swift
@@ -25,7 +25,7 @@ import Swift
 
 /// A Dispatch-based main executor.
 @available(StdlibDeploymentTarget 6.2, *)
-class DispatchMainExecutor: RunLoopExecutor, SchedulingExecutor,
+class DispatchMainExecutor: ThreadDonationExecutor, SchedulingExecutor,
                             @unchecked Sendable {
   var threaded = false
 
@@ -40,10 +40,6 @@ class DispatchMainExecutor: RunLoopExecutor, SchedulingExecutor,
     _dispatchMain()
   }
 
-  public func stop() {
-    fatalError("DispatchMainExecutor cannot be stopped")
-  }
-
   var asScheduling: (any SchedulingExecutor)? {
     return self
   }
diff --git a/stdlib/public/Concurrency/Executor.swift b/stdlib/public/Concurrency/Executor.swift
index c69bb27ba6dca..e8efdb91337e4 100644
--- a/stdlib/public/Concurrency/Executor.swift
+++ b/stdlib/public/Concurrency/Executor.swift
@@ -536,13 +536,22 @@ extension SerialExecutor where Self: Equatable {
 
 }
 
+/// An executor that can take over a thread.
+@available(StdlibDeploymentTarget 6.2, *)
+public protocol ThreadDonationExecutor: Executor {
+  /// Donate the calling thread to this executor.
+  ///
+  /// This method will synchronously block the calling thread.
+  func run() throws
+}
+
 /// An executor that is backed by some kind of run loop.
 ///
 /// The idea here is that some executors may work by running a loop
 /// that processes events of some sort; we want a way to enter that loop,
 /// and we would also like a way to trigger the loop to exit.
 @available(StdlibDeploymentTarget 6.2, *)
-public protocol RunLoopExecutor: Executor {
+public protocol RunLoopExecutor: SerialExecutor, ThreadDonationExecutor {
   /// Run the executor's run loop.
   ///
   /// This method will synchronously block the calling thread.  Nested calls to
@@ -552,10 +561,6 @@ public protocol RunLoopExecutor: Executor {
 
   /// Run the executor's run loop until a condition is satisfied.
   ///
-  /// Not every `RunLoopExecutor` will support this method; you must not call
-  /// it unless you *know* that it is supported.  The default implementation
-  /// generates a fatal error.
-  ///
   /// Parameters:
   ///
   /// - condition: A closure that returns `true` if the run loop should
@@ -572,20 +577,17 @@ public protocol RunLoopExecutor: Executor {
   func stop()
 }
 
-@available(StdlibDeploymentTarget 6.2, *)
-extension RunLoopExecutor {
 
-  public func runUntil(_ condition: () -> Bool) throws {
-    fatalError("run(until condition:) not supported on this executor")
-  }
-
-}
-
-
-/// The main executor must conform to these two protocols; we have to
-/// make this a protocol for compatibility with Embedded Swift.
+/// The main executor protocol only includes the `run` method; some main
+/// executors may not support `runUntil` or `stop`.
 @available(StdlibDeploymentTarget 6.2, *)
-public protocol MainExecutor: RunLoopExecutor, SerialExecutor {
+public protocol MainExecutor: SerialExecutor, ThreadDonationExecutor {
+  /// Run the executor's run loop.
+  ///
+  /// This method will synchronously block the calling thread.  Nested calls to
+  /// `run()` may be permitted, however it is not permitted to call `run()` on a
+  /// single executor instance from more than one thread.
+  func run() throws
 }
 
 
@@ -604,6 +606,22 @@ public protocol ExecutorFactory {
   static var defaultExecutor: any TaskExecutor { get }
 }
 
+// Provide default implementations so you can override just one of the two
+@available(StdlibDeploymentTarget 6.2, *)
+public extension ExecutorFactory {
+  #if os(WASI) || !$Embedded
+  @available(StdlibDeploymentTarget 6.2, *)
+  public static var mainExecutor: any MainExecutor {
+    return DefaultExecutorFactory.mainExecutor
+  }
+  #endif
+
+  @available(StdlibDeploymentTarget 6.2, *)
+  public static var defaultExecutor: any TaskExecutor {
+    return DefaultExecutorFactory.defaultExecutor
+  }
+}
+
 @available(StdlibDeploymentTarget 6.2, *)
 typealias DefaultExecutorFactory = PlatformExecutorFactory
 
diff --git a/stdlib/public/Concurrency/PartialAsyncTask.swift b/stdlib/public/Concurrency/PartialAsyncTask.swift
index a255d34d3454a..4e855d8ab84cf 100644
--- a/stdlib/public/Concurrency/PartialAsyncTask.swift
+++ b/stdlib/public/Concurrency/PartialAsyncTask.swift
@@ -322,6 +322,9 @@ public struct ExecutorJob: Sendable, ~Copyable {
   /// referenced from the private data area are cleared up prior to running the
   /// job.
   ///
+  /// The size and alignment of the private data buffer are both twice the
+  /// machine word size (i.e. `2 * sizeof(void *)`, or `2 * MemoryLayout<UInt>`).
+  ///
   /// Parameters:
   ///
   /// - body: The closure to execute.
@@ -337,28 +340,27 @@ public struct ExecutorJob: Sendable, ~Copyable {
 
   /// Kinds of schedulable jobs
   @available(StdlibDeploymentTarget 6.2, *)
-  @frozen
-  public struct Kind: Sendable, RawRepresentable {
-    public typealias RawValue = UInt8
+  struct Kind: Sendable, RawRepresentable {
+    typealias RawValue = UInt8
 
     /// The raw job kind value.
-    public var rawValue: RawValue
+    var rawValue: RawValue
 
     /// Creates a new instance with the specified raw value.
-    public init?(rawValue: Self.RawValue) {
+    init?(rawValue: Self.RawValue) {
       self.rawValue = rawValue
     }
 
     /// A task.
-    public static let task = Kind(rawValue: RawValue(0))!
+    static let task = Kind(rawValue: RawValue(0))!
 
     // Job kinds >= 192 are private to the implementation.
-    public static let firstReserved = Kind(rawValue: RawValue(192))!
+    static let firstReserved = Kind(rawValue: RawValue(192))!
   }
 
   /// What kind of job this is.
   @available(StdlibDeploymentTarget 6.2, *)
-  public var kind: Kind {
+  var kind: Kind {
     return Kind(rawValue: _jobGetKind(self.context))!
   }
 
diff --git a/test/abi/Inputs/macOS/arm64/concurrency/baseline b/test/abi/Inputs/macOS/arm64/concurrency/baseline
index 9f91995fd1839..e4907cc0753b0 100644
--- a/test/abi/Inputs/macOS/arm64/concurrency/baseline
+++ b/test/abi/Inputs/macOS/arm64/concurrency/baseline
@@ -421,20 +421,6 @@ _$ss11ExecutorJobV14LocalAllocatorVMa
 _$ss11ExecutorJobV14LocalAllocatorVMn
 _$ss11ExecutorJobV14LocalAllocatorVN
 _$ss11ExecutorJobV16createTrampoline2toABx_tScFRzlF
-_$ss11ExecutorJobV4KindV13firstReservedADvgZ
-_$ss11ExecutorJobV4KindV13firstReservedADvpZMV
-_$ss11ExecutorJobV4KindV4taskADvgZ
-_$ss11ExecutorJobV4KindV4taskADvpZMV
-_$ss11ExecutorJobV4KindV8rawValueADSgs5UInt8V_tcfC
-_$ss11ExecutorJobV4KindV8rawValues5UInt8VvM
-_$ss11ExecutorJobV4KindV8rawValues5UInt8Vvg
-_$ss11ExecutorJobV4KindV8rawValues5UInt8VvpMV
-_$ss11ExecutorJobV4KindV8rawValues5UInt8Vvs
-_$ss11ExecutorJobV4KindVMa
-_$ss11ExecutorJobV4KindVMn
-_$ss11ExecutorJobV4KindVN
-_$ss11ExecutorJobV4KindVSYsMc
-_$ss11ExecutorJobV4kindAB4KindVvg
 _$ss11ExecutorJobV7contextABBjn_tcfC
 _$ss11ExecutorJobV8prioritys0B8PriorityVvg
 _$ss11ExecutorJobV9allocatorAB14LocalAllocatorVSgvg
@@ -472,7 +458,7 @@ _$ss11JobPriorityVSQsMc
 _$ss11JobPriorityVyABScPcfC
 _$ss12MainExecutorMp
 _$ss12MainExecutorPScfTb
-_$ss12MainExecutorPs07RunLoopB0Tb
+_$ss12MainExecutorPs014ThreadDonationB0Tb
 _$ss12MainExecutorTL
 _$ss13_runAsyncMainyyyyYaKcF
 _$ss13withTaskGroup2of9returning4bodyq_xm_q_mq_ScGyxGzYaXEtYar0_lF
@@ -516,16 +502,18 @@ _$ss15ExecutorFactoryP04mainA0s04MainA0_pvgZTj
 _$ss15ExecutorFactoryP04mainA0s04MainA0_pvgZTq
 _$ss15ExecutorFactoryP07defaultA0Sch_pvgZTj
 _$ss15ExecutorFactoryP07defaultA0Sch_pvgZTq
+_$ss15ExecutorFactoryPsE04mainA0s04MainA0_pvgZ
+_$ss15ExecutorFactoryPsE04mainA0s04MainA0_pvpZMV
+_$ss15ExecutorFactoryPsE07defaultA0Sch_pvgZ
+_$ss15ExecutorFactoryPsE07defaultA0Sch_pvpZMV
 _$ss15ExecutorFactoryTL
 _$ss15RunLoopExecutorMp
-_$ss15RunLoopExecutorP3runyyKFTj
-_$ss15RunLoopExecutorP3runyyKFTq
 _$ss15RunLoopExecutorP4stopyyFTj
 _$ss15RunLoopExecutorP4stopyyFTq
 _$ss15RunLoopExecutorP8runUntilyySbyXEKFTj
 _$ss15RunLoopExecutorP8runUntilyySbyXEKFTq
-_$ss15RunLoopExecutorPScFTb
-_$ss15RunLoopExecutorPsE8runUntilyySbyXEKF
+_$ss15RunLoopExecutorPScfTb
+_$ss15RunLoopExecutorPs014ThreadDonationC0Tb
 _$ss15RunLoopExecutorTL
 _$ss15SuspendingClockV17minimumResolutions8DurationVvg
 _$ss15SuspendingClockV17minimumResolutions8DurationVvpMV
@@ -734,6 +722,11 @@ _$ss22AsyncDropWhileSequenceVMa
 _$ss22AsyncDropWhileSequenceVMn
 _$ss22AsyncDropWhileSequenceV_9predicateAByxGx_Sb7ElementQzYactcfC
 _$ss22AsyncDropWhileSequenceVyxGScisMc
+_$ss22ThreadDonationExecutorMp
+_$ss22ThreadDonationExecutorP3runyyKFTj
+_$ss22ThreadDonationExecutorP3runyyKFTq
+_$ss22ThreadDonationExecutorPScFTb
+_$ss22ThreadDonationExecutorTL
 _$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
 _$ss23AsyncCompactMapSequenceV04makeA8IteratorAB0F0Vyxq__GyF
 _$ss23AsyncCompactMapSequenceV4basexvg
@@ -841,8 +834,8 @@ _$ss25UnimplementedMainExecutorCScfsMc
 _$ss25UnimplementedMainExecutorCScfsWP
 _$ss25UnimplementedMainExecutorCfD
 _$ss25UnimplementedMainExecutorCfd
-_$ss25UnimplementedMainExecutorCs07RunLoopC0sMc
-_$ss25UnimplementedMainExecutorCs07RunLoopC0sWP
+_$ss25UnimplementedMainExecutorCs014ThreadDonationC0sMc
+_$ss25UnimplementedMainExecutorCs014ThreadDonationC0sWP
 _$ss25UnimplementedMainExecutorCs0bC0sMc
 _$ss25UnimplementedMainExecutorCs0bC0sWP
 _$ss25UnimplementedTaskExecutorC06isMainC0Sbvg
diff --git a/test/abi/Inputs/macOS/arm64/concurrency/baseline-asserts b/test/abi/Inputs/macOS/arm64/concurrency/baseline-asserts
index 9f91995fd1839..e4907cc0753b0 100644
--- a/test/abi/Inputs/macOS/arm64/concurrency/baseline-asserts
+++ b/test/abi/Inputs/macOS/arm64/concurrency/baseline-asserts
@@ -421,20 +421,6 @@ _$ss11ExecutorJobV14LocalAllocatorVMa
 _$ss11ExecutorJobV14LocalAllocatorVMn
 _$ss11ExecutorJobV14LocalAllocatorVN
 _$ss11ExecutorJobV16createTrampoline2toABx_tScFRzlF
-_$ss11ExecutorJobV4KindV13firstReservedADvgZ
-_$ss11ExecutorJobV4KindV13firstReservedADvpZMV
-_$ss11ExecutorJobV4KindV4taskADvgZ
-_$ss11ExecutorJobV4KindV4taskADvpZMV
-_$ss11ExecutorJobV4KindV8rawValueADSgs5UInt8V_tcfC
-_$ss11ExecutorJobV4KindV8rawValues5UInt8VvM
-_$ss11ExecutorJobV4KindV8rawValues5UInt8Vvg
-_$ss11ExecutorJobV4KindV8rawValues5UInt8VvpMV
-_$ss11ExecutorJobV4KindV8rawValues5UInt8Vvs
-_$ss11ExecutorJobV4KindVMa
-_$ss11ExecutorJobV4KindVMn
-_$ss11ExecutorJobV4KindVN
-_$ss11ExecutorJobV4KindVSYsMc
-_$ss11ExecutorJobV4kindAB4KindVvg
 _$ss11ExecutorJobV7contextABBjn_tcfC
 _$ss11ExecutorJobV8prioritys0B8PriorityVvg
 _$ss11ExecutorJobV9allocatorAB14LocalAllocatorVSgvg
@@ -472,7 +458,7 @@ _$ss11JobPriorityVSQsMc
 _$ss11JobPriorityVyABScPcfC
 _$ss12MainExecutorMp
 _$ss12MainExecutorPScfTb
-_$ss12MainExecutorPs07RunLoopB0Tb
+_$ss12MainExecutorPs014ThreadDonationB0Tb
 _$ss12MainExecutorTL
 _$ss13_runAsyncMainyyyyYaKcF
 _$ss13withTaskGroup2of9returning4bodyq_xm_q_mq_ScGyxGzYaXEtYar0_lF
@@ -516,16 +502,18 @@ _$ss15ExecutorFactoryP04mainA0s04MainA0_pvgZTj
 _$ss15ExecutorFactoryP04mainA0s04MainA0_pvgZTq
 _$ss15ExecutorFactoryP07defaultA0Sch_pvgZTj
 _$ss15ExecutorFactoryP07defaultA0Sch_pvgZTq
+_$ss15ExecutorFactoryPsE04mainA0s04MainA0_pvgZ
+_$ss15ExecutorFactoryPsE04mainA0s04MainA0_pvpZMV
+_$ss15ExecutorFactoryPsE07defaultA0Sch_pvgZ
+_$ss15ExecutorFactoryPsE07defaultA0Sch_pvpZMV
 _$ss15ExecutorFactoryTL
 _$ss15RunLoopExecutorMp
-_$ss15RunLoopExecutorP3runyyKFTj
-_$ss15RunLoopExecutorP3runyyKFTq
 _$ss15RunLoopExecutorP4stopyyFTj
 _$ss15RunLoopExecutorP4stopyyFTq
 _$ss15RunLoopExecutorP8runUntilyySbyXEKFTj
 _$ss15RunLoopExecutorP8runUntilyySbyXEKFTq
-_$ss15RunLoopExecutorPScFTb
-_$ss15RunLoopExecutorPsE8runUntilyySbyXEKF
+_$ss15RunLoopExecutorPScfTb
+_$ss15RunLoopExecutorPs014ThreadDonationC0Tb
 _$ss15RunLoopExecutorTL
 _$ss15SuspendingClockV17minimumResolutions8DurationVvg
 _$ss15SuspendingClockV17minimumResolutions8DurationVvpMV
@@ -734,6 +722,11 @@ _$ss22AsyncDropWhileSequenceVMa
 _$ss22AsyncDropWhileSequenceVMn
 _$ss22AsyncDropWhileSequenceV_9predicateAByxGx_Sb7ElementQzYactcfC
 _$ss22AsyncDropWhileSequenceVyxGScisMc
+_$ss22ThreadDonationExecutorMp
+_$ss22ThreadDonationExecutorP3runyyKFTj
+_$ss22ThreadDonationExecutorP3runyyKFTq
+_$ss22ThreadDonationExecutorPScFTb
+_$ss22ThreadDonationExecutorTL
 _$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
 _$ss23AsyncCompactMapSequenceV04makeA8IteratorAB0F0Vyxq__GyF
 _$ss23AsyncCompactMapSequenceV4basexvg
@@ -841,8 +834,8 @@ _$ss25UnimplementedMainExecutorCScfsMc
 _$ss25UnimplementedMainExecutorCScfsWP
 _$ss25UnimplementedMainExecutorCfD
 _$ss25UnimplementedMainExecutorCfd
-_$ss25UnimplementedMainExecutorCs07RunLoopC0sMc
-_$ss25UnimplementedMainExecutorCs07RunLoopC0sWP
+_$ss25UnimplementedMainExecutorCs014ThreadDonationC0sMc
+_$ss25UnimplementedMainExecutorCs014ThreadDonationC0sWP
 _$ss25UnimplementedMainExecutorCs0bC0sMc
 _$ss25UnimplementedMainExecutorCs0bC0sWP
 _$ss25UnimplementedTaskExecutorC06isMainC0Sbvg
diff --git a/test/abi/Inputs/macOS/x86_64/concurrency/baseline b/test/abi/Inputs/macOS/x86_64/concurrency/baseline
index 9f91995fd1839..e4907cc0753b0 100644
--- a/test/abi/Inputs/macOS/x86_64/concurrency/baseline
+++ b/test/abi/Inputs/macOS/x86_64/concurrency/baseline
@@ -421,20 +421,6 @@ _$ss11ExecutorJobV14LocalAllocatorVMa
 _$ss11ExecutorJobV14LocalAllocatorVMn
 _$ss11ExecutorJobV14LocalAllocatorVN
 _$ss11ExecutorJobV16createTrampoline2toABx_tScFRzlF
-_$ss11ExecutorJobV4KindV13firstReservedADvgZ
-_$ss11ExecutorJobV4KindV13firstReservedADvpZMV
-_$ss11ExecutorJobV4KindV4taskADvgZ
-_$ss11ExecutorJobV4KindV4taskADvpZMV
-_$ss11ExecutorJobV4KindV8rawValueADSgs5UInt8V_tcfC
-_$ss11ExecutorJobV4KindV8rawValues5UInt8VvM
-_$ss11ExecutorJobV4KindV8rawValues5UInt8Vvg
-_$ss11ExecutorJobV4KindV8rawValues5UInt8VvpMV
-_$ss11ExecutorJobV4KindV8rawValues5UInt8Vvs
-_$ss11ExecutorJobV4KindVMa
-_$ss11ExecutorJobV4KindVMn
-_$ss11ExecutorJobV4KindVN
-_$ss11ExecutorJobV4KindVSYsMc
-_$ss11ExecutorJobV4kindAB4KindVvg
 _$ss11ExecutorJobV7contextABBjn_tcfC
 _$ss11ExecutorJobV8prioritys0B8PriorityVvg
 _$ss11ExecutorJobV9allocatorAB14LocalAllocatorVSgvg
@@ -472,7 +458,7 @@ _$ss11JobPriorityVSQsMc
 _$ss11JobPriorityVyABScPcfC
 _$ss12MainExecutorMp
 _$ss12MainExecutorPScfTb
-_$ss12MainExecutorPs07RunLoopB0Tb
+_$ss12MainExecutorPs014ThreadDonationB0Tb
 _$ss12MainExecutorTL
 _$ss13_runAsyncMainyyyyYaKcF
 _$ss13withTaskGroup2of9returning4bodyq_xm_q_mq_ScGyxGzYaXEtYar0_lF
@@ -516,16 +502,18 @@ _$ss15ExecutorFactoryP04mainA0s04MainA0_pvgZTj
 _$ss15ExecutorFactoryP04mainA0s04MainA0_pvgZTq
 _$ss15ExecutorFactoryP07defaultA0Sch_pvgZTj
 _$ss15ExecutorFactoryP07defaultA0Sch_pvgZTq
+_$ss15ExecutorFactoryPsE04mainA0s04MainA0_pvgZ
+_$ss15ExecutorFactoryPsE04mainA0s04MainA0_pvpZMV
+_$ss15ExecutorFactoryPsE07defaultA0Sch_pvgZ
+_$ss15ExecutorFactoryPsE07defaultA0Sch_pvpZMV
 _$ss15ExecutorFactoryTL
 _$ss15RunLoopExecutorMp
-_$ss15RunLoopExecutorP3runyyKFTj
-_$ss15RunLoopExecutorP3runyyKFTq
 _$ss15RunLoopExecutorP4stopyyFTj
 _$ss15RunLoopExecutorP4stopyyFTq
 _$ss15RunLoopExecutorP8runUntilyySbyXEKFTj
 _$ss15RunLoopExecutorP8runUntilyySbyXEKFTq
-_$ss15RunLoopExecutorPScFTb
-_$ss15RunLoopExecutorPsE8runUntilyySbyXEKF
+_$ss15RunLoopExecutorPScfTb
+_$ss15RunLoopExecutorPs014ThreadDonationC0Tb
 _$ss15RunLoopExecutorTL
 _$ss15SuspendingClockV17minimumResolutions8DurationVvg
 _$ss15SuspendingClockV17minimumResolutions8DurationVvpMV
@@ -734,6 +722,11 @@ _$ss22AsyncDropWhileSequenceVMa
 _$ss22AsyncDropWhileSequenceVMn
 _$ss22AsyncDropWhileSequenceV_9predicateAByxGx_Sb7ElementQzYactcfC
 _$ss22AsyncDropWhileSequenceVyxGScisMc
+_$ss22ThreadDonationExecutorMp
+_$ss22ThreadDonationExecutorP3runyyKFTj
+_$ss22ThreadDonationExecutorP3runyyKFTq
+_$ss22ThreadDonationExecutorPScFTb
+_$ss22ThreadDonationExecutorTL
 _$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
 _$ss23AsyncCompactMapSequenceV04makeA8IteratorAB0F0Vyxq__GyF
 _$ss23AsyncCompactMapSequenceV4basexvg
@@ -841,8 +834,8 @@ _$ss25UnimplementedMainExecutorCScfsMc
 _$ss25UnimplementedMainExecutorCScfsWP
 _$ss25UnimplementedMainExecutorCfD
 _$ss25UnimplementedMainExecutorCfd
-_$ss25UnimplementedMainExecutorCs07RunLoopC0sMc
-_$ss25UnimplementedMainExecutorCs07RunLoopC0sWP
+_$ss25UnimplementedMainExecutorCs014ThreadDonationC0sMc
+_$ss25UnimplementedMainExecutorCs014ThreadDonationC0sWP
 _$ss25UnimplementedMainExecutorCs0bC0sMc
 _$ss25UnimplementedMainExecutorCs0bC0sWP
 _$ss25UnimplementedTaskExecutorC06isMainC0Sbvg
diff --git a/test/abi/Inputs/macOS/x86_64/concurrency/baseline-asserts b/test/abi/Inputs/macOS/x86_64/concurrency/baseline-asserts
index 9f91995fd1839..e4907cc0753b0 100644
--- a/test/abi/Inputs/macOS/x86_64/concurrency/baseline-asserts
+++ b/test/abi/Inputs/macOS/x86_64/concurrency/baseline-asserts
@@ -421,20 +421,6 @@ _$ss11ExecutorJobV14LocalAllocatorVMa
 _$ss11ExecutorJobV14LocalAllocatorVMn
 _$ss11ExecutorJobV14LocalAllocatorVN
 _$ss11ExecutorJobV16createTrampoline2toABx_tScFRzlF
-_$ss11ExecutorJobV4KindV13firstReservedADvgZ
-_$ss11ExecutorJobV4KindV13firstReservedADvpZMV
-_$ss11ExecutorJobV4KindV4taskADvgZ
-_$ss11ExecutorJobV4KindV4taskADvpZMV
-_$ss11ExecutorJobV4KindV8rawValueADSgs5UInt8V_tcfC
-_$ss11ExecutorJobV4KindV8rawValues5UInt8VvM
-_$ss11ExecutorJobV4KindV8rawValues5UInt8Vvg
-_$ss11ExecutorJobV4KindV8rawValues5UInt8VvpMV
-_$ss11ExecutorJobV4KindV8rawValues5UInt8Vvs
-_$ss11ExecutorJobV4KindVMa
-_$ss11ExecutorJobV4KindVMn
-_$ss11ExecutorJobV4KindVN
-_$ss11ExecutorJobV4KindVSYsMc
-_$ss11ExecutorJobV4kindAB4KindVvg
 _$ss11ExecutorJobV7contextABBjn_tcfC
 _$ss11ExecutorJobV8prioritys0B8PriorityVvg
 _$ss11ExecutorJobV9allocatorAB14LocalAllocatorVSgvg
@@ -472,7 +458,7 @@ _$ss11JobPriorityVSQsMc
 _$ss11JobPriorityVyABScPcfC
 _$ss12MainExecutorMp
 _$ss12MainExecutorPScfTb
-_$ss12MainExecutorPs07RunLoopB0Tb
+_$ss12MainExecutorPs014ThreadDonationB0Tb
 _$ss12MainExecutorTL
 _$ss13_runAsyncMainyyyyYaKcF
 _$ss13withTaskGroup2of9returning4bodyq_xm_q_mq_ScGyxGzYaXEtYar0_lF
@@ -516,16 +502,18 @@ _$ss15ExecutorFactoryP04mainA0s04MainA0_pvgZTj
 _$ss15ExecutorFactoryP04mainA0s04MainA0_pvgZTq
 _$ss15ExecutorFactoryP07defaultA0Sch_pvgZTj
 _$ss15ExecutorFactoryP07defaultA0Sch_pvgZTq
+_$ss15ExecutorFactoryPsE04mainA0s04MainA0_pvgZ
+_$ss15ExecutorFactoryPsE04mainA0s04MainA0_pvpZMV
+_$ss15ExecutorFactoryPsE07defaultA0Sch_pvgZ
+_$ss15ExecutorFactoryPsE07defaultA0Sch_pvpZMV
 _$ss15ExecutorFactoryTL
 _$ss15RunLoopExecutorMp
-_$ss15RunLoopExecutorP3runyyKFTj
-_$ss15RunLoopExecutorP3runyyKFTq
 _$ss15RunLoopExecutorP4stopyyFTj
 _$ss15RunLoopExecutorP4stopyyFTq
 _$ss15RunLoopExecutorP8runUntilyySbyXEKFTj
 _$ss15RunLoopExecutorP8runUntilyySbyXEKFTq
-_$ss15RunLoopExecutorPScFTb
-_$ss15RunLoopExecutorPsE8runUntilyySbyXEKF
+_$ss15RunLoopExecutorPScfTb
+_$ss15RunLoopExecutorPs014ThreadDonationC0Tb
 _$ss15RunLoopExecutorTL
 _$ss15SuspendingClockV17minimumResolutions8DurationVvg
 _$ss15SuspendingClockV17minimumResolutions8DurationVvpMV
@@ -734,6 +722,11 @@ _$ss22AsyncDropWhileSequenceVMa
 _$ss22AsyncDropWhileSequenceVMn
 _$ss22AsyncDropWhileSequenceV_9predicateAByxGx_Sb7ElementQzYactcfC
 _$ss22AsyncDropWhileSequenceVyxGScisMc
+_$ss22ThreadDonationExecutorMp
+_$ss22ThreadDonationExecutorP3runyyKFTj
+_$ss22ThreadDonationExecutorP3runyyKFTq
+_$ss22ThreadDonationExecutorPScFTb
+_$ss22ThreadDonationExecutorTL
 _$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
 _$ss23AsyncCompactMapSequenceV04makeA8IteratorAB0F0Vyxq__GyF
 _$ss23AsyncCompactMapSequenceV4basexvg
@@ -841,8 +834,8 @@ _$ss25UnimplementedMainExecutorCScfsMc
 _$ss25UnimplementedMainExecutorCScfsWP
 _$ss25UnimplementedMainExecutorCfD
 _$ss25UnimplementedMainExecutorCfd
-_$ss25UnimplementedMainExecutorCs07RunLoopC0sMc
-_$ss25UnimplementedMainExecutorCs07RunLoopC0sWP
+_$ss25UnimplementedMainExecutorCs014ThreadDonationC0sMc
+_$ss25UnimplementedMainExecutorCs014ThreadDonationC0sWP
 _$ss25UnimplementedMainExecutorCs0bC0sMc
 _$ss25UnimplementedMainExecutorCs0bC0sWP
 _$ss25UnimplementedTaskExecutorC06isMainC0Sbvg