Merge branch 'master' into combine-previous

Author: andersio

CHANGELOG.md

@@ -3,6 +3,8 @@
 
 1. `combinePrevious` for `Signal` and `SignalProducer` no longer requires an initial value. The first tuple would be emitted as soon as the second value is received by the operator if no initial value is given. (#445, kudos to @andersio)
 
+1. Fixed an impedance mismatch in the `Signal` internals that caused heap corruptions. (#449, kudos to @gparker42)
+
 1. In Swift 3.2 or later, you may create `BindingTarget` for a key path of a specific object. (#440, kudos to @andersio)
 
 # 2.0.0-alpha.2

Sources/Signal.swift

@@ -112,7 +112,7 @@ public final class Signal<Value, Error: Swift.Error> {
 		private var hasDeinitialized: Bool
 
 		fileprivate init(_ generator: (Observer) -> Disposable?) {
-			state = .alive(AliveState())
+			state = .alive(AliveState(observers: Bag()))
 
 			updateLock = Lock.make()
 			sendLock = Lock.make()
@@ -225,7 +225,9 @@ public final class Signal<Value, Error: Swift.Error> {
 			updateLock.lock()
 
 			if case let .alive(state) = state {
-				token = state.observers.insert(observer)
+				var observers = state.observers
+				token = observers.insert(observer)
+				self.state = .alive(AliveState(observers: observers))
 			}
 
 			updateLock.unlock()
@@ -250,7 +252,7 @@ public final class Signal<Value, Error: Swift.Error> {
 			if case let .alive(state) = state {
 				var observers = state.observers
 				let observer = observers.remove(using: token)
-				state.observers = observers
+				self.state = .alive(AliveState(observers: observers))
 
 				var result = OperationResult.none
 
@@ -450,13 +452,14 @@ public final class Signal<Value, Error: Swift.Error> {
 	private final class AliveState {
 		/// The observers of the `Signal`.
 		///
-		/// - note: Since `Bag` is a copy-on-write collection, writes can be done safety
-		///         as long as `updateLock` is acquired.
-		fileprivate var observers: Bag<Observer>
+		/// - important: `observer` should not be mutated directly given the layout of
+		///              `Bag`. Copy the bag, and replace the current `AliveState` with
+		///              a new one created with the bag instead.
+		fileprivate let observers: Bag<Observer>
 
 		/// Create an alive state.
-		init() {
-			self.observers = Bag()
+		init(observers: Bag<Observer>) {
+			self.observers = observers
 		}
 	}
 

Sources/UnidirectionalBinding.swift

@@ -124,53 +124,41 @@ public struct BindingTarget<Value>: BindingTargetProvider {
 		return self
 	}
 
-	/// Creates a binding target.
+	/// Creates a binding target which consumes values on the specified scheduler.
+	///
+	/// If no scheduler is specified, the binding target would consume the value
+	/// immediately.
 	///
 	/// - parameters:
+	///   - scheduler: The scheduler on which the `action` consumes the values.
 	///   - lifetime: The expected lifetime of any bindings towards `self`.
 	///   - action: The action to consume values.
-	public init(lifetime: Lifetime, action: @escaping (Value) -> Void) {
-		self.action = action
+	public init(on scheduler: Scheduler = ImmediateScheduler(), lifetime: Lifetime, action: @escaping (Value) -> Void) {
 		self.lifetime = lifetime
-	}
 
-	/// Creates a binding target which consumes values on the specified scheduler.
-	///
-	/// - parameters:
-	///   - scheduler: The scheduler on which the `setter` consumes the values.
-	///   - lifetime: The expected lifetime of any bindings towards `self`.
-	///   - action: The action to consume values.
-	public init(on scheduler: Scheduler, lifetime: Lifetime, action: @escaping (Value) -> Void) {
-		let setter: (Value) -> Void = { value in
-			scheduler.schedule {
-				action(value)
+		if scheduler is ImmediateScheduler {
+			self.action = action
+		} else {
+			self.action = { value in
+				scheduler.schedule {
+					action(value)
+				}
 			}
 		}
-		self.init(lifetime: lifetime, action: setter)
 	}
 
 	#if swift(>=3.2)
-	// `Lifetime` is required on these overloads. RAC would provide convenience overloads
-	// for these with `lifetime(of:)`.
-
-	/// Creates a binding target.
-	///
-	/// - parameters:
-	///   - lifetime: The expected lifetime of any bindings towards `self`.
-	///   - object: The object to consume values.
-	///   - keyPath: The key path of the object that consumes values.
-	public init<Object: AnyObject>(lifetime: Lifetime, object: Object, keyPath: ReferenceWritableKeyPath<Object, Value>) {
-		self.init(lifetime: lifetime) { [weak object] in object?[keyPath: keyPath] = $0 }
-	}
-
 	/// Creates a binding target which consumes values on the specified scheduler.
 	///
+	/// If no scheduler is specified, the binding target would consume the value
+	/// immediately.
+	///
 	/// - parameters:
-	///   - scheduler: The scheduler on which the `setter` consumes the values.
+	///   - scheduler: The scheduler on which the key path consumes the values.
 	///   - lifetime: The expected lifetime of any bindings towards `self`.
 	///   - object: The object to consume values.
 	///   - keyPath: The key path of the object that consumes values.
-	public init<Object: AnyObject>(on scheduler: Scheduler, lifetime: Lifetime, object: Object, keyPath: ReferenceWritableKeyPath<Object, Value>) {
+	public init<Object: AnyObject>(on scheduler: Scheduler = ImmediateScheduler(), lifetime: Lifetime, object: Object, keyPath: ReferenceWritableKeyPath<Object, Value>) {
 		self.init(on: scheduler, lifetime: lifetime) { [weak object] in object?[keyPath: keyPath] = $0 }
 	}
 	#endif