Merge pull request #200 from weissi/jw-SR-3628

don't hold references to unowned DispatchData objects (SR-3628)

Author: MadCoder

src/swift/DispatchStubs.cc

@@ -165,6 +165,12 @@ _swift_dispatch_release(dispatch_object_t obj) {
   dispatch_release(obj);
 }
 
+SWIFT_CC(swift) DISPATCH_RUNTIME_STDLIB_INTERFACE
+extern "C" void
+_swift_dispatch_retain(dispatch_object_t obj) {
+  dispatch_retain(obj);
+}
+
 // DISPATCH_RUNTIME_STDLIB_INTERFACE
 // extern "C" dispatch_queue_t
 // _swift_apply_current_root_queue() {

src/swift/Wrapper.swift

@@ -188,21 +188,20 @@ extension DispatchSource : DispatchSourceProcess,
 
 internal class __DispatchData : DispatchObject {
 	internal let __wrapped:dispatch_data_t
-	internal let __owned:Bool
 
 	final internal override func wrapped() -> dispatch_object_t {
 		return unsafeBitCast(__wrapped, to: dispatch_object_t.self)
 	}
 
 	internal init(data:dispatch_data_t, owned:Bool) {
 		__wrapped = data
-		__owned = owned
+		if !owned {
+			_swift_dispatch_retain(unsafeBitCast(data, to: dispatch_object_t.self))
+		}
 	}
 
 	deinit {
-		if __owned {
-			_swift_dispatch_release(wrapped())
-		}
+		_swift_dispatch_release(wrapped())
 	}
 }
 
@@ -335,3 +334,6 @@ internal enum _OSQoSClass : UInt32  {
 
 @_silgen_name("_swift_dispatch_release")
 internal func _swift_dispatch_release(_ obj: dispatch_object_t) -> Void
+
+@_silgen_name("_swift_dispatch_retain")
+internal func _swift_dispatch_retain(_ obj: dispatch_object_t) -> Void