Added unowned references

[ashfurrow]

No description provided.

[ksm]

Thanks Ash. 👍

[ksm]

@ashfurrow was this solved with beta 3?

[ashfurrow]

Checking now.

[ashfurrow]

Nope – still exists.

[RuiAAPeres]

@ashfurrow does that exact example still breaks, or is your example (radar one) that still fails?

[ashfurrow]

Yup still crashing on both. For example:

protocol MyProtocol: NSObjectProtocol {
    func method()
}

class MyObject : NSObject {
    unowned let delegate: MyProtocol

    init(delegate: MyProtocol) {
        self.delegate = delegate
        super.init()
    }

    func doSomethingWithDelegate() {
        delegate.method()
    }
}

class DelegateClass: NSObject, MyProtocol {
    func method () {
        for i in 1...10 {
            "Hello!"
        }
    }
}

And later...

let delegate = DelegateClass()
let object = MyObject(delegate: delegate)

object.doSomethingWithDelegate()
println("\(delegate)") // keep it from being released

New stack trace though:

* thread #1: tid = 0x985d15, 0x0028cd60 libswift_stdlib_core.dylib`_swift_release_slow, queue = 'com.apple.main-thread', stop reason = EXC_BREAKPOINT (code=EXC_I386_BPT, subcode=0x0)
  * frame #0: 0x0028cd60 libswift_stdlib_core.dylib`_swift_release_slow
    frame #1: 0xbff2cf88
    frame #2: 0x00298cbe libswift_stdlib_core.dylib`swift_unknownRetainUnowned + 318
    frame #3: 0x000d332f Bug`Bug.MyObject.delegate.getter : @unowned Bug.MyProtocol(self=0x7d13ab30) + 47 at AppDelegate.swift:0
    frame #4: 0x000d322b Bug`Bug.MyObject.doSomethingWithDelegate (self=0x7d13ab30)() -> () + 43 at AppDelegate.swift:25
    frame #5: 0x000d3282 Bug`@objc Bug.MyObject.doSomethingWithDelegate (Bug.MyObject)() -> () + 34 at AppDelegate.swift:0
    frame #6: 0x000d3ab2 Bug`Bug.AppDelegate.application (application=0x7d536080, launchOptions=None, self=0x7be42f90)(ObjectiveC.UIApplication, didFinishLaunchingWithOptions : Swift.Optional<ObjectiveC.NSDictionary>) -> Swift.Bool + 146 at AppDelegate.swift:50
    frame #7: 0x000d3cc5 Bug`@objc Bug.AppDelegate.application (Bug.AppDelegate)(ObjectiveC.UIApplication, didFinishLaunchingWithOptions : Swift.Optional<ObjectiveC.NSDictionary>) -> Swift.Bool + 101 at AppDelegate.swift:0
    frame #8: 0x00d27feb UIKit`-[UIApplication _handleDelegateCallbacksWithOptions:isSuspended:restoreState:] + 291
    frame #9: 0x00d28d29 UIKit`-[UIApplication _callInitializationDelegatesForMainScene:transitionContext:] + 2920
    frame #10: 0x00d2befb UIKit`-[UIApplication _runWithMainScene:transitionContext:completion:] + 1507
    frame #11: 0x00d44742 UIKit`__84-[UIApplication _handleApplicationActivationWithScene:transitionContext:completion:]_block_invoke + 59
    frame #12: 0x00d2ac3e UIKit`-[UIApplication workspaceDidEndTransaction:] + 29
    frame #13: 0x0351bbce FrontBoardServices`__37-[FBSWorkspace clientEndTransaction:]_block_invoke_2 + 43
    frame #14: 0x0351b834 FrontBoardServices`__40-[FBSWorkspace _performDelegateCallOut:]_block_invoke + 54
    frame #15: 0x0352d455 FrontBoardServices`__31-[FBSSerialQueue performAsync:]_block_invoke + 26
    frame #16: 0x0044e540 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 16
    frame #17: 0x004437d3 CoreFoundation`__CFRunLoopDoBlocks + 195
    frame #18: 0x0044362b CoreFoundation`__CFRunLoopRun + 2715
    frame #19: 0x004428cb CoreFoundation`CFRunLoopRunSpecific + 443
    frame #20: 0x004426fb CoreFoundation`CFRunLoopRunInMode + 123
    frame #21: 0x00d2a555 UIKit`-[UIApplication _run] + 571
    frame #22: 0x00d2dba5 UIKit`UIApplicationMain + 1526
    frame #23: 0x000d40a1 Bug`top_level_code + 97 at AppDelegate.swift:39
    frame #24: 0x000d40db Bug`main + 43 at AppDelegate.swift:0
    frame #25: 0x023acac9 libdyld.dylib`start + 1

[RuiAAPeres]

@ashfurrow 👍

[jckarter]

@ashfurrow It looks like the object is getting released before the unowned access, though it shouldn't in this case. Do you have a radar for this? This is a good test case.

[ashfurrow]

Yes, I've filed a radar.

[jeremy-w]

Huh. This seems similar to the sort of problems solved by the objc_precise_lifetime attribute in Obj-C-ARC-land. Only Swift doesn't seem to expose any attribute like that for its ARC.