RxBlocking Deep Dive

Otemachi.swift #02で行ったトークのスライドです。
RxBlockingがスレッドをブロックする仕組みについて解説しています。

関連記事をQiitaにて公開しています。
https://qiita.com/takehilo/items/be30a730599ac0774137

Otemachi.swift #02
https://nikkei.connpass.com/event/98887/

Transcript

1. RxBlocking Deep Dive Otemachi.swift #2 2018/10/16 @takehilo_kaneko
2. ࣗݾ঺հ ۚࢠ ༤େ @takehilo_kaneko 1೥ऑ https://qiita.com/takehilo
3. ͋Μ·Γ໾ʹཱͨͳ͍࿩͠·͢
4. https://speakerdeck.com/takehilo/rxtest-rxblocking-test-patterns
5. https://qiita.com/takehilo/items/09f4a3077e441e5bb9de
6. RxBlockingͬͯͲ͏΍ͬͯ εϨουΛϒϩοΫͯ͠ΔΜͩΖ͏ʁ
7. https://qiita.com/takehilo/items/be30a730599ac0774137 ॻ͖·ͨ͠ʂ
8. RxBlockingͱ͸ʁ
9. ඇಉظίʔυͷςετΛָʹॻͨ͘ΊͷϥΠϒϥϦ • toBlocking() • BlockingObservableܕʹม׵͢Δ • toArray() • ΧϨϯτεϨουΛϒϩοΫ͠ɺObservableΛαϒεΫϥΠϒ͠ɺશ ͯͷΠϕϯτΛड৴ͨ͠Βͦͷશͯͷཁૉฦͯ͠ϒϩοΫΛղআ͢Δ // ඇಉظʹΠϕϯτ͕ൃߦ͞ΕΔObservable let asyncObservable = Observable.of(10, 20, 30) .observeOn(SerialDispatchQueueScheduler(qos: .background)) let elements = try! asyncObservable.toBlocking().toArray() expect(elements).to(equal([10, 20, 30]))
10. ඇಉظίʔυͷςετΛָʹॻͨ͘ΊͷϥΠϒϥϦ • toBlocking() • BlockingObservableܕʹม׵͢Δ • toArray() • ΧϨϯτεϨουΛϒϩοΫ͠ɺObservableΛαϒεΫϥΠϒ͠ɺશ ͯͷΠϕϯτΛड৴ͨ͠Βͦͷશͯͷཁૉฦͯ͠ϒϩοΫΛղআ͢Δ // ඇಉظʹΠϕϯτ͕ൃߦ͞ΕΔObservable let asyncObservable = Observable.of(10, 20, 30) .observeOn(SerialDispatchQueueScheduler(qos: .background)) let elements = try! asyncObservable.toBlocking().toArray() expect(elements).to(equal([10, 20, 30])) ͜͜Λਂ͘۷ͬͯ
    ͍͚͹Αͦ͞͏ʂ
11. Let's deep dive into RxBlocking!
12. extension BlockingObservable { public func toArray() throws -> [E] { let results = materializeResult() return try elementsOrThrow(results) } } ͞Βʹਂ͘
13. extension BlockingObservable { fileprivate func materializeResult(max: Int? = nil, predicate: @escaping (E) throws -> Bool = { _ in true }) -> MaterializedSequenceResult<E> { var elements: [E] = Array<E>() var error: Swift.Error? let lock = RunLoopLock(timeout: timeout) let d = SingleAssignmentDisposable() defer { d.dispose() } lock.dispatch { let subscription = self.source.subscribe { event in if d.isDisposed { return } switch event { case .next(let element): do { if try predicate(element) { elements.append(element) } if let max = max, elements.count >= max { d.dispose() lock.stop() } } catch (let err) { error = err d.dispose() lock.stop() } case .error(let err): error = err d.dispose() lock.stop() case .completed: d.dispose() lock.stop() } } d.setDisposable(subscription) } do { try lock.run() } catch (let err) { error = err } if let error = error { return MaterializedSequenceResult.failed(elements: elements, error: error) } return MaterializedSequenceResult.completed(elements: elements) } }
14. func materializeResult() -> MaterializedSequenceResult<E> { let lock = RunLoopLock(timeout: timeout) lock.dispatch { /*શͯͷΠϕϯτΛऔಘͨ͠Β࣮ߦϧʔϓΛऴྃ͢Δ*/ } lock.run() return MaterializedSequenceResult.completed(elements: elements) } ௕͍ͷͰϙΠϯτ
    ͱͳΔ෦෼͚ͩൈਮ
15. func materializeResult() -> MaterializedSequenceResult<E> { let lock = RunLoopLock(timeout: timeout) lock.dispatch { /*શͯͷΠϕϯτΛऔಘͨ͠Β࣮ߦϧʔϓΛऴྃ͢Δ*/ } lock.run() return MaterializedSequenceResult.completed(elements: elements) } ࣮ߦϧʔϓΛ
    ੍ޚ͢ΔΫϥε
16. func materializeResult() -> MaterializedSequenceResult<E> { let lock = RunLoopLock(timeout: timeout) lock.dispatch { /*શͯͷΠϕϯτΛऔಘͨ͠Β࣮ߦϧʔϓΛऴྃ͢Δ*/ } lock.run() return MaterializedSequenceResult.completed(elements: elements) } ࣮ߦϧʔϓ಺ͷΩϡʔʹ
    ΫϩʔδϟΛొ࿥
17. func materializeResult() -> MaterializedSequenceResult<E> { let lock = RunLoopLock(timeout: timeout) lock.dispatch { /*શͯͷΠϕϯτΛऔಘͨ͠Β࣮ߦϧʔϓΛऴྃ͢Δ*/ } lock.run() return MaterializedSequenceResult.completed(elements: elements) } ࣮ߦϧʔϓΛ։࢝
    ͜͜ͰεϨου͕ϒϩοΫ͞ΕΔ
18. func materializeResult() -> MaterializedSequenceResult<E> { let lock = RunLoopLock(timeout: timeout) lock.dispatch { /*શͯͷΠϕϯτΛऔಘͨ͠Β࣮ߦϧʔϓΛऴྃ͢Δ*/ } lock.run() return MaterializedSequenceResult.completed(elements: elements) } 0CTFSWBCMF͕ൃߦͨ͠
    શΠϕϯτΛฦ͢
19. ͜ΜͳΠϝʔδ εϨου lock.dispatch {} Ωϡʔ ࣮ߦϧʔϓ lock.run() return start stop process શͯͷΠϕϯτΛऔಘͨ͠Β
    ࣮ߦϧʔϓΛऴྃ͢Δ
20. RunLoopLockΛਂ۷Γ
21. RunLoopLockΫϥε • ࣮ߦϧʔϓΛ੍ޚ͢ΔػೳΛ࣋ͭ • ࣮ߦϧʔϓΛ੍ޚ͢ΔͨΊͷAPIͰ͋ΔCore FoundationϑϨʔ ϜϫʔΫͷCFRunLoopΛϥοϓͨ͠Ϋϥε
22. func dispatch(_ action: @escaping () -> ()) { CFRunLoopPerformBlock(_currentRunLoop, runLoopModeRaw) { action() } } func stop() { CFRunLoopPerformBlock(_currentRunLoop, runLoopModeRaw) { CFRunLoopStop(self._currentRunLoop) } } func run() throws { CFRunLoopRun() } ͦΕͧΕϙΠϯτ͚ͩൈਮ
23. func dispatch(_ action: @escaping () -> ()) { CFRunLoopPerformBlock(_currentRunLoop, runLoopModeRaw) { action() } } func stop() { CFRunLoopPerformBlock(_currentRunLoop, runLoopModeRaw) { CFRunLoopStop(self._currentRunLoop) } } func run() throws { CFRunLoopRun() } ࣮ߦϧʔϓ಺ͷΩϡʔʹ
    ΫϩʔδϟΛొ࿥
24. func dispatch(_ action: @escaping () -> ()) { CFRunLoopPerformBlock(_currentRunLoop, runLoopModeRaw) { action() } } func stop() { CFRunLoopPerformBlock(_currentRunLoop, runLoopModeRaw) { CFRunLoopStop(self._currentRunLoop) } } func run() throws { CFRunLoopRun() } ࣮ߦϧʔϓΛऴྃ͢Δ
25. func dispatch(_ action: @escaping () -> ()) { CFRunLoopPerformBlock(_currentRunLoop, runLoopModeRaw) { action() } } func stop() { CFRunLoopPerformBlock(_currentRunLoop, runLoopModeRaw) { CFRunLoopStop(self._currentRunLoop) } } func run() throws { CFRunLoopRun() } ࣮ߦϧʔϓΛ։࢝͢Δ
    $'3VO-PPQ4UPQ ͕ݺ͹ΕΔ·Ͱ
    ࣮ߦ͠ଓ͚Δ
26. func dispatch(_ action: @escaping () -> ()) { CFRunLoopPerformBlock(_currentRunLoop, runLoopModeRaw) { action() } } func stop() { CFRunLoopPerformBlock(_currentRunLoop, runLoopModeRaw) { CFRunLoopStop(self._currentRunLoop) } } func run() throws { CFRunLoopRun() } ͍͕ͭ͜εϨουΛϒϩοΫ͢Δ ࢓૊Έͷਖ਼ମʂʂ
27. RxBlockingͬͯͲ͏΍ͬͯ εϨουΛϒϩοΫͯ͠ΔΜͩΖ͏ʁ
28. ౴͑ • CFRunLoopRun()ʹΑ࣮ͬͯߦϧʔϓ͕։࢝͞ΕɺεϨου͕ϒ ϩοΫ͞ΕΔ • ࣮ߦϧʔϓ಺ʹͯɺʮObservable͕ൃߦ͢ΔશͯͷΠϕϯτΛ औಘͨ͠Β࣮ߦϧʔϓΛऴྃ͢Δʯͱ͍͏ॲཧΛ࣮ߦ͢Δ
29. 5IBOL
    ZPV