Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Unowned / Weak References with Closure
Search
naru-jpn
January 31, 2017
Programming
1
430
Unowned / Weak References with Closure
変数の生存期間を playground を利用しながら確認していきます。
naru-jpn
January 31, 2017
Tweet
Share
More Decks by naru-jpn
See All by naru-jpn
配信アプリのためのリアルタイムプッシュ通知ぼかしの夢
narujpn
3
870
PiPを応用した配信コメントバー機能の開発秘話と技術の詳解 / pip_streaming_comment_bar
narujpn
3
4.1k
Updating an App to Use Swift Concurrency 解説
narujpn
2
330
PiP で実現するミラティブの配信コメントバー / pip-streaming-comment-bar
narujpn
0
1.1k
App Extension のスタックトレース情報からクラッシュを解析/集計する / Analyzing app extension's stack trace
narujpn
3
1.5k
ミラティブとWebRTC - WebRTC framework の中身を覗いてみよう / WebRTC framework AudioUnit Processing
narujpn
1
2.2k
CoreML3のオンデバイストレーニングでつくる母音推定
narujpn
0
430
AltConfと周辺の歩き方
narujpn
0
2k
エンジニア経験を活かしたスクラムマスターとして 開発チームとプロダクトを成長させる
narujpn
1
400
Other Decks in Programming
See All in Programming
Road to Ruby for A Linguistics Nerd
hayat01sh1da
PRO
0
390
事業KPIを基に価値の解像度を上げる
nealle
0
160
クラシルリワードにおける iOSアプリ開発の取り組み
funzin
1
230
Boast Code Party / RubyKaigi 2025 After Event
lemonade_37
0
120
Cloudflare Workersで進めるリモートMCP活用
syumai
12
1.7k
“技術カンファレンスで何か変わる?” ──RubyKaigi後の自分とチームを振り返る
ssagara00
0
170
Orleans + Sekiban + SignalR でリアルタイムWeb作ってみた
tomohisa
0
260
AIコーディングの本質は“コード“ではなく“構造“だった / The essence of AI coding is not “code” but "structure
seike460
2
580
CursorとDevinが仲間!?AI駆動で新規プロダクト開発に挑んだ3ヶ月を振り返る / A Story of New Product Development with Cursor and Devin
rkaga
5
1.4k
CQRS/ESのクラスとシステムフロー ~ RailsでフルスクラッチでCQRSESを組んで みたことから得た学び~
suzukimar
0
150
Flutterでllama.cppをつかってローカルLLMを試してみた
sakuraidayo
0
160
ドメイン駆動設計とXPで支える子どもの未来 / Domain-Driven Design and XP Supporting Children's Future
nrslib
0
330
Featured
See All Featured
Principles of Awesome APIs and How to Build Them.
keavy
126
17k
XXLCSS - How to scale CSS and keep your sanity
sugarenia
248
1.3M
BBQ
matthewcrist
88
9.6k
Adopting Sorbet at Scale
ufuk
76
9.4k
The World Runs on Bad Software
bkeepers
PRO
68
11k
Gamification - CAS2011
davidbonilla
81
5.3k
Building Flexible Design Systems
yeseniaperezcruz
329
39k
Visualization
eitanlees
146
16k
Documentation Writing (for coders)
carmenintech
71
4.8k
Exploring the Power of Turbo Streams & Action Cable | RailsConf2023
kevinliebholz
32
5.8k
The Language of Interfaces
destraynor
158
25k
10 Git Anti Patterns You Should be Aware of
lemiorhan
PRO
656
60k
Transcript
Naruki Chigira - Timers inc. GitHub: naru-jpn, Twitter: @naruchigi Unowned
/ Weak References with Closure
มͷੜଘظؒɺؾʹͯ͠·͔͢ʁ
ΫϩʔδϟͰอ࣋͞ΕΔมɺ͑·͔͢ʁ
DispatchQueue.main.async { [weak self] in // ... }
ΫϩʔδϟͰʰ ͱΓ͋͑ͣ [weak self] ʱͯ͠·ͤΜ͔ʁ
Playground ͰڍಈΛࡉ͔͘ݟͯΈΑ͏ https://gist.github.com/naru-jpn/fa4c39ce2eda8a803358dad75d04058d
class Executor { // MARK: Exeute stored procedure let procedure:
() -> () init(procedure: @escaping () -> ()) { self.procedure = procedure } func execute() { self.procedure() } // MARK: Static execution static func execute(procedure: () -> ()) { procedure() } } ΫϩʔδϟΛ࣮ߦ͢ΔΫϥε Executor
class Object { var child: Object? weak var weakChild: Object?
var closure: (() -> ())? weak var currentExecutor: Executor? } ؍ଌ༻Ϋϥε Object
weak var weakObject: Object? = nil // スコープ内外での挙動を見るために if 文でネストさせる
// object が解放されていれば weakObject の中身は nil になる if true { let object: Object = Object() weakObject = object print(“\(weakObject)") // nil or not nil? } print(“\(weakObject)") // nil or not nil? ม͕ղ์͞Ε͍ͯΔ͔Ͳ͏͔ͷ֬ೝ
object object if true { let object: Object = Object()
weakObject = object // 1 } // 2 1. มείʔϓΛൈ͚ͨΒղ์͞ΕΔ
object child object child if true { let object: Object
= Object() object.child = object weakObject = object // 1 } // 2 weakObject?.child = nil 2. ࢀরʹΑΔϝϞϦϦʔΫ
object child object child if true { let object: Object
= Object() object.weakChild = object weakObject = object // 1 } // 2 weakObject?.child = nil 3. weak ΛͬͯϝϞϦϦʔΫ͠ͳ͍Α͏ʹͨ͠έʔε
॥ࢀরવආ͚·͠ΐ͏
object closure object closure if true { let object: Object
= Object() object.closure = { print("\(object)") } weakObject = object // 1 } // 2 weakObject?.closure = nil 4. Ϋϩʔδϟ͔ΒͷࢀরʹΑΔϝϞϦϦʔΫ
object closure object closure if true { let object: Object
= Object() object.closure = { [weak object] in print("\(object)") } weakObject = object // 1 } // 2 5. [weak ---] ΛͬͯϝϞϦϦʔΫ͠ͳ͍Α͏ʹͨ͠έʔε
Ϋϩʔδϟͷ॥ࢀরʹҙ
object closure object object closure object είʔϓ ࣮ؔߦ࣌ ؔऴྃ࣌ είʔϓ֎
Executor Executor extension Object { func printWeakSelf() { let executor: Executor = Executor(procedure: { [weak self] in debugPrint("\(self)") }) executor.execute() } } 6. Executor ͷΫϩʔδϟͰ [weak self] Λ͏߹
object closure object object closure object είʔϓ ࣮ؔߦ࣌ ؔऴྃ࣌ είʔϓ֎
Executor Executor if true { let object: Object = Object() object.printWeakSelf() weakObject = object } 6. Executor ͷΫϩʔδϟͰ [weak self] Λ͏߹
object closure object object closure object Executor Executor είʔϓ ࣮ؔߦ࣌
ؔऴྃ࣌ είʔϓ֎ extension Object { func printSelf() { let executor: Executor = Executor(procedure: { print("\(self)") }) executor.execute() } } 7. Executor ͷΫϩʔδϟͰ [weak self] ΛΘͳ͍߹
object closure object object closure object Executor Executor είʔϓ ࣮ؔߦ࣌
ؔऴྃ࣌ είʔϓ֎ if true { let object: Object = Object() object.printSelf() weakObject = object } 7. Executor ͷΫϩʔδϟͰ [weak self] ΛΘͳ͍߹
ΫϩʔδϟͰ self Λࢀরͯ͠ϦʔΫ͠ͳ͍߹͋Δ
ඇಉظॲཧػ࣌ ඇಉظॲཧऴྃ࣌ ࣮ؔߦ࣌ object closure closure Executor object closure Executor
extension Object { func printAsynchronousWeakSelf() { let executor: Executor = Executor(procedure: { let time: DispatchTime = .now() + 1.0 DispatchQueue.global().asyncAfter(deadline: time, execute: { [weak self] in print("\(self)") }) }) executor.execute() self.currentExecutor = executor } } 8. ඇಉظॲཧͰ [weak self] Λ͏߹
ඇಉظॲཧػ࣌ ඇಉظॲཧऴྃ࣌ ࣮ؔߦ࣌ object closure closure Executor object closure Executor
if true { let object: Object = Object() object.printAsynchronousSelf() weakObject = object } sleep(UInt32(3.0)) 8. ඇಉظॲཧͰ [weak self] Λ͏߹
ඇಉظॲཧػ࣌ ඇಉظॲཧऴྃ࣌ ࣮ؔߦ࣌ object closure object closure Executor object closure
Executor extension Object { func printAsynchronousSelf() { let executor: Executor = Executor(procedure: { DispatchQueue.global().asyncAfter(deadline: .now() + 1.0, execute: { print("\(self)") }) }) executor.execute() self.currentExecutor = executor } } 9. ඇಉظॲཧͰ [weak self] ΛΘͳ͍߹
ඇಉظॲཧػ࣌ ඇಉظॲཧऴྃ࣌ ࣮ؔߦ࣌ object closure object closure Executor object closure
Executor if true { let object: Object = Object() object.printAsynchronousSelf() weakObject = object } sleep(UInt32(3.0)) 9. ඇಉظॲཧͰ [weak self] ΛΘͳ͍߹
ඇಉظॲཧͰίʔϧόοΫ࣌ʹ object ͕ੜଘ͍ͯ͠Δ͔Ͳ͏͔͕มΘͬͯ͘Δ
ͨͩ͠ɺϦʔΫ͠ͳ͍͜ͱʹมΘΓͳ͍
తʹԠ͍͚ͯ͡ΒΕΔΑ͏ʹͳΓ͍ͨͰ͢Ͷ
͍͔ͭ [weak self] Λݟͨͱ͖ʹࢥ͍ΛͤͯΈ͍ͯͩ͘͞
None
None
None
None
None
Motivation / Concept https://developers.google.com/protocol-buffers/ Template message