メモリー管理の嬉しいバイキング料理

Swiftの初心者の中には、自動参照カウントを使えば、メモリー管理は気にしなくても良いと認識している方が多くいます。確かにSwiftは、ごみ収集システムを使うより、予測可能性は高いと言えます。しかし自動参照カウントを使用する際は、メモリー構造を意識する必要があります。ユーザーは、幾つかの方法でメモリー構造の落とし穴を避けることができます。今回のトークでは、メモリーの取り扱い方法について分かりやく説明します。

Transcript

1. ϝϞϦʔ؅ཧͷඒຯ͍͠ όΠΩϯάྉཧ Ray Fix @rayfix ը૾ఏڙ Yumi Kimura (CC2)
2. Ray Fix͸୭ʁ Source: https://en.wikipedia.org/wiki/La_Jolla
3. RayWenderlich.com
4. iosdc.jp Ray Fix
5. iosdc.jp Ray Fix
6. iosdc.jp Ray Fix ϝϞϦʔ؅ཧ
7. iosdc.jp Ray Fix ελοΫvsώʔϓྖҬ
8. iosdc.jp Ray Fix ελοΫ ελοΫ͸ͱʹ͔͘଎͍ʂ
9. iosdc.jp Ray Fix ελοΫ ελοΫ͸ͱʹ͔͘଎͍ʂ func candy() { let ramune = 10 let pocky = 12 let gummi = 20 }
10. iosdc.jp Ray Fix ελοΫ ελοΫ͸ͱʹ͔͘଎͍ʂ func candy() { let ramune = 10 let pocky = 12 let gummi = 20 } ελοΫ
11. iosdc.jp Ray Fix ελοΫ ελοΫ͸ͱʹ͔͘଎͍ʂ func candy() { let ramune = 10 let pocky = 12 let gummi = 20 } ελοΫ 10 12 20
12. iosdc.jp Ray Fix ελοΫ ελοΫ͸ͱʹ͔͘଎͍ʂ func candy() { let ramune = 10 let pocky = 12 let gummi = 20 } ελοΫ
13. iosdc.jp Ray Fix ελοΫ ελοΫ͸ͱʹ͔͘଎͍ʂ func candy() { let ramune = 10 let pocky = 12 let gummi = 20 } ελοΫ ϩοΫ͢Δඞཁ͸શ͘ͳ͍
14. iosdc.jp Ray Fix ώʔϓྖҬ class Dishɹ{ var name: String init(name: String) { self.name = name print(" Dish \(name)") } deinit { print("☠ Dish \(name)") } }
15. iosdc.jp Ray Fix ώʔϓྖҬ
16. iosdc.jp Ray Fix ώʔϓྖҬ let softCream = Dish(name: “Soft Cream")
17. iosdc.jp Ray Fix ώʔϓྖҬ let softCream = Dish(name: “Soft Cream") Count: 1 “Soft Cream” ώʔϓ
18. iosdc.jp Ray Fix ώʔϓྖҬ let softCream = Dish(name: “Soft Cream") Count: 1 “Soft Cream” ώʔϓ softCream ελοΫ
19. iosdc.jp Ray Fix ώʔϓྖҬ let softCream = Dish(name: “Soft Cream") Count: 1 “Soft Cream” softCream ώʔϓ ελοΫ
20. iosdc.jp Ray Fix ώʔϓྖҬ let softCream = Dish(name: “Soft Cream") let special = softCream Count: 1 “Soft Cream” softCream ώʔϓ ελοΫ
21. iosdc.jp Ray Fix ώʔϓྖҬ let softCream = Dish(name: “Soft Cream") let special = softCream Count: 1 “Soft Cream” softCream ώʔϓ ελοΫ Count: 2 “Soft Cream” special
22. iosdc.jp Ray Fix ڞ༗ softCream.name = "Choco Soft Cream" special.name // "Choco Soft Cream"
23. iosdc.jp Ray Fix ڞ༗ softCream.name = "Choco Soft Cream" special.name // "Choco Soft Cream" ϫΦɺศརʂʂʂ
24. iosdc.jp Ray Fix ڞ༗ softCream.name = "Choco Soft Cream" special.name // "Choco Soft Cream" ϫΦɺศརʂʂʂ ͔͠͠
25. iosdc.jp Ray Fix ڞ༗ softCream.name = "Choco Soft Cream" special.name // "Choco Soft Cream" ϫΦɺศརʂʂʂ ͔͠͠ special.name = "ϐʔϚϯ" softCream.name // "ϐʔϚϯ"
26. iosdc.jp Ray Fix ڞ༗ softCream.name = "Choco Soft Cream" special.name // "Choco Soft Cream" ϫΦɺศརʂʂʂ ͔͠͠ special.name = "ϐʔϚϯ" softCream.name // "ϐʔϚϯ" ૝ఆ֎ͷڞ༗͸ࢀরܕͷܽ఺
27. iosdc.jp Ray Fix ղܾ๏:ఆ਺Λ࢖͏ class Dishɹ{ init(name: String) { self.name = name print(" Dish \(name)") } deinit { print("☠ Dish \(name)") } } var name: String
28. iosdc.jp Ray Fix ղܾ๏:ఆ਺Λ࢖͏ class Dishɹ{ init(name: String) { self.name = name print(" Dish \(name)") } deinit { print("☠ Dish \(name)") } } var name: String
29. iosdc.jp Ray Fix ղܾ๏:ఆ਺Λ࢖͏ class Dishɹ{ init(name: String) { self.name = name print(" Dish \(name)") } deinit { print("☠ Dish \(name)") } } let name: String
30. iosdc.jp Ray Fix ղܾ๏:ఆ਺Λ࢖͏ class Dishɹ{ init(name: String) { self.name = name print(" Dish \(name)") } deinit { print("☠ Dish \(name)") } } let name: String special.name = "ϐʔϚϯ"
31. iosdc.jp Ray Fix ώʔϓྖҬ let softCream = Dish(name: “Soft Cream") let special = softCream Count: 0 “Soft Cream” ώʔϓ ελοΫ Count: 2 “Soft Cream” softCream special
32. iosdc.jp Ray Fix ώʔϓྖҬ let softCream = Dish(name: “Soft Cream") let special = softCream Count: 0 “Soft Cream” ώʔϓ ελοΫ
33. iosdc.jp Ray Fix ώʔϓྖҬ let softCream = Dish(name: “Soft Cream") let special = softCream ώʔϓ ελοΫ
34. iosdc.jp Ray Fix Customer orders ໰୊ɿ॥؀ࢀর Order customer dish Dish name
35. iosdc.jp Ray Fix ࢀরαΠΫϧ class Customer { var orders: [Order] func add(order: Order) { order.customer = self orders.append(order) } } class Order { var customer: Customer? let dish: Dish }
36. iosdc.jp Ray Fix ࢀরαΠΫϧ class Customer { var orders: [Order] func add(order: Order) { order.customer = self orders.append(order) } } class Order { var customer: Customer? let dish: Dish }
37. iosdc.jp Ray Fix ࢀরαΠΫϧ let ray = Customer(name: "Ray") let saikoro = Dish(name: “Saikoro Steak") let order = Order(dish: saikoro) ray.add(order: order)
38. iosdc.jp Ray Fix ࢀরαΠΫϧ let ray = Customer(name: "Ray") let saikoro = Dish(name: “Saikoro Steak") let order = Order(dish: saikoro) ray.add(order: order) ray saikoro order orders
39. iosdc.jp Ray Fix ࢀরαΠΫϧ let ray = Customer(name: "Ray") let saikoro = Dish(name: “Saikoro Steak") let order = Order(dish: saikoro) ray.add(order: order) ray saikoro order orders
40. iosdc.jp Ray Fix Xcode 8 Memory Visualizer
41. iosdc.jp Ray Fix Xcode 8 Memory Visualizer
42. iosdc.jp Ray Fix Xcode 8 Memory Visualizer
43. iosdc.jp Ray Fix Xcode 8 Memory Visualizer
44. iosdc.jp Ray Fix Xcode 8 Memory Visualizer
45. iosdc.jp Ray Fix Customer orders ॥؀ࢀর Order customer dish Dish name
46. iosdc.jp Ray Fix ॥؀ࢀর class Customer { var orders: [Order] func add(order: Order) { order.customer = self orders.append(order) } } class Order { let dish: Dish } var customer: Customer?
47. iosdc.jp Ray Fix ॥؀ࢀর class Customer { var orders: [Order] func add(order: Order) { order.customer = self orders.append(order) } } class Order { let dish: Dish } var customer: Customer? weak
48. iosdc.jp Ray Fix ॥؀ࢀর class Customer { var orders: [Order] func add(order: Order) { order.customer = self orders.append(order) } } class Order { let dish: Dish } var customer: Customer? weak
49. iosdc.jp Ray Fix ॥؀ࢀর let ray = Customer(name: "Ray") let saikoro = Dish(name: "Saikoro") let order = Order(dish: saikoro) ray.add(order: order) ray saikoro order orders
50. iosdc.jp Ray Fix ॥؀ࢀর let ray = Customer(name: "Ray") let saikoro = Dish(name: "Saikoro") let order = Order(dish: saikoro) ray.add(order: order) ray saikoro order orders
51. iosdc.jp Ray Fix ॥؀ࢀর let ray = Customer(name: "Ray") let saikoro = Dish(name: "Saikoro") let order = Order(dish: saikoro) ray.add(order: order) saikoro order nil
52. iosdc.jp Ray Fix ॥؀ࢀর let ray = Customer(name: "Ray") let saikoro = Dish(name: "Saikoro") let order = Order(dish: saikoro) ray.add(order: order) saikoro
53. iosdc.jp Ray Fix ॥؀ࢀর let ray = Customer(name: "Ray") let saikoro = Dish(name: "Saikoro") let order = Order(dish: saikoro) ray.add(order: order)
54. iosdc.jp Ray Fix weak ࢀর̍ ࢀর̎ ࢀর̏
55. iosdc.jp Ray Fix weak ࢀর̍ ࢀর̎ ࢀর̏
56. iosdc.jp Ray Fix weak ࢀর̍ ࢀর̎ ࢀর̏
57. iosdc.jp Ray Fix weak nil nil nil ࢀর̍ ࢀর̎ ࢀর̏
58. iosdc.jp Ray Fix weak nil nil nil ࢀর̍ ࢀর̎ ࢀর̏ reference value ࢀর̍ nil ࢀর̎ nil ࢀর̏ nil άϩʔόϧςʔϒϧ
59. iosdc.jp Ray Fix Swift weak 1 3 ࢀর̎ ࢀর̏ ࢀর̍
60. iosdc.jp Ray Fix Swift weak 1 3 ࢀর̎ ࢀর̏ ࢀর̍
61. iosdc.jp Ray Fix Swift weak 1 3 0 κϯϏ 3 ࢀর̎ ࢀর̏ ࢀর̍
62. ڧ͍ࢀরΧ΢ϯτ͕̌ʹ
63. ڧ͍ࢀরΧ΢ϯτ͕̌ʹ
64. ऑ͍ࢀরΧ΢ϯτ͕̌ʹ
65. ऑ͍ࢀরΧ΢ϯτ͕̌ʹ
66. unowned • unowned ͸ผͷछྨͷऑ͍ࢀর • ࢀরઌ͕ඞͣ͋Δ͜ͱ͕લఏ • ΋͠ࢀরઌ͕ͳ͍ͱɺϓϩάϥϜ͕ఀࢭ͢Δ
67. unowned class Order { let dish: Dish } class Customer { var orders: [Order] func add(dish: Dish) { let order = Order(dish: dish, customer: self) orders.append(order) } } let customer: Customer
68. unowned class Order { let dish: Dish } class Customer { var orders: [Order] func add(dish: Dish) { let order = Order(dish: dish, customer: self) orders.append(order) } } let customer: Customer
69. unowned class Order { let dish: Dish } class Customer { var orders: [Order] func add(dish: Dish) { let order = Order(dish: dish, customer: self) orders.append(order) } } let customer: Customer unowned
70. unowned class Order { let dish: Dish } class Customer { var orders: [Order] func add(dish: Dish) { let order = Order(dish: dish, customer: self) orders.append(order) } } let customer: Customer unowned
71. iosdc.jp Ray Fix unowned 1 3 0 κϯϏ 3 ࢀর̎ ࢀর̏ ࢀর̍
72. iosdc.jp Ray Fix unowned 1 3 0 κϯϏ 3 ࢀর̎ ࢀর̏ ࢀর̍ ϓϩάϥϜ͕ఀࢭ
73. ؔ਺ͱΫϩʔδϟ΋ࢀরܕ { }
74. ؔ਺ͱΫϩʔδϟ΋ࢀরܕ { }
75. ྫɿण࢘԰ enum MenuItem: String { case toro, ebi, anago, uni, ikura, hamachi } typealias Action = ()->()
76. ྫɿ ण࢘԰ class Sushiya { lazy var menu: [MenuItem: Action] = […] func prepare(_ menuItem: MenuItem) { menu[menuItem]?() } private func serve(dish: Dish) { print("Now serving \(dish.name)") } }
77. ྫɿ ण࢘԰ menu = [ .toro: { let dish = Dish(name: "Toro") }, … ] serve(dish: dish)
78. ྫɿ ण࢘԰ menu = [ .toro: { let dish = Dish(name: "Toro") }, … ] serve(dish: dish) self.
79. ྫɿ ण࢘԰ menu = [ .toro: { let dish = Dish(name: "Toro") }, … ] serve(dish: dish) self. let sushiya = Sushiya() sushiya.prepare(.toro)
80. ϝϞϦʔ࿙Ε
81. ղܾ๏ɿ ΩϟϓνϟʔϦετ var value = 0 let showValue = { print(value) }
82. ղܾ๏ɿ ΩϟϓνϟʔϦετ var value = 0 let showValue = { print(value) } showValue() // prints 0 value = 10 showValue() // prints 10
83. ղܾ๏ɿ ΩϟϓνϟʔϦετ var value = 0 let showValue = { print(value) } showValue() // prints 0 value = 10 showValue() // prints 10
84. ղܾ๏ɿ ΩϟϓνϟʔϦετ var value = 0 let showValue = { print(value) } showValue() // prints 0 value = 10 showValue() // prints [value] in 10
85. ղܾ๏ɿ ΩϟϓνϟʔϦετ var value = 0 let showValue = { print(value) } showValue() // prints 0 value = 10 showValue() // prints [value] in 0
86. ղܾ๏ɿ ΩϟϓνϟʔϦετ menu = [ .toro: { let dish = Dish(name: "Toro") self.serve(dish: dish) }, … ]
87. ղܾ๏ɿ ΩϟϓνϟʔϦετ menu = [ .toro: { let dish = Dish(name: "Toro") self.serve(dish: dish) }, … ] [unowned self] in #
88. ඇಉظͷ໰୊ private func serve(dish: Dish) { print("Now serving \(dish.name)") }
89. ඇಉظͷ໰୊ private func serve(dish: Dish) { DispatchQueue.main.async { print("Now serving \(dish.name)") self.served += 1 } } private func serve(dish: Dish) { print("Now serving \(dish.name)") }
90. ඇಉظͷ໰୊ [unowned self] in private func serve(dish: Dish) { DispatchQueue.main.async { print("Now serving \(dish.name)") self.served += 1 } } private func serve(dish: Dish) { print("Now serving \(dish.name)") }
91. ඇಉظͷ໰୊ [unowned self] in private func serve(dish: Dish) { DispatchQueue.main.async { print("Now serving \(dish.name)") self.served += 1 } } private func serve(dish: Dish) { print("Now serving \(dish.name)") } CRASH!!!!
92. ඇಉظͷ໰୊ private func serve(dish: Dish) { DispatchQueue.main.async { print("Now serving \(dish.name)") self.served += 1 } } private func serve(dish: Dish) { print("Now serving \(dish.name)") }
93. weak private func serve(dish: Dish) { DispatchQueue.main.async { [weak self] in print("Now serving \(dish.name)") self?.served += 1 } }
94. strong weak μϯε private func serve(dish: Dish) { DispatchQueue.main.async { [weak self] in guard let strongSelf = self else { print("Cancelled \(dish.name)") return } print("Now serving \(dish.name)") strongSelf.served += 1 } }
95. ඒຯ͍͠SWIFTΛॻ͘ʹ͸ ϝϞϦʔͱͷ૬ੑΛ ೺Ѳ͢Δඞཁ͕͋Δ
96. ͝ਗ਼ௌ͋Γ͕ͱ͏ ͍͟͝·ͨ͠
97. https://www.youtube.com/watch?v=0-vWT-t0UHg ԣ඿ϦφοΫεಡॻձ̒̓ɿmalloc https://www.mikeash.com/pyblog/friday-qa-2015-12-11-swift-weak-references.html SWIFT ऑ͍ࢀরͷৄ͍͠࿩ http://bit.ly/etystamp ༑ୡͷ LINE ελϜϓʂ https://en.wikipedia.org/wiki/La_Jolla ೆΧϦϑΥϧχΞͷࣸਅ https://ja.wikipedia.org/wiki/ण࢘ ण࢘ͷࣸਅ http://echo-labs.com/ ECHO LABS ݦඍڸ http://raywenderlich.com/ Ray Wenderlich ϝϞϦʔνϡʔτ (Maxime Defauwஶऀ) 9݄ެ։༧ఆ ࢀߟϦϯΫ https://github.com/rayfix/MemoryDish ιʔείʔυɺεϥΠυ wwdc2016/416/ WWDC Swift Performance
98. https://www.youtube.com/watch?v=0-vWT-t0UHg ԣ඿ϦφοΫεಡॻձ̒̓ɿmalloc https://www.mikeash.com/pyblog/friday-qa-2015-12-11-swift-weak-references.html SWIFT ऑ͍ࢀরͷৄ͍͠࿩ http://bit.ly/etystamp ༑ୡͷ LINE ελϜϓʂ https://en.wikipedia.org/wiki/La_Jolla ೆΧϦϑΥϧχΞͷࣸਅ https://ja.wikipedia.org/wiki/ण࢘ ण࢘ͷࣸਅ http://echo-labs.com/ ECHO LABS ݦඍڸ http://raywenderlich.com/ Ray Wenderlich ϝϞϦʔνϡʔτ (Maxime Defauwஶऀ) 9݄ެ։༧ఆ ࢀߟϦϯΫ https://github.com/rayfix/MemoryDish ιʔείʔυɺεϥΠυ wwdc2016/416/ WWDC Swift Performance