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@gregheo AltConf, June 2018 Shared Mutable State !

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@gregheo AltConf, June 2018 State

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@gregheo AltConf, June 2018 Exclusive Shared Immutable Mutable

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@gregheo AltConf, June 2018 Make it difficult
 to get wrong

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@gregheo AltConf, June 2018 "

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@gregheo AltConf, June 2018 queue1.async {
 
 } queue2.async {
 
 
 } 
 stuff()
 
 things()
 things2()


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@gregheo AltConf, June 2018 Exclusive Shared Immutable Mutable private let private var
 private queue UIDevice
 Screen size &

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@gregheo AltConf, June 2018 Fewer entry points

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@gregheo AltConf, June 2018 internal
 private
 fileprivate

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@gregheo AltConf, June 2018 Pass in values

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@gregheo AltConf, June 2018 class Printer { var num: Int func print() { print(num) } }

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@gregheo AltConf, June 2018 func printNum(num: Int) { print(num) }

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@gregheo AltConf, June 2018 Who enqueues
 the queues?

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@gregheo AltConf, June 2018 
 // call from anywhere!
 public func something() {
 privateQueue.sync { … } }


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@gregheo AltConf, June 2018 Queue Callback

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@gregheo AltConf, June 2018 
 // always call on the main queue!
 public func something() 


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@gregheo AltConf, June 2018 
 // always call on the main queue!
 public func something() {
 dispatchPrecondition(condition: .onQueue(.main))
 }


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@gregheo AltConf, June 2018 # Do I have order right? Is the order even knowable? Is it concurrent?

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@gregheo AltConf, June 2018 $ Too much access Mutable variables Thread uncertainty

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@gregheo AltConf, June 2018 ✅ “Limit access “Functional” approach “Private queues

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@gregheo AltConf, June 2018 # $ ✅

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@gregheo AltConf, June 2018 Make it difficult
 to get wrong