Ishikawa Book: GCD

Ishikawa Book: GCD

import Foundation
import PlaygroundSupport

PlaygroundPage.current.needsIndefiniteExecution = true


let queue = DispatchQueue.global(qos: .userInitiated)
queue.async {
    let isMainThread = Thread.isMainThread // false
    print("非同期の処理")
    
    let queue = DispatchQueue.main
    queue.async {
        let isMainThread = Thread.isMainThread // true
        print(Array(0...10_000_000).reduce(0, +))
    }
    
    print("ありゃ！先にきちゃった！")
}