tokizuoh

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        print(Thread.isMainThread)  // true or false?
    }
}

tokizuoh

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        Task.init {
            print(Thread.isMainThread)  // true or false?
        }
    }

tokizuoh

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        Task.detached {
            print(Thread.isMainThread)  // true or false?
        }
    }

tokizuoh

import UIKit

func hello() async {
    print(Thread.isMainThread)  // true or false?
}

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        

tokizuoh

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        Task.init {
            hello()
        }
    }

tokizuoh

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        Task.init {
            try await sleep()  // 何秒かかる？
        }
    }

tokizuoh

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        Task.init {
            try await sleep()  // 何秒かかる？
        }
    }

tokizuoh

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        Task.init {
            try await sleep()  // 何秒かかる？
        }
    }

tokizuoh

import UIKit

class ViewController: UIViewController {
    var callback: () -> Void = { @MainActor in
        print(Thread.isMainThread)  // true or false?
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        

tokizuoh

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        Task.detached {
            let y = Y()
            y.f()
        }