suhitp

// MARK: CoreDataStack
final class CoreDataStack: CoreDataStackProvider {
    
    // MARK: Properties
    private let persistentContainer: NSPersistentContainer
    
    /// MainContext
    private(set) lazy var mainContext: NSManagedObjectContext = {
        let viewContext = persistentContainer.viewContext
        viewContext.automaticallyMergesChangesFromParent = false

suhitp

// MARK:  Lock Protocol
protocol Lock: AnyObject {
    /// locks the resource to execute action
    func lock()
    
    /// unlocks the resource
    func unlock()
}

extension Lock {

mattt

import UIKit

#if canImport(SwiftUI) && DEBUG
import SwiftUI
struct UIViewControllerPreview<ViewController: UIViewController>: UIViewControllerRepresentable {
    let viewController: ViewController

    init(_ builder: @escaping () -> ViewController) {
        viewController = builder()
    }

tclementdev

libdispatch efficiency tips

The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).

My take-aways are:

• You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.

• Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse

nicklockwood

// Swift's untyped errors are a goddam PiTA. Here's the pattern I use to try to work around this.
// The goal is basically to try to guarantee that every throwing function in the app throws an
// ApplicationError instead of some unknown error type. We can't actually enforce this statically
// But by following this convention we can simplify error handling

enum ApplicationError: Error, CustomStringConvertible {
    
  // These are application-specific errors that may need special treatment
  case specificError1
  case specificError2(SomeType)

lattner

Swift Concurrency Manifesto

Author: Chris Lattner

Chinese Translation by Jason Yu

Contents

• Introduction
• Overall Vision

steipete

//
//  SpinlockTestTests.swift
//  SpinlockTestTests
//
//  Created by Peter Steinberger on 04/10/2016.
//  Copyright © 2016 PSPDFKit GmbH. All rights reserved.
//

import XCTest

andymatuschak

//
//  CollectionViewDataSource.swift
//  Khan Academy
//
//  Created by Andy Matuschak on 10/14/14.
//  Copyright (c) 2014 Khan Academy. All rights reserved.
//

import UIKit