Atomically locking property wrapper for swift

Locked.swift

//
//  Locked.swift
//  
//
//  Created by Hannes Oud on 29.11.19.
//  Helpful reading https://www.vadimbulavin.com/swift-atomic-properties-with-property-wrappers/

import Foundation

/// Atomically locks a property using `os_unfair_lock`
@propertyWrapper
public struct Locked<Value> {

    private var value: Value
    private let lock = UnfairLock()

    public init(wrappedValue value: Value) {
        self.value = value
    }

    public var wrappedValue: Value {
      get { return load() }
      set { store(newValue: newValue) }
    }
}

private extension Locked {

    func load() -> Value {
        lock.lock()
        defer { lock.unlock() }
        return value
    }

    mutating func store(newValue: Value) {
        lock.lock()
        defer { lock.unlock() }
        value = newValue
    }
}

private final class UnfairLock {

    private var _lock = os_unfair_lock()

    func lock() { os_unfair_lock_lock(&_lock) }
    func locked() -> Bool { return os_unfair_lock_trylock(&_lock) }
    func unlock() { os_unfair_lock_unlock(&_lock) }
}