Swift 3 - 原子布尔

有谁知道如何在iOS 10中创建原子布尔值吗？Swift 3 - 原子布尔

当前代码：

import UIKit 

struct AtomicBoolean { 
    fileprivate var val: UInt8 = 0 

    /// Sets the value, and returns the previous value. 
    /// The test/set is an atomic operation. 
    mutating func testAndSet(_ value: Bool) -> Bool { 
     if value { 
      return OSAtomicTestAndSet(0, &val) 
     } else { 
      return OSAtomicTestAndClear(0, &val) 
     } 
    } 

    /// Returns the current value of the boolean. 
    /// The value may change before this method returns. 
    func test() -> Bool { 
     return val != 0 
    } 
}

的代码按预期工作，但我不断收到警告：

'OSAtomicTestAndSet' was deprecated in iOS 10.0: Use atomic_fetch_or_explicit(memory_order_relaxed) from <stdatomic.h> instead

我不能让它与atomic_fetch_or_explicit工作（memory_order_relaxed）。

有谁知道如何将我的当前代码转换为iOS 10，以摆脱此警告？

谢谢！

来源

2017-06-21 PAK

问题的重点应该是如何让'atomic_fetch_or_explicit'工作。要做到这一点，你需要展示你的使用尝试，并说出失败的原因。 – Carcigenicate

比较https://stackoverflow.com/questions/39356873/swift-3-atomic-compare-exchange-strong。 - 编译器会警告不推荐使用的OSAtomic函数，但不会从''导入函数。 –

的更好的办法是，以避免它...如果你想模拟天生它只是同步访问你的AtomicBoolean，使用同步在GCD缴费

例如

import PlaygroundSupport 
import Foundation 
import Dispatch 

PlaygroundPage.current.needsIndefiniteExecution = true 

let q = DispatchQueue(label: "print") 

struct AtomicBoolean { 
    private var semaphore = DispatchSemaphore(value: 1) 
    private var b: Bool = false 
    var val: Bool { 
     get { 
      q.async { 
       print("try get") 
      } 
      semaphore.wait() 
      let tmp = b 
      q.async { 
       print("got", tmp) 
      } 
      semaphore.signal() 
      return tmp 
     } 
     set { 
      q.async { 
       print("try set", newValue) 
      } 
      semaphore.wait() 
      b = newValue 
      q.async { 
       print("did", newValue) 
      } 
      semaphore.signal() 
     } 
    } 

} 
var b = AtomicBoolean() 

DispatchQueue.concurrentPerform(iterations: 10) { (i) in 
    if (i % 4 == 0) { 
     _ = b.val 
    } 
    b.val = (i % 3 == 0) 
}

打印

try get 
try set false 
try set false 
try set true 
did false 
got false 
try get 
try set true 
did false 
try set false 
did true 
did true 
try set true 
try set false 
got false 
try set false 
did false 
try get 
did true 
try set true 
did false 
did false 
got false 
try set false 
did true 
did false

来源

2017-06-21 21:59:52 user3441734

Swift 3 - 原子布尔

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