//
//  UnfairLock.swift
//  SCNRecorder
//
//  Created by Vladislav Grigoryev on 29.12.2019.
//  Copyright © 2020 GORA Studio. https://gora.studio
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.

import Foundation

public final class UnfairLock {

  let unfairLock: os_unfair_lock_t

  public init() {
    unfairLock = .allocate(capacity: 1)
    unfairLock.initialize(to: os_unfair_lock())
  }

  deinit {
    unfairLock.deinitialize(count: 1)
    unfairLock.deallocate()
  }

  public func `try`() -> Bool { os_unfair_lock_trylock(unfairLock) }

  public func lock() { os_unfair_lock_lock(unfairLock) }

  public func unlock() { os_unfair_lock_unlock(unfairLock) }
}

public extension UnfairLock {

  @discardableResult
  func locked<Result>(_ action: () throws -> Result) rethrows -> Result {
    lock()
    defer { unlock() }
    return try action()
  }
}
