Obtain a <AudioTimeStamp> for Audio Queue Buffer

I'm attempting to create a continuous FIFO audio recorder in Swift. I'm running into and issue while trying to create the audioQueueCallback.

From the docs AudioTimeStamp has this init method:

AudioTimeStamp(mSampleTime: Float64, mHostTime: UInt64, mRateScalar: Float64, mWordClockTime: UInt64, mSMPTETime: SMPTETime, mFlags: AudioTimeStampFlags, mReserved: UInt32)

And I have not idea how to use it.

It seems to me like the device should have a reliable internal clock to be able to manage audioQueues off of but I haven't been able to find any documentation for it.

Here's my attempt at creating a BufferQueue:

ypealias WYNDRInputQueueCallback = ((Data) -> Void)

class WYNDRInputQueue {

  class WYNDRInputQueueUserData {
    let callback: WYNDRInputQueueCallback
    let bufferStub: NSData

    init(callback: @escaping WYNDRInputQueueCallback, bufferStub: NSData){
      self.callback = callback
      self.bufferStub = bufferStub
    }
  }


  private var audioQueueRef: AudioQueueRef?
  private let userData: WYNDRInputQueueUserData



  public init(asbd: inout AudioStreamBasicDescription, callback: @escaping WYNDRInputQueueCallback, buffersCount: UInt32 = 3, bufferSize: UInt32 = 9600) throws {

    self.userData = WYNDRInputQueueUserData(callback: callback, bufferStub: NSMutableData(length: Int(bufferSize))!)

    let userDataUnsafe = UnsafeMutableRawPointer(Unmanaged.passRetained(self.userData).toOpaque())

    let input = AudioQueueNewInput(&asbd,
                                   audioQueueInputCallback,
                                   userDataUnsafe,
                                   .none,
                                   .none,
                                   0,
                                   &audioQueueRef)

    if input != noErr {
      throw InputQueueError.genericError(input)
    }

    assert(audioQueueRef != nil )

    for _ in 0..<buffersCount {
      var bufferRef: AudioQueueBufferRef?

      let bufferInput = AudioQueueAllocateBuffer(audioQueueRef!, bufferSize, &bufferRef)

      if bufferInput != noErr {
        throw InputQueueError.genericError(bufferInput)
      }

      assert(bufferRef != nil)

Here's where I'm using the audioTimeStamp:

      audioQueueInputCallback(userDataUnsafe, audioQueueRef!, bufferRef!, <#T##UnsafePointer<AudioTimeStamp>#>, 0, nil)
    }
  }

  private let audioQueueInputCallback: AudioQueueInputCallback = { (inUserData, inAQ, inBuffer, inStartTime, inNumberPacketDescriptions, inPacketDescs) in

    let userData = Unmanaged<WYNDRInputQueueUserData>.fromOpaque(inUserData!).takeUnretainedValue()

    let dataSize = Int(inBuffer.pointee.mAudioDataByteSize)

    let inputData = Data(bytes: inBuffer.pointee.mAudioData, count: dataSize)

    userData.callback(inputData)

    AudioQueueEnqueueBuffer(inAQ, inBuffer, 0, nil)
  }

Any advice here would be greatly appreciated!