Interface QueueProgressIndicators

  • All Known Implementing Classes:
    SpscUnboundedArrayQueue

    public interface QueueProgressIndicators
    This interface is provided for monitoring purposes only and is only available on queues where it is easy to provide it. The producer/consumer progress indicators usually correspond with the number of elements offered/polled, but they are not guaranteed to maintain that semantic.
    • Method Detail

      • currentProducerIndex

        long currentProducerIndex()
        This method has no concurrent visibility semantics. The value returned may be negative. Under normal circumstances 2 consecutive calls to this method can offer an idea of progress made by producer threads by subtracting the 2 results though in extreme cases (if producers have progressed by more than 2^64) this may also fail.
        This value will normally indicate number of elements passed into the queue, but may under some circumstances be a derivative of that figure. This method should not be used to derive size or emptiness.
        Returns:
        the current value of the producer progress index
      • currentConsumerIndex

        long currentConsumerIndex()
        This method has no concurrent visibility semantics. The value returned may be negative. Under normal circumstances 2 consecutive calls to this method can offer an idea of progress made by consumer threads by subtracting the 2 results though in extreme cases (if consumers have progressed by more than 2^64) this may also fail.
        This value will normally indicate number of elements taken out of the queue, but may under some circumstances be a derivative of that figure. This method should not be used to derive size or emptiness.
        Returns:
        the current value of the consumer progress index