Package org.jctools.queues.varhandle.unpadded

Class MpscBlockingConsumerVarHandleUnpaddedArrayQueue<E>

  • All Implemented Interfaces:
    java.lang.Iterable<E>, java.util.Collection<E>, java.util.concurrent.BlockingQueue<E>, java.util.Queue<E>, IndexedQueueSizeUtil.IndexedQueue, MessagePassingQueue<E>, QueueProgressIndicators
    public class MpscBlockingConsumerVarHandleUnpaddedArrayQueue<E>
extends MpscBlockingConsumerVarHandleUnpaddedArrayQueueConsumerFields<E>
implements MessagePassingQueue<E>, QueueProgressIndicators, java.util.concurrent.BlockingQueue<E>
    NOTE: This class was automatically generated by org.jctools.queues.varhandle.unpadded.JavaParsingVarHandleUnpaddedArrayQueueGenerator which can found in the jctools-build module. The original source file is MpscBlockingConsumerArrayQueue.java. This is a partial implementation of the BlockingQueue on the consumer side only on top of the mechanics described in BaseMpscLinkedArrayQueue, but with the reservation bit used for blocking rather than resizing in this instance.

    • Constructor Detail

      • MpscBlockingConsumerVarHandleUnpaddedArrayQueue

        public MpscBlockingConsumerVarHandleUnpaddedArrayQueue​(int capacity)

    • Method Detail

      • iterator

        public final java.util.Iterator<E> iterator()
        Specified by:
        iterator in interface java.util.Collection<E>
        Specified by:
        iterator in interface java.lang.Iterable<E>
        Specified by:
        iterator in class java.util.AbstractCollection<E>

      • size

        public final int size()
        Description copied from interface: MessagePassingQueue
        This method's accuracy is subject to concurrent modifications happening as the size is estimated and as such is a best effort rather than absolute value. For some implementations this method may be O(n) rather than O(1).
        Specified by:
        size in interface java.util.Collection<E>
        Specified by:
        size in interface MessagePassingQueue<E>
        Specified by:
        size in class java.util.AbstractCollection<E>
        Returns:
        number of messages in the queue, between 0 and Integer.MAX_VALUE but less or equals to capacity (if bounded).

      • isEmpty

        public final boolean isEmpty()
        Description copied from interface: MessagePassingQueue
        This method's accuracy is subject to concurrent modifications happening as the observation is carried out.
        Specified by:
        isEmpty in interface java.util.Collection<E>
        Specified by:
        isEmpty in interface MessagePassingQueue<E>
        Overrides:
        isEmpty in class java.util.AbstractCollection<E>
        Returns:
        true if empty, false otherwise

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.util.AbstractCollection<E>

      • offerIfBelowThreshold

        public boolean offerIfBelowThreshold​(E e,
                                     int threshold)
        offer(E) if size() is less than threshold.
        Parameters:
        e - the object to offer onto the queue, not null
        threshold - the maximum allowable size
        Returns:
        true if the offer is successful, false if queue size exceeds threshold
        Since:
        3.0.1

      • offer

        public boolean offer​(E e)
        Description copied from interface: MessagePassingQueue
        Called from a producer thread subject to the restrictions appropriate to the implementation and according to the Queue.offer(Object) interface.
        Specified by:
        offer in interface java.util.concurrent.BlockingQueue<E>
        Specified by:
        offer in interface MessagePassingQueue<E>
        Specified by:
        offer in interface java.util.Queue<E>
        Parameters:
        e - not null, will throw NPE if it is
        Returns:
        true if element was inserted into the queue, false iff full

      • put

        public void put​(E e)
         throws java.lang.InterruptedException
        Specified by:
        put in interface java.util.concurrent.BlockingQueue<E>
        Throws:
        java.lang.InterruptedException

      • offer

        public boolean offer​(E e,
                     long timeout,
                     java.util.concurrent.TimeUnit unit)
              throws java.lang.InterruptedException
        Specified by:
        offer in interface java.util.concurrent.BlockingQueue<E>
        Throws:
        java.lang.InterruptedException

      • offerAndWakeup

        private boolean offerAndWakeup​(E[] buffer,
                               long mask,
                               long pIndex,
                               E e)

      • recalculateProducerLimit

        private boolean recalculateProducerLimit​(long mask,
                                         long pIndex,
                                         long producerLimit)

      • recalculateProducerLimit

        private boolean recalculateProducerLimit​(long pIndex,
                                         long producerLimit,
                                         long cIndex,
                                         long bufferCapacity,
                                         long threshold)

      • take

        public E take()
       throws java.lang.InterruptedException

        This implementation is correct for single consumer thread use only.

        Specified by:
        take in interface java.util.concurrent.BlockingQueue<E>
        Throws:
        java.lang.InterruptedException

      • poll

        public E poll​(long timeout,
              java.util.concurrent.TimeUnit unit)
       throws java.lang.InterruptedException

        This implementation is correct for single consumer thread use only.

        Specified by:
        poll in interface java.util.concurrent.BlockingQueue<E>
        Throws:
        java.lang.InterruptedException

      • parkUntilNext

        private E parkUntilNext​(E[] buffer,
                        long cIndex,
                        long offset,
                        long timeoutNs)
                 throws java.lang.InterruptedException
        Throws:
        java.lang.InterruptedException

      • remainingCapacity

        public int remainingCapacity()
        Specified by:
        remainingCapacity in interface java.util.concurrent.BlockingQueue<E>

      • drainTo

        public int drainTo​(java.util.Collection<? super E> c)
        Specified by:
        drainTo in interface java.util.concurrent.BlockingQueue<E>

      • drainTo

        public int drainTo​(java.util.Collection<? super E> c,
                   int maxElements)
        Specified by:
        drainTo in interface java.util.concurrent.BlockingQueue<E>

      • poll

        public E poll()
        Called from the consumer thread subject to the restrictions appropriate to the implementation and according to the Queue.poll() interface.

        This implementation is correct for single consumer thread use only.

        Specified by:
        poll in interface MessagePassingQueue<E>
        Specified by:
        poll in interface java.util.Queue<E>
        Returns:
        a message from the queue if one is available, null iff empty

      • spinWaitForElement

        private static <E> E spinWaitForElement​(E[] buffer,
                                        long offset)

      • peek

        public E peek()
        Called from the consumer thread subject to the restrictions appropriate to the implementation and according to the Queue.peek() interface.

        This implementation is correct for single consumer thread use only.

        Specified by:
        peek in interface MessagePassingQueue<E>
        Specified by:
        peek in interface java.util.Queue<E>
        Returns:
        a message from the queue if one is available, null iff empty

      • currentProducerIndex

        public long currentProducerIndex()
        Description copied from interface: QueueProgressIndicators
        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.
        Specified by:
        currentProducerIndex in interface QueueProgressIndicators
        Returns:
        the current value of the producer progress index

      • currentConsumerIndex

        public long currentConsumerIndex()
        Description copied from interface: QueueProgressIndicators
        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.
        Specified by:
        currentConsumerIndex in interface QueueProgressIndicators
        Returns:
        the current value of the consumer progress index

      • relaxedOffer

        public boolean relaxedOffer​(E e)
        Description copied from interface: MessagePassingQueue
        Called from a producer thread subject to the restrictions appropriate to the implementation. As opposed to Queue.offer(Object) this method may return false without the queue being full.
        Specified by:
        relaxedOffer in interface MessagePassingQueue<E>
        Parameters:
        e - not null, will throw NPE if it is
        Returns:
        true if element was inserted into the queue, false if unable to offer

      • relaxedPoll

        public E relaxedPoll()
        Description copied from interface: MessagePassingQueue
        Called from the consumer thread subject to the restrictions appropriate to the implementation. As opposed to Queue.poll() this method may return null without the queue being empty.
        Specified by:
        relaxedPoll in interface MessagePassingQueue<E>
        Returns:
        a message from the queue if one is available, null if unable to poll

      • relaxedPeek

        public E relaxedPeek()
        Description copied from interface: MessagePassingQueue
        Called from the consumer thread subject to the restrictions appropriate to the implementation. As opposed to Queue.peek() this method may return null without the queue being empty.
        Specified by:
        relaxedPeek in interface MessagePassingQueue<E>
        Returns:
        a message from the queue if one is available, null if unable to peek

      • fill

        public int fill​(MessagePassingQueue.Supplier<E> s,
                int limit)
        Description copied from interface: MessagePassingQueue
        Stuff the queue with up to limit elements from the supplier. Semantically similar to: 

        
   for(int i=0; i < limit && relaxedOffer(s.get()); i++);

        There's no strong commitment to the queue being full at the end of a fill. Called from a producer thread subject to the restrictions appropriate to the implementation. WARNING: Explicit assumptions are made with regards to MessagePassingQueue.Supplier.get() make sure you have read and understood these before using this method.

        Specified by:
        fill in interface MessagePassingQueue<E>
        Returns:
        the number of offered elements

      • drain

        public int drain​(MessagePassingQueue.Consumer<E> c,
                 int limit,
                 long timeout,
                 java.util.concurrent.TimeUnit unit)
          throws java.lang.InterruptedException
        Remove up to limit elements from the queue and hand to consume, waiting up to the specified wait time if necessary for an element to become available.

        There's no strong commitment to the queue being empty at the end of it. This implementation is correct for single consumer thread use only.

        WARNING: Explicit assumptions are made with regards to MessagePassingQueue.Consumer.accept(T) make sure you have read and understood these before using this method.

        Returns:
        the number of polled elements
        Throws:
        java.lang.InterruptedException - if interrupted while waiting
        java.lang.IllegalArgumentException - c is null
        java.lang.IllegalArgumentException - if limit is negative

      • fill

        public int fill​(MessagePassingQueue.Supplier<E> s)
        Description copied from interface: MessagePassingQueue
        Stuff the queue with elements from the supplier. Semantically similar to: 
         while(relaxedOffer(s.get());
        There's no strong commitment to the queue being full at the end of a fill. Called from a producer thread subject to the restrictions appropriate to the implementation.

        Unbounded queues will fill up the queue with a fixed amount rather than fill up to oblivion. WARNING: Explicit assumptions are made with regards to MessagePassingQueue.Supplier.get() make sure you have read and understood these before using this method.

        Specified by:
        fill in interface MessagePassingQueue<E>
        Returns:
        the number of offered elements

      • drain

        public int drain​(MessagePassingQueue.Consumer<E> c)
        Description copied from interface: MessagePassingQueue
        Remove all available item from the queue and hand to consume. This should be semantically similar to: 
         M m;
 while((m = relaxedPoll()) != null){
 c.accept(m);
 }
        There's no strong commitment to the queue being empty at the end of a drain. Called from a consumer thread subject to the restrictions appropriate to the implementation.

        WARNING: Explicit assumptions are made with regards to MessagePassingQueue.Consumer.accept(T) make sure you have read and understood these before using this method.

        Specified by:
        drain in interface MessagePassingQueue<E>
        Returns:
        the number of polled elements

      • drain

        public int drain​(MessagePassingQueue.Consumer<E> c,
                 int limit)
        Description copied from interface: MessagePassingQueue
        Remove up to limit elements from the queue and hand to consume. This should be semantically similar to: 

        
   M m;
   int i = 0;
   for(;i < limit && (m = relaxedPoll()) != null; i++){
     c.accept(m);
   }
   return i;

        There's no strong commitment to the queue being empty at the end of a drain. Called from a consumer thread subject to the restrictions appropriate to the implementation.

        WARNING: Explicit assumptions are made with regards to MessagePassingQueue.Consumer.accept(T) make sure you have read and understood these before using this method.

        Specified by:
        drain in interface MessagePassingQueue<E>
        Returns:
        the number of polled elements