Class BaseMpscLinkedArrayQueue<E>
- All Implemented Interfaces:
Iterable<E>
,Collection<E>
,Queue<E>
,IndexedQueueSizeUtil.IndexedQueue
,MessagePassingQueue<E>
,QueueProgressIndicators
- Direct Known Subclasses:
MpscChunkedArrayQueueColdProducerFields
,MpscUnboundedArrayQueue
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Nested Class Summary
Nested ClassesNested classes/interfaces inherited from interface org.jctools.queues.MessagePassingQueue
MessagePassingQueue.Consumer<T>, MessagePassingQueue.ExitCondition, MessagePassingQueue.Supplier<T>, MessagePassingQueue.WaitStrategy
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final Object
private static final int
private static final Object
private static final int
private static final int
private static final int
Fields inherited from class org.jctools.queues.BaseMpscLinkedArrayQueueColdProducerFields
producerBuffer, producerMask
Fields inherited from class org.jctools.queues.BaseMpscLinkedArrayQueuePad3
b000, b001, b002, b003, b004, b005, b006, b007, b010, b011, b012, b013, b014, b015, b016, b017, b020, b021, b022, b023, b024, b025, b026, b027, b030, b031, b032, b033, b034, b035, b036, b037, b040, b041, b042, b043, b044, b045, b046, b047, b050, b051, b052, b053, b054, b055, b056, b057, b060, b061, b062, b063, b064, b065, b066, b067, b070, b071, b072, b073, b074, b075, b076, b077, b100, b101, b102, b103, b104, b105, b106, b107, b110, b111, b112, b113, b114, b115, b116, b117, b120, b121, b122, b123, b124, b125, b126, b127, b130, b131, b132, b133, b134, b135, b136, b137, b140, b141, b142, b143, b144, b145, b146, b147, b150, b151, b152, b153, b154, b155, b156, b157, b160, b161, b162, b163, b164, b165, b166, b167, b170, b171, b172, b173, b174, b175, b176, b177
Fields inherited from class org.jctools.queues.BaseMpscLinkedArrayQueueConsumerFields
consumerBuffer, consumerMask
Fields inherited from interface org.jctools.queues.MessagePassingQueue
UNBOUNDED_CAPACITY
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionprotected abstract long
availableInQueue
(long pIndex, long cIndex) abstract int
capacity()
long
This method has no concurrent visibility semantics.long
This method has no concurrent visibility semantics.int
Remove all available item from the queue and hand to consume.int
drain
(MessagePassingQueue.Consumer<E> c, int limit) Remove up to limit elements from the queue and hand to consume.void
drain
(MessagePassingQueue.Consumer<E> c, MessagePassingQueue.WaitStrategy wait, MessagePassingQueue.ExitCondition exit) Remove elements from the queue and hand to consume forever.int
Stuff the queue with elements from the supplier.int
fill
(MessagePassingQueue.Supplier<E> s, int limit) Stuff the queue with up to limit elements from the supplier.void
fill
(MessagePassingQueue.Supplier<E> s, MessagePassingQueue.WaitStrategy wait, MessagePassingQueue.ExitCondition exit) Stuff the queue with elements from the supplier forever.protected abstract long
getCurrentBufferCapacity
(long mask) protected abstract int
getNextBufferSize
(E[] buffer) boolean
isEmpty()
This method's accuracy is subject to concurrent modifications happening as the observation is carried out.iterator()
Get an iterator for this queue.private E
newBufferPeek
(E[] nextBuffer, long index) private E
newBufferPoll
(E[] nextBuffer, long index) private static long
nextArrayOffset
(long mask) private E[]
nextBuffer
(E[] buffer, long mask) boolean
Called from a producer thread subject to the restrictions appropriate to the implementation and according to theQueue.offer(Object)
interface.private int
offerSlowPath
(long mask, long pIndex, long producerLimit) We do not inline resize into this method because we do not resize on fill.peek()
Called from the consumer thread subject to the restrictions appropriate to the implementation and according to theQueue.peek()
interface.poll()
Called from the consumer thread subject to the restrictions appropriate to the implementation and according to theQueue.poll()
interface.boolean
relaxedOffer
(E e) Called from a producer thread subject to the restrictions appropriate to the implementation.Called from the consumer thread subject to the restrictions appropriate to the implementation.Called from the consumer thread subject to the restrictions appropriate to the implementation.private void
resize
(long oldMask, E[] oldBuffer, long pIndex, E e, MessagePassingQueue.Supplier<E> s) int
size()
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.toString()
Methods inherited from class org.jctools.queues.BaseMpscLinkedArrayQueueColdProducerFields
casProducerLimit, lvProducerLimit, soProducerLimit
Methods inherited from class org.jctools.queues.BaseMpscLinkedArrayQueueConsumerFields
lpConsumerIndex, lvConsumerIndex, soConsumerIndex
Methods inherited from class org.jctools.queues.BaseMpscLinkedArrayQueueProducerFields
casProducerIndex, lvProducerIndex, soProducerIndex
Methods inherited from class java.util.AbstractCollection
contains, containsAll, remove, removeAll, retainAll, toArray, toArray
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface java.util.Collection
contains, containsAll, equals, hashCode, parallelStream, remove, removeAll, removeIf, retainAll, spliterator, stream, toArray, toArray, toArray
Methods inherited from interface org.jctools.queues.MessagePassingQueue
clear
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Field Details
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JUMP
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BUFFER_CONSUMED
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CONTINUE_TO_P_INDEX_CAS
private static final int CONTINUE_TO_P_INDEX_CAS- See Also:
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RETRY
private static final int RETRY- See Also:
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QUEUE_FULL
private static final int QUEUE_FULL- See Also:
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QUEUE_RESIZE
private static final int QUEUE_RESIZE- See Also:
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Constructor Details
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BaseMpscLinkedArrayQueue
public BaseMpscLinkedArrayQueue(int initialCapacity) - Parameters:
initialCapacity
- the queue initial capacity. If chunk size is fixed this will be the chunk size. Must be 2 or more.
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Method Details
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size
public 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 interfaceCollection<E>
- Specified by:
size
in interfaceMessagePassingQueue<E>
- Specified by:
size
in classAbstractCollection<E>
- Returns:
- number of messages in the queue, between 0 and
Integer.MAX_VALUE
but less or equals to capacity (if bounded).
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isEmpty
public 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 interfaceCollection<E>
- Specified by:
isEmpty
in interfaceMessagePassingQueue<E>
- Overrides:
isEmpty
in classAbstractCollection<E>
- Returns:
- true if empty, false otherwise
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toString
- Overrides:
toString
in classAbstractCollection<E>
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offer
Description copied from interface:MessagePassingQueue
Called from a producer thread subject to the restrictions appropriate to the implementation and according to theQueue.offer(Object)
interface. -
poll
Called from the consumer thread subject to the restrictions appropriate to the implementation and according to theQueue.poll()
interface.This implementation is correct for single consumer thread use only.
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peek
Called from the consumer thread subject to the restrictions appropriate to the implementation and according to theQueue.peek()
interface.This implementation is correct for single consumer thread use only.
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offerSlowPath
private int offerSlowPath(long mask, long pIndex, long producerLimit) We do not inline resize into this method because we do not resize on fill. -
availableInQueue
protected abstract long availableInQueue(long pIndex, long cIndex) - Returns:
- available elements in queue * 2
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nextBuffer
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nextArrayOffset
private static long nextArrayOffset(long mask) -
newBufferPoll
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newBufferPeek
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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 interfaceQueueProgressIndicators
- Returns:
- the current value of the producer progress index
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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 interfaceQueueProgressIndicators
- Returns:
- the current value of the consumer progress index
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capacity
public abstract int capacity()- Specified by:
capacity
in interfaceIndexedQueueSizeUtil.IndexedQueue
- Specified by:
capacity
in interfaceMessagePassingQueue<E>
- Returns:
- the capacity of this queue or
MessagePassingQueue.UNBOUNDED_CAPACITY
if not bounded
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relaxedOffer
Description copied from interface:MessagePassingQueue
Called from a producer thread subject to the restrictions appropriate to the implementation. As opposed toQueue.offer(Object)
this method may return false without the queue being full.- Specified by:
relaxedOffer
in interfaceMessagePassingQueue<E>
- Parameters:
e
- notnull
, will throw NPE if it is- Returns:
- true if element was inserted into the queue, false if unable to offer
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relaxedPoll
Description copied from interface:MessagePassingQueue
Called from the consumer thread subject to the restrictions appropriate to the implementation. As opposed toQueue.poll()
this method may returnnull
without the queue being empty.- Specified by:
relaxedPoll
in interfaceMessagePassingQueue<E>
- Returns:
- a message from the queue if one is available,
null
if unable to poll
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relaxedPeek
Description copied from interface:MessagePassingQueue
Called from the consumer thread subject to the restrictions appropriate to the implementation. As opposed toQueue.peek()
this method may returnnull
without the queue being empty.- Specified by:
relaxedPeek
in interfaceMessagePassingQueue<E>
- Returns:
- a message from the queue if one is available,
null
if unable to peek
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fill
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 interfaceMessagePassingQueue<E>
- Returns:
- the number of offered elements
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fill
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 interfaceMessagePassingQueue<E>
- Returns:
- the number of offered elements
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fill
public void fill(MessagePassingQueue.Supplier<E> s, MessagePassingQueue.WaitStrategy wait, MessagePassingQueue.ExitCondition exit) Description copied from interface:MessagePassingQueue
Stuff the queue with elements from the supplier forever. Semantically similar to:int idleCounter = 0; while (exit.keepRunning()) { E e = s.get(); while (!relaxedOffer(e)) { idleCounter = wait.idle(idleCounter); continue; } idleCounter = 0; }
Called from a producer thread subject to the restrictions appropriate to the implementation. The main difference being that implementors MUST assure room in the queue is available BEFORE calling
MessagePassingQueue.Supplier.get()
. WARNING: Explicit assumptions are made with regards toMessagePassingQueue.Supplier.get()
make sure you have read and understood these before using this method.- Specified by:
fill
in interfaceMessagePassingQueue<E>
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drain
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 interfaceMessagePassingQueue<E>
- Returns:
- the number of polled elements
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drain
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 interfaceMessagePassingQueue<E>
- Returns:
- the number of polled elements
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drain
public void drain(MessagePassingQueue.Consumer<E> c, MessagePassingQueue.WaitStrategy wait, MessagePassingQueue.ExitCondition exit) Description copied from interface:MessagePassingQueue
Remove elements from the queue and hand to consume forever. Semantically similar to:int idleCounter = 0; while (exit.keepRunning()) { E e = relaxedPoll(); if(e==null){ idleCounter = wait.idle(idleCounter); continue; } idleCounter = 0; c.accept(e); }
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 interfaceMessagePassingQueue<E>
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iterator
Get an iterator for this queue. This method is thread safe.The iterator provides a best-effort snapshot of the elements in the queue. The returned iterator is not guaranteed to return elements in queue order, and races with the consumer thread may cause gaps in the sequence of returned elements. Like {link #relaxedPoll}, the iterator may not immediately return newly inserted elements.
- Specified by:
iterator
in interfaceCollection<E>
- Specified by:
iterator
in interfaceIterable<E>
- Specified by:
iterator
in classAbstractCollection<E>
- Returns:
- The iterator.
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resize
private void resize(long oldMask, E[] oldBuffer, long pIndex, E e, MessagePassingQueue.Supplier<E> s) -
getNextBufferSize
- Returns:
- next buffer size(inclusive of next array pointer)
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getCurrentBufferCapacity
protected abstract long getCurrentBufferCapacity(long mask) - Returns:
- current buffer capacity for elements (excluding next pointer and jump entry) * 2
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