Class MpscRelaxedAtomicArrayQueue<E>
- java.lang.Object
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- java.util.AbstractCollection<E>
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- java.util.AbstractQueue<E>
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- org.jctools.queues.atomic.MpscAtomicArrayQueueL0Pad<E>
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- org.jctools.queues.atomic.MpscAtomicArrayQueueActiveCycleIdField<E>
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- org.jctools.queues.atomic.MpscRelaxedAtomicArrayQueueMidPad<E>
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- org.jctools.queues.atomic.MpscRelaxedAtomicArrayQueueProducerLimitField<E>
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- org.jctools.queues.atomic.MpscRelaxedAtomicArrayQueueL2Pad<E>
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- org.jctools.queues.atomic.MpscAtomicArrayQueueConsumerPositionField<E>
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- org.jctools.queues.atomic.MpscRelaxedAtomicArrayQueueL3Pad<E>
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- org.jctools.queues.atomic.MpscRelaxedAtomicArrayQueue<E>
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- All Implemented Interfaces:
java.lang.Iterable<E>
,java.util.Collection<E>
,java.util.Queue<E>
,MessagePassingQueue<E>
public final class MpscRelaxedAtomicArrayQueue<E> extends MpscRelaxedAtomicArrayQueueL3Pad<E> implements MessagePassingQueue<E>
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Nested Class Summary
Nested Classes Modifier and Type Class Description private static class
MpscRelaxedAtomicArrayQueue.AtomicLongArrayAccess
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Nested 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
Fields Modifier and Type Field Description private java.util.concurrent.atomic.AtomicReferenceArray<E>
buffer
private int
capacity
private int
cycleIdBitShift
private int
cycleLength
private int
cycleLengthLog2
private long
mask
private long
maxCycleId
private int
positionOnCycleMask
private java.util.concurrent.atomic.AtomicLongArray
producerCycleClaim
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Fields inherited from class org.jctools.queues.atomic.MpscRelaxedAtomicArrayQueueL3Pad
p01, p02, p03, p04, p05, p06, p07, p10, p11, p12, p13, p14, p15, p16, p17
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Fields inherited from class org.jctools.queues.atomic.MpscAtomicArrayQueueConsumerPositionField
consumerPosition
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Fields inherited from class org.jctools.queues.atomic.MpscRelaxedAtomicArrayQueueL2Pad
p00
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Fields inherited from interface org.jctools.queues.MessagePassingQueue
UNBOUNDED_CAPACITY
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Constructor Summary
Constructors Constructor Description MpscRelaxedAtomicArrayQueue(int capacity)
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description private static int
calcElementOffset(int cycle, int positionWithinCycle, int cycleLengthLog2)
private static int
calcElementOffset(long position, long mask)
int
capacity()
void
clear()
Removes all items from the queue.private static long
cycleId(long producerCycleClaim, int cycleIdBitShift)
int
drain(MessagePassingQueue.Consumer<E> c)
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 w, MessagePassingQueue.ExitCondition exit)
Remove elements from the queue and hand to consume forever.int
fill(MessagePassingQueue.Supplier<E> s)
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 w, MessagePassingQueue.ExitCondition exit)
Stuff the queue with elements from the supplier forever.private boolean
isBackPressured(long producerPosition)
boolean
isEmpty()
This method's accuracy is subject to concurrent modifications happening as the observation is carried out.java.util.Iterator<E>
iterator()
boolean
offer(E e)
Called from a producer thread subject to the restrictions appropriate to the implementation and according to theQueue.offer(Object)
interface.E
peek()
Called from the consumer thread subject to the restrictions appropriate to the implementation and according to theQueue.peek()
interface.E
poll()
Called from the consumer thread subject to the restrictions appropriate to the implementation and according to theQueue.poll()
interface.private E
pollMaybeEmpty(java.util.concurrent.atomic.AtomicReferenceArray<E> buffer, int offset, long consumerPosition)
private static int
positionOnCycle(long producerCycleClaim, int positionOnCycleMask)
private static long
producerPosition(long cycleId, int positionWithinCycle, int cycleLengthLog2)
boolean
relaxedOffer(E e)
Called from a producer thread subject to the restrictions appropriate to the implementation.E
relaxedPeek()
Called from the consumer thread subject to the restrictions appropriate to the implementation.E
relaxedPoll()
Called from the consumer thread subject to the restrictions appropriate to the implementation.private void
rotateCycle(java.util.concurrent.atomic.AtomicLongArray producerCycleClaims, int activeCycle, long producerCycleClaim, int cycleIdBitShift, long maxCycleId)
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.java.lang.String
toString()
private void
validateSlowProducerClaim(long cycleId, int positionOnCycle, int cycleLengthLog2)
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Methods inherited from class org.jctools.queues.atomic.MpscAtomicArrayQueueConsumerPositionField
lvConsumerPosition, soConsumerPosition
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Methods inherited from class org.jctools.queues.atomic.MpscRelaxedAtomicArrayQueueProducerLimitField
lvProducerLimit, soProducerLimit
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Methods inherited from class org.jctools.queues.atomic.MpscAtomicArrayQueueActiveCycleIdField
activeCycleIndex, casActiveCycleId, lvActiveCycleId, soActiveCycleId
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Methods inherited from class java.util.AbstractCollection
contains, containsAll, remove, removeAll, retainAll, toArray, toArray
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Field Detail
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mask
private final long mask
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capacity
private final int capacity
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cycleLength
private final int cycleLength
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cycleLengthLog2
private final int cycleLengthLog2
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buffer
private final java.util.concurrent.atomic.AtomicReferenceArray<E> buffer
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producerCycleClaim
private final java.util.concurrent.atomic.AtomicLongArray producerCycleClaim
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positionOnCycleMask
private final int positionOnCycleMask
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cycleIdBitShift
private final int cycleIdBitShift
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maxCycleId
private final long maxCycleId
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Method Detail
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iterator
public java.util.Iterator<E> iterator()
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positionOnCycle
private static int positionOnCycle(long producerCycleClaim, int positionOnCycleMask)
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cycleId
private static long cycleId(long producerCycleClaim, int cycleIdBitShift)
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producerPosition
private static long producerPosition(long cycleId, int positionWithinCycle, int cycleLengthLog2)
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calcElementOffset
private static int calcElementOffset(int cycle, int positionWithinCycle, int cycleLengthLog2)
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calcElementOffset
private static int calcElementOffset(long position, long mask)
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isBackPressured
private boolean isBackPressured(long producerPosition)
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rotateCycle
private void rotateCycle(java.util.concurrent.atomic.AtomicLongArray producerCycleClaims, int activeCycle, long producerCycleClaim, int cycleIdBitShift, long maxCycleId)
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validateSlowProducerClaim
private void validateSlowProducerClaim(long cycleId, int positionOnCycle, int cycleLengthLog2)
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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 theQueue.offer(Object)
interface.- Specified by:
offer
in interfaceMessagePassingQueue<E>
- Specified by:
offer
in interfacejava.util.Queue<E>
- Parameters:
e
- notnull
, will throw NPE if it is- Returns:
- true if element was inserted into the queue, false iff full
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poll
public E poll()
Description copied from interface:MessagePassingQueue
Called from the consumer thread subject to the restrictions appropriate to the implementation and according to theQueue.poll()
interface.- Specified by:
poll
in interfaceMessagePassingQueue<E>
- Specified by:
poll
in interfacejava.util.Queue<E>
- Returns:
- a message from the queue if one is available,
null
iff empty
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pollMaybeEmpty
private E pollMaybeEmpty(java.util.concurrent.atomic.AtomicReferenceArray<E> buffer, int offset, long consumerPosition)
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peek
public E peek()
Description copied from interface:MessagePassingQueue
Called from the consumer thread subject to the restrictions appropriate to the implementation and according to theQueue.peek()
interface.- Specified by:
peek
in interfaceMessagePassingQueue<E>
- Specified by:
peek
in interfacejava.util.Queue<E>
- Returns:
- a message from the queue if one is available,
null
iff empty
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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 interfacejava.util.Collection<E>
- Specified by:
size
in interfaceMessagePassingQueue<E>
- Specified by:
size
in classjava.util.AbstractCollection<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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clear
public void clear()
Description copied from interface:MessagePassingQueue
Removes all items from the queue. Called from the consumer thread subject to the restrictions appropriate to the implementation and according to theCollection.clear()
interface.- Specified by:
clear
in interfacejava.util.Collection<E>
- Specified by:
clear
in interfaceMessagePassingQueue<E>
- Overrides:
clear
in classjava.util.AbstractQueue<E>
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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 interfacejava.util.Collection<E>
- Specified by:
isEmpty
in interfaceMessagePassingQueue<E>
- Overrides:
isEmpty
in classjava.util.AbstractCollection<E>
- Returns:
- true if empty, false otherwise
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capacity
public int capacity()
- Specified by:
capacity
in interfaceMessagePassingQueue<E>
- Returns:
- the capacity of this queue or
MessagePassingQueue.UNBOUNDED_CAPACITY
if not bounded
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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 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
public E 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
public E 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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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 interfaceMessagePassingQueue<E>
- Returns:
- the number of polled elements
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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 interfaceMessagePassingQueue<E>
- Returns:
- the number of offered elements
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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 interfaceMessagePassingQueue<E>
- Returns:
- the number of polled elements
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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 interfaceMessagePassingQueue<E>
- Returns:
- the number of offered elements
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drain
public void drain(MessagePassingQueue.Consumer<E> c, MessagePassingQueue.WaitStrategy w, 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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fill
public void fill(MessagePassingQueue.Supplier<E> s, MessagePassingQueue.WaitStrategy w, 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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toString
public java.lang.String toString()
- Overrides:
toString
in classjava.util.AbstractCollection<E>
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