E - public class MpscArrayQueue<E> extends ConcurrentCircularArrayQueue<E> implements QueueProgressIndicators
ConcurrentCircularArrayQueue. This implies that
any thread may call the offer method, but only a single thread may call poll/peek for correctness to
maintained. MessagePassingQueue.Consumer<T>, MessagePassingQueue.ExitCondition, MessagePassingQueue.Supplier<T>, MessagePassingQueue.WaitStrategy| Modifier and Type | Field and Description |
|---|---|
protected long |
consumerIndex |
buffer, maskUNBOUNDED_CAPACITY| Constructor and Description |
|---|
MpscArrayQueue(int capacity) |
| Modifier and Type | Method and Description |
|---|---|
protected boolean |
casProducerIndex(long expect,
long newValue) |
long |
currentConsumerIndex()
This method has no concurrent visibility semantics.
|
long |
currentProducerIndex()
This method has no concurrent visibility semantics.
|
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 |
failFastOffer(E e)
A wait free alternative to offer which fails on CAS failure.
|
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.
|
boolean |
isEmpty()
This method's accuracy is subject to concurrent modifications happening as the observation is carried
out.
|
protected long |
lpConsumerIndex() |
protected long |
lvConsumerIndex() |
protected long |
lvProducerIndex() |
protected long |
lvProducerLimit() |
boolean |
offer(E e)
Called from a producer thread subject to the restrictions appropriate to the implementation and
according to the
Queue.offer(Object) interface. |
boolean |
offerIfBelowThreshold(E e,
int threshold)
MpscArrayQueue#offer(E)} if size() is less than threshold. |
E |
peek()
Called from the consumer thread subject to the restrictions appropriate to the implementation and
according to the
Queue.peek() interface. |
E |
poll()
Called from the consumer thread subject to the restrictions appropriate to the implementation and
according to the
Queue.poll() interface. |
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.
|
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.
|
protected void |
soConsumerIndex(long l) |
protected void |
soProducerLimit(long v) |
calcElementOffset, calcElementOffset, capacity, clear, iteratoradd, addAll, element, removecontains, containsAll, remove, removeAll, retainAll, toArray, toArray, toStringclone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, waitcontains, containsAll, equals, hashCode, parallelStream, remove, removeAll, removeIf, retainAll, spliterator, stream, toArray, toArraypublic boolean offerIfBelowThreshold(E e, int threshold)
MpscArrayQueue#offer(E)} if size() is less than threshold.e - the object to offer onto the queue, not nullthreshold - the maximum allowable sizepublic boolean offer(E e)
Queue.offer(Object) interface. offer in interface Queue<E>offer in interface MessagePassingQueue<E>e - not null, will throw NPE if it isQueue.offer(java.lang.Object),
MessagePassingQueue.offer(Object)public final int failFastOffer(E e)
e - new element, not nullpublic E poll()
Queue.poll() interface.
IMPLEMENTATION NOTES:
Lock free poll using ordered loads/stores. As class name suggests access is limited to a single thread.
poll in interface Queue<E>poll in interface MessagePassingQueue<E>Queue.poll(),
MessagePassingQueue.poll()public E peek()
Queue.peek() interface.
IMPLEMENTATION NOTES:
Lock free peek using ordered loads. As class name suggests access is limited to a single thread.
peek in interface Queue<E>peek in interface MessagePassingQueue<E>Queue.poll(),
MessagePassingQueue.poll()public int size()
size in interface Collection<E>size in interface MessagePassingQueue<E>size in class AbstractCollection<E>Integer.MAX_VALUE but less or equals to
capacity (if bounded).public boolean isEmpty()
MessagePassingQueueisEmpty in interface Collection<E>isEmpty in interface MessagePassingQueue<E>isEmpty in class AbstractCollection<E>public long currentProducerIndex()
QueueProgressIndicatorscurrentProducerIndex in interface QueueProgressIndicatorspublic long currentConsumerIndex()
QueueProgressIndicatorscurrentConsumerIndex in interface QueueProgressIndicatorspublic boolean relaxedOffer(E e)
MessagePassingQueueQueue.offer(Object) this method may return false without the queue being full.relaxedOffer in interface MessagePassingQueue<E>e - not null, will throw NPE if it ispublic E relaxedPoll()
MessagePassingQueueQueue.poll() this method may return null without the queue being empty.relaxedPoll in interface MessagePassingQueue<E>public E relaxedPeek()
MessagePassingQueueQueue.peek() this method may return null without the queue being empty.relaxedPeek in interface MessagePassingQueue<E>public int drain(MessagePassingQueue.Consumer<E> c)
MessagePassingQueue
M m;
while((m = relaxedPoll()) != null){
c.accept(m);
}
drain in interface MessagePassingQueue<E>public int fill(MessagePassingQueue.Supplier<E> s)
MessagePassingQueue
while(relaxedOffer(s.get());
fill in interface MessagePassingQueue<E>public int drain(MessagePassingQueue.Consumer<E> c, int limit)
MessagePassingQueue
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.drain in interface MessagePassingQueue<E>public int fill(MessagePassingQueue.Supplier<E> s, int limit)
MessagePassingQueue
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.fill in interface MessagePassingQueue<E>public void drain(MessagePassingQueue.Consumer<E> c, MessagePassingQueue.WaitStrategy w, MessagePassingQueue.ExitCondition exit)
MessagePassingQueue
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.drain in interface MessagePassingQueue<E>public void fill(MessagePassingQueue.Supplier<E> s, MessagePassingQueue.WaitStrategy w, MessagePassingQueue.ExitCondition exit)
MessagePassingQueue
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.fill in interface MessagePassingQueue<E>protected final long lpConsumerIndex()
protected final long lvConsumerIndex()
protected void soConsumerIndex(long l)
protected final long lvProducerLimit()
protected final void soProducerLimit(long v)
protected final long lvProducerIndex()
protected final boolean casProducerIndex(long expect,
long newValue)
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