public class SpmcArrayQueue<E> extends AbstractQueue<E>
MessagePassingQueue.Consumer<T>, MessagePassingQueue.ExitCondition, MessagePassingQueue.Supplier<T>, MessagePassingQueue.WaitStrategy
Modifier and Type | Field and Description |
---|---|
protected E[] |
buffer |
protected static long |
C_INDEX_OFFSET |
protected long |
mask |
protected static long |
P_INDEX_OFFSET |
UNBOUNDED_CAPACITY
Constructor and Description |
---|
SpmcArrayQueue(int capacity) |
Modifier and Type | Method and Description |
---|---|
int |
capacity() |
void |
clear()
Removes all items from the queue.
|
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 |
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 e)
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.
|
Iterator<E> |
iterator()
Get an iterator for this queue.
|
long |
lvConsumerIndex() |
long |
lvProducerIndex() |
protected long |
lvProducerIndexCache() |
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. |
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 |
svProducerIndexCache(long newValue) |
String |
toString() |
add, addAll, element, remove
contains, containsAll, remove, removeAll, retainAll, toArray, toArray
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
contains, containsAll, equals, hashCode, parallelStream, remove, removeAll, removeIf, retainAll, spliterator, stream, toArray, toArray
protected static final long C_INDEX_OFFSET
protected static final long P_INDEX_OFFSET
protected final long mask
protected final E[] buffer
public boolean offer(E e)
MessagePassingQueue
Queue.offer(Object)
interface.e
- not null
, will throw NPE if it ispublic E poll()
MessagePassingQueue
Queue.poll()
interface.null
iff emptypublic E peek()
MessagePassingQueue
Queue.peek()
interface.null
iff emptypublic boolean relaxedOffer(E e)
MessagePassingQueue
Queue.offer(Object)
this method may return false without the queue being full.e
- not null
, will throw NPE if it ispublic E relaxedPoll()
MessagePassingQueue
Queue.poll()
this method may return null
without the queue being empty.null
if unable to pollpublic E relaxedPeek()
MessagePassingQueue
Queue.peek()
this method may return null
without the queue being empty.null
if unable to peekpublic int drain(MessagePassingQueue.Consumer<E> c, int limit)
MessagePassingQueue
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.
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.
WARNING: Explicit assumptions are made with regards to MessagePassingQueue.Supplier.get()
make sure you have read
and understood these before using this method.
public int drain(MessagePassingQueue.Consumer<E> c)
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.
WARNING: Explicit assumptions are made with regards to MessagePassingQueue.Consumer.accept(T)
make sure you have read
and understood these before using this method.
public int fill(MessagePassingQueue.Supplier<E> s)
MessagePassingQueue
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.
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.
WARNING: Explicit assumptions are made with regards to MessagePassingQueue.Consumer.accept(T)
make sure you have read
and understood these before using this method.
public void fill(MessagePassingQueue.Supplier<E> s, MessagePassingQueue.WaitStrategy w, MessagePassingQueue.ExitCondition e)
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. 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 to MessagePassingQueue.Supplier.get()
make sure you have read
and understood these before using this method.
protected final long lvProducerIndexCache()
protected final void svProducerIndexCache(long newValue)
public final long lvConsumerIndex()
public final long lvProducerIndex()
public int size()
MessagePassingQueue
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()
MessagePassingQueue
isEmpty
in interface Collection<E>
isEmpty
in interface MessagePassingQueue<E>
isEmpty
in class AbstractCollection<E>
public String toString()
toString
in class AbstractCollection<E>
public void clear()
MessagePassingQueue
Collection.clear()
interface.clear
in interface Collection<E>
clear
in interface MessagePassingQueue<E>
clear
in class AbstractQueue<E>
public int capacity()
capacity
in interface MessagePassingQueue<E>
MessagePassingQueue.UNBOUNDED_CAPACITY
if not boundedpublic long currentProducerIndex()
QueueProgressIndicators
currentProducerIndex
in interface QueueProgressIndicators
public long currentConsumerIndex()
QueueProgressIndicators
currentConsumerIndex
in interface QueueProgressIndicators
public Iterator<E> iterator()
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.
iterator
in interface Iterable<E>
iterator
in interface Collection<E>
iterator
in class AbstractCollection<E>
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