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A reactive Java web server.
/*
* Copyright (c) 1998-2015 Caucho Technology -- all rights reserved
*
* This file is part of Baratine(TM)(TM)
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Baratine is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Baratine is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Baratine; if not, write to the
*
* Free Software Foundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.v5.amp.queue;
import java.util.Objects;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import com.caucho.v5.amp.deliver.Deliver;
import com.caucho.v5.amp.deliver.Outbox;
import com.caucho.v5.amp.deliver.WorkerDeliver;
import com.caucho.v5.amp.spi.ShutdownModeAmp;
import com.caucho.v5.util.L10N;
/**
* Value queue with atomic reference.
*/
public final class QueueRingSingleWriter
extends QueueRingBase
{
private static final L10N L = new L10N(QueueRingSingleWriter.class);
// private final RingValueArray _ring;
private final ArrayRing _ring;
private final RingTailGetter _tailGetter;
private final RingNonTailGetter _nonTailGetter;
// private final RingUnsafeArray _ring;
private final int _capacity;
private final AtomicLong []_counterGroup;
private final AtomicLong _headRef;
private final AtomicLong _tail;
private final RingBlocker _blocker;
private volatile boolean _isWriteClosed;
public QueueRingSingleWriter(int capacity)
{
this(capacity, CounterBuilder.create(1));
}
public QueueRingSingleWriter(int capacity,
CounterBuilder counterBuilder)
{
this(capacity, 0, counterBuilder, new RingBlockerBasic());
}
public QueueRingSingleWriter(int capacity,
int initialIndex,
CounterBuilder counterBuilder,
RingBlocker blocker)
{
if (Integer.bitCount(capacity) != 1 || capacity < 2) {
throw new IllegalArgumentException(L.l("Invalid ring capacity {0}",
Long.toHexString(capacity)));
}
if (blocker == null) {
throw new NullPointerException(L.l("RingBlocker is required"));
}
_capacity = capacity;
ArrayRing ring = null;
// ring = RingValueArrayUnsafe.create(capacity);
if (ring == null) {
ring = new ArrayRingImpl(capacity);
}
_ring = ring;
_tailGetter = new RingTailGetter(_ring);
_nonTailGetter = new RingNonTailGetter(_ring);
_counterGroup = counterBuilder.build(initialIndex);
_headRef = _counterGroup[0];
_tail = _counterGroup[_counterGroup.length - 1];
_blocker = blocker;
}
public int getCapacity()
{
return _capacity;
}
/*
@Override
public int getOfferReserve()
{
return _capacity / 2;
}
*/
@Override
public final boolean isEmpty()
{
return _headRef.get() == _tail.get();
}
@Override
public final int size()
{
long head = _headRef.get();
long tail = _tail.get();
return (int) (head - tail);
}
@Override
public int remainingCapacity()
{
return getCapacity() - size() - 1;
}
public final long head()
{
return _headRef.get();
}
public final long getHeadAlloc()
{
return _headRef.get();
}
public final long getTail()
{
return _tail.get();
}
public final long getTailAlloc()
{
return _tail.get();
}
@Override
public int counterGroupSize()
{
return _counterGroup.length;
}
/*
@Override
public WorkerDeliverLifecycle worker()
{
return _blocker;
}
*/
public final M getValue(long ptr)
{
return get(ptr);
}
private final M get(long ptr)
{
return _ring.get(ptr);
}
/*
private final M getAndClear(long ptr)
{
return _ring.takeAndClear(ptr);
}
private final boolean isSet(long ptr)
{
return _ring.get(ptr) != null;
}
*/
@Override
public final boolean offer(final M value,
final long timeout,
final TimeUnit unit)
{
Objects.requireNonNull(value);
// completePoll();
final AtomicLong headRef = _headRef;
final AtomicLong tailRef = _tail;
final int capacity = _capacity;
while (true) {
// final AtomicReferenceArray ring = _ring;
final long tail = tailRef.get();
final long head = headRef.get();
final long nextHead = head + 1;
if (nextHead - tail < capacity) {
headRef.lazySet(nextHead);
_ring.setLazy(head, value);
return true;
}
else {
long offerSequence = _blocker.nextOfferSequence();
if (capacity <= headRef.get() + 1 - tailRef.get()
&& ! _blocker.offerWait(offerSequence, timeout, unit)) {
return false;
}
}
}
}
@Override
public final M peek()
{
long head = _headRef.get();
long tailAlloc = _tail.get();
if (tailAlloc < head) {
return get(tailAlloc);
}
return null;
}
@Override
public final M poll(long timeout, TimeUnit unit)
{
// final AtomicLong tailAllocRef = _tailAlloc;
final AtomicLong headRef = _headRef;
final AtomicLong tailRef = _tail;
final ArrayRing ring = _ring;
final RingBlocker blocker = _blocker;
while (true) {
long tail = tailRef.get();
final long head = headRef.get();
M value;
if (tail == head) {
blocker.offerWake();
if (timeout <= 0) {
return null;
}
long pollSequence = blocker.nextPollSequence();
if (headRef.get() == tailRef.get()
&& ! blocker.pollWait(pollSequence, timeout, unit)) {
// repeat test after pollSequence allocation because of wake
// timing
return null;
}
}
else if ((value = ring.pollAndClear(tail)) != null) {
if (tailRef.compareAndSet(tail, tail + 1)) {
blocker.offerWake();
return value;
}
else {
ring.set(tail, value);
}
}
}
}
@Override
public void deliver(final Deliver deliver,
final Outbox outbox)
throws Exception
{
final AtomicLong headCounter = _headRef;
final AtomicLong tailCounter = _tail;
long initialTail = tailCounter.get();
long tail = initialTail;
long head = headCounter.get();
try {
do {
tail = deliver(head, tail, deliver, outbox);
head = headCounter.get();
} while (tail < head);
} finally {
_blocker.offerWake();
}
}
public void wake()
{
}
private long deliver(long head,
long tail,
final Deliver deliver,
final Outbox outbox)
throws Exception
{
final int tailChunk = 32;
final ArrayRing ring = _ring;
final AtomicLong tailCounter = _tail;
long lastTail = tail;
try {
while (tail < head) {
long tailChunkEnd = Math.min(head, tail + tailChunk);
while (tail < tailChunkEnd) {
M item = ring.takeAndClear(tail);
if (item != null) {
tail++;
deliver.deliver(item, outbox);
}
}
tailCounter.set(tail);
lastTail = tail;
}
} finally {
if (tail != lastTail) {
tailCounter.set(tail);
}
}
return lastTail;
}
@Override
public void deliver(final Deliver processor,
final Outbox outbox,
final int headIndex,
final int tailIndex,
final WorkerDeliver nextWorker,
boolean isTail)
throws Exception
{
final AtomicLong []counterGroup = _counterGroup;
final AtomicLong headCounter = counterGroup[headIndex];
final AtomicLong tailCounter = counterGroup[tailIndex];
final RingGetter ringGetter = isTail ? _tailGetter : _nonTailGetter;
int tailChunk = 2;
long initialTail = tailCounter.get();
long tail = initialTail;
long head = headCounter.get();
try {
do {
long tailChunkEnd = Math.min(head, tail + tailChunk);
while (tail < tailChunkEnd) {
M item = ringGetter.get(tail);
if (item != null) {
tail++;
processor.deliver(item, outbox);
}
}
tailCounter.set(tail);
initialTail = tail;
tailChunk = Math.min(256, 2 * tailChunk);
nextWorker.wake();
head = headCounter.get();
} while (head != tail);
} finally {
if (tail != initialTail) {
tailCounter.set(tail);
}
nextWorker.wake();
}
}
/*
@Override
public void deliverMulti(DeliverOutbox actor,
Outbox outbox,
int headCounter,
int tailCounter,
WorkerOutbox tailWorker)
{
throw new UnsupportedOperationException(getClass().getName());
}
*/
public final boolean isWriteClosed()
{
return _isWriteClosed;
}
public final void closeWrite()
{
_isWriteClosed = true;
_blocker.offerWake();
_blocker.pollWake();
}
public final void shutdown(ShutdownModeAmp mode)
{
closeWrite();
_blocker.shutdown(mode);
}
@Override
public String toString()
{
return getClass().getSimpleName() + "[" + getCapacity() + "]";
}
abstract private static class RingGetter {
abstract public T get(long index);
}
private final static class RingTailGetter extends RingGetter {
private final ArrayRing _ring;
RingTailGetter(ArrayRing ring)
{
_ring = ring;
}
@Override
public final T get(long index)
{
return _ring.takeAndClear(index);
}
}
private final static class RingNonTailGetter extends RingGetter {
private final ArrayRing _ring;
RingNonTailGetter(ArrayRing ring)
{
_ring = ring;
}
@Override
public final T get(long index)
{
return _ring.get(index);
}
}
/* (non-Javadoc)
* @see com.caucho.env.actor.ActorQueue#deliverMultiTail(com.caucho.env.actor.Actor, int, int, com.caucho.env.thread.TaskWorker)
*/
/*
@Override
public void deliverMultiTail(DeliverOutbox actor,
Outbox outbox,
int headIndex,
int tailIndex,
WorkerOutbox tailWorker) throws Exception
{
throw new UnsupportedOperationException(getClass().getName());
}
*/
}
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