org.jctools.queues.atomic.SpscAtomicArrayQueue Maven / Gradle / Ivy
/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jctools.queues.atomic;
import org.jctools.util.SpscLookAheadUtil;
import java.util.concurrent.atomic.*;
import org.jctools.queues.*;
import static org.jctools.queues.atomic.AtomicQueueUtil.*;
/**
* NOTE: This class was automatically generated by org.jctools.queues.atomic.JavaParsingAtomicArrayQueueGenerator
* which can found in the jctools-build module. The original source file is SpscArrayQueue.java.
*/
abstract class SpscAtomicArrayQueueColdField extends AtomicReferenceArrayQueue {
final int lookAheadStep;
SpscAtomicArrayQueueColdField(int capacity) {
super(capacity);
int actualCapacity = capacity();
lookAheadStep = SpscLookAheadUtil.computeLookAheadStep(actualCapacity);
}
}
/**
* NOTE: This class was automatically generated by org.jctools.queues.atomic.JavaParsingAtomicArrayQueueGenerator
* which can found in the jctools-build module. The original source file is SpscArrayQueue.java.
*/
abstract class SpscAtomicArrayQueueL1Pad extends SpscAtomicArrayQueueColdField {
// 8b
byte b000, b001, b002, b003, b004, b005, b006, b007;
// 16b
byte b010, b011, b012, b013, b014, b015, b016, b017;
// 24b
byte b020, b021, b022, b023, b024, b025, b026, b027;
// 32b
byte b030, b031, b032, b033, b034, b035, b036, b037;
// 40b
byte b040, b041, b042, b043, b044, b045, b046, b047;
// 48b
byte b050, b051, b052, b053, b054, b055, b056, b057;
// 56b
byte b060, b061, b062, b063, b064, b065, b066, b067;
// 64b
byte b070, b071, b072, b073, b074, b075, b076, b077;
// 72b
byte b100, b101, b102, b103, b104, b105, b106, b107;
// 80b
byte b110, b111, b112, b113, b114, b115, b116, b117;
// 88b
byte b120, b121, b122, b123, b124, b125, b126, b127;
// 96b
byte b130, b131, b132, b133, b134, b135, b136, b137;
// 104b
byte b140, b141, b142, b143, b144, b145, b146, b147;
// 112b
byte b150, b151, b152, b153, b154, b155, b156, b157;
// 120b
byte b160, b161, b162, b163, b164, b165, b166, b167;
// 128b
byte b170, b171, b172, b173, b174, b175, b176, b177;
SpscAtomicArrayQueueL1Pad(int capacity) {
super(capacity);
}
}
/**
* NOTE: This class was automatically generated by org.jctools.queues.atomic.JavaParsingAtomicArrayQueueGenerator
* which can found in the jctools-build module. The original source file is SpscArrayQueue.java.
*/
abstract class SpscAtomicArrayQueueProducerIndexFields extends SpscAtomicArrayQueueL1Pad {
private static final AtomicLongFieldUpdater P_INDEX_UPDATER = AtomicLongFieldUpdater.newUpdater(SpscAtomicArrayQueueProducerIndexFields.class, "producerIndex");
private volatile long producerIndex;
protected long producerLimit;
SpscAtomicArrayQueueProducerIndexFields(int capacity) {
super(capacity);
}
@Override
public final long lvProducerIndex() {
return producerIndex;
}
final long lpProducerIndex() {
return producerIndex;
}
final void soProducerIndex(final long newValue) {
P_INDEX_UPDATER.lazySet(this, newValue);
}
}
/**
* NOTE: This class was automatically generated by org.jctools.queues.atomic.JavaParsingAtomicArrayQueueGenerator
* which can found in the jctools-build module. The original source file is SpscArrayQueue.java.
*/
abstract class SpscAtomicArrayQueueL2Pad extends SpscAtomicArrayQueueProducerIndexFields {
// 8b
byte b000, b001, b002, b003, b004, b005, b006, b007;
// 16b
byte b010, b011, b012, b013, b014, b015, b016, b017;
// 24b
byte b020, b021, b022, b023, b024, b025, b026, b027;
// 32b
byte b030, b031, b032, b033, b034, b035, b036, b037;
// 40b
byte b040, b041, b042, b043, b044, b045, b046, b047;
// 48b
byte b050, b051, b052, b053, b054, b055, b056, b057;
// 56b
byte b060, b061, b062, b063, b064, b065, b066, b067;
// 64b
byte b070, b071, b072, b073, b074, b075, b076, b077;
// 72b
byte b100, b101, b102, b103, b104, b105, b106, b107;
// 80b
byte b110, b111, b112, b113, b114, b115, b116, b117;
// 88b
byte b120, b121, b122, b123, b124, b125, b126, b127;
// 96b
byte b130, b131, b132, b133, b134, b135, b136, b137;
// 104b
byte b140, b141, b142, b143, b144, b145, b146, b147;
// 112b
byte b150, b151, b152, b153, b154, b155, b156, b157;
// 120b
byte b160, b161, b162, b163, b164, b165, b166, b167;
// 128b
byte b170, b171, b172, b173, b174, b175, b176, b177;
SpscAtomicArrayQueueL2Pad(int capacity) {
super(capacity);
}
}
/**
* NOTE: This class was automatically generated by org.jctools.queues.atomic.JavaParsingAtomicArrayQueueGenerator
* which can found in the jctools-build module. The original source file is SpscArrayQueue.java.
*/
abstract class SpscAtomicArrayQueueConsumerIndexField extends SpscAtomicArrayQueueL2Pad {
private static final AtomicLongFieldUpdater C_INDEX_UPDATER = AtomicLongFieldUpdater.newUpdater(SpscAtomicArrayQueueConsumerIndexField.class, "consumerIndex");
private volatile long consumerIndex;
SpscAtomicArrayQueueConsumerIndexField(int capacity) {
super(capacity);
}
public final long lvConsumerIndex() {
return consumerIndex;
}
final long lpConsumerIndex() {
return consumerIndex;
}
final void soConsumerIndex(final long newValue) {
C_INDEX_UPDATER.lazySet(this, newValue);
}
}
/**
* NOTE: This class was automatically generated by org.jctools.queues.atomic.JavaParsingAtomicArrayQueueGenerator
* which can found in the jctools-build module. The original source file is SpscArrayQueue.java.
*/
abstract class SpscAtomicArrayQueueL3Pad extends SpscAtomicArrayQueueConsumerIndexField {
// 8b
byte b000, b001, b002, b003, b004, b005, b006, b007;
// 16b
byte b010, b011, b012, b013, b014, b015, b016, b017;
// 24b
byte b020, b021, b022, b023, b024, b025, b026, b027;
// 32b
byte b030, b031, b032, b033, b034, b035, b036, b037;
// 40b
byte b040, b041, b042, b043, b044, b045, b046, b047;
// 48b
byte b050, b051, b052, b053, b054, b055, b056, b057;
// 56b
byte b060, b061, b062, b063, b064, b065, b066, b067;
// 64b
byte b070, b071, b072, b073, b074, b075, b076, b077;
// 72b
byte b100, b101, b102, b103, b104, b105, b106, b107;
// 80b
byte b110, b111, b112, b113, b114, b115, b116, b117;
// 88b
byte b120, b121, b122, b123, b124, b125, b126, b127;
// 96b
byte b130, b131, b132, b133, b134, b135, b136, b137;
// 104b
byte b140, b141, b142, b143, b144, b145, b146, b147;
// 112b
byte b150, b151, b152, b153, b154, b155, b156, b157;
// 120b
byte b160, b161, b162, b163, b164, b165, b166, b167;
// 128b
byte b170, b171, b172, b173, b174, b175, b176, b177;
SpscAtomicArrayQueueL3Pad(int capacity) {
super(capacity);
}
}
/**
* NOTE: This class was automatically generated by org.jctools.queues.atomic.JavaParsingAtomicArrayQueueGenerator
* which can found in the jctools-build module. The original source file is SpscArrayQueue.java.
*
* A Single-Producer-Single-Consumer queue backed by a pre-allocated buffer.
*
* This implementation is a mashup of the Fast Flow
* algorithm with an optimization of the offer method taken from the BQueue algorithm (a variation on Fast
* Flow), and adjusted to comply with Queue.offer semantics with regards to capacity.
* For convenience the relevant papers are available in the `resources` folder:
*
* 2010 - Pisa - SPSC Queues on Shared Cache Multi-Core Systems.pdf
* 2012 - Junchang- BQueue- Efficient and Practical Queuing.pdf
*
* This implementation is wait free.
*/
public class SpscAtomicArrayQueue extends SpscAtomicArrayQueueL3Pad {
public SpscAtomicArrayQueue(final int capacity) {
super(Math.max(capacity, 4));
}
/**
* {@inheritDoc}
*
* This implementation is correct for single producer thread use only.
*/
@Override
public boolean offer(final E e) {
if (null == e) {
throw new NullPointerException();
}
// local load of field to avoid repeated loads after volatile reads
final AtomicReferenceArray buffer = this.buffer;
final int mask = this.mask;
final long producerIndex = this.lpProducerIndex();
if (producerIndex >= producerLimit && !offerSlowPath(buffer, mask, producerIndex)) {
return false;
}
final int offset = calcCircularRefElementOffset(producerIndex, mask);
soRefElement(buffer, offset, e);
// ordered store -> atomic and ordered for size()
soProducerIndex(producerIndex + 1);
return true;
}
private boolean offerSlowPath(final AtomicReferenceArray buffer, final int mask, final long producerIndex) {
final int lookAheadStep = this.lookAheadStep;
if (null == lvRefElement(buffer, calcCircularRefElementOffset(producerIndex + lookAheadStep, mask))) {
producerLimit = producerIndex + lookAheadStep;
} else {
final int offset = calcCircularRefElementOffset(producerIndex, mask);
if (null != lvRefElement(buffer, offset)) {
return false;
}
}
return true;
}
/**
* {@inheritDoc}
*
* This implementation is correct for single consumer thread use only.
*/
@Override
public E poll() {
final long consumerIndex = this.lpConsumerIndex();
final int offset = calcCircularRefElementOffset(consumerIndex, mask);
// local load of field to avoid repeated loads after volatile reads
final AtomicReferenceArray buffer = this.buffer;
final E e = lvRefElement(buffer, offset);
if (null == e) {
return null;
}
soRefElement(buffer, offset, null);
// ordered store -> atomic and ordered for size()
soConsumerIndex(consumerIndex + 1);
return e;
}
/**
* {@inheritDoc}
*
* This implementation is correct for single consumer thread use only.
*/
@Override
public E peek() {
return lvRefElement(buffer, calcCircularRefElementOffset(lpConsumerIndex(), mask));
}
@Override
public boolean relaxedOffer(final E message) {
return offer(message);
}
@Override
public E relaxedPoll() {
return poll();
}
@Override
public E relaxedPeek() {
return peek();
}
@Override
public int drain(final Consumer c) {
return drain(c, capacity());
}
@Override
public int fill(final Supplier s) {
return fill(s, capacity());
}
@Override
public int drain(final Consumer c, final int limit) {
if (null == c)
throw new IllegalArgumentException("c is null");
if (limit < 0)
throw new IllegalArgumentException("limit is negative: " + limit);
if (limit == 0)
return 0;
final AtomicReferenceArray buffer = this.buffer;
final int mask = this.mask;
final long consumerIndex = this.lpConsumerIndex();
for (int i = 0; i < limit; i++) {
final long index = consumerIndex + i;
final int offset = calcCircularRefElementOffset(index, mask);
final E e = lvRefElement(buffer, offset);
if (null == e) {
return i;
}
soRefElement(buffer, offset, null);
// ordered store -> atomic and ordered for size()
soConsumerIndex(index + 1);
c.accept(e);
}
return limit;
}
@Override
public int fill(final Supplier s, final int limit) {
if (null == s)
throw new IllegalArgumentException("supplier is null");
if (limit < 0)
throw new IllegalArgumentException("limit is negative:" + limit);
if (limit == 0)
return 0;
final AtomicReferenceArray buffer = this.buffer;
final int mask = this.mask;
final int lookAheadStep = this.lookAheadStep;
final long producerIndex = this.lpProducerIndex();
for (int i = 0; i < limit; i++) {
final long index = producerIndex + i;
final int lookAheadElementOffset = calcCircularRefElementOffset(index + lookAheadStep, mask);
if (null == lvRefElement(buffer, lookAheadElementOffset)) {
int lookAheadLimit = Math.min(lookAheadStep, limit - i);
for (int j = 0; j < lookAheadLimit; j++) {
final int offset = calcCircularRefElementOffset(index + j, mask);
soRefElement(buffer, offset, s.get());
// ordered store -> atomic and ordered for size()
soProducerIndex(index + j + 1);
}
i += lookAheadLimit - 1;
} else {
final int offset = calcCircularRefElementOffset(index, mask);
if (null != lvRefElement(buffer, offset)) {
return i;
}
soRefElement(buffer, offset, s.get());
// ordered store -> atomic and ordered for size()
soProducerIndex(index + 1);
}
}
return limit;
}
@Override
public void drain(final Consumer c, final WaitStrategy w, final ExitCondition exit) {
if (null == c)
throw new IllegalArgumentException("c is null");
if (null == w)
throw new IllegalArgumentException("wait is null");
if (null == exit)
throw new IllegalArgumentException("exit condition is null");
final AtomicReferenceArray buffer = this.buffer;
final int mask = this.mask;
long consumerIndex = this.lpConsumerIndex();
int counter = 0;
while (exit.keepRunning()) {
for (int i = 0; i < 4096; i++) {
final int offset = calcCircularRefElementOffset(consumerIndex, mask);
final E e = lvRefElement(buffer, offset);
if (null == e) {
counter = w.idle(counter);
continue;
}
consumerIndex++;
counter = 0;
soRefElement(buffer, offset, null);
// ordered store -> atomic and ordered for size()
soConsumerIndex(consumerIndex);
c.accept(e);
}
}
}
@Override
public void fill(final Supplier s, final WaitStrategy w, final ExitCondition e) {
if (null == w)
throw new IllegalArgumentException("waiter is null");
if (null == e)
throw new IllegalArgumentException("exit condition is null");
if (null == s)
throw new IllegalArgumentException("supplier is null");
final AtomicReferenceArray buffer = this.buffer;
final int mask = this.mask;
final int lookAheadStep = this.lookAheadStep;
long producerIndex = this.lpProducerIndex();
int counter = 0;
while (e.keepRunning()) {
final int lookAheadElementOffset = calcCircularRefElementOffset(producerIndex + lookAheadStep, mask);
if (null == lvRefElement(buffer, lookAheadElementOffset)) {
for (int j = 0; j < lookAheadStep; j++) {
final int offset = calcCircularRefElementOffset(producerIndex, mask);
producerIndex++;
soRefElement(buffer, offset, s.get());
// ordered store -> atomic and ordered for size()
soProducerIndex(producerIndex);
}
} else {
final int offset = calcCircularRefElementOffset(producerIndex, mask);
if (null != lvRefElement(buffer, offset)) {
counter = w.idle(counter);
continue;
}
producerIndex++;
counter = 0;
soRefElement(buffer, offset, s.get());
// ordered store -> atomic and ordered for size()
soProducerIndex(producerIndex);
}
}
}
}