/*
* 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;
import static org.jctools.util.JvmInfo.CPUs;
import static org.jctools.util.Pow2.isPowerOfTwo;
import static org.jctools.util.Pow2.roundToPowerOfTwo;
import java.util.AbstractQueue;
import java.util.Iterator;
import org.jctools.util.RangeUtil;
/**
* Use a set number of parallel MPSC queues to diffuse the contention on tail.
*/
abstract class MpscCompoundQueueL0Pad<E> extends AbstractQueue<E> implements MessagePassingQueue<E> {
long p01, p02, p03, p04, p05, p06, p07;
long p10, p11, p12, p13, p14, p15, p16, p17;
}
abstract class MpscCompoundQueueColdFields<E> extends MpscCompoundQueueL0Pad<E> {
// must be power of 2
protected final int parallelQueues;
protected final int parallelQueuesMask;
protected final MpscArrayQueue<E>[] queues;
@SuppressWarnings("unchecked")
public MpscCompoundQueueColdFields(int capacity, int queueParallelism) {
parallelQueues = isPowerOfTwo(queueParallelism) ? queueParallelism
: roundToPowerOfTwo(queueParallelism) / 2;
parallelQueuesMask = parallelQueues - 1;
queues = new MpscArrayQueue[parallelQueues];
int fullCapacity = roundToPowerOfTwo(capacity);
RangeUtil.checkGreaterThanOrEqual(fullCapacity, parallelQueues, "fullCapacity");
for (int i = 0; i < parallelQueues; i++) {
queues[i] = new MpscArrayQueue<E>(fullCapacity / parallelQueues);
}
}
}
abstract class MpscCompoundQueueMidPad<E> extends MpscCompoundQueueColdFields<E> {
long p01, p02, p03, p04, p05, p06, p07;
long p10, p11, p12, p13, p14, p15, p16, p17;
public MpscCompoundQueueMidPad(int capacity, int queueParallelism) {
super(capacity, queueParallelism);
}
}
abstract class MpscCompoundQueueConsumerQueueIndex<E> extends MpscCompoundQueueMidPad<E> {
int consumerQueueIndex;
public MpscCompoundQueueConsumerQueueIndex(int capacity, int queueParallelism) {
super(capacity, queueParallelism);
}
}
public class MpscCompoundQueue<E> extends MpscCompoundQueueConsumerQueueIndex<E> {
long p01, p02, p03, p04, p05, p06, p07;
long p10, p11, p12, p13, p14, p15, p16, p17;
public MpscCompoundQueue(int capacity) {
this(capacity, CPUs);
}
public MpscCompoundQueue(int capacity, int queueParallelism) {
super(capacity, queueParallelism);
}
@Override
public boolean offer(final E e) {
if (null == e) {
throw new NullPointerException();
}
int start = (int) (Thread.currentThread().getId() & parallelQueuesMask);
if (queues[start].offer(e)) {
return true;
} else {
for (;;) {
int status = 0;
for (int i = start; i < start + parallelQueues; i++) {
int s = queues[i & parallelQueuesMask].failFastOffer(e);
if (s == 0) {
return true;
}
status += s;
}
if (status == parallelQueues) {
return false;
}
}
}
}
@Override
public E poll() {
int qIndex = consumerQueueIndex & parallelQueuesMask;
int limit = qIndex + parallelQueues;
E e = null;
for (; qIndex < limit; qIndex++) {
e = queues[qIndex & parallelQueuesMask].poll();
if (e != null) {
break;
}
}
consumerQueueIndex = qIndex;
return e;
}
@Override
public E peek() {
int qIndex = consumerQueueIndex & parallelQueuesMask;
int limit = qIndex + parallelQueues;
E e = null;
for (; qIndex < limit; qIndex++) {
e = queues[qIndex & parallelQueuesMask].peek();
if (e != null) {
break;
}
}
consumerQueueIndex = qIndex;
return e;
}
@Override
public int size() {
int size = 0;
for (MpscArrayQueue<E> lane : queues) {
size += lane.size();
}
return size;
}
@Override
public Iterator<E> iterator() {
throw new UnsupportedOperationException();
}
@Override
public String toString() {
return this.getClass().getName();
}
@Override
public boolean relaxedOffer(E e) {
if (null == e) {
throw new NullPointerException();
}
final int parallelQueuesMask = this.parallelQueuesMask;
int start = (int) (Thread.currentThread().getId() & parallelQueuesMask);
final MpscArrayQueue<E>[] queues = this.queues;
int status = 0;
if ((status = queues[start].failFastOffer(e)) == 0) {
return true;
} else {
for (;;) {
final int parallelQueues = this.parallelQueues;
for (int i = start + 1; i < start + parallelQueues; i++) {
int s = queues[i & parallelQueuesMask].failFastOffer(e);
if (s == 0) {
return true;
}
status += s;
}
if (status == parallelQueues) {
return false;
}
status = 0;
}
}
}
@Override
public E relaxedPoll() {
int qIndex = consumerQueueIndex & parallelQueuesMask;
int limit = qIndex + parallelQueues;
E e = null;
for (; qIndex < limit; qIndex++) {
e = queues[qIndex & parallelQueuesMask].relaxedPoll();
if (e != null) {
break;
}
}
consumerQueueIndex = qIndex;
return e;
}
@Override
public E relaxedPeek() {
int qIndex = consumerQueueIndex & parallelQueuesMask;
int limit = qIndex + parallelQueues;
E e = null;
for (; qIndex < limit; qIndex++) {
e = queues[qIndex & parallelQueuesMask].relaxedPeek();
if (e != null) {
break;
}
}
consumerQueueIndex = qIndex;
return e;
}
@Override
public int capacity() {
return queues.length * queues[0].capacity();
}
@Override
public int drain(Consumer<E> c) {
final int limit = capacity();
return drain(c,limit);
}
@Override
public int fill(Supplier<E> s) {
throw new UnsupportedOperationException();
}
@Override
public int drain(Consumer<E> c, int limit) {
for (int i=0;i<limit;i++) {
E e = relaxedPoll();
if(e==null){
return i;
}
c.accept(e);
}
return limit;
}
@Override
public int fill(Supplier<E> s, int limit) {
throw new UnsupportedOperationException();
}
@Override
public void drain(Consumer<E> c,
WaitStrategy wait,
ExitCondition exit) {
int idleCounter = 0;
while (exit.keepRunning()) {
E e = relaxedPoll();
if(e==null){
idleCounter = wait.idle(idleCounter);
continue;
}
idleCounter = 0;
c.accept(e);
}
}
@Override
public void fill(Supplier<E> s,
WaitStrategy wait,
ExitCondition exit) {
int idleCounter = 0;
while (exit.keepRunning()) {
E e = s.get();
while (!relaxedOffer(e)) {
idleCounter = wait.idle(idleCounter);
continue;
}
idleCounter = 0;
}
}
}