io.rsocket.internal.jctools.queues.MpscUnboundedArrayQueue Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of rsocket-core Show documentation

Core functionality for the RSocket library

There is a newer version: 1.1.4

/*
 * 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 io.rsocket.internal.jctools.queues;

import static io.rsocket.internal.jctools.queues.LinkedArrayQueueUtil.length;

import io.rsocket.internal.jctools.util.PortableJvmInfo;

/**
 * An MPSC array queue which starts at initialCapacity and grows indefinitely in linked
 * chunks of the initial size. The queue grows only when the current chunk is full and elements are
 * not copied on resize, instead a link to the new chunk is stored in the old chunk for the consumer
 * to follow.

 *
 * @param 
 */
public class MpscUnboundedArrayQueue extends BaseMpscLinkedArrayQueue {
  long p0, p1, p2, p3, p4, p5, p6, p7;
  long p10, p11, p12, p13, p14, p15, p16, p17;

  public MpscUnboundedArrayQueue(int chunkSize) {
    super(chunkSize);
  }

  @Override
  protected long availableInQueue(long pIndex, long cIndex) {
    return Integer.MAX_VALUE;
  }

  @Override
  public int capacity() {
    return MessagePassingQueue.UNBOUNDED_CAPACITY;
  }

  @Override
  public int drain(Consumer c) {
    return drain(c, 4096);
  }

  @Override
  public int fill(Supplier s) {
    long result =
        0; // result is a long because we want to have a safepoint check at regular intervals
    final int capacity = 4096;
    do {
      final int filled = fill(s, PortableJvmInfo.RECOMENDED_OFFER_BATCH);
      if (filled == 0) {
        return (int) result;
      }
      result += filled;
    } while (result <= capacity);
    return (int) result;
  }

  @Override
  protected int getNextBufferSize(E[] buffer) {
    return length(buffer);
  }

  @Override
  protected long getCurrentBufferCapacity(long mask) {
    return mask;
  }
}