PoolSubpage.java — netty Source File

Source Code

/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you 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:
 *
 *   https://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.netty.buffer;

import java.util.concurrent.locks.ReentrantLock;

import static io.netty.buffer.PoolChunk.RUN_OFFSET_SHIFT;
import static io.netty.buffer.PoolChunk.SIZE_SHIFT;
import static io.netty.buffer.PoolChunk.IS_USED_SHIFT;
import static io.netty.buffer.PoolChunk.IS_SUBPAGE_SHIFT;

final class PoolSubpage<T> implements PoolSubpageMetric {

    final PoolChunk<T> chunk;
    final int elemSize;
    private final int pageShifts;
    private final int runOffset;
    private final int runSize;
    private final long[] bitmap;
    private final int bitmapLength;
    private final int maxNumElems;
    final int headIndex;

    PoolSubpage<T> prev;
    PoolSubpage<T> next;

    boolean doNotDestroy;
    private int nextAvail;
    private int numAvail;

    final ReentrantLock lock;

    // TODO: Test if adding padding helps under contention
    //private long pad0, pad1, pad2, pad3, pad4, pad5, pad6, pad7;

    /** Special constructor that creates a linked list head */
    PoolSubpage(int headIndex) {
        chunk = null;
        lock = new ReentrantLock();
        pageShifts = -1;
        runOffset = -1;
        elemSize = -1;
        runSize = -1;
        bitmap = null;
        bitmapLength = -1;
        maxNumElems = 0;
// ... (241 more lines)