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This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and Jakarta Messaging BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).
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/*
 * Copyright 2014 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:
 *
 *   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.netty.channel.epoll;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.buffer.ByteBufUtil;
import io.netty.buffer.Unpooled;
import io.netty.channel.AbstractChannel;
import io.netty.channel.Channel;
import io.netty.channel.ChannelMetadata;
import io.netty.channel.EventLoop;
import io.netty.channel.unix.FileDescriptor;
import io.netty.channel.unix.UnixChannel;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.internal.OneTimeTask;

import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.UnresolvedAddressException;

abstract class AbstractEpollChannel extends AbstractChannel implements UnixChannel {
    private static final ChannelMetadata DATA = new ChannelMetadata(false);
    private final int readFlag;
    private final FileDescriptor fileDescriptor;
    protected int flags = Native.EPOLLET;

    protected volatile boolean active;

    AbstractEpollChannel(int fd, int flag) {
        this(null, fd, flag, false);
    }

    AbstractEpollChannel(Channel parent, int fd, int flag, boolean active) {
        this(parent, new FileDescriptor(fd), flag, active);
    }

    AbstractEpollChannel(Channel parent, FileDescriptor fd, int flag, boolean active) {
        super(parent);
        if (fd == null) {
            throw new NullPointerException("fd");
        }
        readFlag = flag;
        flags |= flag;
        this.active = active;
        fileDescriptor = fd;
    }

    void setFlag(int flag) {
        if (!isFlagSet(flag)) {
            flags |= flag;
            modifyEvents();
        }
    }

    void clearFlag(int flag) {
        if (isFlagSet(flag)) {
            flags &= ~flag;
            modifyEvents();
        }
    }

    boolean isFlagSet(int flag) {
        return (flags & flag) != 0;
    }

    @Override
    public final FileDescriptor fd() {
        return fileDescriptor;
    }

    @Override
    public abstract EpollChannelConfig config();

    @Override
    public boolean isActive() {
        return active;
    }

    @Override
    public ChannelMetadata metadata() {
        return DATA;
    }

    @Override
    protected void doClose() throws Exception {
        active = false;

        // deregister from epoll now
        doDeregister();

        FileDescriptor fd = fileDescriptor;
        fd.close();
    }

    @Override
    protected void doDisconnect() throws Exception {
        doClose();
    }

    @Override
    protected boolean isCompatible(EventLoop loop) {
        return loop instanceof EpollEventLoop;
    }

    @Override
    public boolean isOpen() {
        return fileDescriptor.isOpen();
    }

    @Override
    protected void doDeregister() throws Exception {
        ((EpollEventLoop) eventLoop()).remove(this);
    }

    @Override
    protected void doBeginRead() throws Exception {
        // Channel.read() or ChannelHandlerContext.read() was called
        ((AbstractEpollUnsafe) unsafe()).readPending = true;

        setFlag(readFlag);
    }

    final void clearEpollIn() {
        // Only clear if registered with an EventLoop as otherwise
        if (isRegistered()) {
            final EventLoop loop = eventLoop();
            final AbstractEpollUnsafe unsafe = (AbstractEpollUnsafe) unsafe();
            if (loop.inEventLoop()) {
                unsafe.clearEpollIn0();
            } else {
                // schedule a task to clear the EPOLLIN as it is not safe to modify it directly
                loop.execute(new OneTimeTask() {
                    @Override
                    public void run() {
                        if (!config().isAutoRead() && !unsafe.readPending) {
                            // Still no read triggered so clear it now
                            unsafe.clearEpollIn0();
                        }
                    }
                });
            }
        } else  {
            // The EventLoop is not registered atm so just update the flags so the correct value
            // will be used once the channel is registered
            flags &= ~readFlag;
        }
    }

    private void modifyEvents() {
        if (isOpen() && isRegistered()) {
            ((EpollEventLoop) eventLoop()).modify(this);
        }
    }

    @Override
    protected void doRegister() throws Exception {
        EpollEventLoop loop = (EpollEventLoop) eventLoop();
        loop.add(this);
    }

    @Override
    protected abstract AbstractEpollUnsafe newUnsafe();

    /**
     * Returns an off-heap copy of the specified {@link ByteBuf}, and releases the original one.
     */
    protected final ByteBuf newDirectBuffer(ByteBuf buf) {
        return newDirectBuffer(buf, buf);
    }

    /**
     * Returns an off-heap copy of the specified {@link ByteBuf}, and releases the specified holder.
     * The caller must ensure that the holder releases the original {@link ByteBuf} when the holder is released by
     * this method.
     */
    protected final ByteBuf newDirectBuffer(Object holder, ByteBuf buf) {
        final int readableBytes = buf.readableBytes();
        if (readableBytes == 0) {
            ReferenceCountUtil.safeRelease(holder);
            return Unpooled.EMPTY_BUFFER;
        }

        final ByteBufAllocator alloc = alloc();
        if (alloc.isDirectBufferPooled()) {
            return newDirectBuffer0(holder, buf, alloc, readableBytes);
        }

        final ByteBuf directBuf = ByteBufUtil.threadLocalDirectBuffer();
        if (directBuf == null) {
            return newDirectBuffer0(holder, buf, alloc, readableBytes);
        }

        directBuf.writeBytes(buf, buf.readerIndex(), readableBytes);
        ReferenceCountUtil.safeRelease(holder);
        return directBuf;
    }

    private static ByteBuf newDirectBuffer0(Object holder, ByteBuf buf, ByteBufAllocator alloc, int capacity) {
        final ByteBuf directBuf = alloc.directBuffer(capacity);
        directBuf.writeBytes(buf, buf.readerIndex(), capacity);
        ReferenceCountUtil.safeRelease(holder);
        return directBuf;
    }

    protected static void checkResolvable(InetSocketAddress addr) {
        if (addr.isUnresolved()) {
            throw new UnresolvedAddressException();
        }
    }

    /**
     * Read bytes into the given {@link ByteBuf} and return the amount.
     */
    protected final int doReadBytes(ByteBuf byteBuf) throws Exception {
        int writerIndex = byteBuf.writerIndex();
        int localReadAmount;
        if (byteBuf.hasMemoryAddress()) {
            localReadAmount = Native.readAddress(
                    fileDescriptor.intValue(), byteBuf.memoryAddress(), writerIndex, byteBuf.capacity());
        } else {
            ByteBuffer buf = byteBuf.internalNioBuffer(writerIndex, byteBuf.writableBytes());
            localReadAmount = Native.read(fileDescriptor.intValue(), buf, buf.position(), buf.limit());
        }
        if (localReadAmount > 0) {
            byteBuf.writerIndex(writerIndex + localReadAmount);
        }
        return localReadAmount;
    }

    protected final int doWriteBytes(ByteBuf buf, int writeSpinCount) throws Exception {
        int readableBytes = buf.readableBytes();
        int writtenBytes = 0;
        if (buf.hasMemoryAddress()) {
            long memoryAddress = buf.memoryAddress();
            int readerIndex = buf.readerIndex();
            int writerIndex = buf.writerIndex();
            for (int i = writeSpinCount - 1; i >= 0; i--) {
                int localFlushedAmount = Native.writeAddress(
                        fileDescriptor.intValue(), memoryAddress, readerIndex, writerIndex);
                if (localFlushedAmount > 0) {
                    writtenBytes += localFlushedAmount;
                    if (writtenBytes == readableBytes) {
                        return writtenBytes;
                    }
                    readerIndex += localFlushedAmount;
                } else {
                    break;
                }
            }
        } else {
            ByteBuffer nioBuf;
            if (buf.nioBufferCount() == 1) {
                nioBuf = buf.internalNioBuffer(buf.readerIndex(), buf.readableBytes());
            } else {
                nioBuf = buf.nioBuffer();
            }
            for (int i = writeSpinCount - 1; i >= 0; i--) {
                int pos = nioBuf.position();
                int limit = nioBuf.limit();
                int localFlushedAmount = Native.write(fileDescriptor.intValue(), nioBuf, pos, limit);
                if (localFlushedAmount > 0) {
                    nioBuf.position(pos + localFlushedAmount);
                    writtenBytes += localFlushedAmount;
                    if (writtenBytes == readableBytes) {
                        return writtenBytes;
                    }
                } else {
                    break;
                }
            }
        }
        if (writtenBytes < readableBytes) {
            // Returned EAGAIN need to set EPOLLOUT
            setFlag(Native.EPOLLOUT);
        }
        return writtenBytes;
    }

    protected abstract class AbstractEpollUnsafe extends AbstractUnsafe {
        protected boolean readPending;

        /**
         * Called once EPOLLIN event is ready to be processed
         */
        abstract void epollInReady();

        /**
         * Called once EPOLLRDHUP event is ready to be processed
         */
        void epollRdHupReady() {
            // NOOP
        }

        @Override
        protected void flush0() {
            // Flush immediately only when there's no pending flush.
            // If there's a pending flush operation, event loop will call forceFlush() later,
            // and thus there's no need to call it now.
            if (isFlagSet(Native.EPOLLOUT)) {
                return;
            }
            super.flush0();
        }

        /**
         * Called once a EPOLLOUT event is ready to be processed
         */
        void epollOutReady() {
            // directly call super.flush0() to force a flush now
            super.flush0();
        }

        protected final void clearEpollIn0() {
            clearFlag(readFlag);
        }
    }
}