IoUringDomainSocketChannel Class — netty Architecture

Source Code

transport-classes-io_uring/src/main/java/io/netty/channel/uring/IoUringDomainSocketChannel.java lines 39–267

public final class IoUringDomainSocketChannel extends AbstractIoUringStreamChannel implements DomainSocketChannel {

    private final IoUringDomainSocketChannelConfig config;

    private volatile DomainSocketAddress local;
    private volatile DomainSocketAddress remote;

    public IoUringDomainSocketChannel() {
        super(null, LinuxSocket.newSocketDomain(), false);
        config = new IoUringDomainSocketChannelConfig(this);
    }

    IoUringDomainSocketChannel(Channel parent, FileDescriptor fd) {
        this(parent, new LinuxSocket(fd.intValue()));
    }

    IoUringDomainSocketChannel(Channel parent, LinuxSocket fd) {
        super(parent, fd, true);
        local = fd.localDomainSocketAddress();
        remote = fd.remoteDomainSocketAddress();
        config = new IoUringDomainSocketChannelConfig(this);
    }

    @Override
    public DomainSocketChannelConfig config() {
        return config;
    }

    @Override
    public DomainSocketAddress localAddress() {
        return local;
    }

    @Override
    public DomainSocketAddress remoteAddress() {
        return remote;
    }

    /**
     * Returns the unix credentials (uid, gid, pid) of the peer
     * <a href=https://man7.org/linux/man-pages/man7/socket.7.html>SO_PEERCRED</a>
     */
    public PeerCredentials peerCredentials() throws IOException {
        return socket.getPeerCredentials();
    }

    @Override
    protected Object filterOutboundMessage(Object msg) {
        if (msg instanceof FileDescriptor) {
            return msg;
        }
        return super.filterOutboundMessage(msg);
    }

    @Override
    protected AbstractUringUnsafe newUnsafe() {
        return new IoUringDomainSocketUnsafe();
    }

    @Override
    protected boolean allowMultiShotPollIn() {
        // UNIX domain sockets do not support IORING_CQE_F_SOCK_NONEMPTY and POLL_ADD_MULTI is edge-triggered
        // so we should disable it
        return false;
    }

    private final class IoUringDomainSocketUnsafe extends IoUringStreamUnsafe {

        private MsgHdrMemory writeMsgHdrMemory;
        private MsgHdrMemory readMsgHdrMemory;

        @Override
        protected int scheduleWriteSingle(Object msg) {
            if (msg instanceof FileDescriptor) {
                // we can reuse the same memory for any fd
                // because we never have more than a single outstanding write.
                if (writeMsgHdrMemory == null) {
                    writeMsgHdrMemory = new MsgHdrMemory();
                }
                IoRegistration registration = registration();
                IoUringIoOps ioUringIoOps = prepSendFdIoOps((FileDescriptor) msg, writeMsgHdrMemory);