Native Class — netty Architecture

Source Code

transport-classes-kqueue/src/main/java/io/netty/channel/kqueue/Native.java lines 56–198

final class Native {
    private static final InternalLogger logger = InternalLoggerFactory.getInstance(Native.class);

    static {
        // Preload all classes that will be used in the OnLoad(...) function of JNI to eliminate the possiblity of a
        // class-loader deadlock. This is a workaround for https://github.com/netty/netty/issues/11209.

        // This needs to match all the classes that are loaded via NETTY_JNI_UTIL_LOAD_CLASS or looked up via
        // NETTY_JNI_UTIL_FIND_CLASS.
        ClassInitializerUtil.tryLoadClasses(Native.class,
                // netty_kqueue_bsdsocket
                PeerCredentials.class, DefaultFileRegion.class, FileChannel.class, java.io.FileDescriptor.class
        );

        try {
            // First, try calling a side-effect free JNI method to see if the library was already
            // loaded by the application.
            sizeofKEvent();
        } catch (UnsatisfiedLinkError ignore) {
            // The library was not previously loaded, load it now.
            loadNativeLibrary();
        }
        Unix.registerInternal(new Runnable() {
            @Override
            public void run() {
                registerUnix();
            }
        });
    }

    private static native int registerUnix();

    static final short EV_ADD = evAdd();
    static final short EV_ENABLE = evEnable();
    static final short EV_DISABLE = evDisable();
    static final short EV_DELETE = evDelete();
    static final short EV_CLEAR = evClear();
    static final short EV_ERROR = evError();
    static final short EV_EOF = evEOF();

    static final int NOTE_READCLOSED = noteReadClosed();
    static final int NOTE_CONNRESET = noteConnReset();
    static final int NOTE_DISCONNECTED = noteDisconnected();

    static final int NOTE_RDHUP = NOTE_READCLOSED | NOTE_CONNRESET | NOTE_DISCONNECTED;

    // Commonly used combinations of EV defines
    static final short EV_ADD_ENABLE = (short) (EV_ADD | EV_ENABLE);
    static final short EV_DELETE_DISABLE = (short) (EV_DELETE | EV_DISABLE);

    static final short EVFILT_READ = evfiltRead();
    static final short EVFILT_WRITE = evfiltWrite();
    static final short EVFILT_USER = evfiltUser();
    static final short EVFILT_SOCK = evfiltSock();

    // Flags for connectx(2)
    private static final int CONNECT_RESUME_ON_READ_WRITE = connectResumeOnReadWrite();
    private static final int CONNECT_DATA_IDEMPOTENT = connectDataIdempotent();
    static final int CONNECT_TCP_FASTOPEN = CONNECT_RESUME_ON_READ_WRITE | CONNECT_DATA_IDEMPOTENT;
    static final boolean IS_SUPPORTING_TCP_FASTOPEN_CLIENT = isSupportingFastOpenClient();
    static final boolean IS_SUPPORTING_TCP_FASTOPEN_SERVER = isSupportingFastOpenServer();

    static final KQueueIoOps READ_ENABLED_OPS =
            KQueueIoOps.newOps(Native.EVFILT_READ, Native.EV_ADD_ENABLE, 0);
    static final KQueueIoOps WRITE_ENABLED_OPS =
            KQueueIoOps.newOps(Native.EVFILT_WRITE, Native.EV_ADD_ENABLE, 0);
    static final KQueueIoOps READ_DISABLED_OPS =
            KQueueIoOps.newOps(Native.EVFILT_READ, Native.EV_DELETE_DISABLE, 0);
    static final KQueueIoOps WRITE_DISABLED_OPS =
            KQueueIoOps.newOps(Native.EVFILT_WRITE, Native.EV_DELETE_DISABLE, 0);

    static FileDescriptor newKQueue() {
        return new FileDescriptor(kqueueCreate());
    }

    static int keventWait(int kqueueFd, KQueueEventArray changeList, KQueueEventArray eventList,
                          int tvSec, int tvNsec) throws IOException {
        int ready = keventWait(kqueueFd, changeList.memoryAddress(), changeList.size(),
                               eventList.memoryAddress(), eventList.capacity(), tvSec, tvNsec);
        if (ready < 0) {
            throw newIOException("kevent", ready);