Errors Class — netty Architecture

Source Code

transport-native-unix-common/src/main/java/io/netty/channel/unix/Errors.java lines 48–223

public final class Errors {
    // As all our JNI methods return -errno on error we need to compare with the negative errno codes.
    public static final int ERRNO_ENOENT_NEGATIVE = -errnoENOENT();
    public static final int ERRNO_ENOTCONN_NEGATIVE = -errnoENOTCONN();
    public static final int ERRNO_EBADF_NEGATIVE = -errnoEBADF();
    public static final int ERRNO_EPIPE_NEGATIVE = -errnoEPIPE();
    public static final int ERRNO_ECONNRESET_NEGATIVE = -errnoECONNRESET();
    public static final int ERRNO_EAGAIN_NEGATIVE = -errnoEAGAIN();
    public static final int ERRNO_EWOULDBLOCK_NEGATIVE = -errnoEWOULDBLOCK();
    public static final int ERRNO_EINPROGRESS_NEGATIVE = -errnoEINPROGRESS();
    public static final int ERROR_ECONNREFUSED_NEGATIVE = -errorECONNREFUSED();
    public static final int ERROR_EISCONN_NEGATIVE = -errorEISCONN();
    public static final int ERROR_EALREADY_NEGATIVE = -errorEALREADY();
    public static final int ERROR_ENETUNREACH_NEGATIVE = -errorENETUNREACH();
    public static final int ERROR_EHOSTUNREACH_NEGATIVE = -errorEHOSTUNREACH();

    /**
     * Holds the mappings for errno codes to String messages.
     * This eliminates the need to call back into JNI to get the right String message on an exception
     * and thus is faster.
     *
     * Choose an array length which should give us enough space in the future even when more errno codes
     * will be added.
     */
    private static final String[] ERRORS = new String[2048];

    /**
     * <strong>Internal usage only!</strong>
     */
    public static final class NativeIoException extends IOException {
        private static final long serialVersionUID = 8222160204268655526L;
        private final int expectedErr;
        private final boolean fillInStackTrace;

        public NativeIoException(String method, int expectedErr) {
            this(method, expectedErr, true);
        }

        public NativeIoException(String method, int expectedErr, boolean fillInStackTrace) {
            super(method + "(..) failed with error(" + expectedErr + "): " + errnoString(-expectedErr));
            this.expectedErr = expectedErr;
            this.fillInStackTrace = fillInStackTrace;
        }

        public int expectedErr() {
            return expectedErr;
        }

        @Override
        public synchronized Throwable fillInStackTrace() {
            if (fillInStackTrace) {
                return super.fillInStackTrace();
            }
            return this;
        }
    }

    static final class NativeConnectException extends ConnectException {
        private static final long serialVersionUID = -5532328671712318161L;
        private final int expectedErr;
        NativeConnectException(String method, int expectedErr) {
            super(method + "(..) failed with error(" + expectedErr + "):" + errnoString(-expectedErr));
            this.expectedErr = expectedErr;
        }

        int expectedErr() {
            return expectedErr;
        }
    }

    static {
        for (int i = 0; i < ERRORS.length; i++) {
            // This is ok as strerror returns 'Unknown error i' when the message is not known.
            ERRORS[i] = strError(i);
        }
    }

    public static boolean handleConnectErrno(String method, int err) throws IOException {
        if (err == ERRNO_EINPROGRESS_NEGATIVE || err == ERROR_EALREADY_NEGATIVE) {
            // connect not complete yet need to wait for EPOLLOUT event.
            // EALREADY has been observed when using tcp fast open on centos8.