DefaultChannelId Class — netty Architecture

Source Code

transport/src/main/java/io/netty/channel/DefaultChannelId.java lines 39–342

public final class DefaultChannelId implements ChannelId {

    private static final long serialVersionUID = 3884076183504074063L;

    private static final InternalLogger logger = InternalLoggerFactory.getInstance(DefaultChannelId.class);
    private static final byte[] MACHINE_ID;
    private static final int PROCESS_ID_LEN = 4;
    private static final int PROCESS_ID;
    private static final int SEQUENCE_LEN = 4;
    private static final int TIMESTAMP_LEN = 8;
    private static final int RANDOM_LEN = 4;

    private static final AtomicInteger nextSequence = new AtomicInteger();

    /**
     * Returns a new {@link DefaultChannelId} instance.
     */
    public static DefaultChannelId newInstance() {
        return new DefaultChannelId(MACHINE_ID,
                                    PROCESS_ID,
                                    nextSequence.getAndIncrement(),
                                    Long.reverse(System.nanoTime()) ^ System.currentTimeMillis(),
                                    ThreadLocalRandom.current().nextInt());
    }

    static {
        int processId = -1;
        String customProcessId = SystemPropertyUtil.get("io.netty.processId");
        if (customProcessId != null) {
            try {
                processId = Integer.parseInt(customProcessId);
            } catch (NumberFormatException e) {
                // Malformed input.
            }

            if (processId < 0) {
                processId = -1;
                logger.warn("-Dio.netty.processId: {} (malformed)", customProcessId);
            } else if (logger.isDebugEnabled()) {
                logger.debug("-Dio.netty.processId: {} (user-set)", processId);
            }
        }

        if (processId < 0) {
            processId = defaultProcessId();
            if (logger.isDebugEnabled()) {
                logger.debug("-Dio.netty.processId: {} (auto-detected)", processId);
            }
        }

        PROCESS_ID = processId;

        byte[] machineId = null;
        String customMachineId = SystemPropertyUtil.get("io.netty.machineId");
        if (customMachineId != null) {
            try {
                machineId = parseMAC(customMachineId);
            } catch (Exception e) {
                logger.warn("-Dio.netty.machineId: {} (malformed)", customMachineId, e);
            }
            if (machineId != null) {
                logger.debug("-Dio.netty.machineId: {} (user-set)", customMachineId);
            }
        }

        if (machineId == null) {
            machineId = defaultMachineId();
            if (logger.isDebugEnabled()) {
                logger.debug("-Dio.netty.machineId: {} (auto-detected)", MacAddressUtil.formatAddress(machineId));
            }
        }

        MACHINE_ID = machineId;
    }

    static int processHandlePid(ClassLoader loader) {
        // pid is positive on unix, non{-1,0} on windows
        int nilValue = -1;
        if (PlatformDependent.javaVersion() >= 9) {
            Long pid;
            try {