dubbo源码学习笔记----monitor

public abstract class AbstractMonitorFactory implements MonitorFactory {    private static final Logger logger = LoggerFactory.getLogger(AbstractMonitorFactory.class);    // lock for getting monitor center
    private static final ReentrantLock LOCK = new ReentrantLock();    // monitor centers Map<RegistryAddress, Registry>
    private static final Map<String, Monitor> MONITORS = new ConcurrentHashMap<String, Monitor>();    private static final Map<String, ListenableFuture<Monitor>> FUTURES = new ConcurrentHashMap<String, ListenableFuture<Monitor>>();    private static final ExecutorService executor = new ThreadPoolExecutor(0, 10, 60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), new NamedThreadFactory("DubboMonitorCreator", true));    public static Collection<Monitor> getMonitors() {        return Collections.unmodifiableCollection(MONITORS.values());
    }

    class MonitorListener implements Runnable {        private String key;        public MonitorListener(String key) {            this.key = key;
        }        @Override
        public void run() {            try {
                ListenableFuture<Monitor> listenableFuture = AbstractMonitorFactory.FUTURES.get(key);
                AbstractMonitorFactory.MONITORS.put(key, listenableFuture.get());
                AbstractMonitorFactory.FUTURES.remove(key);
            } catch (InterruptedException e) {
                logger.warn("Thread was interrupted unexpectedly, monitor will never be got.");
                AbstractMonitorFactory.FUTURES.remove(key);
            } catch (ExecutionException e) {
                logger.warn("Create monitor failed, monitor data will not be collected until you fix this problem. ", e);
            }
        }
    }

        LOCK.lock();        try {
            monitor = MONITORS.get(key);
            future = FUTURES.get(key);            if (monitor != null || future != null) {                return monitor;
            }            final URL monitorUrl = url;            final ListenableFutureTask<Monitor> listenableFutureTask = ListenableFutureTask.create(new MonitorCreator(monitorUrl));
            listenableFutureTask.addListener(new MonitorListener(key));
            executor.execute(listenableFutureTask);
            FUTURES.put(key, listenableFutureTask);            return null;
        } finally {            // unlock
            LOCK.unlock();
        }

    <bean id="monitorService" class="com.alibaba.dubbo.monitor.simple.SimpleMonitorService">
    </bean>

    <dubbo:application name="${dubbo.application.name}" owner="${dubbo.application.owner}"/>

    <dubbo:registry address="${dubbo.registry.address}"/>

    <dubbo:protocol name="dubbo" port="${dubbo.protocol.port}"/>

    <dubbo:service interface="com.alibaba.dubbo.monitor.MonitorService" ref="monitorService" delay="-1"/>

    <dubbo:reference id="registryService" interface="com.alibaba.dubbo.registry.RegistryService"/>

public interface Container {    /**
     * start.
     */
    void start();    /**
     * stop.
     */
    void stop();

}

    public SimpleMonitorService() {
        queue = new LinkedBlockingQueue<URL>(Integer.parseInt(ConfigUtils.getProperty("dubbo.monitor.queue", "100000")));
        writeThread = new Thread(new Runnable() {            public void run() {                while (running) {                    try {
                        write(); // write statistics
                    } catch (Throwable t) {
                        logger.error("Unexpected error occur at write stat log, cause: " + t.getMessage(), t);                        try {
                            Thread.sleep(5000); // retry after 5 secs
                        } catch (Throwable t2) {
                        }
                    }
                }
            }
        });
        writeThread.setDaemon(true);
        writeThread.setName("DubboMonitorAsyncWriteLogThread");
        writeThread.start();
        chartFuture = scheduledExecutorService.scheduleWithFixedDelay(new Runnable() {            public void run() {                try {
                    draw(); // draw chart
                } catch (Throwable t) {
                    logger.error("Unexpected error occur at draw stat chart, cause: " + t.getMessage(), t);
                }
            }
        }, 1, 300, TimeUnit.SECONDS);
        statisticsDirectory = ConfigUtils.getProperty("dubbo.statistics.directory");
        chartsDirectory = ConfigUtils.getProperty("dubbo.charts.directory");
    }