org.freshvanilla.net.DataSockets Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of com.paremus.dosgi.net Show documentation
An implementation of OSGi Remote Service Admin, enhanced to provide support for OSGi Promises and streaming using OSGi PushStreams.
The newest version!
/*
 Copyright 2008-2011 the original author or authors

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */

package org.freshvanilla.net;

import java.lang.reflect.Field;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;

import org.freshvanilla.utils.NamedThreadFactory;

public class DataSockets {

    private static final AtomicReference MANAGER = new AtomicReference();
    private static final Map DATA_SOCKETS = new ConcurrentHashMap();

    static final long CHECK_PERIOD_MS = 1000;

    private DataSockets() {
        // forbidden
    }

    public static void registerDataSocket(DataSocket ds) {
        synchronized (MANAGER) {
            ScheduledExecutorService service = MANAGER.get();
            if (service == null || service.isShutdown()) {
                ThreadFactory tf = new NamedThreadFactory("data-socket-manager", Thread.NORM_PRIORITY, true);
                service = Executors.newSingleThreadScheduledExecutor(tf);
                MANAGER.set(service);

                Runnable checker = new Runnable() {
                    public void run() {
                        long now = System.currentTimeMillis();
                        for (Entry e : DATA_SOCKETS.entrySet()) {
                            DataSocket ds = e.getKey();
                            if (ds != null) {
                                ds.timedCheck(now);
                                if (ds.isClosed()) {
                                    DATA_SOCKETS.remove(ds);
                                }
                            }
                        }
                    }
                };

                service.scheduleAtFixedRate(checker, CHECK_PERIOD_MS, CHECK_PERIOD_MS, TimeUnit.MILLISECONDS);
            }
        }

        DATA_SOCKETS.put(ds, "");
    }

    public static void unregisterDataSocket(DataSocket ds) {
        DATA_SOCKETS.remove(ds);
        synchronized (MANAGER) {
            if (DATA_SOCKETS.isEmpty()) {
                reset();
            }
        }
    }

    public static void reset() {
        ScheduledExecutorService service = MANAGER.getAndSet(null);
        if (service != null) {
            service.shutdownNow();
        }

        for (DataSocket dataSocket : DATA_SOCKETS.keySet()) {
            dataSocket.close();
        }

        DATA_SOCKETS.clear();
    }

    public static void appendStackTrace(DataSocket ds, Throwable t) {
        try {
            Field stackTraceField = Throwable.class.getDeclaredField("stackTrace");
            stackTraceField.setAccessible(true);

            List original = Arrays.asList(t.getStackTrace());
            int pos;

            for (pos = original.size() - 1; pos > 0; pos--) {
                if ("invoke0".equals(original.get(pos).getMethodName())) {
                    break;
                }
            }

            if (pos <= 0) {
                pos = original.size() - 6;
            }

            // protect against missing/mangled remote stack traces
            if (pos < 0) {
                pos = 0;
            }

            List extended = new ArrayList(original.subList(0, pos));

            InetSocketAddress address = ds.getAddress();

            if (address != null) {
                String hostName = address.getHostName();
                if ("0.0.0.0".equals(hostName)) {
                    hostName = "localhost";
                }

                extended.add(new StackTraceElement("~ call to server ~", "call", hostName, address.getPort()));
            }

            List here = Arrays.asList(new Throwable().getStackTrace());
            extended.addAll(here.subList(3, here.size()));
            stackTraceField.set(t, extended.toArray(new StackTraceElement[extended.size()]));
        }
        catch (NoSuchFieldException nsf) {
            throw new AssertionError(nsf);
        }
        catch (IllegalAccessException iae) {
            throw new AssertionError(iae);
        }
    }

}