Mercurial > hg > thermostat-ng > agent
view plugins/jvm-overview/agent/src/main/java/com/redhat/thermostat/jvm/overview/agent/internal/VmStatusChangeNotifier.java @ 2763:845c5af7b42f
Add VM Mapper service
review-thread: http://icedtea.classpath.org/pipermail/thermostat/2017-September/025088.html
reviwed-by: jerboaa
author | Mario Torre <neugens.limasoftware@gmail.com> |
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date | Tue, 26 Sep 2017 15:10:31 +0200 |
parents | 48e1cf54c238 |
children |
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/* * Copyright 2012-2017 Red Hat, Inc. * * This file is part of Thermostat. * * Thermostat is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published * by the Free Software Foundation; either version 2, or (at your * option) any later version. * * Thermostat is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with Thermostat; see the file COPYING. If not see * <http://www.gnu.org/licenses/>. * * Linking this code with other modules is making a combined work * based on this code. Thus, the terms and conditions of the GNU * General Public License cover the whole combination. * * As a special exception, the copyright holders of this code give * you permission to link this code with independent modules to * produce an executable, regardless of the license terms of these * independent modules, and to copy and distribute the resulting * executable under terms of your choice, provided that you also * meet, for each linked independent module, the terms and conditions * of the license of that module. An independent module is a module * which is not derived from or based on this code. If you modify * this code, you may extend this exception to your version of the * library, but you are not obligated to do so. If you do not wish * to do so, delete this exception statement from your version. */ package com.redhat.thermostat.jvm.overview.agent.internal; import java.util.HashMap; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import java.util.TreeSet; import java.util.concurrent.ConcurrentHashMap; import com.redhat.thermostat.jvm.overview.agent.VmStatusListener; import com.redhat.thermostat.jvm.overview.agent.VmStatusListener.Status; import com.redhat.thermostat.jvm.overview.agent.internal.model.VmMapperServiceImpl; import org.osgi.framework.BundleContext; import org.osgi.framework.ServiceReference; import org.osgi.util.tracker.ServiceTracker; /** * Notifies any and all {@link com.redhat.thermostat.jvm.overview.agent.VmStatusListener} registered as OSGi Services * about VM status changes: {@link com.redhat.thermostat.jvm.overview.agent.VmStatusListener.Status#VM_STARTED} and * {@link com.redhat.thermostat.jvm.overview.agent.VmStatusListener.Status#VM_STOPPED}. * <p> * Any listeners registered after a {@link com.redhat.thermostat.jvm.overview.agent.VmStatusListener.Status#VM_STARTED} * was delivered receive a {@link com.redhat.thermostat.jvm.overview.agent.VmStatusListener.Status#VM_ACTIVE} event * instead as an indication that a VM was started at some unknown point * previously. */ public class VmStatusChangeNotifier { private final Object listenerLock = new Object(); private final Map<Integer, String> activePids; private final Map<VmStatusListener, Set<Integer>> listeners = new ConcurrentHashMap<>(); private final ServiceTracker tracker; private VmMapperServiceImpl vmMapperService; public VmStatusChangeNotifier(BundleContext bundleContext, VmMapperServiceImpl vmMapperService) { this.vmMapperService = vmMapperService; this.activePids = new HashMap<>(); tracker = new ServiceTracker(bundleContext, VmStatusListener.class, null) { @Override public VmStatusListener addingService(ServiceReference reference) { VmStatusListener listener = (VmStatusListener) super.addingService(reference); synchronized (listenerLock) { Set<Integer> notifiedAbout = new TreeSet<>(); for (Entry<Integer, String> entry : activePids.entrySet()) { Integer pid = entry.getKey(); listener.vmStatusChanged(Status.VM_ACTIVE, entry.getValue(), pid); notifiedAbout.add(pid); } listeners.put(listener, notifiedAbout); } return listener; } @Override public void removedService(ServiceReference reference, Object service) { VmStatusListener listener = (VmStatusListener) service; listeners.remove(listener); super.removedService(reference, service); } }; } public void start() { tracker.open(); } public void stop() { tracker.close(); } /** * Notify all registered listeners about a Vm status change. * * @param newStatus either {@link VmStatusListener.Status#VM_STARTED} or * {@link VmStatusListener.Status#VM_STOPPED} * @param vmId unique identifier for the VM * @param pid process ID for the VM */ public void notifyVmStatusChange(VmStatusListener.Status newStatus, String vmId, int pid) { if (newStatus == Status.VM_ACTIVE) { throw new IllegalArgumentException("Dont pass in " + Status.VM_ACTIVE + ", that will be handled automatically"); } synchronized (listenerLock) { for (Entry<VmStatusListener, Set<Integer>> entry : listeners.entrySet()) { entry.getKey().vmStatusChanged(newStatus, vmId, pid); entry.getValue().add(pid); } if (newStatus == Status.VM_STARTED) { activePids.put(pid, vmId); vmMapperService.cache(vmId, pid); } else { activePids.remove(pid); } } } }