Mercurial > hg > release > thermostat-1.0
view agent/core/src/main/java/com/redhat/thermostat/backend/VmListenerBackend.java @ 1412:a0592d702416
Update copyright year in release branch.
reviewed-by: neugens
review-thread: http://icedtea.classpath.org/pipermail/thermostat/2014-June/009965.html
PR1821
author | Jon VanAlten <jon.vanalten@redhat.com> |
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date | Tue, 03 Jun 2014 11:55:56 -0600 |
parents | bac262a2c98f |
children |
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/* * Copyright 2012-2014 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.backend; import java.util.logging.Level; import java.util.logging.Logger; import com.redhat.thermostat.agent.VmStatusListener; import com.redhat.thermostat.agent.VmStatusListenerRegistrar; import com.redhat.thermostat.backend.internal.BackendException; import com.redhat.thermostat.backend.internal.VmMonitor; import com.redhat.thermostat.common.utils.LoggingUtils; import com.redhat.thermostat.storage.core.WriterID; /** * This class is a convenient subclass of {@link Backend} (via {@link BaseBackend}) for those * that need to attach {@link VmUpdateListener} in response to starting and stopping of JVMs on a * host. * * @see VmStatusListener * @see Backend * @see BaseBackend */ public abstract class VmListenerBackend extends BaseBackend implements VmStatusListener { private static final Logger logger = LoggingUtils.getLogger(VmListenerBackend.class); private final VmStatusListenerRegistrar registrar; private final WriterID writerId; private VmMonitor monitor; private boolean started; public VmListenerBackend(String backendName, String description, String vendor, String version, VmStatusListenerRegistrar registrar, WriterID writerId) { this(backendName, description, vendor, version, false, registrar, writerId); } public VmListenerBackend(String backendName, String description, String vendor, String version, boolean observeNewJvm, VmStatusListenerRegistrar registrar, WriterID writerId) { super(backendName, description, vendor, version, observeNewJvm); this.registrar = registrar; this.writerId = writerId; try { this.monitor = new VmMonitor(); } catch (BackendException e) { logger.log(Level.SEVERE, "Unable to create backend", e); } } /** * {@inheritDoc} * * <p> * Registers a VmUpdateListener to begin receiving VM lifecycle events. * Subclasses should call <code>super.activate()</code> when overriding this method. * </p> */ @Override public boolean activate() { if (!started && monitor != null) { registrar.register(this); started = true; } return started; } /** * {@inheritDoc} * * <p> * Unregisters the VmUpdateListener to stop receiving VM lifecycle events. * Subclasses should call <code>super.deactivate()</code> when overriding this method. * </p> */ @Override public boolean deactivate() { if (started && monitor != null) { registrar.unregister(this); monitor.removeVmListeners(); started = false; } return !started; } @Override public boolean isActive() { return started; } public void vmStatusChanged(Status newStatus, String vmId, int pid) { switch (newStatus) { case VM_STARTED: /* fall-through */ case VM_ACTIVE: if (getObserveNewJvm()) { String wId = writerId.getWriterID(); VmUpdateListener listener = createVmListener(wId, vmId, pid); monitor.handleNewVm(listener, pid); } else { logger.log(Level.FINE, "skipping new vm " + pid); } break; case VM_STOPPED: monitor.handleStoppedVm(pid); break; default: break; } } /** * Creates a new {@link VmUpdateListener} for the virtual machine * specified by the pid. This method is called when a new * JVM is started or for JVMs already active when this Backend * was activated. * @param vmId unique identifier of the JVM * @param pid the process ID of the JVM * @return a new listener for the VM specified by pid */ protected abstract VmUpdateListener createVmListener(String writerId, String vmId, int pid); /* * For testing purposes only. */ void setMonitor(VmMonitor monitor) { this.monitor = monitor; } }