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Java example source code file (MonitorVmStartTerminate.java)
The MonitorVmStartTerminate.java Java example source code/* * Copyright (c) 2004, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ import java.util.concurrent.CountDownLatch; import java.util.regex.*; import java.util.*; import java.net.URISyntaxException; import java.io.IOException; import sun.jvmstat.monitor.*; import sun.jvmstat.monitor.event.*; public class MonitorVmStartTerminate { private static final int SLEEPERS = 10; private static final int SLEEPTIME = 5000; // sleep time for a sleeper private static final int EXECINTERVAL = 3000; // wait time between exec's public static void main(String args[]) throws Exception { long now = System.currentTimeMillis(); String sleeperArgs = SLEEPTIME + " " + now; String sleeperPattern = "Sleeper " + sleeperArgs + " \\d+$"; MonitoredHost host = MonitoredHost.getMonitoredHost("localhost"); host.setInterval(200); Matcher matcher = Pattern.compile(sleeperPattern).matcher(""); SleeperListener listener = new SleeperListener(host, matcher, SLEEPERS); host.addHostListener(listener); SleeperStarter ss = new SleeperStarter(SLEEPERS, EXECINTERVAL, sleeperArgs); ss.start(); System.out.println("Waiting for " + SLEEPERS + " sleepers to terminate"); try { ss.join(); } catch (InterruptedException e) { throw new Exception("Timed out waiting for sleepers"); } listener.waitForSleepersToStart(); listener.waitForSleepersToTerminate(); } public static class SleeperListener implements HostListener { private final List<Integer> targets = new ArrayList<>(); private final CountDownLatch terminateLatch; private final CountDownLatch startLatch; private final MonitoredHost host; private final Matcher patternMatcher; public SleeperListener(MonitoredHost host, Matcher matcher, int count) { this.host = host; this.patternMatcher = matcher; this.terminateLatch = new CountDownLatch(count); this.startLatch = new CountDownLatch(count); } public void waitForSleepersToTerminate() throws InterruptedException { terminateLatch.await(); } public void waitForSleepersToStart() throws InterruptedException { startLatch.await(); } private void printList(Set<Integer> list, String msg) { System.out.println(msg + ":"); for (Integer lvmid : list) { try { VmIdentifier vmid = new VmIdentifier("//" + lvmid.intValue()); MonitoredVm target = host.getMonitoredVm(vmid); StringMonitor cmdMonitor = (StringMonitor)target.findByName("sun.rt.javaCommand"); String cmd = cmdMonitor.stringValue(); System.out.println("\t" + lvmid.intValue() + ": " + "\"" + cmd + "\"" + ": "); } catch (URISyntaxException e) { System.err.println("Unexpected URISyntaxException: " + e.getMessage()); } catch (MonitorException e) { System.out.println("\t" + lvmid.intValue() + ": error reading monitoring data: " + " target possibly terminated?"); } } } private int addStarted(Set<Integer> started) { int found = 0; for (Integer lvmid : started) { try { VmIdentifier vmid = new VmIdentifier("//" + lvmid.intValue()); MonitoredVm target = host.getMonitoredVm(vmid); StringMonitor cmdMonitor = (StringMonitor)target.findByName("sun.rt.javaCommand"); String cmd = cmdMonitor.stringValue(); patternMatcher.reset(cmd); System.out.print("Started: " + lvmid.intValue() + ": " + "\"" + cmd + "\"" + ": "); if (patternMatcher.matches()) { System.out.println("matches pattern - recorded"); targets.add(lvmid); found++; } else { System.out.println("does not match pattern - ignored"); } } catch (URISyntaxException e) { System.err.println("Unexpected URISyntaxException: " + e.getMessage()); } catch (MonitorException e) { System.err.println("Unexpected MonitorException: " + e.getMessage()); } } return found; } private int removeTerminated(Set<Integer> terminated) { int found = 0; for (Integer lvmid : terminated) { /* * we don't attempt to attach to the target here as it's * now dead and has no jvmstat share memory file. Just see * if the process id is among those that we saved when we * started the targets (note - duplicated allowed and somewhat * expected on windows); */ System.out.print("Terminated: " + lvmid.intValue() + ": "); if (targets.contains(lvmid)) { System.out.println("matches pattern - termination recorded"); targets.remove(lvmid); found++; } else { System.out.println("does not match pattern - ignored"); } } return found; } @SuppressWarnings("unchecked") public void vmStatusChanged(VmStatusChangeEvent ev) { printList(ev.getActive(), "Active"); printList(ev.getStarted(), "Started"); printList(ev.getTerminated(), "Terminated"); int recentlyStarted = addStarted(ev.getStarted()); int recentlyTerminated = removeTerminated(ev.getTerminated()); for (int i = 0; i < recentlyTerminated; i++) { terminateLatch.countDown(); } for (int i = 0; i < recentlyStarted; i++) { startLatch.countDown(); } } public void disconnected(HostEvent ev) { } } public static class SleeperStarter extends Thread { private final JavaProcess[] processes; private final int execInterval; private final String args; public SleeperStarter(int sleepers, int execInterval, String args) { this.execInterval = execInterval; this.args = args; this.processes = new JavaProcess[sleepers]; } private synchronized int active() { int active = processes.length; for(JavaProcess jp : processes) { try { jp.exitValue(); active--; } catch (IllegalThreadStateException e) { // process hasn't exited yet } } return active; } public void run() { System.out.println("Starting " + processes.length + " sleepers"); String[] classpath = { "-classpath", System.getProperty("java.class.path") }; for (int i = 0; i < processes.length; i++) { try { System.out.println("Starting Sleeper " + i); synchronized(this) { processes[i] = new JavaProcess("Sleeper", args + " " + i); processes[i].addOptions(classpath); } processes[i].start(); Thread.sleep(execInterval); } catch (InterruptedException ignore) { } catch (IOException e) { System.err.println( "IOException trying to start Sleeper " + i + ": " + e.getMessage()); } } // spin waiting for the processes to terminate while (active() > 0) ; } } } Other Java examples (source code examples)Here is a short list of links related to this Java MonitorVmStartTerminate.java source code file: |
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