src/jdk.jcmd/share/classes/sun/tools/jstat/Jstat.java

/*
 * Copyright (c) 2004, 2021, 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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
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package sun.tools.jstat;

import java.util.*;
import sun.jvmstat.monitor.*;
import sun.jvmstat.monitor.event.*;

/**
 * Application to output jvmstat statistics exported by a target Java
 * Virtual Machine. The jstat tool gets its inspiration from the suite
 * of 'stat' tools, such as vmstat, iostat, mpstat, etc., available in
 * various UNIX platforms.
 *
 * @author Brian Doherty
 * @since 1.5
 */
public class Jstat {
    private static Arguments arguments;

    public static void main(String[] args) {
        try {
            arguments = new Arguments(args);
        } catch (IllegalArgumentException e) {
            System.err.println(e.getMessage());
            Arguments.printUsage(System.err);
            System.exit(1);
        }

        if (arguments.isHelp()) {
            Arguments.printUsage(System.out);
            System.exit(0);
        }

        if (arguments.isOptions()) {
            OptionLister ol = new OptionLister(arguments.optionsSources());
            ol.print(System.out);
            System.exit(0);
        }

        try {
            if (arguments.isList()) {
                logNames();
            } else if (arguments.isSnap()) {
                logSnapShot();
            } else {
                logSamples();
            }
        } catch (MonitorException e) {
            e.printStackTrace();
            System.exit(1);
        }
        System.exit(0);
    }

    static void logNames() throws MonitorException {
        VmIdentifier vmId = arguments.vmId();
        int interval = arguments.sampleInterval();
        MonitoredHost monitoredHost = MonitoredHost.getMonitoredHost(vmId);
        MonitoredVm monitoredVm = monitoredHost.getMonitoredVm(vmId, interval);
        JStatLogger logger = new JStatLogger(monitoredVm);
        logger.printNames(arguments.counterNames(), arguments.comparator(),
                          arguments.showUnsupported(), System.out);
        monitoredHost.detach(monitoredVm);
    }

    static void logSnapShot() throws MonitorException {
        VmIdentifier vmId = arguments.vmId();
        int interval = arguments.sampleInterval();
        MonitoredHost monitoredHost = MonitoredHost.getMonitoredHost(vmId);
        MonitoredVm monitoredVm = monitoredHost.getMonitoredVm(vmId, interval);
        JStatLogger logger = new JStatLogger(monitoredVm);
        logger.printSnapShot(arguments.counterNames(), arguments.comparator(),
                             arguments.isVerbose(), arguments.showUnsupported(),
                             System.out);
        monitoredHost.detach(monitoredVm);
    }

    static void logSamples() throws MonitorException {
        final VmIdentifier vmId = arguments.vmId();
        int interval = arguments.sampleInterval();
        final MonitoredHost monitoredHost =
                MonitoredHost.getMonitoredHost(vmId);
        MonitoredVm monitoredVm = monitoredHost.getMonitoredVm(vmId, interval);
        final JStatLogger logger = new JStatLogger(monitoredVm);
        OutputFormatter formatter = null;

        if (arguments.isSpecialOption()) {
            OptionFormat format = arguments.optionFormat();
            formatter = new OptionOutputFormatter(monitoredVm, format);
        } else {
            List<Monitor> logged = monitoredVm.findByPattern(arguments.counterNames());
            logged.sort(arguments.comparator());
            List<Monitor> constants = new ArrayList<Monitor>();

            for (Iterator<Monitor> i = logged.iterator(); i.hasNext(); /* empty */) {
                Monitor m = i.next();
                if (!(m.isSupported() || arguments.showUnsupported())) {
                    i.remove();
                    continue;
                }
                if (m.getVariability() == Variability.CONSTANT) {
                    i.remove();
                    if (arguments.printConstants()) constants.add(m);
                } else if ((m.getUnits() == Units.STRING)
                        && !arguments.printStrings()) {
                    i.remove();
                }
            }

            if (!constants.isEmpty()) {
                logger.printList(constants, arguments.isVerbose(),
                                 arguments.showUnsupported(), System.out);
                if (!logged.isEmpty()) {
                    System.out.println();
                }
            }

            if (logged.isEmpty()) {
                monitoredHost.detach(monitoredVm);
                return;
            }

            formatter = new RawOutputFormatter(logged,
                                               arguments.printStrings());
        }

        // handle user termination requests by stopping sampling loops
        Runtime.getRuntime().addShutdownHook(new Thread() {
            public void run() {
                logger.stopLogging();
            }
        });

        // handle target termination events for targets other than ourself
        HostListener terminator = new HostListener() {
            public void vmStatusChanged(VmStatusChangeEvent ev) {
                Integer lvmid = vmId.getLocalVmId();
                if (ev.getTerminated().contains(lvmid)) {
                    logger.stopLogging();
                } else if (!ev.getActive().contains(lvmid)) {
                    logger.stopLogging();
                }
            }

            public void disconnected(HostEvent ev) {
                if (monitoredHost == ev.getMonitoredHost()) {
                    logger.stopLogging();
                }
            }
        };

        if (vmId.getLocalVmId() != 0) {
            monitoredHost.addHostListener(terminator);
        }

        logger.logSamples(formatter, arguments.headerRate(),
                          arguments.sampleInterval(), arguments.sampleCount(),
                          System.out);

        // detach from host events and from the monitored target jvm
        if (terminator != null) {
            monitoredHost.removeHostListener(terminator);
        }
        monitoredHost.detach(monitoredVm);
    }
}