JDK 11 jdk.jcmd.jmod is the JMOD file for JDK 11 JCmd tool, which can be invoked by the "jcmd" command.

JDK 11 JCmd tool compiled class files are stored in \fyicenter\jdk-11.0.1\jmods\jdk.jcmd.jmod.

JDK 11 JCmd tool compiled class files are also linked and stored in the \fyicenter\jdk-11.0.1\lib\modules JImage file.

JDK 11 JCmd source code files are stored in \fyicenter\jdk-11.0.1\lib\src.zip\jdk.jcmd.

You can click and view the content of each source code file in the list below.

⏎ sun/tools/jstack/JStack.java

/*
 * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

package sun.tools.jstack;

import java.io.InputStream;
import java.util.Collection;

import com.sun.tools.attach.VirtualMachine;
import com.sun.tools.attach.VirtualMachineDescriptor;
import sun.tools.attach.HotSpotVirtualMachine;
import sun.tools.common.ProcessArgumentMatcher;

/*
 * This class is the main class for the JStack utility. It parses its arguments
 * and decides if the command should be executed by the SA JStack tool or by
 * obtained the thread dump from a target process using the VM attach mechanism
 */
public class JStack {

    public static void main(String[] args) throws Exception {
        if (args.length == 0) {
            usage(1); // no arguments
        }

        checkForUnsupportedOptions(args);

        boolean locks = false;
        boolean extended = false;

        // Parse the options (arguments starting with "-" )
        int optionCount = 0;
        while (optionCount < args.length) {
            String arg = args[optionCount];
            if (!arg.startsWith("-")) {
                break;
            }
            if (arg.equals("-?")     ||
                arg.equals("-h")     ||
                arg.equals("--help") ||
                // -help: legacy.
                arg.equals("-help")) {
                usage(0);
            }
            else {
                if (arg.equals("-l")) {
                    locks = true;
                } else {
                    if (arg.equals("-e")) {
                        extended = true;
                    } else {
                        usage(1);
                    }
                }
            }
            optionCount++;
        }

        // Next we check the parameter count.
        int paramCount = args.length - optionCount;
        if (paramCount != 1) {
            usage(1);
        }

        // pass -l to thread dump operation to get extra lock info
        String pidArg = args[optionCount];
        String params[]= new String[] { "" };
        if (extended) {
            params[0] += "-e ";
        }
        if (locks) {
            params[0] += "-l";
        }

        ProcessArgumentMatcher ap = new ProcessArgumentMatcher(pidArg);
        Collection<String> pids = ap.getVirtualMachinePids(JStack.class);

        if (pids.isEmpty()) {
            System.err.println("Could not find any processes matching : '" + pidArg + "'");
            System.exit(1);
        }

        for (String pid : pids) {
            if (pids.size() > 1) {
                System.out.println("Pid:" + pid);
            }
            runThreadDump(pid, params);
        }
    }

    // Attach to pid and perform a thread dump
    private static void runThreadDump(String pid, String args[]) throws Exception {
        VirtualMachine vm = null;
        try {
            vm = VirtualMachine.attach(pid);
        } catch (Exception x) {
            String msg = x.getMessage();
            if (msg != null) {
                System.err.println(pid + ": " + msg);
            } else {
                x.printStackTrace();
            }
            System.exit(1);
        }

        // Cast to HotSpotVirtualMachine as this is implementation specific
        // method.
        InputStream in = ((HotSpotVirtualMachine)vm).remoteDataDump((Object[])args);

        // read to EOF and just print output
        byte b[] = new byte[256];
        int n;
        do {
            n = in.read(b);
            if (n > 0) {
                String s = new String(b, 0, n, "UTF-8");
                System.out.print(s);
            }
        } while (n > 0);
        in.close();
        vm.detach();
    }

    private static void checkForUnsupportedOptions(String[] args) {
        // Check arguments for -F, -m, and non-numeric value
        // and warn the user that SA is not supported anymore

        int paramCount = 0;

        for (String s : args) {
            if (s.equals("-F")) {
                SAOptionError("-F option used");
            }

            if (s.equals("-m")) {
                SAOptionError("-m option used");
            }

            if (! s.startsWith("-")) {
                paramCount += 1;
            }
        }

        if (paramCount > 1) {
            SAOptionError("More than one non-option argument");
        }
    }

    private static void SAOptionError(String msg) {
        System.err.println("Error: " + msg);
        System.err.println("Cannot connect to core dump or remote debug server. Use jhsdb jstack instead");
        System.exit(1);
    }

    // print usage message
    private static void usage(int exit) {
        System.err.println("Usage:");
        System.err.println("    jstack [-l][-e] <pid>");
        System.err.println("        (to connect to running process)");
        System.err.println("");
        System.err.println("Options:");
        System.err.println("    -l  long listing. Prints additional information about locks");
        System.err.println("    -e  extended listing. Prints additional information about threads");
        System.err.println("    -? -h --help -help to print this help message");
        System.exit(exit);
    }
}

⏎ sun/tools/jstack/JStack.java

Or download all of them as a single archive file:

File name: jdk.jcmd-11.0.1-src.zip
File size: 47892 bytes
Release date: 2018-11-04
Download 

⇒ JDK 11 jdk.jconsole.jmod - JConsole Tool

⇐ JDK 11 jdk.javadoc.jmod - Java Document Tool

⇑ Download and Use JDK 11

⇑⇑ FAQ for JDK (Java Development Kit)