--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/containers/docker/EventGeneratorLoop.java	Tue Jul 23 11:36:05 2019 -0700
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2019, 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 jdk.jfr.Event;
+import jdk.jfr.Description;
+import jdk.jfr.Label;
+
+
+// This class generates simple event in a loop
+// for a specified time.
+// Pass the time in seconds as a parameter.
+public class EventGeneratorLoop {
+
+    @Label("SimpleEvent")
+    @Description("Simple custom event")
+    static class SimpleEvent extends Event {
+        @Label("Message")
+        String msg;
+
+        @Label("Count")
+        int count;
+    }
+
+
+    public static void main(String[] args) throws Exception {
+        if ((args.length < 1) || (args[0] == null)) {
+            throw new IllegalArgumentException("Expecting one argument: time to run (seconds)");
+        }
+        int howLong = Integer.parseInt(args[0]);
+
+        for (int i=0; i < howLong; i++) {
+            SimpleEvent ev = new SimpleEvent();
+            ev.msg = "Hello";
+            ev.count = i;
+            ev.commit();
+
+            try { Thread.sleep(1000); } catch (InterruptedException e) {}
+            System.out.print(".");
+        }
+    }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/containers/docker/TestJcmdWithSideCar.java	Tue Jul 23 11:36:05 2019 -0700
@@ -0,0 +1,231 @@
+/*
+ * Copyright (c) 2019, 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.
+ */
+
+
+/*
+ * @test
+ * @summary Test JCMD with side car pattern.
+ *          Sidecar is a common pattern used in the cloud environments for monitoring
+ *          and other uses. In side car pattern the main application/service container
+ *          is paired with a sidecar container by sharing certain aspects of container
+ *          namespace such as PID namespace, specific sub-directories, IPC and more.
+ * @requires docker.support
+ * @library /test/lib
+ * @modules java.base/jdk.internal.misc
+ *          java.management
+ *          jdk.jartool/sun.tools.jar
+ * @build EventGeneratorLoop
+ * @run driver TestJcmdWithSideCar
+ */
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+import jdk.test.lib.Container;
+import jdk.test.lib.Utils;
+import jdk.test.lib.containers.docker.Common;
+import jdk.test.lib.containers.docker.DockerRunOptions;
+import jdk.test.lib.containers.docker.DockerTestUtils;
+import jdk.test.lib.process.OutputAnalyzer;
+
+
+public class TestJcmdWithSideCar {
+    private static final String IMAGE_NAME = Common.imageName("jfr-jcmd");
+    private static final int TIME_TO_RUN_MAIN_PROCESS = (int) (30 * Utils.TIMEOUT_FACTOR); // seconds
+    private static final String MAIN_CONTAINER_NAME = "test-container-main";
+
+    public static void main(String[] args) throws Exception {
+        if (!DockerTestUtils.canTestDocker()) {
+            return;
+        }
+
+        DockerTestUtils.buildJdkDockerImage(IMAGE_NAME, "Dockerfile-BasicTest", "jdk-docker");
+
+        try {
+            // Start the loop process in the "main" container, then run test cases
+            // using a sidecar container.
+            DockerThread t = startMainContainer();
+
+            waitForMainContainerToStart(500, 10);
+            t.checkForErrors();
+
+            OutputAnalyzer jcmdOut = testCase01();
+            long mainProcPid = findProcess(jcmdOut, "EventGeneratorLoop");
+
+            t.assertIsAlive();
+            testCase02(mainProcPid);
+
+            // JCMD does not work in sidecar configuration, except for "jcmd -l".
+            // Including this test case to assist in reproduction of the problem.
+            // t.assertIsAlive();
+            // testCase03(mainProcPid);
+
+            t.join(TIME_TO_RUN_MAIN_PROCESS * 1000);
+            t.checkForErrors();
+        } finally {
+            DockerTestUtils.removeDockerImage(IMAGE_NAME);
+        }
+    }
+
+
+    // Run "jcmd -l" in a sidecar container and find a process that runs EventGeneratorLoop
+    private static OutputAnalyzer testCase01() throws Exception {
+        return runSideCar(MAIN_CONTAINER_NAME, "/jdk/bin/jcmd", "-l")
+            .shouldHaveExitValue(0)
+            .shouldContain("sun.tools.jcmd.JCmd")
+            .shouldContain("EventGeneratorLoop");
+    }
+
+    // run jhsdb jinfo <PID> (jhsdb uses PTRACE)
+    private static void testCase02(long pid) throws Exception {
+        runSideCar(MAIN_CONTAINER_NAME, "/jdk/bin/jhsdb", "jinfo", "--pid", "" + pid)
+            .shouldHaveExitValue(0)
+            .shouldContain("Java System Properties")
+            .shouldContain("VM Flags");
+    }
+
+    // test jcmd with some commands (help, start JFR recording)
+    // JCMD will use signal mechanism and Unix Socket
+    private static void testCase03(long pid) throws Exception {
+        runSideCar(MAIN_CONTAINER_NAME, "/jdk/bin/jcmd", "" + pid, "help")
+            .shouldHaveExitValue(0)
+            .shouldContain("VM.version");
+        runSideCar(MAIN_CONTAINER_NAME, "/jdk/bin/jcmd", "" + pid, "JFR.start")
+            .shouldHaveExitValue(0)
+            .shouldContain("Started recording");
+    }
+
+    private static DockerThread startMainContainer() throws Exception {
+        // start "main" container (the observee)
+        DockerRunOptions opts = commonDockerOpts("EventGeneratorLoop");
+        opts.addDockerOpts("--cap-add=SYS_PTRACE")
+            .addDockerOpts("--name", MAIN_CONTAINER_NAME)
+            .addDockerOpts("-v", "/tmp")
+            .addJavaOpts("-XX:+UsePerfData")
+            .addClassOptions("" + TIME_TO_RUN_MAIN_PROCESS);
+        DockerThread t = new DockerThread(opts);
+        t.start();
+
+        return t;
+    }
+
+    private static void waitForMainContainerToStart(int delayMillis, int count) throws Exception {
+        boolean started = false;
+        for(int i=0; i < count; i++) {
+            try {
+                Thread.sleep(delayMillis);
+            } catch (InterruptedException e) {}
+            if (isMainContainerRunning()) {
+                started = true;
+                break;
+            }
+        }
+        if (!started) {
+            throw new RuntimeException("Main container did not start");
+        }
+    }
+
+    private static boolean isMainContainerRunning() throws Exception {
+        OutputAnalyzer out =
+            DockerTestUtils.execute(Container.ENGINE_COMMAND,
+                                    "ps", "--no-trunc",
+                                    "--filter", "name=" + MAIN_CONTAINER_NAME);
+        return out.getStdout().contains(MAIN_CONTAINER_NAME);
+    }
+
+    // JCMD relies on the attach mechanism (com.sun.tools.attach),
+    // which in turn relies on JVMSTAT mechanism, which puts its mapped
+    // buffers in /tmp directory (hsperfdata_<user>). Thus, in sidecar
+    // we mount /tmp via --volumes-from from the main container.
+    private static OutputAnalyzer runSideCar(String MAIN_CONTAINER_NAME, String whatToRun,
+                                             String... args) throws Exception {
+        List<String> cmd = new ArrayList<>();
+        String[] command = new String[] {
+            Container.ENGINE_COMMAND, "run",
+            "--tty=true", "--rm",
+            "--cap-add=SYS_PTRACE", "--sig-proxy=true",
+            "--pid=container:" + MAIN_CONTAINER_NAME,
+            "--volumes-from", MAIN_CONTAINER_NAME,
+            IMAGE_NAME, whatToRun
+        };
+
+        cmd.addAll(Arrays.asList(command));
+        cmd.addAll(Arrays.asList(args));
+        return DockerTestUtils.execute(cmd);
+    }
+
+    private static long findProcess(OutputAnalyzer out, String name) throws Exception {
+        List<String> l = out.asLines()
+            .stream()
+            .filter(s -> s.contains(name))
+            .collect(Collectors.toList());
+        if (l.isEmpty()) {
+            throw new RuntimeException("Could not find matching process");
+        }
+        String psInfo = l.get(0);
+        System.out.println("findProcess(): psInfo: " + psInfo);
+        String pid = psInfo.substring(0, psInfo.indexOf(' '));
+        System.out.println("findProcess(): pid: " + pid);
+        return Long.parseLong(pid);
+    }
+
+    private static DockerRunOptions commonDockerOpts(String className) {
+        return new DockerRunOptions(IMAGE_NAME, "/jdk/bin/java", className)
+            .addDockerOpts("--volume", Utils.TEST_CLASSES + ":/test-classes/")
+            .addJavaOpts("-cp", "/test-classes/");
+    }
+
+
+    static class DockerThread extends Thread {
+        DockerRunOptions runOpts;
+        Exception exception;
+
+        DockerThread(DockerRunOptions opts) {
+            runOpts = opts;
+        }
+
+        public void run() {
+            try {
+                DockerTestUtils.dockerRunJava(runOpts);
+            } catch (Exception e) {
+                exception = e;
+            }
+        }
+
+        public void assertIsAlive() throws Exception {
+            if (!isAlive()) {
+                throw new RuntimeException("DockerThread stopped unexpectedly");
+            }
+        }
+
+        public void checkForErrors() throws Exception {
+            if (exception != null) {
+                throw new RuntimeException("DockerThread threw exception"
+                                           + exception.getMessage());
+            }
+        }
+    }
+
+}

--- a/test/lib/jdk/test/lib/containers/docker/DockerTestUtils.java	Tue Jul 23 13:56:41 2019 -0400
+++ b/test/lib/jdk/test/lib/containers/docker/DockerTestUtils.java	Tue Jul 23 11:36:05 2019 -0700
@@ -189,7 +189,7 @@
     /**
      * Build the docker command to run java inside a container
      *
-     * @param DockerRunOptions optins for running docker
+     * @param DockerRunOptions options for running docker
      *
      * @return command
      * @throws Exception
@@ -222,7 +222,7 @@
     /**
      * Run Java inside the docker image with specified parameters and options.
      *
-     * @param DockerRunOptions optins for running docker
+     * @param DockerRunOptions options for running docker
      *
      * @return output of the run command
      * @throws Exception
@@ -235,7 +235,7 @@
      /**
      * Remove docker image
      *
-     * @param DockerRunOptions optins for running docker
+     * @param DockerRunOptions options for running docker
      * @throws Exception
      */
     public static void removeDockerImage(String imageNameAndTag) throws Exception {