Java HotSpotVirtualMachine.detach方法代码示例

import sun.tools.attach.HotSpotVirtualMachine; //导入方法依赖的package包/类
public static boolean runTest() throws Exception {
  ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
    "-XX:+UnlockDiagnosticVMOptions", "-XX:+PauseAtStartup", "AttachWithStalePidFileTarget");
  Process target = pb.start();
  Path pidFile = null;

  try {
    int pid = getUnixProcessId(target);

    // create the stale .java_pid file. use hard-coded /tmp path as in th VM
    pidFile = createJavaPidFile(pid);
    if(pidFile == null) {
      return false;
    }

    // wait for vm.paused file to be created and delete it once we find it.
    waitForAndResumeVM(pid);

    // unfortunately there's no reliable way to know the VM is ready to receive the
    // attach request so we have to do an arbitrary sleep.
    Thread.sleep(5000);

    HotSpotVirtualMachine vm = (HotSpotVirtualMachine)VirtualMachine.attach(((Integer)pid).toString());
    BufferedReader remoteDataReader = new BufferedReader(new InputStreamReader(vm.remoteDataDump()));
    String line = null;
    while((line = remoteDataReader.readLine()) != null);

    vm.detach();
    return true;
  }
  finally {
    target.destroy();
    target.waitFor();

    if(pidFile != null && Files.exists(pidFile)) {
      Files.delete(pidFile);
    }
  }
}
 

import sun.tools.attach.HotSpotVirtualMachine; //导入方法依赖的package包/类
public static boolean runTest() throws Exception {
  ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
    "-XX:+UnlockDiagnosticVMOptions", "-XX:+PauseAtStartup", "AttachWithStalePidFileTarget");
  Process target = pb.start();
  Path pidFile = null;

  try {
    int pid = getUnixProcessId(target);

    // create the stale .java_pid file. use hard-coded /tmp path as in th VM
    pidFile = createJavaPidFile(pid);
    if(pidFile == null) {
      return false;
    }

    // wait for vm.paused file to be created and delete it once we find it.
    waitForAndResumeVM(pid);

    waitForTargetReady(target);

    HotSpotVirtualMachine vm = (HotSpotVirtualMachine)VirtualMachine.attach(((Integer)pid).toString());
    BufferedReader remoteDataReader = new BufferedReader(new InputStreamReader(vm.remoteDataDump()));
    String line = null;
    while((line = remoteDataReader.readLine()) != null);

    vm.detach();
    return true;
  }
  finally {
    target.destroy();
    target.waitFor();

    if(pidFile != null && Files.exists(pidFile)) {
      Files.delete(pidFile);
    }
  }
}
 

import sun.tools.attach.HotSpotVirtualMachine; //导入方法依赖的package包/类
public static void testGetFlag(String flagName, String flagValue) throws Exception {
  ProcessBuilder pb = runTarget(flagName, flagValue);

  Process target = pb.start();

  try {
    waitForReady(target);

    int pid = (int)target.pid();

    HotSpotVirtualMachine vm = (HotSpotVirtualMachine)VirtualMachine.attach(((Integer)pid).toString());

    // Test Get
    BufferedReader remoteDataReader = new BufferedReader(new InputStreamReader(
        vm.printFlag(flagName)));

    boolean foundExpectedLine = false;

    String line = null;
    while((line = remoteDataReader.readLine()) != null) {
      System.out.println("printFlag: " + line);
      if (line.equals("-XX:" + flagName + "=" + flagValue)) {
        foundExpectedLine = true;
      }
    }

    Asserts.assertTrue(foundExpectedLine, "Didn't get the expected output: '-XX:" + flagName + "=" + flagValue + "'");

    vm.detach();
  }
  finally {
    target.destroy();
    target.waitFor();
  }
}
 

import sun.tools.attach.HotSpotVirtualMachine; //导入方法依赖的package包/类
/**
 * 'vm.heapHisto("-live")' will request a full GC
 */
private static int getInstanceCountFromHeapHisto() throws AttachNotSupportedException, Exception {
    int instanceCount = 0;

    HotSpotVirtualMachine vm = (HotSpotVirtualMachine) VirtualMachine
            .attach(Long.toString(ProcessTools.getProcessId()));
    try {
        try (InputStream heapHistoStream = vm.heapHisto("-live");
                BufferedReader in = new BufferedReader(new InputStreamReader(heapHistoStream))) {
            String inputLine;
            while ((inputLine = in.readLine()) != null) {
                if (inputLine.contains(TARGET_CLASS)) {
                    instanceCount = Integer.parseInt(inputLine
                            .split("[ ]+")[2]);
                    System.out.println("instance count: " + instanceCount);
                    break;
                }
            }
        }
    } finally {
        vm.detach();
    }

    assertGreaterThan(instanceCount, 0, "No instances of " + TARGET_CLASS + " are found");

    return instanceCount;
}
 

import sun.tools.attach.HotSpotVirtualMachine; //导入方法依赖的package包/类
public static void testGetFlag(String flagName, String flagValue) throws Exception {
  ProcessBuilder pb = runTarget(flagName, flagValue);

  Process target = pb.start();

  try {
    waitForReady(target);

    int pid = (int)target.getPid();

    HotSpotVirtualMachine vm = (HotSpotVirtualMachine)VirtualMachine.attach(((Integer)pid).toString());

    // Test Get
    BufferedReader remoteDataReader = new BufferedReader(new InputStreamReader(
        vm.printFlag(flagName)));

    boolean foundExpectedLine = false;

    String line = null;
    while((line = remoteDataReader.readLine()) != null) {
      System.out.println("printFlag: " + line);
      if (line.equals("-XX:" + flagName + "=" + flagValue)) {
        foundExpectedLine = true;
      }
    }

    Asserts.assertTrue(foundExpectedLine, "Didn't get the expected output: '-XX:" + flagName + "=" + flagValue + "'");

    vm.detach();
  }
  finally {
    target.destroy();
    target.waitFor();
  }
}
 

import sun.tools.attach.HotSpotVirtualMachine; //导入方法依赖的package包/类
public static void testSetFlag(String flagName, String initialFlagValue, String flagValue) throws Exception {
  ProcessBuilder pb = runTarget(flagName, initialFlagValue);

  Process target = pb.start();

  try {
    waitForReady(target);

    int pid = (int)target.getPid();

    HotSpotVirtualMachine vm = (HotSpotVirtualMachine)VirtualMachine.attach(((Integer)pid).toString());

    // First set the value.
    BufferedReader remoteDataReader = new BufferedReader(new InputStreamReader(
        vm.setFlag(flagName, flagValue)));

    String line;
    while((line = remoteDataReader.readLine()) != null) {
      System.out.println("setFlag: " + line);
      // Just empty the stream.
    }
    remoteDataReader.close();

    // Then read and make sure we get back the set value.
    remoteDataReader = new BufferedReader(new InputStreamReader(vm.printFlag(flagName)));

    boolean foundExpectedLine = false;
    line = null;
    while((line = remoteDataReader.readLine()) != null) {
      System.out.println("getFlag: " + line);
      if (line.equals("-XX:" + flagName + "=" + flagValue)) {
        foundExpectedLine = true;
      }
    }

    Asserts.assertTrue(foundExpectedLine, "Didn't get the expected output: '-XX:" + flagName + "=" + flagValue + "'");

    vm.detach();

  } finally {
    target.destroy();
    target.waitFor();
  }
}