!747

m {
  static Map<Long, Thread> idToThread;
  
  p {
    ThreadMXBean mx = ManagementFactory.getThreadMXBean();
    
    // just for fun
    print("Total started thread count: " + mx.getTotalStartedThreadCount());
    
    boolean cpuTimeSupported = mx.isThreadCpuTimeSupported();
    print("CPU time supported: " + cpuTimeSupported);
    if (!cpuTimeSupported) fail("No CPU time info available on platform.");
    
    long[] threads = mx.getAllThreadIds();
    
    long time = now();
    L<Thread> l = getAllThreads();
    print((now()-time) + " ms for getAllThreads()");
    print(l.size() + " threads");
    
    idToThread = new TreeMap();
    for (Thread t : l)
      idToThread.put(t.getId(), t);
      
    for (long id : threads) {
      long nano = mx.getThreadCpuTime(id);
      long ms = nano/1000000;
      Thread t = idToThread.get(id);
      if (t == null)
        print("? thread not found: " + id);
      else
        print("Thread " + quote(t.getName()) + ": CPU time = " + ms + " ms");
    }
    
  }
  
  static L<Thread> getAllThreads() {
    ThreadGroup rootGroup = Thread.currentThread().getThreadGroup();
    ThreadGroup parentGroup;
    while ( ( parentGroup = rootGroup.getParent() ) != null )
      rootGroup = parentGroup;
    Thread[] threads = new Thread[rootGroup.activeCount()];
    int n;
    while ((n = rootGroup.enumerate(threads, true)) == threads.length)       threads = new Thread[threads.length*2];
    L<Thread> l = new ArrayList<Thread>(n);
    for (int i = 0; i < n; i++) l.add(threads[i]);
    ret l;
  }
}