static new MultiSet<S> poorMansProfiling_results;

static int poorMansProfiling_samples;

static java.util.Timer poorMansProfiling_timer;

static Lock poorMansProfiling_lock = lock();

static Thread poorMansProfiling_threadToSample; // otherwise sample all threads

static void poorMansProfiling() {

  poorMansProfiling(poorMansProfiling_defaultInterval());

}

static void poorMansProfiling(Thread thread) {

  poorMansProfiling(poorMansProfiling_defaultInterval(), thread);

}

static void poorMansProfiling(int interval) {

  poorMansProfiling(interval, null);

}

static void poorMansProfiling(int interval, Thread thread) {

  lock poorMansProfiling_lock;

  poorMansProfiling_threadToSample = thread;

  poorMansProfiling_stop();

  poorMansProfiling_clear();

  poorMansProfiling_timer = doEvery_daemon(interval, r {

    Map<Thread, StackTraceElement[]> map =

      poorMansProfiling_threadToSample != null

        ? litmap(poorMansProfiling_threadToSample, poorMansProfiling_threadToSample.getStackTrace())

        : runnableThreadsWithStackTraces();

    lock poorMansProfiling_lock;

    poorMansProfiling_samples++;

    for (Thread t : keys(map)) {

      continue if isSystemThread(t);

      new StringBuilder buf;

      for (StackTraceElement e : map.get(t))

        buf.append(e).append("\n");

      poorMansProfiling_results.add(str(buf));

    }

  });

}

static void poorMansProfiling_stop() {

  lock poorMansProfiling_lock;

  if (poorMansProfiling_timer != null) {

    stopTimer(poorMansProfiling_timer);

    poorMansProfiling_timer = null;

  }

}

static void poorMansProfiling_clear() {

  lock poorMansProfiling_lock;

  poorMansProfiling_results.clear();

  poorMansProfiling_samples = 0;

}

static MultiSet<S> poorMansProfiling_results() {

  ret new MultiSet(poorMansProfiling_results);

}

static MultiSet<S> poorMansProfiling_stopAndGetResults() {

  lock poorMansProfiling_lock;

  poorMansProfiling_stop();

  ret poorMansProfiling_results();

}