import java.util.concurrent.TimeUnit;

/**
 * Simple benchmark: create, start, read. This does not currently report the most useful result
 * because it's ambiguous to what extent the stopwatch benchmark is being affected by GC.
 *
 * @author Kevin Bourrillion
 */
public class StopwatchBenchmark {
  @Benchmark
  long stopwatch(int reps) {
    long total = 0;
    for (int i = 0; i < reps; i++) {

import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Unit test for {@link FinalizableReferenceQueue}.
 *
 * @author Bob Lee
 */
// - depends on details of GC and classloading
// - .class files aren't available
// - possibly no real concept of separate ClassLoaders?
@AndroidIncompatible
@GwtIncompatible
public class FinalizableReferenceQueueTest extends TestCase {

import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Unit test for {@link FinalizableReferenceQueue}.
 *
 * @author Bob Lee
 */
// - depends on details of GC and classloading
// - .class files aren't available
// - possibly no real concept of separate ClassLoaders?
@AndroidIncompatible
@GwtIncompatible
public class FinalizableReferenceQueueTest extends TestCase {

  // app (like the FrqUser class above), then the app's ClassLoader will never be gc'd. The reason
  // is that we attempt to run a thread in a separate ClassLoader that will detect when the FRQ
  // is no longer referenced, meaning that the app's ClassLoader has been gc'd, and when that
  // happens. But the thread's supposedly separate ClassLoader actually has a reference to the app's

      fail("No exception thrown");
    } catch (UnsupportedOperationException expected) {
    }
  }


  @GwtIncompatible // weak references
  @J2ktIncompatible
  @AndroidIncompatible // depends on details of GC
  public void testFreesNextReference() {
    Iterator<Object> itr =
        new AbstractIterator<Object>() {
          @Override
          public Object computeNext() {
            return new Object();

      fail("No exception thrown");
    } catch (UnsupportedOperationException expected) {
    }
  }


  @GwtIncompatible // weak references
  @J2ktIncompatible
  @AndroidIncompatible // depends on details of GC
  public void testFreesNextReference() {
    Iterator<Object> itr =
        new AbstractIterator<Object>() {
          @Override
          public Object computeNext() {
            return new Object();

    // initialSize will most likely be 2, but it's possible for the GC to have already run, so we'll
    // observe a size of 1
    long initialSize = cache.size();
    assertTrue(initialSize == 1 || initialSize == 2);

    // wait up to 5s
    byte[] filler = new byte[1024];
    for (int i = 0; i < 500; i++) {
      System.gc();

      CacheTesting.drainReferenceQueues(cache);
      if (cache.size() == 1) {

  }

  @Footprint
  Object sizeOfStriped() {
    return impl.get(numStripes);
  }

  // a place to put the locks in sizeOfPopulatedStriped so they don't get GC'd before we measure
  final List<Lock> locks = new ArrayList<>(numStripes);

  @Footprint
  Object sizeOfPopulatedStriped() {
    locks.clear();
    Striped<Lock> striped = impl.get(numStripes);

  }

  @Footprint
  Object sizeOfStriped() {
    return impl.get(numStripes);
  }

  // a place to put the locks in sizeOfPopulatedStriped so they don't get GC'd before we measure
  final List<Lock> locks = new ArrayList<>(numStripes);

  @Footprint
  Object sizeOfPopulatedStriped() {
    locks.clear();
    Striped<Lock> striped = impl.get(numStripes);

    } catch (NoSuchElementException expected) {
    }
  }


  @J2ktIncompatible // weak references, details of GC
  @GwtIncompatible // weak references
  @AndroidIncompatible // depends on details of GC
  public void testFreesNextReference() {
    Iterator<Object> itr =
        new AbstractIterator<Object>() {
          @Override
          public Object computeNext() {