* @since 3.0
 */
@Named
@Singleton
public class DefaultLegacySupport implements LegacySupport {

    private static final ThreadLocal<AtomicReference<MavenSession>> SESSION = new InheritableThreadLocal<>();

    @Override
    public void setSession(MavenSession session) {
        AtomicReference<MavenSession> reference = DefaultLegacySupport.SESSION.get();
        if (reference != null) {
            reference.set(null);
        }

@NullUnmarked
public class AbstractLoadingCacheTest extends TestCase {

  public void testGetUnchecked_checked() {
    Exception cause = new Exception();
    AtomicReference<Object> valueRef = new AtomicReference<>();
    LoadingCache<Object, Object> cache =
        new AbstractLoadingCache<Object, Object>() {
          @Override
          public Object get(Object key) throws ExecutionException {
            Object v = valueRef.get();

    val tags = EmptyTags
    val atomicTags = AtomicReference<Tags>(tags)
    assertThat(atomicTags.computeIfAbsent(String::class) { "a" }).isEqualTo("a")
    assertThat(atomicTags.get()[String::class]).isEqualTo("a")
  }

  @Test
  fun computeIfAbsentWhenPresent() {
    val tags = EmptyTags.plus(String::class, "a")
    val atomicTags = AtomicReference(tags)

    assertThat(sepLoader).isSameInstanceAs(sepStopwatchC.getClassLoader());
    AtomicReference<Object> sepStopwatchA =
        new AtomicReference<Object>(sepStopwatchC.getMethod("createUnstarted").invoke(null));
    AtomicReference<WeakReference<?>> sepStopwatchRef =
        new AtomicReference<WeakReference<?>>(
            (WeakReference<?>) sepFwrCons.newInstance(sepStopwatchA.get(), sepFrqA.get()));

        int numIterations = 100;
        ExecutorService executor = Executors.newFixedThreadPool(numThreads);
        CountDownLatch latch = new CountDownLatch(numThreads);
        AtomicReference<Exception> exception = new AtomicReference<>();

        for (int i = 0; i < numThreads; i++) {
            executor.submit(() -> {
                try {
                    for (int j = 0; j < numIterations; j++) {

    AtomicBoolean actualIsOccupied = new AtomicBoolean();
    AtomicBoolean actualIsOccupiedByCurrentThread = new AtomicBoolean();
    AtomicInteger actualOccupiedDepth = new AtomicInteger();
    AtomicReference<Throwable> thrown = new AtomicReference<>();
    joinUninterruptibly(
        startThread(
            new Runnable() {
              @Override
              public void run() {
                try {

    AtomicBoolean actualIsOccupied = new AtomicBoolean();
    AtomicBoolean actualIsOccupiedByCurrentThread = new AtomicBoolean();
    AtomicInteger actualOccupiedDepth = new AtomicInteger();
    AtomicReference<Throwable> thrown = new AtomicReference<>();
    joinUninterruptibly(
        startThread(
            new Runnable() {
              @Override
              public void run() {
                try {

        class ProcessorHolder {
            /**
             * Cached processor instance for performance.
             */
            private static final AtomicReference<ModelObjectProcessor> CACHED_PROCESSOR = new AtomicReference<>();
        }

        ModelObjectProcessor processor = ProcessorHolder.CACHED_PROCESSOR.get();
        if (processor == null) {
            processor = loadProcessor();

 * logger is created at start, and it exists while no logging is available yet.
 */
public class AccumulatingLogger implements Logger {
    private final AtomicReference<List<Entry>> entries = new AtomicReference<>(new CopyOnWriteArrayList<>());

    @Override
    public void log(Level level, String message, Throwable error) {
        requireNonNull(level, "level");
        requireNonNull(message, "message");

            keyMap.bind(new Reference("tailtip-toggle"), KeyMap.alt("s"));

            // start the shell and process input until the user quits with Ctrl-D
            AtomicReference<Exception> failure = new AtomicReference<>();
            while (true) {
                try {
                    failure.set(null);
                    systemRegistry.cleanUp();