import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import javax.annotation.CheckForNull;

/**
 * Weak reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

        this.attrs = attrs;
        this.options = options;
        this.tree = tree.acquire();
        this.tree_num = tree.getTreeId();

        if ( cfg.isTraceResourceUsage() ) {
            this.creationBacktrace = Thread.currentThread().getStackTrace();
        }
        else {
            this.creationBacktrace = null;
        }
    }


    /**
     * @param cfg
     * @param fid
     * @param tree

import okhttp3.internal.okHttpName

/**
 * A set of tasks that are executed in sequential order.
 *
 * Work within queues is not concurrent. This is equivalent to each queue having a dedicated thread
 * for its work; in practice a set of queues may share a set of threads to save resources.
 */
class TaskQueue internal constructor(
  internal val taskRunner: TaskRunner,
  internal val name: String,
) {
  val lock: ReentrantLock = ReentrantLock()

  /**
   * Invoked when a call is canceled.
   *
   * Like all methods in this interface, this is invoked on the thread that triggered the event. But
   * while other events occur sequentially; cancels may occur concurrently with other events. For
   * example, thread A may be executing [responseBodyStart] while thread B executes [canceled].
   * Implementations must support such concurrent calls.
   *

 * not consistent with {@code equals}.
 *
 * <p>The {@code standard} methods and the collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

      MoreFiles.deleteDirectoryContents(symlink, ALLOW_INSECURE);
      assertEquals(0, MoreFiles.listFiles(dir).size());
    }
  }

  /**
   * This test attempts to create a situation in which one thread is constantly changing a file from
   * being a real directory to being a symlink to another directory. It then calls
   * deleteDirectoryContents thousands of times on a directory whose subtree contains the file

  private Runtime runtimeMock;

  @Override
  protected void setUp() {
    runtimeMock = mock(Runtime.class);
  }

  public void testExiter() {
    new Exiter(runtimeMock).uncaughtException(new Thread(), new Exception());
    verify(runtimeMock).exit(1);
  }

   * Futures#addCallback addCallback()}.
   *
   * <p>Memory consistency effects: Actions in a thread prior to adding a listener <a
   * href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-17.html#jls-17.4.5">
   * <i>happen-before</i></a> its execution begins, perhaps in another thread.
   *
   * <p>Guava implementations of {@code ListenableFuture} promptly release references to listeners

import java.util.LinkedList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * A {@code TearDownStack} contains a stack of {@link TearDown} instances.
 *
 * <p>This class is thread-safe.
 *
 * @author Kevin Bourrillion
 * @since 10.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class TearDownStack implements TearDownAccepter {

import java.util.LinkedList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * A {@code TearDownStack} contains a stack of {@link TearDown} instances.
 *
 * <p>This class is thread-safe.
 *
 * @author Kevin Bourrillion
 * @since 10.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class TearDownStack implements TearDownAccepter {