*
   * (Perhaps it should also have required that its cause was a RuntimeException. However, that
   * would have required that we throw a different kind of exception for wrapping *checked*
   * exceptions in methods like Futures.getUnchecked and LoadingCache.get.)
   */

  /**
   * Creates a new instance with {@code null} as its detail message and no cause.
   *

 * the License.
 */

package com.google.common.cache;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.util.concurrent.Futures.immediateFuture;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;

    }

    final SettableFuture<V> delegate = SettableFuture.create();

    @Override
    protected Future<V> delegate() {
      return delegate;
    }

    void set(V value) {
      delegate.set(value);
    }
  }

  private static final class RuntimeExceptionThrowingFuture<V> implements Future<V> {
    final CountDownLatch allowGetToComplete = new CountDownLatch(1);

    @Override

   * Future} instances to be upgraded to {@code ListenableFuture} after the fact.
   */
  public static <V extends @Nullable Object> ListenableFuture<V> listenInPoolThread(
      Future<V> future) {
    if (future instanceof ListenableFuture) {
      return (ListenableFuture<V>) future;
    }
    return new ListenableFutureAdapter<>(future);
  }

  /**

    }

    final SettableFuture<V> delegate = SettableFuture.create();

    @Override
    protected Future<V> delegate() {
      return delegate;
    }

    void set(V value) {
      delegate.set(value);
    }
  }

  private static final class RuntimeExceptionThrowingFuture<V> implements Future<V> {
    final CountDownLatch allowGetToComplete = new CountDownLatch(1);

    @Override

 * the License.
 */

package com.google.common.cache;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.util.concurrent.Futures.immediateFuture;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;

    /**
     * Contains the most recently submitted {@code Future}, which may be cancelled or updated,
     * always under a lock.
     */
    private static final class SupplantableFuture implements Cancellable {
      private final ReentrantLock lock;

      @GuardedBy("lock")
      private Future<@Nullable Void> currentFuture;

      SupplantableFuture(ReentrantLock lock, Future<@Nullable Void> currentFuture) {
        this.lock = lock;

import static com.google.common.truth.Truth.assertThat;
import static com.google.common.truth.Truth.assertWithMessage;
import static com.google.common.util.concurrent.Futures.immediateFailedFuture;
import static com.google.common.util.concurrent.Futures.immediateFuture;
import static java.util.Arrays.asList;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;

import static com.google.common.cache.CacheBuilder.UNSET_INT;
import static com.google.common.util.concurrent.Futures.immediateFailedFuture;
import static com.google.common.util.concurrent.Futures.immediateFuture;
import static com.google.common.util.concurrent.Futures.transform;
import static com.google.common.util.concurrent.MoreExecutors.directExecutor;

import static com.google.common.truth.Truth.assertThat;
import static com.google.common.truth.Truth.assertWithMessage;
import static com.google.common.util.concurrent.Futures.immediateFailedFuture;
import static com.google.common.util.concurrent.Futures.immediateFuture;
import static java.util.Arrays.asList;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;