return (timeoutNanos <= 0L) ? 0L : timeoutNanos - (System.nanoTime() - startTime);
  }

  /**
   * Signals some other thread waiting on a satisfied guard, if one exists.
   *
   * <p>We manage calls to this method carefully, to signal only when necessary, but never losing a
   * signal, which is the classic problem of this kind of concurrency construct. We must signal if

import java.util.concurrent.Executor;
import java.util.logging.Level;
import javax.annotation.CheckForNull;

/**
 * A support class for {@code ListenableFuture} implementations to manage their listeners. An
 * instance contains a list of listeners, each with an associated {@code Executor}, and guarantees
 * that every {@code Runnable} that is {@linkplain #add added} will be executed after {@link

         * invoke interruptTask on any subsequent futures.
         */
        callInterruptTask = false;
      }
      // We call this before the listeners in order to avoid needing to manage a separate stack data
      // structure for them.  Also, some implementations rely on this running prior to listeners
      // so that the cleanup work is visible to listeners.

  private final ServiceManagerState state;

  private final ImmutableList<Service> services;

  /**
   * Constructs a new instance for managing the given services.
   *
   * @param services The services to manage
   * @throws IllegalArgumentException if not all services are {@linkplain State#NEW new} or if there
   *     are any duplicate services.
   */
  public ServiceManager(Iterable<? extends Service> services) {

/**
 * Base class for services that can implement {@link #startUp}, {@link #run} and {@link #shutDown}
 * methods. This class uses a single thread to execute the service; consider {@link AbstractService}
 * if you would like to manage any threading manually.
 *
 * @author Jesse Wilson
 * @since 1.0
 */
@GwtIncompatible
@J2ktIncompatible
@ElementTypesAreNonnullByDefault
public abstract class AbstractExecutionThreadService implements Service {