code: package io.ray.runtime;
  
  import io.ray.api.BaseActorHandle;
  import io.ray.api.id.ActorId;
  import io.ray.api.id.JobId;
  import io.ray.api.id.ObjectId;
  import io.ray.api.id.PlacementGroupId;
  import io.ray.api.id.UniqueId;
  import io.ray.api.placementgroup.PlacementGroup;
  import io.ray.api.runtimecontext.ResourceValue;
  import io.ray.runtime.config.RayConfig;
  import io.ray.runtime.context.LocalModeWorkerContext;
  import io.ray.runtime.functionmanager.FunctionManager;
  import io.ray.runtime.gcs.GcsClient;
  import io.ray.runtime.object.LocalModeObjectStore;
  import io.ray.runtime.task.LocalModeTaskExecutor;
  import io.ray.runtime.task.LocalModeTaskSubmitter;
  import io.ray.runtime.util.BinaryFileUtil;
  import io.ray.runtime.util.JniUtils;
  import io.ray.runtime.util.SystemUtil;
  import java.text.SimpleDateFormat;
  import java.util.Date;
  import java.util.List;
  import java.util.Map;
  import java.util.Optional;
  import java.util.concurrent.atomic.AtomicInteger;
  
  public class RayDevRuntime extends AbstractRayRuntime {
  
    private AtomicInteger jobCounter = new AtomicInteger(0);
  
    public RayDevRuntime(RayConfig rayConfig) {
      super(rayConfig);
    }
  
    @Override
    public void start() {
      if (rayConfig.getJobId().isNil()) {
        rayConfig.setJobId(nextJobId());
      }
  
      updateSessionDir(rayConfig);
      JniUtils.loadLibrary(rayConfig.sessionDir, BinaryFileUtil.CORE_WORKER_JAVA_LIBRARY, true);
  
      taskExecutor = new LocalModeTaskExecutor(this);
      workerContext = new LocalModeWorkerContext(rayConfig.getJobId());
      objectStore = new LocalModeObjectStore(workerContext);
      functionManager = new FunctionManager(rayConfig.codeSearchPath);
      taskSubmitter =
          new LocalModeTaskSubmitter(this, taskExecutor, (LocalModeObjectStore) objectStore);
      ((LocalModeObjectStore) objectStore)
          .addObjectPutCallback(
              objectId -> {
                if (taskSubmitter != null) {
                  ((LocalModeTaskSubmitter) taskSubmitter).onObjectPut(objectId);
                }
              });
    }
  
    @Override
    public void run() {
      throw new UnsupportedOperationException();
    }
  
    @Override
    public void shutdown() {
      if (taskSubmitter != null) {
        ((LocalModeTaskSubmitter) taskSubmitter).shutdown();
        taskSubmitter = null;
      }
      taskExecutor = null;
    }
  
    @Override
    public void killActor(BaseActorHandle actor, boolean noRestart) {
      throw new UnsupportedOperationException();
    }
  
    @SuppressWarnings("unchecked")
    @Override
    public <T extends BaseActorHandle> Optional<T> getActor(String name, String namespace) {
      return (Optional<T>) ((LocalModeTaskSubmitter) taskSubmitter).getActor(name);
    }
  
    @Override
    public GcsClient getGcsClient() {
      throw new UnsupportedOperationException("Ray doesn't have gcs client in local mode.");
    }
  
    @Override
    public Map<String, List<ResourceValue>> getAvailableResourceIds() {
      throw new UnsupportedOperationException("Ray doesn't support get resources ids in local mode.");
    }
  
    @Override
    List<ObjectId> getCurrentReturnIds(int numReturns, ActorId actorId) {
      return null;
    }
  
    @Override
    public PlacementGroup getPlacementGroup(PlacementGroupId id) {
      // @TODO(clay4444): We need a LocalGcsClient before implements this.
      throw new UnsupportedOperationException(
          "Ray doesn't support placement group operations in local mode.");
    }
  
    @Override
    public List<PlacementGroup> getAllPlacementGroups() {
      // @TODO(clay4444): We need a LocalGcsClient before implements this.
      throw new UnsupportedOperationException(
          "Ray doesn't support placement group operations in local mode.");
    }
  
    @Override
    public String getNamespace() {
      return null;
    }
  
    @Override
    public UniqueId getCurrentNodeId() {
      throw new UnsupportedOperationException("Ray doesn't support it in local mode.");
    }
  
    @Override
    public void exitActor() {}
  
    private JobId nextJobId() {
      return JobId.fromInt(jobCounter.getAndIncrement());
    }
  
    private static void updateSessionDir(RayConfig rayConfig) {
      SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd_hh-mm-ss-ms");
      Date date = new Date();
      String sessionDir =
          String.format("/tmp/ray/session_local_mode_%s_%d", format.format(date), SystemUtil.pid());
      rayConfig.setSessionDir(sessionDir);
    }
  }
  