content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.cassandra.concurrent;
  
  import java.util.concurrent.Callable;
  
  import javax.annotation.Nullable;
  
  import org.apache.cassandra.utils.concurrent.AsyncFuture;
  import org.apache.cassandra.utils.concurrent.RunnableFuture;
  
  /**
   * A FutureTask that utilises Cassandra's {@link AsyncFuture}, making it compatible with {@link ExecutorPlus}.
   * Propagates exceptions to the uncaught exception handler.
   */
  public class FutureTask<V> extends AsyncFuture<V> implements RunnableFuture<V>
  {
      private Callable<? extends V> call;
      private volatile DebuggableTask debuggable;
  
      public FutureTask(Callable<? extends V> call)
      {
          this(call, call instanceof DebuggableTask ? (DebuggableTask) call : null);
      }
  
      public FutureTask(Runnable run)
      {
          this(callable(run), run instanceof DebuggableTask ? (DebuggableTask) run : null);
      }
  
      private FutureTask(Callable<? extends V> call, DebuggableTask debuggable)
      {
          this.call = call;
          this.debuggable = debuggable;
      }
  
      @Nullable
      DebuggableTask debuggableTask()
      {
          return debuggable;
      }
  
      V call() throws Exception
      {
          return call.call();
      }
  
      public void run()
      {
          try
          {
              if (!setUncancellable())
                  return;
  
              trySuccess(call());
          }
          catch (Throwable t)
          {
              tryFailure(t);
          }
          finally
          {
              call = null;
              debuggable = null;
          }
      }
  
      protected boolean tryFailure(Throwable t)
      {
          ExecutionFailure.handle(t);
          return super.tryFailure(t);
      }
  
      public static <T> Callable<T> callable(Runnable run)
      {
          if (run instanceof DebuggableTask.RunnableDebuggableTask)
          {
              return new DebuggableTask.CallableDebuggableTask<T>()
              {
                  final RunnableDebuggableTask task = (RunnableDebuggableTask) run;
                  public T call()
                  {
                      run.run();
                      return null;
                  }
  
                  public long creationTimeNanos()
                  {
                      return task.creationTimeNanos();
                  }
  
                  public long startTimeNanos()
                  {
                      return task.startTimeNanos();
                  }
  
                  public String description()
                  {
                      return task.description();
                  }
              };
          }
  
          return new Callable<T>()
          {
              public T call()
              {
                  run.run();
                  return null;
              }
  
              public String toString()
              {
                  return run.toString();
              }
          };
      }
  
      public static <T> Callable<T> callable(Object id, Runnable run)
      {
          return new Callable<T>()
          {
              public T call()
              {
                  run.run();
                  return null;
              }
  
              public String toString()
              {
                  return id.toString();
              }
          };
      }
  
      public static <T> Callable<T> callable(Runnable run, T result)
      {
          return new Callable<T>()
          {
              public T call()
              {
                  run.run();
                  return result;
              }
  
              public String toString()
              {
                  return run + "->" + result;
              }
          };
      }
  
      public static <T> Callable<T> callable(Object id, Runnable run, T result)
      {
          return new Callable<T>()
          {
              public T call()
              {
                  run.run();
                  return result;
              }
  
              public String toString()
              {
                  return id.toString();
              }
          };
      }
  
      @Override
      protected String description()
      {
          Object desc = call;
          return desc == null ? null : call.toString();
      }
  }
  