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 accord.utils.async;
  
  import java.util.concurrent.CountDownLatch;
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.TimeoutException;
  import java.util.concurrent.atomic.AtomicReference;
  
  import static accord.utils.Invariants.illegalState;
  
  // TODO (expected): these methods are test-only; in Cassandra we should not be using these as not simulator safe
  public class AsyncChainUtils
  {
      public static <V> V getBlocking(AsyncChain<V> chain) throws InterruptedException, ExecutionException
      {
          try
          {
              return getBlocking(chain, 0, TimeUnit.DAYS);
          }
          catch (TimeoutException e)
          {
              throw illegalState("Should not throw timeout exception e");
          }
      }
  
      public static <V> V getBlockingAndRethrow(AsyncChain<V> chain)
      {
          class Result
          {
              final V result;
              final Throwable failure;
  
              public Result(V result, Throwable failure)
              {
                  this.result = result;
                  this.failure = failure;
              }
          }
  
          AtomicReference<Result> callbackResult = new AtomicReference<>();
          CountDownLatch latch = new CountDownLatch(1);
  
          chain.begin((result, failure) -> {
              callbackResult.set(new Result(result, failure));
              latch.countDown();
          });
  
          try
          {
              latch.await();
          }
          catch (InterruptedException e)
          {
              throw new RuntimeException(e);
          }
  
          Result result = callbackResult.get();
          if (result.failure == null) return result.result;
          else throw new RuntimeException(result.failure);
      }
  
      public static <V> V getBlocking(AsyncChain<V> chain, long timeout, TimeUnit unit) throws InterruptedException, TimeoutException, ExecutionException
      {
          class Result
          {
              final V result;
              final Throwable failure;
  
              public Result(V result, Throwable failure)
              {
                  this.result = result;
                  this.failure = failure;
              }
          }
  
          AtomicReference<Result> callbackResult = new AtomicReference<>();
          CountDownLatch latch = new CountDownLatch(1);
  
          chain.begin((result, failure) -> {
              callbackResult.set(new Result(result, failure));
              latch.countDown();
          });
  
          if (timeout > 0)
          {
              if (!latch.await(timeout, unit))
                  throw new TimeoutException();
          }
          else
              latch.await();
  
          Result result = callbackResult.get();
          if (result.failure == null) return result.result;
          else throw new ExecutionException(result.failure);
      }
  
      public static <V> V getUninterruptibly(AsyncResult<V> result) throws ExecutionException
      {
          return getUninterruptibly(result.chain());
      }
  
      public static <V> V getUninterruptibly(AsyncChain<V> chain) throws ExecutionException
      {
          try
          {
              return getUninterruptibly(chain, 1, TimeUnit.DAYS);
          }
          catch (TimeoutException e)
          {
              throw illegalState("Should not throw timeout exception e");
          }
      }
  
      public static <V> V getUninterruptibly(AsyncResult<V> result, long time, TimeUnit unit) throws ExecutionException, TimeoutException
      {
          return getUninterruptibly(result.chain(), time, unit);
      }
  
      public static <V> V getUninterruptibly(AsyncChain<V> chain, long time, TimeUnit unit) throws ExecutionException, TimeoutException
      {
          boolean interrupted = false;
          try
          {
              while (true)
              {
                  try
                  {
                      return getBlocking(chain, time, unit);
                  }
                  catch (InterruptedException e)
                  {
                      interrupted = true;
                  }
              }
          }
          finally
          {
              if (interrupted)
                  Thread.currentThread().interrupt();
          }
      }
  
      public static <V> V getUnchecked(AsyncResult<V> result)
      {
          return getUnchecked(result.chain());
      }
  
      public static <V> V getUnchecked(AsyncChain<V> chain)
      {
          try
          {
              return getUninterruptibly(chain);
          }
          catch (ExecutionException e)
          {
              throw new RuntimeException(e);
          }
      }
  
      public static void awaitUninterruptibly(AsyncResult<?> result)
      {
          awaitUninterruptibly(result.chain());
      }
  
      public static void awaitUninterruptibly(AsyncChain<?> chain)
      {
          try
          {
              getUninterruptibly(chain);
          }
          catch (ExecutionException e)
          {
              // ignore
          }
      }
  
      public static void awaitUninterruptiblyAndRethrow(AsyncChain<?> chain)
      {
          try
          {
              getUninterruptibly(chain);
          }
          catch (ExecutionException e)
          {
              throw new RuntimeException(e.getCause());
          }
      }
  }
  