content: /*
   * Copyright 2023 Adaptive Financial Consulting Limited.
   *
   * Licensed 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
   *
   * https://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 io.aeron.benchmarks.aeron;
  
  import org.agrona.CloseHelper;
  
  import java.util.concurrent.locks.ReentrantLock;
  import java.util.function.Supplier;
  
  import static java.util.Objects.requireNonNull;
  
  public final class Component<T extends AutoCloseable> implements AutoCloseable
  {
      private final ReentrantLock lock = new ReentrantLock();
      private final Supplier<T> factory;
      private T resource;
  
      public Component(final Supplier<T> factory)
      {
          this.factory = requireNonNull(factory, "factory must not be null");
      }
  
      public Component<T> start()
      {
          lock.lock();
          try
          {
              if (resource != null)
              {
                  throw new IllegalStateException("already started");
              }
  
              resource = factory.get();
  
              return this;
          }
          finally
          {
              lock.unlock();
          }
      }
  
      public void close()
      {
          lock.lock();
          try
          {
              if (resource != null)
              {
                  try
                  {
                      CloseHelper.close(resource);
                  }
                  finally
                  {
                      resource = null;
                  }
              }
          }
          finally
          {
              lock.unlock();
          }
      }
  }
  