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.service.accord;
  
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.locks.Condition;
  import java.util.concurrent.locks.ReentrantLock;
  import java.util.function.IntFunction;
  
  import accord.api.Agent;
  
  // WARNING: experimental - needs more testing
  class AccordExecutorSemiSyncSubmit extends AccordExecutorAbstractSemiSyncSubmit
  {
      private final AccordExecutorLoops loops;
      private final ReentrantLock lock;
      private final Condition hasWork;
  
      public AccordExecutorSemiSyncSubmit(int executorId, Mode mode, int threads, IntFunction<String> name, Agent agent)
      {
          this(new ReentrantLock(), executorId, mode, threads, name, agent);
      }
  
      private AccordExecutorSemiSyncSubmit(ReentrantLock lock, int executorId, Mode mode, int threads, IntFunction<String> name, Agent agent)
      {
          super(lock, executorId, agent);
          this.lock = lock;
          this.hasWork = lock.newCondition();
          this.loops = new AccordExecutorLoops(mode, threads, name, this::task);
      }
  
      @Override
      void awaitExclusive() throws InterruptedException
      {
          if (submitted.isEmpty())
              hasWork.await();
      }
  
      @Override
      AccordExecutorLoops loops()
      {
          return loops;
      }
  
      @Override
      boolean isInLoop()
      {
          return loops.isInLoop();
      }
  
      @Override
      void notifyWork()
      {
          // we check running both sides of tryLock for ordering guarantees
          boolean hadRunning = isHeldByExecutor;
          if (lock.tryLock())
          {
              try { hasWork.signal(); }
              finally { lock.unlock(); }
          }
          else if (!hadRunning || !isHeldByExecutor)
          {
              lock.lock();
              try { hasWork.signal(); }
              finally { lock.unlock(); }
          }
      }
      
      @Override
      void notifyWorkExclusive()
      {
          hasWork.signal();
      }
  
      @Override
      boolean isOwningThread()
      {
          return lock.isHeldByCurrentThread();
      }
  
      @Override
      public boolean isTerminated()
      {
          return loops.isTerminated();
      }
  
      @Override
      public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException
      {
          return loops.awaitTermination(timeout, unit);
      }
  }
  