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.simulator.systems;
  
  import org.apache.cassandra.utils.Shared;
  import org.apache.cassandra.utils.concurrent.UncheckedInterruptedException;
  
  import static org.apache.cassandra.utils.Shared.Scope.SIMULATION;
  
  /**
   * An abstraction for the simulation to permit the main scheduling thread
   * to trigger a simulation thread and then wait synchronously for the end
   * of this part of its simulation, i.e. until its next wait is intercepted.
   *
   * This permits more efficient scheduling, by (often) ensuring the simulated
   * thread and the scheduling thread do not run simultaneously.
   */
  @Shared(scope = SIMULATION)
  public interface NotifyThreadPaused
  {
      void notifyThreadPaused();
  
      class AwaitPaused implements NotifyThreadPaused
      {
          final Object monitor;
          boolean isDone;
          AwaitPaused(Object monitor) { this.monitor = monitor; }
          AwaitPaused() { this.monitor = this; }
  
          @Override
          public void notifyThreadPaused()
          {
              synchronized (monitor)
              {
                  isDone = true;
                  monitor.notifyAll();
              }
          }
  
          public void awaitPause()
          {
              try
              {
                  synchronized (monitor)
                  {
                      while (!isDone)
                          monitor.wait();
                  }
              }
              catch (InterruptedException ie)
              {
                  throw new UncheckedInterruptedException(ie);
              }
          }
      }
  
  }
  