content: /*
   * Copyright (C) 2016 The Android Open Source Project
   *
   * 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
   *
   *      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.
   */
  
  public class RacyMisbehavingLoader extends DefiningLoader {
      static {
          // For JVM, register as parallel capable.
          // Android treats all class loaders as parallel capable and makes this a no-op.
          registerAsParallelCapable();
      }
  
      private Object lock = new Object();
      private int index = 0;
      private int count;
      private boolean throw_error;
  
      private DefiningLoader[] defining_loaders;
  
      public RacyMisbehavingLoader(ClassLoader parent, int count, boolean throw_error) {
          super(parent);
          this.count = count;
          this.throw_error = throw_error;
          defining_loaders = new DefiningLoader[2];
          for (int i = 0; i != defining_loaders.length; ++i) {
              defining_loaders[i] = new DefiningLoader(parent);
          }
      }
  
      public void reportAfterLoading() {
          synchronized (lock) {
              ++index;
              if (index == 2 * count) {
                  lock.notifyAll();
              }
          }
      }
  
      protected Class<?> findClass(String name) throws ClassNotFoundException
      {
          if (name.equals("Test")) {
              throw new Error("Unexpected RacyLoader.findClass(\"" + name + "\")");
          }
          return super.findClass(name);
      }
  
      protected Class<?> loadClass(String name, boolean resolve)
          throws ClassNotFoundException
      {
          if (name.equals("Test")) {
              int my_index = syncWithOtherInstances(count);
              Class<?> result;
              if ((my_index & 1) == 0) {
                // Do not delay loading the correct class.
                result = defining_loaders[my_index & 1].loadClass(name, resolve);
              } else {
                // Delay loading the wrong class.
                syncWithOtherInstances(2 * count);
                if (throw_error) {
                  throw new Error("RacyMisbehavingLoader throw_error=true");
                }
                result = defining_loaders[my_index & 1].loadClass("Test3", resolve);
              }
              return result;
          }
          return super.loadClass(name, resolve);
      }
  
      private int syncWithOtherInstances(int limit) {
          int my_index;
          synchronized (lock) {
              my_index = index;
              ++index;
              if (index != limit) {
                  do {
                      try {
                          lock.wait();
                      } catch (InterruptedException ie) {
                          throw new Error(ie);
                      }
                  } while (index < limit);
              } else {
                  lock.notifyAll();
              }
          }
          return my_index;
      }
  }
  