content: /*
   * Copyright (C) 2015 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.
   */
  
  import dalvik.system.VMDebug;
  import java.io.IOException;
  import java.lang.ref.PhantomReference;
  import java.lang.ref.ReferenceQueue;
  import java.lang.ref.SoftReference;
  import java.lang.ref.WeakReference;
  import org.apache.harmony.dalvik.ddmc.DdmVmInternal;
  
  /**
   * Program used to create a heap dump for test purposes.
   */
  public class Main {
    // Keep a reference to the DumpedStuff instance so that it is not garbage
    // collected before we take the heap dump.
    public static DumpedStuff stuff;
  
    public static class ObjectTree {
      public ObjectTree left;
      public ObjectTree right;
  
      public ObjectTree(ObjectTree left, ObjectTree right) {
        this.left = left;
        this.right = right;
      }
    }
  
    public static class AddedObject {
    }
  
    public static class RemovedObject {
    }
  
    public static class UnchangedObject {
    }
  
    public static class ModifiedObject {
      public int value;
      public String modifiedRefField;
      public String unmodifiedRefField;
    }
  
    public static class StackSmasher {
      public StackSmasher child;
    }
  
    // We will take a heap dump that includes a single instance of this
    // DumpedStuff class. Objects stored as fields in this class can be easily
    // found in the hprof dump by searching for the instance of the DumpedStuff
    // class and reading the desired field.
    public static class DumpedStuff {
      public String basicString = "hello, world";
      public String nonAscii = "Sigma (Ʃ) is not ASCII";
      public String embeddedZero = "embedded\0...";  // Non-ASCII for string compression purposes.
      public char[] charArray = "char thing".toCharArray();
      public String nullString = null;
      public Object anObject = new Object();
      public ReferenceQueue<Object> referenceQueue = new ReferenceQueue<Object>();
      public PhantomReference aPhantomReference = new PhantomReference(anObject, referenceQueue);
      public WeakReference aWeakReference = new WeakReference(anObject, referenceQueue);
      public WeakReference aNullReferentReference = new WeakReference(null, referenceQueue);
      public SoftReference aSoftReference = new SoftReference(new Object());
      public byte[] bigArray;
      public ObjectTree[] gcPathArray = new ObjectTree[]{null, null,
        new ObjectTree(
            new ObjectTree(null, new ObjectTree(null, null)),
            new ObjectTree(null, null)),
        null};
      public Object[] basicStringRef;
      public AddedObject addedObject;
      public UnchangedObject unchangedObject = new UnchangedObject();
      public RemovedObject removedObject;
      public ModifiedObject modifiedObject;
      public StackSmasher stackSmasher;
      public StackSmasher stackSmasherAdded;
      public static String modifiedStaticField;
      public int[] modifiedArray;
  
      DumpedStuff(boolean baseline) {
        int N = baseline ? 400000 : 1000000;
        bigArray = new byte[N];
        for (int i = 0; i < N; i++) {
          bigArray[i] = (byte)((i*i) & 0xFF);
        }
  
        addedObject = baseline ? null : new AddedObject();
        removedObject = baseline ? new RemovedObject() : null;
        modifiedObject = new ModifiedObject();
        modifiedObject.value = baseline ? 5 : 8;
        modifiedObject.modifiedRefField = baseline ? "A1" : "A2";
        modifiedObject.unmodifiedRefField = "B";
        modifiedStaticField = baseline ? "C1" : "C2";
        modifiedArray = baseline ? new int[]{0,1,2,3} : new int[]{3,1,2,0};
  
        // Deep matching dominator trees shouldn't smash the stack when we try
        // to diff them. Make some deep dominator trees to help test it.
        for (int i = 0; i < 10000; i++) {
          StackSmasher smasher = new StackSmasher();
          smasher.child = stackSmasher;
          stackSmasher = smasher;
  
          if (!baseline) {
            smasher = new StackSmasher();
            smasher.child = stackSmasherAdded;
            stackSmasherAdded = smasher;
          }
        }
  
        gcPathArray[2].right.left = gcPathArray[2].left.right;
      }
    }
  
    public static void main(String[] args) throws IOException {
      if (args.length < 1) {
        System.err.println("no output file specified");
        return;
      }
      String file = args[0];
  
      // If a --base argument is provided, it means we should generate a
      // baseline hprof file suitable for using in testing diff.
      boolean baseline = args.length > 1 && args[1].equals("--base");
  
      // Enable allocation tracking so we get stack traces in the heap dump.
      DdmVmInternal.enableRecentAllocations(true);
  
      // Allocate the instance of DumpedStuff.
      stuff = new DumpedStuff(baseline);
  
      // Create a bunch of unreachable objects pointing to basicString for the
      // reverseReferencesAreNotUnreachable test
      for (int i = 0; i < 100; i++) {
        stuff.basicStringRef = new Object[]{stuff.basicString};
      }
  
      // Take a heap dump that will include that instance of DumpedStuff.
      System.err.println("Dumping hprof data to " + file);
      VMDebug.dumpHprofData(file);
    }
  }
  