test/1974-resize-array/src/art/Test1974.java - LeafOS-Project/android_art - Gitiles

 /*
  * Copyright (C) 2019 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.
  */

 package art;

 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.concurrent.CountDownLatch;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Supplier;

 public class Test1974 {

   public static final boolean DEBUG = false;

   public static int[] static_field = new int[] {1, 2, 3};
   public static Object[] static_field_ref = new String[] {"a", "b", "c"};

   public static final class InstanceClass {
     public int[] instance_field = new int[] {1, 2, 3};
     public Object[] self_ref;

     public InstanceClass() {
       self_ref = new Object[] {null, "A", "B", "C"};
       self_ref[0] = self_ref;
     }
   }

   static InstanceClass theInstanceClass;
   static InstanceClass theOtherInstanceClass;

   static {
     theInstanceClass = new InstanceClass();
     theOtherInstanceClass = new InstanceClass();
     theOtherInstanceClass.instance_field = theInstanceClass.instance_field;
     theOtherInstanceClass.self_ref = theInstanceClass.self_ref;
   }

   public static void DbgPrintln(String s) {
     if (DEBUG) {
       System.out.println(s);
     }
   }

   public interface ThrowRunnable extends Runnable {
     public default void run() {
       try {
         throwRun();
       } catch (Exception e) {
         throw new Error("Exception in runner!", e);
       }
     }

     public void throwRun() throws Exception;
   }

   public static void runAsThread(ThrowRunnable r) throws Exception {
     Thread t = new Thread(r);
     t.start();
     t.join();
     System.out.println("");
   }

   public static void runInstance() {
     System.out.println("Test instance");
     DbgPrintln("Pre hash: " + theInstanceClass.instance_field.hashCode());
     System.out.println(
         "val is: " + Arrays.toString(theInstanceClass.instance_field) + " resize +3");
     ResizeArray(() -> theInstanceClass.instance_field, theInstanceClass.instance_field.length + 5);
     System.out.println("val is: " + Arrays.toString(theInstanceClass.instance_field));
     DbgPrintln("Post hash: " + theInstanceClass.instance_field.hashCode());
     System.out.println(
         "Same value? " + (theInstanceClass.instance_field == theOtherInstanceClass.instance_field));
   }

   public static void runHashMap() {
     System.out.println("Test HashMap");
     HashMap<byte[], Comparable> map = new HashMap();
     Comparable the_value = "THE VALUE";
     Supplier<byte[]> get_the_value =
         () ->
             map.entrySet().stream()
                 .filter((x) -> x.getValue().equals(the_value))
                 .findFirst()
                 .get()
                 .getKey();
     map.put(new byte[] {1, 2, 3, 4}, the_value);
     map.put(new byte[] {1, 2, 3, 4}, "Other Value");
     map.put(new byte[] {1, 4}, "Third value");
     System.out.println("val is: " + Arrays.toString(get_the_value.get()) + " resize +3");
     System.out.print("Map is: ");
     map.entrySet().stream()
         .sorted((x, y) -> x.getValue().compareTo(y.getValue()))
         .forEach(
             (e) -> {
               System.out.print("(" + Arrays.toString(e.getKey()) + "->" + e.getValue() + "), ");
             });
     System.out.println();
     ResizeArray(get_the_value, 7);
     System.out.println("val is: " + Arrays.toString(get_the_value.get()));
     System.out.print("Map is: ");
     map.entrySet().stream()
         .sorted((x, y) -> x.getValue().compareTo(y.getValue()))
         .forEach(
             (e) -> {
               System.out.print("(" + Arrays.toString(e.getKey()) + "->" + e.getValue() + "), ");
             });
     System.out.println();
   }

   public static void runWeakReference() {
     System.out.println("Test j.l.r.WeakReference");
     String[] arr = new String[] {"weak", "ref"};
     WeakReference<String[]> wr = new WeakReference(arr);
     DbgPrintln("Pre hash: " + wr.get().hashCode());
     System.out.println("val is: " + Arrays.toString(wr.get()) + " resize +3");
     ResizeArray(wr::get, wr.get().length + 5);
     System.out.println("val is: " + Arrays.toString(wr.get()));
     DbgPrintln("Post hash: " + wr.get().hashCode());
     System.out.println("Same value? " + (wr.get() == arr));
   }

   public static void runInstanceSelfRef() {
     System.out.println("Test instance self-ref");
     DbgPrintln("Pre hash: " + Integer.toHexString(theInstanceClass.self_ref.hashCode()));
     String pre_to_string = theInstanceClass.self_ref.toString();
     System.out.println(
         "val is: "
             + Arrays.toString(theInstanceClass.self_ref).replace(pre_to_string, "<SELF REF>")
             + " resize +5 item 0 is "
             + Arrays.toString((Object[]) theInstanceClass.self_ref[0])
                 .replace(pre_to_string, "<SELF REF>"));
     ResizeArray(() -> theInstanceClass.self_ref, theInstanceClass.self_ref.length + 5);
     System.out.println(
         "val is: "
             + Arrays.toString(theInstanceClass.self_ref).replace(pre_to_string, "<SELF REF>"));
     System.out.println(
         "val is: "
             + Arrays.toString((Object[]) theInstanceClass.self_ref[0])
                 .replace(pre_to_string, "<SELF REF>"));
     DbgPrintln("Post hash: " + Integer.toHexString(theInstanceClass.self_ref.hashCode()));
     System.out.println(
         "Same value? " + (theInstanceClass.self_ref == theOtherInstanceClass.self_ref));
     System.out.println(
         "Same structure? " + (theInstanceClass.self_ref == theInstanceClass.self_ref[0]));
     System.out.println(
         "Same inner-structure? "
             + (theInstanceClass.self_ref[0] == ((Object[]) theInstanceClass.self_ref[0])[0]));
   }

   public static void runInstanceSelfRefSmall() {
     System.out.println("Test instance self-ref smaller");
     DbgPrintln("Pre hash: " + Integer.toHexString(theInstanceClass.self_ref.hashCode()));
     String pre_to_string = theInstanceClass.self_ref.toString();
     System.out.println(
         "val is: "
             + Arrays.toString(theInstanceClass.self_ref).replace(pre_to_string, "<SELF REF>")
             + " resize -7 item 0 is "
             + Arrays.toString((Object[]) theInstanceClass.self_ref[0])
                 .replace(pre_to_string, "<SELF REF>"));
     ResizeArray(() -> theInstanceClass.self_ref, theInstanceClass.self_ref.length - 7);
     System.out.println(
         "val is: "
             + Arrays.toString(theInstanceClass.self_ref).replace(pre_to_string, "<SELF REF>"));
     System.out.println(
         "val is: "
             + Arrays.toString((Object[]) theInstanceClass.self_ref[0])
                 .replace(pre_to_string, "<SELF REF>"));
     DbgPrintln("Post hash: " + Integer.toHexString(theInstanceClass.self_ref.hashCode()));
     System.out.println(
         "Same value? " + (theInstanceClass.self_ref == theOtherInstanceClass.self_ref));
     System.out.println(
         "Same structure? " + (theInstanceClass.self_ref == theInstanceClass.self_ref[0]));
     System.out.println(
         "Same inner-structure? "
             + (theInstanceClass.self_ref[0] == ((Object[]) theInstanceClass.self_ref[0])[0]));
   }

   public static void runLocal() throws Exception {
     final int[] arr_loc = new int[] {2, 3, 4};
     int[] arr_loc_2 = arr_loc;

     System.out.println("Test local");
     DbgPrintln("Pre hash: " + arr_loc.hashCode());
     System.out.println("val is: " + Arrays.toString(arr_loc) + " resize +5");
     ResizeArray(() -> arr_loc, arr_loc.length + 5);
     System.out.println("val is: " + Arrays.toString(arr_loc));
     DbgPrintln("Post hash: " + arr_loc.hashCode());
     System.out.println("Same value? " + (arr_loc == arr_loc_2));
   }

   public static void runLocalSmall() throws Exception {
     final int[] arr_loc = new int[] {1, 2, 3, 4, 5};
     int[] arr_loc_2 = arr_loc;

     System.out.println("Test local smaller");
     DbgPrintln("Pre hash: " + arr_loc.hashCode());
     System.out.println("val is: " + Arrays.toString(arr_loc) + " resize -2");
     ResizeArray(() -> arr_loc, arr_loc.length - 2);
     System.out.println("val is: " + Arrays.toString(arr_loc));
     DbgPrintln("Post hash: " + arr_loc.hashCode());
     System.out.println("Same value? " + (arr_loc == arr_loc_2));
   }

   public static void runMultiThreadLocal() throws Exception {
     final CountDownLatch cdl = new CountDownLatch(1);
     final CountDownLatch start_cdl = new CountDownLatch(2);
     final Supplier<Object[]> getArr =
         new Supplier<Object[]>() {
           public final Object[] arr = new Object[] {"1", "2", "3"};

           public Object[] get() {
             return arr;
           }
         };
     final ArrayList<String> msg1 = new ArrayList();
     final ArrayList<String> msg2 = new ArrayList();
     final Consumer<String> print1 =
         (String s) -> {
           msg1.add(s);
         };
     final Consumer<String> print2 =
         (String s) -> {
           msg2.add(s);
         };
     Function<Consumer<String>, Runnable> r =
         (final Consumer<String> c) ->
             () -> {
               c.accept("Test local multi-thread");
               Object[] arr_loc = getArr.get();
               Object[] arr_loc_2 = getArr.get();

               DbgPrintln("Pre hash: " + arr_loc.hashCode());
               c.accept("val is: " + Arrays.toString(arr_loc) + " resize -2");

               try {
                 start_cdl.countDown();
                 cdl.await();
               } catch (Exception e) {
                 throw new Error("failed await", e);
               }
               c.accept("val is: " + Arrays.toString(arr_loc));
               DbgPrintln("Post hash: " + arr_loc.hashCode());
               c.accept("Same value? " + (arr_loc == arr_loc_2));
             };
     Thread t1 = new Thread(r.apply(print1));
     Thread t2 = new Thread(r.apply(print2));
     t1.start();
     t2.start();
     start_cdl.await();
     ResizeArray(getArr, 1);
     cdl.countDown();
     t1.join();
     t2.join();
     for (String s : msg1) {
       System.out.println("T1: " + s);
     }
     for (String s : msg2) {
       System.out.println("T2: " + s);
     }
   }

   public static void runWithLocks() throws Exception {
     final CountDownLatch cdl = new CountDownLatch(1);
     final CountDownLatch start_cdl = new CountDownLatch(2);
     final CountDownLatch waiter_start_cdl = new CountDownLatch(1);
     final Supplier<Object[]> getArr =
         new Supplier<Object[]>() {
           public final Object[] arr = new Object[] {"A", "2", "C"};

           public Object[] get() {
             return arr;
           }
         };
     // basic order of operations noted above each line.
     // Waiter runs to the 'wait' then t1 runs to the cdl.await, then current thread runs.
     Runnable r =
         () -> {
           System.out.println("Test locks");
           Object[] arr_loc = getArr.get();
           Object[] arr_loc_2 = getArr.get();

           DbgPrintln("Pre hash: " + arr_loc.hashCode());
           System.out.println("val is: " + Arrays.toString(arr_loc) + " resize -2");

           try {
             // OP 1
             waiter_start_cdl.await();
             // OP 6
             synchronized (arr_loc) {
               // OP 7
               synchronized (arr_loc_2) {
                 // OP 8
                 start_cdl.countDown();
                 // OP 9
                 cdl.await();
                 // OP 13
               }
             }
           } catch (Exception e) {
             throw new Error("failed await", e);
           }
           System.out.println("val is: " + Arrays.toString(arr_loc));
           DbgPrintln("Post hash: " + arr_loc.hashCode());
           System.out.println("Same value? " + (arr_loc == arr_loc_2));
         };
     Thread t1 = new Thread(r);
     Thread waiter =
         new Thread(
             () -> {
               try {
                 Object a = getArr.get();
                 // OP 2
                 synchronized (a) {
                   // OP 3
                   waiter_start_cdl.countDown();
                   // OP 4
                   start_cdl.countDown();
                   // OP 5
                   a.wait();
                   // OP 15
                 }
               } catch (Exception e) {
                 throw new Error("Failed wait!", e);
               }
             });
     waiter.start();
     t1.start();
     // OP 10
     start_cdl.await();
     // OP 11
     ResizeArray(getArr, 1);
     // OP 12
     cdl.countDown();
     // OP 14
     synchronized (getArr.get()) {
       // Make sure thread wakes up and has the right lock.
       getArr.get().notifyAll();
     }
     waiter.join();
     t1.join();
     // Make sure other threads can still lock it.
     synchronized (getArr.get()) {
     }
     System.out.println("Locks seem to all work.");
   }

   public static void runWithJniGlobal() throws Exception {
     Object[] arr = new Object[] {"1", "11", "111"};
     final long globalID = GetGlobalJniRef(arr);
     System.out.println("Test jni-ref");
     DbgPrintln("Pre hash: " + ReadJniRef(globalID).hashCode());
     System.out.println(
         "val is: " + Arrays.toString((Object[]) ReadJniRef(globalID)) + " resize +5");
     ResizeArray(() -> ReadJniRef(globalID), ((Object[]) ReadJniRef(globalID)).length + 5);
     System.out.println("val is: " + Arrays.toString((Object[]) ReadJniRef(globalID)));
     DbgPrintln("Post hash: " + ReadJniRef(globalID).hashCode());
     System.out.println("Same value? " + (ReadJniRef(globalID) == arr));
   }

   public static void runWithJniWeakGlobal() throws Exception {
     Object[] arr = new Object[] {"2", "22", "222"};
     final long globalID = GetWeakGlobalJniRef(arr);
     System.out.println("Test weak jni-ref");
     DbgPrintln("Pre hash: " + ReadJniRef(globalID).hashCode());
     System.out.println(
         "val is: " + Arrays.toString((Object[]) ReadJniRef(globalID)) + " resize +5");
     ResizeArray(() -> ReadJniRef(globalID), ((Object[]) ReadJniRef(globalID)).length + 5);
     System.out.println("val is: " + Arrays.toString((Object[]) ReadJniRef(globalID)));
     DbgPrintln("Post hash: " + ReadJniRef(globalID).hashCode());
     System.out.println("Same value? " + (ReadJniRef(globalID) == arr));
     if (ReadJniRef(globalID) != arr) {
       throw new Error("Didn't update weak global!");
     }
   }

   public static void runWithJniLocals() throws Exception {
     final Object[] arr = new Object[] {"3", "32", "322"};
     System.out.println("Test jni local ref");
     Consumer<Object> checker = (o) -> System.out.println("Same value? " + (o == arr));
     Consumer<Object> printer =
         (o) -> System.out.println("val is: " + Arrays.toString((Object[]) o));
     Runnable resize =
         () -> {
           System.out.println("Resize +4");
           ResizeArray(() -> arr, arr.length + 4);
         };
     runNativeTest(arr, resize, printer, checker);
   }

   public static native void runNativeTest(
       Object[] arr, Runnable resize, Consumer<Object> printer, Consumer<Object> checker);

   public static void runWithJvmtiTags() throws Exception {
     Object[] arr = new Object[] {"3", "33", "333"};
     long globalID = 333_333_333l;
     Main.setTag(arr, globalID);
     System.out.println("Test jvmti-tags");
     DbgPrintln("Pre hash: " + arr.hashCode());
     System.out.println(
         "val is: " + Arrays.deepToString(GetObjectsWithTag(globalID)) + " resize +5");
     ResizeArray(() -> arr, arr.length + 5);
     Object[] after_tagged_obj = GetObjectsWithTag(globalID);
     System.out.println("val is: " + Arrays.deepToString(GetObjectsWithTag(globalID)));
     DbgPrintln("Post hash: " + after_tagged_obj[0].hashCode());
     System.out.println("Same value? " + (after_tagged_obj[0] == arr));
   }

   public static void runWithJvmtiTagsObsolete() throws Exception {
     Object[] arr = new Object[] {"4", "44", "444"};
     long globalID = 444_444_444l;
     System.out.println("Test jvmti-tags with obsolete");
     Main.setTag(arr, globalID);
     StartCollectFrees();
     StartAssignObsoleteIncrementedId();
     DbgPrintln("Pre hash: " + arr.hashCode());
     System.out.println(
         "val is: " + Arrays.deepToString(GetObjectsWithTag(globalID)) + " resize +5");
     ResizeArray(() -> arr, arr.length + 5);
     Object[] after_tagged_obj = GetObjectsWithTag(globalID);
     Object[] obsolete_tagged_obj = GetObjectsWithTag(globalID + 1);
     System.out.println("val is: " + Arrays.deepToString(GetObjectsWithTag(globalID)));
     EndAssignObsoleteIncrementedId();
     long[] obsoletes_freed = CollectFreedTags();
     DbgPrintln("Post hash: " + after_tagged_obj[0].hashCode());
     System.out.println("Same value? " + (after_tagged_obj[0] == arr));
     if (obsolete_tagged_obj.length >= 1) {
       DbgPrintln("Found objects with obsolete tag: " + Arrays.deepToString(obsolete_tagged_obj));
       boolean bad = false;
       if (obsolete_tagged_obj.length != 1) {
         System.out.println(
             "Found obsolete tag'd objects: "
                 + Arrays.deepHashCode(obsolete_tagged_obj)
                 + " but only expected one!");
         bad = true;
       }
       if (!Arrays.deepEquals(
           Arrays.copyOf(arr, ((Object[]) obsolete_tagged_obj[0]).length),
           (Object[]) obsolete_tagged_obj[0])) {
         System.out.println("Obsolete array was unexpectedly different than non-obsolete one!");
         bad = true;
       }
       if (!Arrays.stream(obsoletes_freed).anyMatch((l) -> l == globalID + 1)) {
         DbgPrintln("Didn't see a free of the obsolete id");
       }
       if (!bad) {
         System.out.println("Everything looks good WRT obsolete object!");
       }
     } else {
       if (!Arrays.stream(obsoletes_freed).anyMatch((l) -> l == globalID + 1)) {
         System.out.println("Didn't see a free of the obsolete id");
       } else {
         DbgPrintln("Saw a free of obsolete id!");
         System.out.println("Everything looks good WRT obsolete object!");
       }
     }
   }

   public static void run() throws Exception {
     // Simple
     runAsThread(Test1974::runInstance);

     // HashMap
     runAsThread(Test1974::runHashMap);

     // j.l.ref.WeakReference
     runAsThread(Test1974::runWeakReference);

     // Self-referential arrays.
     runAsThread(Test1974::runInstanceSelfRef);
     runAsThread(Test1974::runInstanceSelfRefSmall);

     // Local variables simple
     runAsThread(Test1974::runLocal);
     runAsThread(Test1974::runLocalSmall);

     // multiple threads local variables
     runAsThread(Test1974::runMultiThreadLocal);

     // using as monitors and waiting
     runAsThread(Test1974::runWithLocks);

     // Basic jni global refs
     runAsThread(Test1974::runWithJniGlobal);

     // Basic jni weak global refs
     runAsThread(Test1974::runWithJniWeakGlobal);

     // Basic JNI local refs
     runAsThread(Test1974::runWithJniLocals);

     // Basic jvmti tags
     runAsThread(Test1974::runWithJvmtiTags);

     // Grab obsolete reference using tags/detect free
     runAsThread(Test1974::runWithJvmtiTagsObsolete);
   }

   // Use a supplier so that we don't have to have a local ref to the resized
   // array if we don't want it
   public static native <T> void ResizeArray(Supplier<T> arr, int new_size);

   public static native <T> long GetGlobalJniRef(T t);

   public static native <T> long GetWeakGlobalJniRef(T t);

   public static native <T> T ReadJniRef(long t);

   public static native Object[] GetObjectsWithTag(long tag);

   public static native void StartCollectFrees();

   public static native void StartAssignObsoleteIncrementedId();

   public static native void EndAssignObsoleteIncrementedId();

   public static native long[] CollectFreedTags();
 }
	/*
	* Copyright (C) 2019 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.
	*/

	package art;

	import java.lang.ref.WeakReference;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.HashMap;
	import java.util.concurrent.CountDownLatch;
	import java.util.function.Consumer;
	import java.util.function.Function;
	import java.util.function.Supplier;

	public class Test1974 {

	public static final boolean DEBUG = false;

	public static int[] static_field = new int[] {1, 2, 3};
	public static Object[] static_field_ref = new String[] {"a", "b", "c"};

	public static final class InstanceClass {
	public int[] instance_field = new int[] {1, 2, 3};
	public Object[] self_ref;

	public InstanceClass() {
	self_ref = new Object[] {null, "A", "B", "C"};
	self_ref[0] = self_ref;
	}
	}

	static InstanceClass theInstanceClass;
	static InstanceClass theOtherInstanceClass;

	static {
	theInstanceClass = new InstanceClass();
	theOtherInstanceClass = new InstanceClass();
	theOtherInstanceClass.instance_field = theInstanceClass.instance_field;
	theOtherInstanceClass.self_ref = theInstanceClass.self_ref;
	}

	public static void DbgPrintln(String s) {
	if (DEBUG) {
	System.out.println(s);
	}
	}

	public interface ThrowRunnable extends Runnable {
	public default void run() {
	try {
	throwRun();
	} catch (Exception e) {
	throw new Error("Exception in runner!", e);
	}
	}

	public void throwRun() throws Exception;
	}

	public static void runAsThread(ThrowRunnable r) throws Exception {
	Thread t = new Thread(r);
	t.start();
	t.join();
	System.out.println("");
	}

	public static void runInstance() {
	System.out.println("Test instance");
	DbgPrintln("Pre hash: " + theInstanceClass.instance_field.hashCode());
	System.out.println(
	"val is: " + Arrays.toString(theInstanceClass.instance_field) + " resize +3");
	ResizeArray(() -> theInstanceClass.instance_field, theInstanceClass.instance_field.length + 5);
	System.out.println("val is: " + Arrays.toString(theInstanceClass.instance_field));
	DbgPrintln("Post hash: " + theInstanceClass.instance_field.hashCode());
	System.out.println(
	"Same value? " + (theInstanceClass.instance_field == theOtherInstanceClass.instance_field));
	}

	public static void runHashMap() {
	System.out.println("Test HashMap");
	HashMap<byte[], Comparable> map = new HashMap();
	Comparable the_value = "THE VALUE";
	Supplier<byte[]> get_the_value =
	() ->
	map.entrySet().stream()
	.filter((x) -> x.getValue().equals(the_value))
	.findFirst()
	.get()
	.getKey();
	map.put(new byte[] {1, 2, 3, 4}, the_value);
	map.put(new byte[] {1, 2, 3, 4}, "Other Value");
	map.put(new byte[] {1, 4}, "Third value");
	System.out.println("val is: " + Arrays.toString(get_the_value.get()) + " resize +3");
	System.out.print("Map is: ");
	map.entrySet().stream()
	.sorted((x, y) -> x.getValue().compareTo(y.getValue()))
	.forEach(
	(e) -> {
	System.out.print("(" + Arrays.toString(e.getKey()) + "->" + e.getValue() + "), ");
	});
	System.out.println();
	ResizeArray(get_the_value, 7);
	System.out.println("val is: " + Arrays.toString(get_the_value.get()));
	System.out.print("Map is: ");
	map.entrySet().stream()
	.sorted((x, y) -> x.getValue().compareTo(y.getValue()))
	.forEach(
	(e) -> {
	System.out.print("(" + Arrays.toString(e.getKey()) + "->" + e.getValue() + "), ");
	});
	System.out.println();
	}

	public static void runWeakReference() {
	System.out.println("Test j.l.r.WeakReference");
	String[] arr = new String[] {"weak", "ref"};
	WeakReference<String[]> wr = new WeakReference(arr);
	DbgPrintln("Pre hash: " + wr.get().hashCode());
	System.out.println("val is: " + Arrays.toString(wr.get()) + " resize +3");
	ResizeArray(wr::get, wr.get().length + 5);
	System.out.println("val is: " + Arrays.toString(wr.get()));
	DbgPrintln("Post hash: " + wr.get().hashCode());
	System.out.println("Same value? " + (wr.get() == arr));
	}

	public static void runInstanceSelfRef() {
	System.out.println("Test instance self-ref");
	DbgPrintln("Pre hash: " + Integer.toHexString(theInstanceClass.self_ref.hashCode()));
	String pre_to_string = theInstanceClass.self_ref.toString();
	System.out.println(
	"val is: "
	+ Arrays.toString(theInstanceClass.self_ref).replace(pre_to_string, "<SELF REF>")
	+ " resize +5 item 0 is "
	+ Arrays.toString((Object[]) theInstanceClass.self_ref[0])
	.replace(pre_to_string, "<SELF REF>"));
	ResizeArray(() -> theInstanceClass.self_ref, theInstanceClass.self_ref.length + 5);
	System.out.println(
	"val is: "
	+ Arrays.toString(theInstanceClass.self_ref).replace(pre_to_string, "<SELF REF>"));
	System.out.println(
	"val is: "
	+ Arrays.toString((Object[]) theInstanceClass.self_ref[0])
	.replace(pre_to_string, "<SELF REF>"));
	DbgPrintln("Post hash: " + Integer.toHexString(theInstanceClass.self_ref.hashCode()));
	System.out.println(
	"Same value? " + (theInstanceClass.self_ref == theOtherInstanceClass.self_ref));
	System.out.println(
	"Same structure? " + (theInstanceClass.self_ref == theInstanceClass.self_ref[0]));
	System.out.println(
	"Same inner-structure? "
	+ (theInstanceClass.self_ref[0] == ((Object[]) theInstanceClass.self_ref[0])[0]));
	}

	public static void runInstanceSelfRefSmall() {
	System.out.println("Test instance self-ref smaller");
	DbgPrintln("Pre hash: " + Integer.toHexString(theInstanceClass.self_ref.hashCode()));
	String pre_to_string = theInstanceClass.self_ref.toString();
	System.out.println(
	"val is: "
	+ Arrays.toString(theInstanceClass.self_ref).replace(pre_to_string, "<SELF REF>")
	+ " resize -7 item 0 is "
	+ Arrays.toString((Object[]) theInstanceClass.self_ref[0])
	.replace(pre_to_string, "<SELF REF>"));
	ResizeArray(() -> theInstanceClass.self_ref, theInstanceClass.self_ref.length - 7);
	System.out.println(
	"val is: "
	+ Arrays.toString(theInstanceClass.self_ref).replace(pre_to_string, "<SELF REF>"));
	System.out.println(
	"val is: "
	+ Arrays.toString((Object[]) theInstanceClass.self_ref[0])
	.replace(pre_to_string, "<SELF REF>"));
	DbgPrintln("Post hash: " + Integer.toHexString(theInstanceClass.self_ref.hashCode()));
	System.out.println(
	"Same value? " + (theInstanceClass.self_ref == theOtherInstanceClass.self_ref));
	System.out.println(
	"Same structure? " + (theInstanceClass.self_ref == theInstanceClass.self_ref[0]));
	System.out.println(
	"Same inner-structure? "
	+ (theInstanceClass.self_ref[0] == ((Object[]) theInstanceClass.self_ref[0])[0]));
	}

	public static void runLocal() throws Exception {
	final int[] arr_loc = new int[] {2, 3, 4};
	int[] arr_loc_2 = arr_loc;

	System.out.println("Test local");
	DbgPrintln("Pre hash: " + arr_loc.hashCode());
	System.out.println("val is: " + Arrays.toString(arr_loc) + " resize +5");
	ResizeArray(() -> arr_loc, arr_loc.length + 5);
	System.out.println("val is: " + Arrays.toString(arr_loc));
	DbgPrintln("Post hash: " + arr_loc.hashCode());
	System.out.println("Same value? " + (arr_loc == arr_loc_2));
	}

	public static void runLocalSmall() throws Exception {
	final int[] arr_loc = new int[] {1, 2, 3, 4, 5};
	int[] arr_loc_2 = arr_loc;

	System.out.println("Test local smaller");
	DbgPrintln("Pre hash: " + arr_loc.hashCode());
	System.out.println("val is: " + Arrays.toString(arr_loc) + " resize -2");
	ResizeArray(() -> arr_loc, arr_loc.length - 2);
	System.out.println("val is: " + Arrays.toString(arr_loc));
	DbgPrintln("Post hash: " + arr_loc.hashCode());
	System.out.println("Same value? " + (arr_loc == arr_loc_2));
	}

	public static void runMultiThreadLocal() throws Exception {
	final CountDownLatch cdl = new CountDownLatch(1);
	final CountDownLatch start_cdl = new CountDownLatch(2);
	final Supplier<Object[]> getArr =
	new Supplier<Object[]>() {
	public final Object[] arr = new Object[] {"1", "2", "3"};

	public Object[] get() {
	return arr;
	}
	};
	final ArrayList<String> msg1 = new ArrayList();
	final ArrayList<String> msg2 = new ArrayList();
	final Consumer<String> print1 =
	(String s) -> {
	msg1.add(s);
	};
	final Consumer<String> print2 =
	(String s) -> {
	msg2.add(s);
	};
	Function<Consumer<String>, Runnable> r =
	(final Consumer<String> c) ->
	() -> {
	c.accept("Test local multi-thread");
	Object[] arr_loc = getArr.get();
	Object[] arr_loc_2 = getArr.get();

	DbgPrintln("Pre hash: " + arr_loc.hashCode());
	c.accept("val is: " + Arrays.toString(arr_loc) + " resize -2");

	try {
	start_cdl.countDown();
	cdl.await();
	} catch (Exception e) {
	throw new Error("failed await", e);
	}
	c.accept("val is: " + Arrays.toString(arr_loc));
	DbgPrintln("Post hash: " + arr_loc.hashCode());
	c.accept("Same value? " + (arr_loc == arr_loc_2));
	};
	Thread t1 = new Thread(r.apply(print1));
	Thread t2 = new Thread(r.apply(print2));
	t1.start();
	t2.start();
	start_cdl.await();
	ResizeArray(getArr, 1);
	cdl.countDown();
	t1.join();
	t2.join();
	for (String s : msg1) {
	System.out.println("T1: " + s);
	}
	for (String s : msg2) {
	System.out.println("T2: " + s);
	}
	}

	public static void runWithLocks() throws Exception {
	final CountDownLatch cdl = new CountDownLatch(1);
	final CountDownLatch start_cdl = new CountDownLatch(2);
	final CountDownLatch waiter_start_cdl = new CountDownLatch(1);
	final Supplier<Object[]> getArr =
	new Supplier<Object[]>() {
	public final Object[] arr = new Object[] {"A", "2", "C"};

	public Object[] get() {
	return arr;
	}
	};
	// basic order of operations noted above each line.
	// Waiter runs to the 'wait' then t1 runs to the cdl.await, then current thread runs.
	Runnable r =
	() -> {
	System.out.println("Test locks");
	Object[] arr_loc = getArr.get();
	Object[] arr_loc_2 = getArr.get();

	DbgPrintln("Pre hash: " + arr_loc.hashCode());
	System.out.println("val is: " + Arrays.toString(arr_loc) + " resize -2");

	try {
	// OP 1
	waiter_start_cdl.await();
	// OP 6
	synchronized (arr_loc) {
	// OP 7
	synchronized (arr_loc_2) {
	// OP 8
	start_cdl.countDown();
	// OP 9
	cdl.await();
	// OP 13
	}
	}
	} catch (Exception e) {
	throw new Error("failed await", e);
	}
	System.out.println("val is: " + Arrays.toString(arr_loc));
	DbgPrintln("Post hash: " + arr_loc.hashCode());
	System.out.println("Same value? " + (arr_loc == arr_loc_2));
	};
	Thread t1 = new Thread(r);
	Thread waiter =
	new Thread(
	() -> {
	try {
	Object a = getArr.get();
	// OP 2
	synchronized (a) {
	// OP 3
	waiter_start_cdl.countDown();
	// OP 4
	start_cdl.countDown();
	// OP 5
	a.wait();
	// OP 15
	}
	} catch (Exception e) {
	throw new Error("Failed wait!", e);
	}
	});
	waiter.start();
	t1.start();
	// OP 10
	start_cdl.await();
	// OP 11
	ResizeArray(getArr, 1);
	// OP 12
	cdl.countDown();
	// OP 14
	synchronized (getArr.get()) {
	// Make sure thread wakes up and has the right lock.
	getArr.get().notifyAll();
	}
	waiter.join();
	t1.join();
	// Make sure other threads can still lock it.
	synchronized (getArr.get()) {
	}
	System.out.println("Locks seem to all work.");
	}

	public static void runWithJniGlobal() throws Exception {
	Object[] arr = new Object[] {"1", "11", "111"};
	final long globalID = GetGlobalJniRef(arr);
	System.out.println("Test jni-ref");
	DbgPrintln("Pre hash: " + ReadJniRef(globalID).hashCode());
	System.out.println(
	"val is: " + Arrays.toString((Object[]) ReadJniRef(globalID)) + " resize +5");
	ResizeArray(() -> ReadJniRef(globalID), ((Object[]) ReadJniRef(globalID)).length + 5);
	System.out.println("val is: " + Arrays.toString((Object[]) ReadJniRef(globalID)));
	DbgPrintln("Post hash: " + ReadJniRef(globalID).hashCode());
	System.out.println("Same value? " + (ReadJniRef(globalID) == arr));
	}

	public static void runWithJniWeakGlobal() throws Exception {
	Object[] arr = new Object[] {"2", "22", "222"};
	final long globalID = GetWeakGlobalJniRef(arr);
	System.out.println("Test weak jni-ref");
	DbgPrintln("Pre hash: " + ReadJniRef(globalID).hashCode());
	System.out.println(
	"val is: " + Arrays.toString((Object[]) ReadJniRef(globalID)) + " resize +5");
	ResizeArray(() -> ReadJniRef(globalID), ((Object[]) ReadJniRef(globalID)).length + 5);
	System.out.println("val is: " + Arrays.toString((Object[]) ReadJniRef(globalID)));
	DbgPrintln("Post hash: " + ReadJniRef(globalID).hashCode());
	System.out.println("Same value? " + (ReadJniRef(globalID) == arr));
	if (ReadJniRef(globalID) != arr) {
	throw new Error("Didn't update weak global!");
	}
	}

	public static void runWithJniLocals() throws Exception {
	final Object[] arr = new Object[] {"3", "32", "322"};
	System.out.println("Test jni local ref");
	Consumer<Object> checker = (o) -> System.out.println("Same value? " + (o == arr));
	Consumer<Object> printer =
	(o) -> System.out.println("val is: " + Arrays.toString((Object[]) o));
	Runnable resize =
	() -> {
	System.out.println("Resize +4");
	ResizeArray(() -> arr, arr.length + 4);
	};
	runNativeTest(arr, resize, printer, checker);
	}

	public static native void runNativeTest(
	Object[] arr, Runnable resize, Consumer<Object> printer, Consumer<Object> checker);

	public static void runWithJvmtiTags() throws Exception {
	Object[] arr = new Object[] {"3", "33", "333"};
	long globalID = 333_333_333l;
	Main.setTag(arr, globalID);
	System.out.println("Test jvmti-tags");
	DbgPrintln("Pre hash: " + arr.hashCode());
	System.out.println(
	"val is: " + Arrays.deepToString(GetObjectsWithTag(globalID)) + " resize +5");
	ResizeArray(() -> arr, arr.length + 5);
	Object[] after_tagged_obj = GetObjectsWithTag(globalID);
	System.out.println("val is: " + Arrays.deepToString(GetObjectsWithTag(globalID)));
	DbgPrintln("Post hash: " + after_tagged_obj[0].hashCode());
	System.out.println("Same value? " + (after_tagged_obj[0] == arr));
	}

	public static void runWithJvmtiTagsObsolete() throws Exception {
	Object[] arr = new Object[] {"4", "44", "444"};
	long globalID = 444_444_444l;
	System.out.println("Test jvmti-tags with obsolete");
	Main.setTag(arr, globalID);
	StartCollectFrees();
	StartAssignObsoleteIncrementedId();
	DbgPrintln("Pre hash: " + arr.hashCode());
	System.out.println(
	"val is: " + Arrays.deepToString(GetObjectsWithTag(globalID)) + " resize +5");
	ResizeArray(() -> arr, arr.length + 5);
	Object[] after_tagged_obj = GetObjectsWithTag(globalID);
	Object[] obsolete_tagged_obj = GetObjectsWithTag(globalID + 1);
	System.out.println("val is: " + Arrays.deepToString(GetObjectsWithTag(globalID)));
	EndAssignObsoleteIncrementedId();
	long[] obsoletes_freed = CollectFreedTags();
	DbgPrintln("Post hash: " + after_tagged_obj[0].hashCode());
	System.out.println("Same value? " + (after_tagged_obj[0] == arr));
	if (obsolete_tagged_obj.length >= 1) {
	DbgPrintln("Found objects with obsolete tag: " + Arrays.deepToString(obsolete_tagged_obj));
	boolean bad = false;
	if (obsolete_tagged_obj.length != 1) {
	System.out.println(
	"Found obsolete tag'd objects: "
	+ Arrays.deepHashCode(obsolete_tagged_obj)
	+ " but only expected one!");
	bad = true;
	}
	if (!Arrays.deepEquals(
	Arrays.copyOf(arr, ((Object[]) obsolete_tagged_obj[0]).length),
	(Object[]) obsolete_tagged_obj[0])) {
	System.out.println("Obsolete array was unexpectedly different than non-obsolete one!");
	bad = true;
	}
	if (!Arrays.stream(obsoletes_freed).anyMatch((l) -> l == globalID + 1)) {
	DbgPrintln("Didn't see a free of the obsolete id");
	}
	if (!bad) {
	System.out.println("Everything looks good WRT obsolete object!");
	}
	} else {
	if (!Arrays.stream(obsoletes_freed).anyMatch((l) -> l == globalID + 1)) {
	System.out.println("Didn't see a free of the obsolete id");
	} else {
	DbgPrintln("Saw a free of obsolete id!");
	System.out.println("Everything looks good WRT obsolete object!");
	}
	}
	}

	public static void run() throws Exception {
	// Simple
	runAsThread(Test1974::runInstance);

	// HashMap
	runAsThread(Test1974::runHashMap);

	// j.l.ref.WeakReference
	runAsThread(Test1974::runWeakReference);

	// Self-referential arrays.
	runAsThread(Test1974::runInstanceSelfRef);
	runAsThread(Test1974::runInstanceSelfRefSmall);

	// Local variables simple
	runAsThread(Test1974::runLocal);
	runAsThread(Test1974::runLocalSmall);

	// multiple threads local variables
	runAsThread(Test1974::runMultiThreadLocal);

	// using as monitors and waiting
	runAsThread(Test1974::runWithLocks);

	// Basic jni global refs
	runAsThread(Test1974::runWithJniGlobal);

	// Basic jni weak global refs
	runAsThread(Test1974::runWithJniWeakGlobal);

	// Basic JNI local refs
	runAsThread(Test1974::runWithJniLocals);

	// Basic jvmti tags
	runAsThread(Test1974::runWithJvmtiTags);

	// Grab obsolete reference using tags/detect free
	runAsThread(Test1974::runWithJvmtiTagsObsolete);
	}

	// Use a supplier so that we don't have to have a local ref to the resized
	// array if we don't want it
	public static native <T> void ResizeArray(Supplier<T> arr, int new_size);

	public static native <T> long GetGlobalJniRef(T t);

	public static native <T> long GetWeakGlobalJniRef(T t);

	public static native <T> T ReadJniRef(long t);

	public static native Object[] GetObjectsWithTag(long tag);

	public static native void StartCollectFrees();

	public static native void StartAssignObsoleteIncrementedId();

	public static native void EndAssignObsoleteIncrementedId();

	public static native long[] CollectFreedTags();
	}