8010697: DeletedArrayFilter seems to leak memory

Reviewed-by: hannesw, sundar

nashorn/src/jdk/nashorn/internal/objects/NativeArray.java

@@ -856,8 +856,12 @@ public final class NativeArray extends ScriptObject {
                 }
 
                 // delete missing elements - which are at the end of sorted array
-                sobj.setArray(array.delete(sorted.length, len - 1));
-            }
+                if (sorted.length != len) {
+                    array = array.delete(sorted.length, len - 1);
+                }
+
+                sobj.setArray(array);
+           }
 
             return sobj;
         } catch (final ClassCastException | NullPointerException e) {

nashorn/src/jdk/nashorn/internal/runtime/arrays/ArrayData.java

@@ -294,6 +294,29 @@ public abstract class ArrayData {
      */
     public abstract ArrayData set(int index, double value, boolean strict);
 
+    /**
+     * Set an empty value at a given index. Should only affect Object array.
+     *
+     * @param index the index
+     * @return new array data (or same)
+     */
+    public ArrayData setEmpty(final int index) {
+        // Do nothing.
+        return this;
+    }
+
+    /**
+     * Set an empty value for a given range. Should only affect Object array.
+     *
+     * @param lo range low end
+     * @param hi range high end
+     * @return new array data (or same)
+     */
+    public ArrayData setEmpty(final long lo, final long hi) {
+        // Do nothing.
+        return this;
+    }
+
     /**
      * Get an int value from a given index
      *

nashorn/src/jdk/nashorn/internal/runtime/arrays/ArrayFilter.java

@@ -128,6 +128,18 @@ abstract class ArrayFilter extends ArrayData {
         return this;
     }
 
+    @Override
+    public ArrayData setEmpty(final int index) {
+        underlying.setEmpty(index);
+        return this;
+    }
+
+    @Override
+    public ArrayData setEmpty(final long lo, final long hi) {
+        underlying.setEmpty(lo, hi);
+        return this;
+    }
+
     @Override
     public int getInt(final int index) {
         return underlying.getInt(index);

nashorn/src/jdk/nashorn/internal/runtime/arrays/DeletedArrayFilter.java

@@ -142,6 +142,7 @@ final class DeletedArrayFilter extends ArrayFilter {
         final long longIndex = ArrayIndex.toLongIndex(index);
         assert longIndex >= 0 && longIndex < length();
         deleted.set(longIndex);
+        underlying.setEmpty(index);
         return this;
     }
 
@@ -149,6 +150,7 @@ final class DeletedArrayFilter extends ArrayFilter {
     public ArrayData delete(final long fromIndex, final long toIndex) {
         assert fromIndex >= 0 && fromIndex <= toIndex && toIndex < length();
         deleted.setRange(fromIndex, toIndex + 1);
+        underlying.setEmpty(fromIndex, toIndex);
         return this;
     }
 

nashorn/src/jdk/nashorn/internal/runtime/arrays/DeletedRangeArrayFilter.java

@@ -202,6 +202,8 @@ final class DeletedRangeArrayFilter extends ArrayFilter {
     @Override
     public ArrayData delete(final int index) {
         final long longIndex = ArrayIndex.toLongIndex(index);
+        underlying.setEmpty(index);
+
         if (longIndex + 1 == lo) {
             lo = longIndex;
         } else if (longIndex - 1 == hi) {
@@ -220,6 +222,7 @@ final class DeletedRangeArrayFilter extends ArrayFilter {
         }
         lo = Math.min(fromIndex, lo);
         hi = Math.max(toIndex, hi);
+        underlying.setEmpty(lo, hi);
         return this;
     }
 

nashorn/src/jdk/nashorn/internal/runtime/arrays/ObjectArrayData.java

@@ -138,6 +138,18 @@ final class ObjectArrayData extends ArrayData {
         return this;
     }
 
+    @Override
+    public ArrayData setEmpty(final int index) {
+        array[index] = ScriptRuntime.EMPTY;
+        return this;
+    }
+
+    @Override
+    public ArrayData setEmpty(final long lo, final long hi) {
+        Arrays.fill(array, (int)Math.max(lo, 0L), (int)Math.min(hi, (long)Integer.MAX_VALUE), ScriptRuntime.EMPTY);
+        return this;
+    }
+
     @Override
     public int getInt(final int index) {
         return JSType.toInt32(array[index]);
@@ -165,11 +177,13 @@ final class ObjectArrayData extends ArrayData {
 
     @Override
     public ArrayData delete(final int index) {
+        setEmpty(index);
         return new DeletedRangeArrayFilter(this, index, index);
     }
 
     @Override
     public ArrayData delete(final long fromIndex, final long toIndex) {
+        setEmpty(fromIndex, toIndex);
         return new DeletedRangeArrayFilter(this, fromIndex, toIndex);
     }
 
@@ -181,7 +195,7 @@ final class ObjectArrayData extends ArrayData {
 
         final int newLength = (int) (length() - 1);
         final Object elem = array[newLength];
-        array[newLength] = 0;
+        setEmpty(newLength);
         setLength(newLength);
         return elem;
     }

nashorn/src/jdk/nashorn/internal/runtime/arrays/SparseArrayData.java

@@ -203,6 +203,18 @@ class SparseArrayData extends ArrayData {
         return this;
     }
 
+    @Override
+    public ArrayData setEmpty(final int index) {
+        underlying.setEmpty(index);
+        return this;
+    }
+
+    @Override
+    public ArrayData setEmpty(final long lo, final long hi) {
+        underlying.setEmpty(lo, hi);
+        return this;
+    }
+
     @Override
     public int getInt(final int index) {
         if (index >= 0 && index < maxDenseLength) {

nashorn/test/script/basic/JDK-8010697.js

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * JDK-8010697: DeletedArrayFilter seems to leak memory
+ *
+ * @test
+ * @run
+ */
+
+var N = 1000;
+
+var array = new Array(N);
+var WeakReferenceArray = Java.type("java.lang.ref.WeakReference[]");
+var refArray = new WeakReferenceArray(N);
+
+for (var i = 0; i < N; i ++) {
+    var object = new java.lang.Object();
+    array[i] = object;
+    refArray[i] = new java.lang.ref.WeakReference(object);
+}
+
+object = null;
+
+for (var i = 0; i < N; i ++) {
+    delete array[i];
+}
+
+java.lang.System.gc();
+java.lang.System.gc();
+
+for (var i = 0; i < N; i ++) {
+    if (refArray[i].get() != null) {
+        print("Reference found at " + i);
+        exit(0);
+    }
+}
+
+print("All references gone");

nashorn/test/script/basic/JDK-8010697.js.EXPECTED

@@ -0,0 +1 @@
+All references gone