8154539: Examine the desktop module's use of sun.misc.SoftCache
authoralexsch
Thu, 12 May 2016 20:43:37 +0400
changeset 38413 d9e49b45fd7d
parent 38412 96e1d2c5d435
child 38414 3e22d8fd4912
8154539: Examine the desktop module's use of sun.misc.SoftCache Reviewed-by: prr, chegar, mchung
jdk/src/java.desktop/share/classes/module-info.java
jdk/src/java.desktop/share/classes/sun/awt/SoftCache.java
jdk/src/java.desktop/share/classes/sun/awt/SunToolkit.java
jdk/src/java.desktop/share/classes/sun/awt/image/MultiResolutionToolkitImage.java
jdk/src/jdk.unsupported/share/classes/sun/misc/SoftCache.java
jdk/test/com/sun/jdi/ReferrersTest.java
--- a/jdk/src/java.desktop/share/classes/module-info.java	Thu May 12 09:16:17 2016 -0700
+++ b/jdk/src/java.desktop/share/classes/module-info.java	Thu May 12 20:43:37 2016 +0400
@@ -27,8 +27,6 @@
     requires public java.datatransfer;
     requires public java.xml;
     requires java.prefs;
-    // 8147544
-    requires jdk.unsupported;
 
     exports java.applet;
     exports java.awt;
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.desktop/share/classes/sun/awt/SoftCache.java	Thu May 12 20:43:37 2016 +0400
@@ -0,0 +1,462 @@
+/*
+ * Copyright (c) 1998, 2014, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+
+package sun.awt;
+
+import java.lang.ref.SoftReference;
+import java.lang.ref.ReferenceQueue;
+
+import java.util.Iterator;
+import java.util.Map;
+import java.util.AbstractMap;
+import java.util.HashMap;
+import java.util.Set;
+import java.util.AbstractSet;
+import java.util.NoSuchElementException;
+
+
+/**
+ * A memory-sensitive implementation of the <code>Map</code> interface.
+ *
+ * <p> A <code>SoftCache</code> object uses {@link java.lang.ref.SoftReference
+ * soft references} to implement a memory-sensitive hash map.  If the garbage
+ * collector determines at a certain point in time that a value object in a
+ * <code>SoftCache</code> entry is no longer strongly reachable, then it may
+ * remove that entry in order to release the memory occupied by the value
+ * object.  All <code>SoftCache</code> objects are guaranteed to be completely
+ * cleared before the virtual machine will throw an
+ * <code>OutOfMemoryError</code>.  Because of this automatic clearing feature,
+ * the behavior of this class is somewhat different from that of other
+ * <code>Map</code> implementations.
+ *
+ * <p> Both null values and the null key are supported.  This class has the
+ * same performance characteristics as the <code>HashMap</code> class, and has
+ * the same efficiency parameters of <em>initial capacity</em> and <em>load
+ * factor</em>.
+ *
+ * <p> Like most collection classes, this class is not synchronized.  A
+ * synchronized <code>SoftCache</code> may be constructed using the
+ * <code>Collections.synchronizedMap</code> method.
+ *
+ * <p> In typical usage this class will be subclassed and the <code>fill</code>
+ * method will be overridden.  When the <code>get</code> method is invoked on a
+ * key for which there is no mapping in the cache, it will in turn invoke the
+ * <code>fill</code> method on that key in an attempt to construct a
+ * corresponding value.  If the <code>fill</code> method returns such a value
+ * then the cache will be updated and the new value will be returned.  Thus,
+ * for example, a simple URL-content cache can be constructed as follows:
+ *
+ * <pre>
+ *     public class URLCache extends SoftCache {
+ *         protected Object fill(Object key) {
+ *             return ((URL)key).getContent();
+ *         }
+ *     }
+ * </pre>
+ *
+ * <p> The behavior of the <code>SoftCache</code> class depends in part upon
+ * the actions of the garbage collector, so several familiar (though not
+ * required) <code>Map</code> invariants do not hold for this class.  <p>
+ * Because entries are removed from a <code>SoftCache</code> in response to
+ * dynamic advice from the garbage collector, a <code>SoftCache</code> may
+ * behave as though an unknown thread is silently removing entries.  In
+ * particular, even if you synchronize on a <code>SoftCache</code> instance and
+ * invoke none of its mutator methods, it is possible for the <code>size</code>
+ * method to return smaller values over time, for the <code>isEmpty</code>
+ * method to return <code>false</code> and then <code>true</code>, for the
+ * <code>containsKey</code> method to return <code>true</code> and later
+ * <code>false</code> for a given key, for the <code>get</code> method to
+ * return a value for a given key but later return <code>null</code>, for the
+ * <code>put</code> method to return <code>null</code> and the
+ * <code>remove</code> method to return <code>false</code> for a key that
+ * previously appeared to be in the map, and for successive examinations of the
+ * key set, the value set, and the entry set to yield successively smaller
+ * numbers of elements.
+ *
+ * @author      Mark Reinhold
+ * @since       1.2
+ * @see         java.util.HashMap
+ * @see         java.lang.ref.SoftReference
+ * @deprecated No direct replacement; {@link java.util.WeakHashMap}
+ * addresses a related by different use-case.
+ */
+
+@Deprecated
+public class SoftCache extends AbstractMap<Object, Object> implements Map<Object, Object> {
+
+    /* The basic idea of this implementation is to maintain an internal HashMap
+       that maps keys to soft references whose referents are the keys' values;
+       the various accessor methods dereference these soft references before
+       returning values.  Because we don't have access to the innards of the
+       HashMap, each soft reference must contain the key that maps to it so
+       that the processQueue method can remove keys whose values have been
+       discarded.  Thus the HashMap actually maps keys to instances of the
+       ValueCell class, which is a simple extension of the SoftReference class.
+     */
+
+
+    private static class ValueCell extends SoftReference<Object> {
+        private static Object INVALID_KEY = new Object();
+        private static int dropped = 0;
+        private Object key;
+
+        private ValueCell(Object key, Object value, ReferenceQueue<Object> queue) {
+            super(value, queue);
+            this.key = key;
+        }
+
+        private static ValueCell create(Object key, Object value,
+                                        ReferenceQueue<Object> queue)
+        {
+            if (value == null) return null;
+            return new ValueCell(key, value, queue);
+        }
+
+        private static Object strip(Object val, boolean drop) {
+            if (val == null) return null;
+            ValueCell vc = (ValueCell)val;
+            Object o = vc.get();
+            if (drop) vc.drop();
+            return o;
+        }
+
+        private boolean isValid() {
+            return (key != INVALID_KEY);
+        }
+
+        private void drop() {
+            super.clear();
+            key = INVALID_KEY;
+            dropped++;
+        }
+
+    }
+
+
+    /* Hash table mapping keys to ValueCells */
+    private Map<Object, Object> hash;
+
+    /* Reference queue for cleared ValueCells */
+    private ReferenceQueue<Object> queue = new ReferenceQueue<>();
+
+
+    /* Process any ValueCells that have been cleared and enqueued by the
+       garbage collector.  This method should be invoked once by each public
+       mutator in this class.  We don't invoke this method in public accessors
+       because that can lead to surprising ConcurrentModificationExceptions.
+     */
+    private void processQueue() {
+        ValueCell vc;
+        while ((vc = (ValueCell)queue.poll()) != null) {
+            if (vc.isValid()) hash.remove(vc.key);
+            else ValueCell.dropped--;
+        }
+    }
+
+
+    /* -- Constructors -- */
+
+    /**
+     * Construct a new, empty <code>SoftCache</code> with the given
+     * initial capacity and the given load factor.
+     *
+     * @param  initialCapacity  The initial capacity of the cache
+     *
+     * @param  loadFactor       A number between 0.0 and 1.0
+     *
+     * @throws IllegalArgumentException  If the initial capacity is less than
+     *                                   or equal to zero, or if the load
+     *                                   factor is less than zero
+     */
+    public SoftCache(int initialCapacity, float loadFactor) {
+        hash = new HashMap<>(initialCapacity, loadFactor);
+    }
+
+    /**
+     * Construct a new, empty <code>SoftCache</code> with the given
+     * initial capacity and the default load factor.
+     *
+     * @param  initialCapacity  The initial capacity of the cache
+     *
+     * @throws IllegalArgumentException  If the initial capacity is less than
+     *                                   or equal to zero
+     */
+    public SoftCache(int initialCapacity) {
+        hash = new HashMap<>(initialCapacity);
+    }
+
+    /**
+     * Construct a new, empty <code>SoftCache</code> with the default
+     * capacity and the default load factor.
+     */
+    public SoftCache() {
+        hash = new HashMap<>();
+    }
+
+
+    /* -- Simple queries -- */
+
+    /**
+     * Return the number of key-value mappings in this cache.  The time
+     * required by this operation is linear in the size of the map.
+     */
+    public int size() {
+        return entrySet().size();
+    }
+
+    /**
+     * Return <code>true</code> if this cache contains no key-value mappings.
+     */
+    public boolean isEmpty() {
+        return entrySet().isEmpty();
+    }
+
+    /**
+     * Return <code>true</code> if this cache contains a mapping for the
+     * specified key.  If there is no mapping for the key, this method will not
+     * attempt to construct one by invoking the <code>fill</code> method.
+     *
+     * @param   key   The key whose presence in the cache is to be tested
+     */
+    public boolean containsKey(Object key) {
+        return ValueCell.strip(hash.get(key), false) != null;
+    }
+
+
+    /* -- Lookup and modification operations -- */
+
+    /**
+     * Create a value object for the given <code>key</code>.  This method is
+     * invoked by the <code>get</code> method when there is no entry for
+     * <code>key</code>.  If this method returns a non-<code>null</code> value,
+     * then the cache will be updated to map <code>key</code> to that value,
+     * and that value will be returned by the <code>get</code> method.
+     *
+     * <p> The default implementation of this method simply returns
+     * <code>null</code> for every <code>key</code> value.  A subclass may
+     * override this method to provide more useful behavior.
+     *
+     * @param  key  The key for which a value is to be computed
+     *
+     * @return      A value for <code>key</code>, or <code>null</code> if one
+     *              could not be computed
+     * @see #get
+     */
+    protected Object fill(Object key) {
+        return null;
+    }
+
+    /**
+     * Return the value to which this cache maps the specified
+     * <code>key</code>.  If the cache does not presently contain a value for
+     * this key, then invoke the <code>fill</code> method in an attempt to
+     * compute such a value.  If that method returns a non-<code>null</code>
+     * value, then update the cache and return the new value.  Otherwise,
+     * return <code>null</code>.
+     *
+     * <p> Note that because this method may update the cache, it is considered
+     * a mutator and may cause <code>ConcurrentModificationException</code>s to
+     * be thrown if invoked while an iterator is in use.
+     *
+     * @param  key  The key whose associated value, if any, is to be returned
+     *
+     * @see #fill
+     */
+    public Object get(Object key) {
+        processQueue();
+        Object v = hash.get(key);
+        if (v == null) {
+            v = fill(key);
+            if (v != null) {
+                hash.put(key, ValueCell.create(key, v, queue));
+                return v;
+            }
+        }
+        return ValueCell.strip(v, false);
+    }
+
+    /**
+     * Update this cache so that the given <code>key</code> maps to the given
+     * <code>value</code>.  If the cache previously contained a mapping for
+     * <code>key</code> then that mapping is replaced and the old value is
+     * returned.
+     *
+     * @param  key    The key that is to be mapped to the given
+     *                <code>value</code>
+     * @param  value  The value to which the given <code>key</code> is to be
+     *                mapped
+     *
+     * @return  The previous value to which this key was mapped, or
+     *          <code>null</code> if there was no mapping for the key
+     */
+    public Object put(Object key, Object value) {
+        processQueue();
+        ValueCell vc = ValueCell.create(key, value, queue);
+        return ValueCell.strip(hash.put(key, vc), true);
+    }
+
+    /**
+     * Remove the mapping for the given <code>key</code> from this cache, if
+     * present.
+     *
+     * @param  key  The key whose mapping is to be removed
+     *
+     * @return  The value to which this key was mapped, or <code>null</code> if
+     *          there was no mapping for the key
+     */
+    public Object remove(Object key) {
+        processQueue();
+        return ValueCell.strip(hash.remove(key), true);
+    }
+
+    /**
+     * Remove all mappings from this cache.
+     */
+    public void clear() {
+        processQueue();
+        hash.clear();
+    }
+
+
+    /* -- Views -- */
+
+    private static boolean valEquals(Object o1, Object o2) {
+        return (o1 == null) ? (o2 == null) : o1.equals(o2);
+    }
+
+
+    /* Internal class for entries.
+       Because it uses SoftCache.this.queue, this class cannot be static.
+     */
+    private class Entry implements Map.Entry<Object, Object> {
+        private Map.Entry<Object, Object> ent;
+        private Object value;   /* Strong reference to value, to prevent the GC
+                                   from flushing the value while this Entry
+                                   exists */
+
+        Entry(Map.Entry<Object, Object> ent, Object value) {
+            this.ent = ent;
+            this.value = value;
+        }
+
+        public Object getKey() {
+            return ent.getKey();
+        }
+
+        public Object getValue() {
+            return value;
+        }
+
+        public Object setValue(Object value) {
+            return ent.setValue(ValueCell.create(ent.getKey(), value, queue));
+        }
+
+        @SuppressWarnings("unchecked")
+        public boolean equals(Object o) {
+            if (! (o instanceof Map.Entry)) return false;
+            Map.Entry<Object, Object> e = (Map.Entry<Object, Object>)o;
+            return (valEquals(ent.getKey(), e.getKey())
+                    && valEquals(value, e.getValue()));
+        }
+
+        public int hashCode() {
+            Object k;
+            return ((((k = getKey()) == null) ? 0 : k.hashCode())
+                    ^ ((value == null) ? 0 : value.hashCode()));
+        }
+
+    }
+
+
+    /* Internal class for entry sets */
+    private class EntrySet extends AbstractSet<Map.Entry<Object, Object>> {
+        Set<Map.Entry<Object, Object>> hashEntries = hash.entrySet();
+
+        public Iterator<Map.Entry<Object, Object>> iterator() {
+
+            return new Iterator<Map.Entry<Object, Object>>() {
+                Iterator<Map.Entry<Object, Object>> hashIterator = hashEntries.iterator();
+                Entry next = null;
+
+                public boolean hasNext() {
+                    while (hashIterator.hasNext()) {
+                        Map.Entry<Object, Object> ent = hashIterator.next();
+                        ValueCell vc = (ValueCell)ent.getValue();
+                        Object v = null;
+                        if ((vc != null) && ((v = vc.get()) == null)) {
+                            /* Value has been flushed by GC */
+                            continue;
+                        }
+                        next = new Entry(ent, v);
+                        return true;
+                    }
+                    return false;
+                }
+
+                public Map.Entry<Object, Object> next() {
+                    if ((next == null) && !hasNext())
+                        throw new NoSuchElementException();
+                    Entry e = next;
+                    next = null;
+                    return e;
+                }
+
+                public void remove() {
+                    hashIterator.remove();
+                }
+
+            };
+        }
+
+        public boolean isEmpty() {
+            return !(iterator().hasNext());
+        }
+
+        public int size() {
+            int j = 0;
+            for (Iterator<Map.Entry<Object, Object>> i = iterator(); i.hasNext(); i.next()) j++;
+            return j;
+        }
+
+        public boolean remove(Object o) {
+            processQueue();
+            if (o instanceof Entry) return hashEntries.remove(((Entry)o).ent);
+            else return false;
+        }
+
+    }
+
+
+    private Set<Map.Entry<Object, Object>> entrySet = null;
+
+    /**
+     * Return a <code>Set</code> view of the mappings in this cache.
+     */
+    public Set<Map.Entry<Object, Object>> entrySet() {
+        if (entrySet == null) entrySet = new EntrySet();
+        return entrySet;
+    }
+
+}
--- a/jdk/src/java.desktop/share/classes/sun/awt/SunToolkit.java	Thu May 12 09:16:17 2016 -0700
+++ b/jdk/src/java.desktop/share/classes/sun/awt/SunToolkit.java	Thu May 12 20:43:37 2016 +0400
@@ -65,7 +65,6 @@
 import sun.awt.image.ToolkitImage;
 import sun.awt.image.URLImageSource;
 import sun.font.FontDesignMetrics;
-import sun.misc.SoftCache;
 import sun.net.util.URLUtil;
 import sun.security.action.GetBooleanAction;
 import sun.security.action.GetPropertyAction;
--- a/jdk/src/java.desktop/share/classes/sun/awt/image/MultiResolutionToolkitImage.java	Thu May 12 09:16:17 2016 -0700
+++ b/jdk/src/java.desktop/share/classes/sun/awt/image/MultiResolutionToolkitImage.java	Thu May 12 20:43:37 2016 +0400
@@ -29,7 +29,7 @@
 import java.awt.image.MultiResolutionImage;
 import java.util.Arrays;
 import java.util.List;
-import sun.misc.SoftCache;
+import sun.awt.SoftCache;
 
 public class MultiResolutionToolkitImage extends ToolkitImage implements MultiResolutionImage {
 
--- a/jdk/src/jdk.unsupported/share/classes/sun/misc/SoftCache.java	Thu May 12 09:16:17 2016 -0700
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,462 +0,0 @@
-/*
- * Copyright (c) 1998, 2014, 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.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * 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.
- */
-
-package sun.misc;
-
-import java.lang.ref.SoftReference;
-import java.lang.ref.ReferenceQueue;
-
-import java.util.Iterator;
-import java.util.Map;
-import java.util.AbstractMap;
-import java.util.HashMap;
-import java.util.Set;
-import java.util.AbstractSet;
-import java.util.NoSuchElementException;
-
-
-/**
- * A memory-sensitive implementation of the <code>Map</code> interface.
- *
- * <p> A <code>SoftCache</code> object uses {@link java.lang.ref.SoftReference
- * soft references} to implement a memory-sensitive hash map.  If the garbage
- * collector determines at a certain point in time that a value object in a
- * <code>SoftCache</code> entry is no longer strongly reachable, then it may
- * remove that entry in order to release the memory occupied by the value
- * object.  All <code>SoftCache</code> objects are guaranteed to be completely
- * cleared before the virtual machine will throw an
- * <code>OutOfMemoryError</code>.  Because of this automatic clearing feature,
- * the behavior of this class is somewhat different from that of other
- * <code>Map</code> implementations.
- *
- * <p> Both null values and the null key are supported.  This class has the
- * same performance characteristics as the <code>HashMap</code> class, and has
- * the same efficiency parameters of <em>initial capacity</em> and <em>load
- * factor</em>.
- *
- * <p> Like most collection classes, this class is not synchronized.  A
- * synchronized <code>SoftCache</code> may be constructed using the
- * <code>Collections.synchronizedMap</code> method.
- *
- * <p> In typical usage this class will be subclassed and the <code>fill</code>
- * method will be overridden.  When the <code>get</code> method is invoked on a
- * key for which there is no mapping in the cache, it will in turn invoke the
- * <code>fill</code> method on that key in an attempt to construct a
- * corresponding value.  If the <code>fill</code> method returns such a value
- * then the cache will be updated and the new value will be returned.  Thus,
- * for example, a simple URL-content cache can be constructed as follows:
- *
- * <pre>
- *     public class URLCache extends SoftCache {
- *         protected Object fill(Object key) {
- *             return ((URL)key).getContent();
- *         }
- *     }
- * </pre>
- *
- * <p> The behavior of the <code>SoftCache</code> class depends in part upon
- * the actions of the garbage collector, so several familiar (though not
- * required) <code>Map</code> invariants do not hold for this class.  <p>
- * Because entries are removed from a <code>SoftCache</code> in response to
- * dynamic advice from the garbage collector, a <code>SoftCache</code> may
- * behave as though an unknown thread is silently removing entries.  In
- * particular, even if you synchronize on a <code>SoftCache</code> instance and
- * invoke none of its mutator methods, it is possible for the <code>size</code>
- * method to return smaller values over time, for the <code>isEmpty</code>
- * method to return <code>false</code> and then <code>true</code>, for the
- * <code>containsKey</code> method to return <code>true</code> and later
- * <code>false</code> for a given key, for the <code>get</code> method to
- * return a value for a given key but later return <code>null</code>, for the
- * <code>put</code> method to return <code>null</code> and the
- * <code>remove</code> method to return <code>false</code> for a key that
- * previously appeared to be in the map, and for successive examinations of the
- * key set, the value set, and the entry set to yield successively smaller
- * numbers of elements.
- *
- * @author      Mark Reinhold
- * @since       1.2
- * @see         java.util.HashMap
- * @see         java.lang.ref.SoftReference
- * @deprecated No direct replacement; {@link java.util.WeakHashMap}
- * addresses a related by different use-case.
- */
-
-@Deprecated
-public class SoftCache extends AbstractMap<Object, Object> implements Map<Object, Object> {
-
-    /* The basic idea of this implementation is to maintain an internal HashMap
-       that maps keys to soft references whose referents are the keys' values;
-       the various accessor methods dereference these soft references before
-       returning values.  Because we don't have access to the innards of the
-       HashMap, each soft reference must contain the key that maps to it so
-       that the processQueue method can remove keys whose values have been
-       discarded.  Thus the HashMap actually maps keys to instances of the
-       ValueCell class, which is a simple extension of the SoftReference class.
-     */
-
-
-    private static class ValueCell extends SoftReference<Object> {
-        private static Object INVALID_KEY = new Object();
-        private static int dropped = 0;
-        private Object key;
-
-        private ValueCell(Object key, Object value, ReferenceQueue<Object> queue) {
-            super(value, queue);
-            this.key = key;
-        }
-
-        private static ValueCell create(Object key, Object value,
-                                        ReferenceQueue<Object> queue)
-        {
-            if (value == null) return null;
-            return new ValueCell(key, value, queue);
-        }
-
-        private static Object strip(Object val, boolean drop) {
-            if (val == null) return null;
-            ValueCell vc = (ValueCell)val;
-            Object o = vc.get();
-            if (drop) vc.drop();
-            return o;
-        }
-
-        private boolean isValid() {
-            return (key != INVALID_KEY);
-        }
-
-        private void drop() {
-            super.clear();
-            key = INVALID_KEY;
-            dropped++;
-        }
-
-    }
-
-
-    /* Hash table mapping keys to ValueCells */
-    private Map<Object, Object> hash;
-
-    /* Reference queue for cleared ValueCells */
-    private ReferenceQueue<Object> queue = new ReferenceQueue<>();
-
-
-    /* Process any ValueCells that have been cleared and enqueued by the
-       garbage collector.  This method should be invoked once by each public
-       mutator in this class.  We don't invoke this method in public accessors
-       because that can lead to surprising ConcurrentModificationExceptions.
-     */
-    private void processQueue() {
-        ValueCell vc;
-        while ((vc = (ValueCell)queue.poll()) != null) {
-            if (vc.isValid()) hash.remove(vc.key);
-            else ValueCell.dropped--;
-        }
-    }
-
-
-    /* -- Constructors -- */
-
-    /**
-     * Construct a new, empty <code>SoftCache</code> with the given
-     * initial capacity and the given load factor.
-     *
-     * @param  initialCapacity  The initial capacity of the cache
-     *
-     * @param  loadFactor       A number between 0.0 and 1.0
-     *
-     * @throws IllegalArgumentException  If the initial capacity is less than
-     *                                   or equal to zero, or if the load
-     *                                   factor is less than zero
-     */
-    public SoftCache(int initialCapacity, float loadFactor) {
-        hash = new HashMap<>(initialCapacity, loadFactor);
-    }
-
-    /**
-     * Construct a new, empty <code>SoftCache</code> with the given
-     * initial capacity and the default load factor.
-     *
-     * @param  initialCapacity  The initial capacity of the cache
-     *
-     * @throws IllegalArgumentException  If the initial capacity is less than
-     *                                   or equal to zero
-     */
-    public SoftCache(int initialCapacity) {
-        hash = new HashMap<>(initialCapacity);
-    }
-
-    /**
-     * Construct a new, empty <code>SoftCache</code> with the default
-     * capacity and the default load factor.
-     */
-    public SoftCache() {
-        hash = new HashMap<>();
-    }
-
-
-    /* -- Simple queries -- */
-
-    /**
-     * Return the number of key-value mappings in this cache.  The time
-     * required by this operation is linear in the size of the map.
-     */
-    public int size() {
-        return entrySet().size();
-    }
-
-    /**
-     * Return <code>true</code> if this cache contains no key-value mappings.
-     */
-    public boolean isEmpty() {
-        return entrySet().isEmpty();
-    }
-
-    /**
-     * Return <code>true</code> if this cache contains a mapping for the
-     * specified key.  If there is no mapping for the key, this method will not
-     * attempt to construct one by invoking the <code>fill</code> method.
-     *
-     * @param   key   The key whose presence in the cache is to be tested
-     */
-    public boolean containsKey(Object key) {
-        return ValueCell.strip(hash.get(key), false) != null;
-    }
-
-
-    /* -- Lookup and modification operations -- */
-
-    /**
-     * Create a value object for the given <code>key</code>.  This method is
-     * invoked by the <code>get</code> method when there is no entry for
-     * <code>key</code>.  If this method returns a non-<code>null</code> value,
-     * then the cache will be updated to map <code>key</code> to that value,
-     * and that value will be returned by the <code>get</code> method.
-     *
-     * <p> The default implementation of this method simply returns
-     * <code>null</code> for every <code>key</code> value.  A subclass may
-     * override this method to provide more useful behavior.
-     *
-     * @param  key  The key for which a value is to be computed
-     *
-     * @return      A value for <code>key</code>, or <code>null</code> if one
-     *              could not be computed
-     * @see #get
-     */
-    protected Object fill(Object key) {
-        return null;
-    }
-
-    /**
-     * Return the value to which this cache maps the specified
-     * <code>key</code>.  If the cache does not presently contain a value for
-     * this key, then invoke the <code>fill</code> method in an attempt to
-     * compute such a value.  If that method returns a non-<code>null</code>
-     * value, then update the cache and return the new value.  Otherwise,
-     * return <code>null</code>.
-     *
-     * <p> Note that because this method may update the cache, it is considered
-     * a mutator and may cause <code>ConcurrentModificationException</code>s to
-     * be thrown if invoked while an iterator is in use.
-     *
-     * @param  key  The key whose associated value, if any, is to be returned
-     *
-     * @see #fill
-     */
-    public Object get(Object key) {
-        processQueue();
-        Object v = hash.get(key);
-        if (v == null) {
-            v = fill(key);
-            if (v != null) {
-                hash.put(key, ValueCell.create(key, v, queue));
-                return v;
-            }
-        }
-        return ValueCell.strip(v, false);
-    }
-
-    /**
-     * Update this cache so that the given <code>key</code> maps to the given
-     * <code>value</code>.  If the cache previously contained a mapping for
-     * <code>key</code> then that mapping is replaced and the old value is
-     * returned.
-     *
-     * @param  key    The key that is to be mapped to the given
-     *                <code>value</code>
-     * @param  value  The value to which the given <code>key</code> is to be
-     *                mapped
-     *
-     * @return  The previous value to which this key was mapped, or
-     *          <code>null</code> if there was no mapping for the key
-     */
-    public Object put(Object key, Object value) {
-        processQueue();
-        ValueCell vc = ValueCell.create(key, value, queue);
-        return ValueCell.strip(hash.put(key, vc), true);
-    }
-
-    /**
-     * Remove the mapping for the given <code>key</code> from this cache, if
-     * present.
-     *
-     * @param  key  The key whose mapping is to be removed
-     *
-     * @return  The value to which this key was mapped, or <code>null</code> if
-     *          there was no mapping for the key
-     */
-    public Object remove(Object key) {
-        processQueue();
-        return ValueCell.strip(hash.remove(key), true);
-    }
-
-    /**
-     * Remove all mappings from this cache.
-     */
-    public void clear() {
-        processQueue();
-        hash.clear();
-    }
-
-
-    /* -- Views -- */
-
-    private static boolean valEquals(Object o1, Object o2) {
-        return (o1 == null) ? (o2 == null) : o1.equals(o2);
-    }
-
-
-    /* Internal class for entries.
-       Because it uses SoftCache.this.queue, this class cannot be static.
-     */
-    private class Entry implements Map.Entry<Object, Object> {
-        private Map.Entry<Object, Object> ent;
-        private Object value;   /* Strong reference to value, to prevent the GC
-                                   from flushing the value while this Entry
-                                   exists */
-
-        Entry(Map.Entry<Object, Object> ent, Object value) {
-            this.ent = ent;
-            this.value = value;
-        }
-
-        public Object getKey() {
-            return ent.getKey();
-        }
-
-        public Object getValue() {
-            return value;
-        }
-
-        public Object setValue(Object value) {
-            return ent.setValue(ValueCell.create(ent.getKey(), value, queue));
-        }
-
-        @SuppressWarnings("unchecked")
-        public boolean equals(Object o) {
-            if (! (o instanceof Map.Entry)) return false;
-            Map.Entry<Object, Object> e = (Map.Entry<Object, Object>)o;
-            return (valEquals(ent.getKey(), e.getKey())
-                    && valEquals(value, e.getValue()));
-        }
-
-        public int hashCode() {
-            Object k;
-            return ((((k = getKey()) == null) ? 0 : k.hashCode())
-                    ^ ((value == null) ? 0 : value.hashCode()));
-        }
-
-    }
-
-
-    /* Internal class for entry sets */
-    private class EntrySet extends AbstractSet<Map.Entry<Object, Object>> {
-        Set<Map.Entry<Object, Object>> hashEntries = hash.entrySet();
-
-        public Iterator<Map.Entry<Object, Object>> iterator() {
-
-            return new Iterator<Map.Entry<Object, Object>>() {
-                Iterator<Map.Entry<Object, Object>> hashIterator = hashEntries.iterator();
-                Entry next = null;
-
-                public boolean hasNext() {
-                    while (hashIterator.hasNext()) {
-                        Map.Entry<Object, Object> ent = hashIterator.next();
-                        ValueCell vc = (ValueCell)ent.getValue();
-                        Object v = null;
-                        if ((vc != null) && ((v = vc.get()) == null)) {
-                            /* Value has been flushed by GC */
-                            continue;
-                        }
-                        next = new Entry(ent, v);
-                        return true;
-                    }
-                    return false;
-                }
-
-                public Map.Entry<Object, Object> next() {
-                    if ((next == null) && !hasNext())
-                        throw new NoSuchElementException();
-                    Entry e = next;
-                    next = null;
-                    return e;
-                }
-
-                public void remove() {
-                    hashIterator.remove();
-                }
-
-            };
-        }
-
-        public boolean isEmpty() {
-            return !(iterator().hasNext());
-        }
-
-        public int size() {
-            int j = 0;
-            for (Iterator<Map.Entry<Object, Object>> i = iterator(); i.hasNext(); i.next()) j++;
-            return j;
-        }
-
-        public boolean remove(Object o) {
-            processQueue();
-            if (o instanceof Entry) return hashEntries.remove(((Entry)o).ent);
-            else return false;
-        }
-
-    }
-
-
-    private Set<Map.Entry<Object, Object>> entrySet = null;
-
-    /**
-     * Return a <code>Set</code> view of the mappings in this cache.
-     */
-    public Set<Map.Entry<Object, Object>> entrySet() {
-        if (entrySet == null) entrySet = new EntrySet();
-        return entrySet;
-    }
-
-}
--- a/jdk/test/com/sun/jdi/ReferrersTest.java	Thu May 12 09:16:17 2016 -0700
+++ b/jdk/test/com/sun/jdi/ReferrersTest.java	Thu May 12 20:43:37 2016 +0400
@@ -446,7 +446,7 @@
         if (rt instanceof ClassType) {
             ClassType ct = (ClassType)rt;
             String name = ct.name();
-            if (name.equals("sun.misc.SoftCache$ValueCell")) {
+            if (name.equals("sun.awt.SoftCache$ValueCell")) {
                 return;
             }
             if (name.equals("java.lang.ref.Finalizer")) {