8028054: com.sun.beans.finder.MethodFinder has unsynchronized access to a static Map

Reviewed-by: alexsch, serb

src/share/classes/com/sun/beans/finder/ConstructorFinder.java

@@ -24,11 +24,12 @@
  */
 package com.sun.beans.finder;
 
-import com.sun.beans.WeakCache;
+import com.sun.beans.util.Cache;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Modifier;
 
+import static com.sun.beans.util.Cache.Kind.SOFT;
 import static sun.reflect.misc.ReflectUtil.isPackageAccessible;
 
 /**
@@ -41,7 +42,18 @@ import static sun.reflect.misc.ReflectUtil.isPackageAccessible;
  * @author Sergey A. Malenkov
  */
 public final class ConstructorFinder extends AbstractFinder<Constructor<?>> {
-    private static final WeakCache<Signature, Constructor<?>> CACHE = new WeakCache<Signature, Constructor<?>>();
+    private static final Cache<Signature, Constructor<?>> CACHE = new Cache<Signature, Constructor<?>>(SOFT, SOFT) {
+        @Override
+        public Constructor create(Signature signature) {
+            try {
+                ConstructorFinder finder = new ConstructorFinder(signature.getArgs());
+                return finder.find(signature.getType().getConstructors());
+            }
+            catch (Exception exception) {
+                throw new SignatureException(exception);
+            }
+        }
+    };
 
     /**
      * Finds public constructor
@@ -69,13 +81,12 @@ public final class ConstructorFinder extends AbstractFinder<Constructor<?>> {
         PrimitiveWrapperMap.replacePrimitivesWithWrappers(args);
         Signature signature = new Signature(type, args);
 
-        Constructor<?> constructor = CACHE.get(signature);
-        if (constructor != null) {
-            return constructor;
+        try {
+            return CACHE.get(signature);
+        }
+        catch (SignatureException exception) {
+            throw exception.toNoSuchMethodException("Constructor is not found");
         }
-        constructor = new ConstructorFinder(args).find(type.getConstructors());
-        CACHE.put(signature, constructor);
-        return constructor;
     }
 
     /**

src/share/classes/com/sun/beans/finder/MethodFinder.java

@@ -25,7 +25,7 @@
 package com.sun.beans.finder;
 
 import com.sun.beans.TypeResolver;
-import com.sun.beans.WeakCache;
+import com.sun.beans.util.Cache;
 
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
@@ -33,6 +33,7 @@ import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.util.Arrays;
 
+import static com.sun.beans.util.Cache.Kind.SOFT;
 import static sun.reflect.misc.ReflectUtil.isPackageAccessible;
 
 /**
@@ -45,7 +46,18 @@ import static sun.reflect.misc.ReflectUtil.isPackageAccessible;
  * @author Sergey A. Malenkov
  */
 public final class MethodFinder extends AbstractFinder<Method> {
-    private static final WeakCache<Signature, Method> CACHE = new WeakCache<Signature, Method>();
+    private static final Cache<Signature, Method> CACHE = new Cache<Signature, Method>(SOFT, SOFT) {
+        @Override
+        public Method create(Signature signature) {
+            try {
+                MethodFinder finder = new MethodFinder(signature.getName(), signature.getArgs());
+                return findAccessibleMethod(finder.find(signature.getType().getMethods()));
+            }
+            catch (Exception exception) {
+                throw new SignatureException(exception);
+            }
+        }
+    };
 
     /**
      * Finds public method (static or non-static)
@@ -65,16 +77,13 @@ public final class MethodFinder extends AbstractFinder<Method> {
         PrimitiveWrapperMap.replacePrimitivesWithWrappers(args);
         Signature signature = new Signature(type, name, args);
 
-        Method method = CACHE.get(signature);
-        boolean cached = method != null;
-        if (cached && isPackageAccessible(method.getDeclaringClass())) {
-            return method;
+        try {
+            Method method = CACHE.get(signature);
+            return (method == null) || isPackageAccessible(method.getDeclaringClass()) ? method : CACHE.create(signature);
         }
-        method = findAccessibleMethod(new MethodFinder(name, args).find(type.getMethods()));
-        if (!cached) {
-            CACHE.put(signature, method);
+        catch (SignatureException exception) {
+            throw exception.toNoSuchMethodException("Method '" + name + "' is not found");
         }
-        return method;
     }
 
     /**

src/share/classes/com/sun/beans/finder/Signature.java

@@ -62,6 +62,18 @@ final class Signature {
         this.args = args;
     }
 
+    Class<?> getType() {
+        return this.type;
+    }
+
+    String getName() {
+        return this.name;
+    }
+
+    Class<?>[] getArgs() {
+        return this.args;
+    }
+
     /**
      * Indicates whether some other object is "equal to" this one.
      *

src/share/classes/com/sun/beans/finder/SignatureException.java

+/*
+ * Copyright (c) 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.  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 com.sun.beans.finder;
+
+final class SignatureException extends RuntimeException {
+    SignatureException(Throwable cause) {
+        super(cause);
+    }
+
+    NoSuchMethodException toNoSuchMethodException(String message) {
+        Throwable throwable = getCause();
+        if (throwable instanceof NoSuchMethodException) {
+            return (NoSuchMethodException) throwable;
+        }
+        NoSuchMethodException exception = new NoSuchMethodException(message);
+        exception.initCause(throwable);
+        return exception;
+    }
+}

src/share/classes/com/sun/beans/util/Cache.java

+/*
+ * Copyright (c) 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.  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 com.sun.beans.util;
+
+import java.lang.ref.ReferenceQueue;
+import java.lang.ref.SoftReference;
+import java.lang.ref.WeakReference;
+import java.util.Objects;
+
+/**
+ * Hash table based implementation of the cache,
+ * which allows to use weak or soft references for keys and values.
+ * An entry in a {@code Cache} will automatically be removed
+ * when its key or value is no longer in ordinary use.
+ *
+ * @author Sergey Malenkov
+ * @since 1.8
+ */
+public abstract class Cache<K,V> {
+    private static final int MAXIMUM_CAPACITY = 1 << 30; // maximum capacity MUST be a power of two <= 1<<30
+
+    private final boolean identity; // defines whether the identity comparison is used
+    private final Kind keyKind; // a reference kind for the cache keys
+    private final Kind valueKind; // a reference kind for the cache values
+
+    private final ReferenceQueue<Object> queue = new ReferenceQueue<>(); // queue for references to remove
+
+    private volatile CacheEntry<K,V>[] table = newTable(1 << 3); // table's length MUST be a power of two
+    private int threshold = 6; // the next size value at which to resize
+    private int size; // the number of key-value mappings contained in this map
+
+    /**
+     * Creates a corresponding value for the specified key.
+     *
+     * @param key a key that can be used to create a value
+     * @return a corresponding value for the specified key
+     */
+    public abstract V create(K key);
+
+    /**
+     * Constructs an empty {@code Cache}.
+     * The default initial capacity is 8.
+     * The default load factor is 0.75.
+     *
+     * @param keyKind   a reference kind for keys
+     * @param valueKind a reference kind for values
+     *
+     * @throws NullPointerException if {@code keyKind} or {@code valueKind} are {@code null}
+     */
+    public Cache(Kind keyKind, Kind valueKind) {
+        this(keyKind, valueKind, false);
+    }
+
+    /**
+     * Constructs an empty {@code Cache}
+     * with the specified comparison method.
+     * The default initial capacity is 8.
+     * The default load factor is 0.75.
+     *
+     * @param keyKind   a reference kind for keys
+     * @param valueKind a reference kind for values
+     * @param identity  defines whether reference-equality
+     *                  is used in place of object-equality
+     *
+     * @throws NullPointerException if {@code keyKind} or {@code valueKind} are {@code null}
+     */
+    public Cache(Kind keyKind, Kind valueKind, boolean identity) {
+        Objects.requireNonNull(keyKind, "keyKind");
+        Objects.requireNonNull(valueKind, "valueKind");
+        this.keyKind = keyKind;
+        this.valueKind = valueKind;
+        this.identity = identity;
+    }
+
+    /**
+     * Returns the value to which the specified key is mapped,
+     * or {@code null} if there is no mapping for the key.
+     *
+     * @param key the key whose cached value is to be returned
+     * @return a value to which the specified key is mapped,
+     *         or {@code null} if there is no mapping for {@code key}
+     *
+     * @throws NullPointerException if {@code key} is {@code null}
+     *                              or corresponding value is {@code null}
+     */
+    public final V get(K key) {
+        Objects.requireNonNull(key, "key");
+        removeStaleEntries();
+        int hash = hash(key);
+        // unsynchronized search improves performance
+        // the null value does not mean that there are no needed entry
+        CacheEntry<K,V>[] table = this.table; // unsynchronized access
+        V current = getEntryValue(key, hash, table[index(hash, table)]);
+        if (current != null) {
+            return current;
+        }
+        synchronized (this.queue) {
+            // synchronized search improves stability
+            // we must create and add new value if there are no needed entry
+            int index = index(hash, this.table);
+            current = getEntryValue(key, hash, this.table[index]);
+            if (current != null) {
+                return current;
+            }
+            V value = create(key);
+            Objects.requireNonNull(value, "value");
+            this.table[index] = new CacheEntry<>(hash, key, value, this.table[index]);
+            if (++this.size >= this.threshold) {
+                if (this.table.length == MAXIMUM_CAPACITY) {
+                    this.threshold = Integer.MAX_VALUE;
+                } else {
+                    removeStaleEntries();
+                    table = newTable(this.table.length << 1);
+                    transfer(this.table, table);
+                    // If ignoring null elements and processing ref queue caused massive
+                    // shrinkage, then restore old table.  This should be rare, but avoids
+                    // unbounded expansion of garbage-filled tables.
+                    if (this.size >= this.threshold / 2) {
+                        this.table = table;
+                        this.threshold <<= 1;
+                    } else {
+                        transfer(table, this.table);
+                    }
+                    removeStaleEntries();
+                }
+            }
+            return value;
+        }
+    }
+
+    /**
+     * Removes the cached value that corresponds to the specified key.
+     *
+     * @param key the key whose mapping is to be removed from this cache
+     */
+    public final void remove(K key) {
+        if (key != null) {
+            synchronized (this.queue) {
+                removeStaleEntries();
+                int hash = hash(key);
+                int index = index(hash, this.table);
+                CacheEntry<K,V> prev = this.table[index];
+                CacheEntry<K,V> entry = prev;
+                while (entry != null) {
+                    CacheEntry<K,V> next = entry.next;
+                    if (entry.matches(hash, key)) {
+                        if (entry == prev) {
+                            this.table[index] = next;
+                        } else {
+                            prev.next = next;
+                        }
+                        entry.unlink();
+                        break;
+                    }
+                    prev = entry;
+                    entry = next;
+                }
+            }
+        }
+    }
+
+    /**
+     * Removes all of the mappings from this cache.
+     * It will be empty after this call returns.
+     */
+    public final void clear() {
+        synchronized (this.queue) {
+            int index = this.table.length;
+            while (0 < index--) {
+                CacheEntry<K,V> entry = this.table[index];
+                while (entry != null) {
+                    CacheEntry<K,V> next = entry.next;
+                    entry.unlink();
+                    entry = next;
+                }
+                this.table[index] = null;
+            }
+            while (null != this.queue.poll()) {
+                // Clear out the reference queue.
+            }
+        }
+    }
+
+    /**
+     * Retrieves object hash code and applies a supplemental hash function
+     * to the result hash, which defends against poor quality hash functions.
+     * This is critical because {@code Cache} uses power-of-two length hash tables,
+     * that otherwise encounter collisions for hashCodes that do not differ
+     * in lower bits.
+     *
+     * @param key the object which hash code is to be calculated
+     * @return a hash code value for the specified object
+     */
+    private int hash(Object key) {
+        if (this.identity) {
+            int hash = System.identityHashCode(key);
+            return (hash << 1) - (hash << 8);
+        }
+        int hash = key.hashCode();
+        // This function ensures that hashCodes that differ only by
+        // constant multiples at each bit position have a bounded
+        // number of collisions (approximately 8 at default load factor).
+        hash ^= (hash >>> 20) ^ (hash >>> 12);
+        return hash ^ (hash >>> 7) ^ (hash >>> 4);
+    }
+
+    /**
+     * Returns index of the specified hash code in the given table.
+     * Note that the table size must be a power of two.
+     *
+     * @param hash  the hash code
+     * @param table the table
+     * @return an index of the specified hash code in the given table
+     */
+    private static int index(int hash, Object[] table) {
+        return hash & (table.length - 1);
+    }
+
+    /**
+     * Creates a new array for the cache entries.
+     *
+     * @param size requested capacity MUST be a power of two
+     * @return a new array for the cache entries
+     */
+    @SuppressWarnings("unchecked")
+    private CacheEntry<K,V>[] newTable(int size) {
+        return (CacheEntry<K,V>[]) new CacheEntry[size];
+    }
+
+    private V getEntryValue(K key, int hash, CacheEntry<K,V> entry) {
+        while (entry != null) {
+            if (entry.matches(hash, key)) {
+                return entry.value.getReferent();
+            }
+            entry = entry.next;
+        }
+        return null;
+    }
+
+    private void removeStaleEntries() {
+        Object reference = this.queue.poll();
+        if (reference != null) {
+            synchronized (this.queue) {
+                do {
+                    if (reference instanceof Ref) {
+                        Ref ref = (Ref) reference;
+                        @SuppressWarnings("unchecked")
+                        CacheEntry<K,V> owner = (CacheEntry<K,V>) ref.getOwner();
+                        if (owner != null) {
+                            int index = index(owner.hash, this.table);
+                            CacheEntry<K,V> prev = this.table[index];
+                            CacheEntry<K,V> entry = prev;
+                            while (entry != null) {
+                                CacheEntry<K,V> next = entry.next;
+                                if (entry == owner) {
+                                    if (entry == prev) {
+                                        this.table[index] = next;
+                                    } else {
+                                        prev.next = next;
+                                    }
+                                    entry.unlink();
+                                    break;
+                                }
+                                prev = entry;
+                                entry = next;
+                            }
+                        }
+                    }
+                    reference = this.queue.poll();
+                }
+                while (reference != null);
+            }
+        }
+    }
+
+    private void transfer(CacheEntry<K,V>[] oldTable, CacheEntry<K,V>[] newTable) {
+        int oldIndex = oldTable.length;
+        while (0 < oldIndex--) {
+            CacheEntry<K,V> entry = oldTable[oldIndex];
+            oldTable[oldIndex] = null;
+            while (entry != null) {
+                CacheEntry<K,V> next = entry.next;
+                if (entry.key.isStale() || entry.value.isStale()) {
+                    entry.unlink();
+                } else {
+                    int newIndex = index(entry.hash, newTable);
+                    entry.next = newTable[newIndex];
+                    newTable[newIndex] = entry;
+                }
+                entry = next;
+            }
+        }
+    }
+
+    /**
+     * Represents a cache entry (key-value pair).
+     */
+    private final class CacheEntry<K,V> {
+        private final int hash;
+        private final Ref<K> key;
+        private final Ref<V> value;
+        private volatile CacheEntry<K,V> next;
+
+        /**
+         * Constructs an entry for the cache.
+         *
+         * @param hash  the hash code calculated for the entry key
+         * @param key   the entry key
+         * @param value the initial value of the entry
+         * @param next  the next entry in a chain
+         */
+        private CacheEntry(int hash, K key, V value, CacheEntry<K,V> next) {
+            this.hash = hash;
+            this.key = Cache.this.keyKind.create(this, key, Cache.this.queue);
+            this.value = Cache.this.valueKind.create(this, value, Cache.this.queue);
+            this.next = next;
+        }
+
+        /**
+         * Determines whether the entry has the given key with the given hash code.
+         *
+         * @param hash   an expected hash code
+         * @param object an object to be compared with the entry key
+         * @return {@code true} if the entry has the given key with the given hash code;
+         *         {@code false} otherwise
+         */
+        private boolean matches(int hash, Object object) {
+            if (this.hash != hash) {
+                return false;
+            }
+            Object key = this.key.getReferent();
+            return (key == object) || !Cache.this.identity && (key != null) && key.equals(object);
+        }
+
+        /**
+         * Marks the entry as actually removed from the cache.
+         */
+        private void unlink() {
+            this.next = null;
+            this.key.removeOwner();
+            this.value.removeOwner();
+            Cache.this.size--;
+        }
+    }
+
+    /**
+     * Basic interface for references.
+     * It defines the operations common for the all kind of references.
+     *
+     * @param <T> the type of object to refer
+     */
+    private static interface Ref<T> {
+        /**
+         * Returns the object that possesses information about the reference.
+         *
+         * @return the owner of the reference or {@code null} if the owner is unknown
+         */
+        Object getOwner();
+
+        /**
+         * Returns the object to refer.
+         *
+         * @return the referred object or {@code null} if it was collected
+         */
+        T getReferent();
+
+        /**
+         * Determines whether the referred object was taken by the garbage collector or not.
+         *
+         * @return {@code true} if the referred object was collected
+         */
+        boolean isStale();
+
+        /**
+         * Marks this reference as removed from the cache.
+         */
+        void removeOwner();
+    }
+
+    /**
+     * Represents a reference kind.
+     */
+    public static enum Kind {
+        STRONG {
+            <T> Ref<T> create(Object owner, T value, ReferenceQueue<? super T> queue) {
+                return new Strong<>(owner, value);
+            }
+        },
+        SOFT {
+            <T> Ref<T> create(Object owner, T referent, ReferenceQueue<? super T> queue) {
+                return (referent == null)
+                        ? new Strong<>(owner, referent)
+                        : new Soft<>(owner, referent, queue);
+            }
+        },
+        WEAK {
+            <T> Ref<T> create(Object owner, T referent, ReferenceQueue<? super T> queue) {
+                return (referent == null)
+                        ? new Strong<>(owner, referent)
+                        : new Weak<>(owner, referent, queue);
+            }
+        };
+
+        /**
+         * Creates a reference to the specified object.
+         *
+         * @param <T>      the type of object to refer
+         * @param owner    the owner of the reference, if needed
+         * @param referent the object to refer
+         * @param queue    the queue to register the reference with,
+         *                 or {@code null} if registration is not required
+         * @return the reference to the specified object
+         */
+        abstract <T> Ref<T> create(Object owner, T referent, ReferenceQueue<? super T> queue);
+
+        /**
+         * This is an implementation of the {@link Cache.Ref} interface
+         * that uses the strong references that prevent their referents
+         * from being made finalizable, finalized, and then reclaimed.
+         *
+         * @param <T> the type of object to refer
+         */
+        private static final class Strong<T> implements Ref<T> {
+            private Object owner;
+            private final T referent;
+
+            /**
+             * Creates a strong reference to the specified object.
+             *
+             * @param owner    the owner of the reference, if needed
+             * @param referent the non-null object to refer
+             */
+            private Strong(Object owner, T referent) {
+                this.owner = owner;
+                this.referent = referent;
+            }
+
+            /**
+             * Returns the object that possesses information about the reference.
+             *
+             * @return the owner of the reference or {@code null} if the owner is unknown
+             */
+            public Object getOwner() {
+                return this.owner;
+            }
+
+            /**
+             * Returns the object to refer.
+             *
+             * @return the referred object
+             */
+            public T getReferent() {
+                return this.referent;
+            }
+
+            /**
+             * Determines whether the referred object was taken by the garbage collector or not.
+             *
+             * @return {@code true} if the referred object was collected
+             */
+            public boolean isStale() {
+                return false;
+            }
+
+            /**
+             * Marks this reference as removed from the cache.
+             */
+            public void removeOwner() {
+                this.owner = null;
+            }
+        }
+
+        /**
+         * This is an implementation of the {@link Cache.Ref} interface
+         * that uses the soft references that are cleared at the discretion
+         * of the garbage collector in response to a memory request.
+         *
+         * @param <T> the type of object to refer
+         * @see java.lang.ref.SoftReference
+         */
+        private static final class Soft<T> extends SoftReference<T> implements Ref<T> {
+            private Object owner;
+
+            /**
+             * Creates a soft reference to the specified object.
+             *
+             * @param owner    the owner of the reference, if needed
+             * @param referent the non-null object to refer
+             * @param queue    the queue to register the reference with,
+             *                 or {@code null} if registration is not required
+             */
+            private Soft(Object owner, T referent, ReferenceQueue<? super T> queue) {
+                super(referent, queue);
+                this.owner = owner;
+            }
+
+            /**
+             * Returns the object that possesses information about the reference.
+             *
+             * @return the owner of the reference or {@code null} if the owner is unknown
+             */
+            public Object getOwner() {
+                return this.owner;
+            }
+
+            /**
+             * Returns the object to refer.
+             *
+             * @return the referred object or {@code null} if it was collected
+             */
+            public T getReferent() {
+                return get();
+            }
+
+            /**
+             * Determines whether the referred object was taken by the garbage collector or not.
+             *
+             * @return {@code true} if the referred object was collected
+             */
+            public boolean isStale() {
+                return null == get();
+            }
+
+            /**
+             * Marks this reference as removed from the cache.
+             */
+            public void removeOwner() {
+                this.owner = null;
+            }
+        }
+
+        /**
+         * This is an implementation of the {@link Cache.Ref} interface
+         * that uses the weak references that do not prevent their referents
+         * from being made finalizable, finalized, and then reclaimed.
+         *
+         * @param <T> the type of object to refer
+         * @see java.lang.ref.WeakReference
+         */
+        private static final class Weak<T> extends WeakReference<T> implements Ref<T> {
+            private Object owner;
+
+            /**
+             * Creates a weak reference to the specified object.
+             *
+             * @param owner    the owner of the reference, if needed
+             * @param referent the non-null object to refer
+             * @param queue    the queue to register the reference with,
+             *                 or {@code null} if registration is not required
+             */
+            private Weak(Object owner, T referent, ReferenceQueue<? super T> queue) {
+                super(referent, queue);
+                this.owner = owner;
+            }
+
+            /**
+             * Returns the object that possesses information about the reference.
+             *
+             * @return the owner of the reference or {@code null} if the owner is unknown
+             */
+            public Object getOwner() {
+                return this.owner;
+            }
+
+            /**
+             * Returns the object to refer.
+             *
+             * @return the referred object or {@code null} if it was collected
+             */
+            public T getReferent() {
+                return get();
+            }
+
+            /**
+             * Determines whether the referred object was taken by the garbage collector or not.
+             *
+             * @return {@code true} if the referred object was collected
+             */
+            public boolean isStale() {
+                return null == get();
+            }
+
+            /**
+             * Marks this reference as removed from the cache.
+             */
+            public void removeOwner() {
+                this.owner = null;
+            }
+        }
+    }
+}

test/java/beans/XMLDecoder/8028054/Task.java

+/*
+ * Copyright (c) 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.
+ */
+
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+abstract class Task<T> implements Runnable {
+    private transient boolean working = true;
+    private final List<T> methods;
+    private final Thread thread;
+
+    Task(List<T> methods) {
+        this.methods = methods;
+        this.thread = new Thread(this);
+        this.thread.start();
+    }
+
+    boolean isAlive() {
+        return this.thread.isAlive();
+    }
+
+    boolean isWorking() {
+        boolean working = this.working && this.thread.isAlive();
+        this.working = false;
+        return working;
+    }
+
+    @Override
+    public void run() {
+        long time = -System.currentTimeMillis();
+        for (T method : this.methods) {
+            this.working = true;
+            try {
+                for (int i = 0; i < 100; i++) {
+                    process(method);
+                }
+            } catch (NoSuchMethodException ignore) {
+            }
+        }
+        time += System.currentTimeMillis();
+        print("thread done in " + time / 1000 + " seconds");
+    }
+
+    protected abstract void process(T method) throws NoSuchMethodException;
+
+    static synchronized void print(Object message) {
+        System.out.println(message);
+        System.out.flush();
+    }
+
+    static List<Class<?>> getClasses(int count) throws Exception {
+        String resource = ClassLoader.getSystemClassLoader().getResource("java/lang/Object.class").toString();
+
+        Pattern pattern = Pattern.compile("jar:file:(.*)!.*");
+        Matcher matcher = pattern.matcher(resource);
+        matcher.matches();
+        resource = matcher.group(1);
+
+        List<Class<?>> classes = new ArrayList<>();
+        try (JarFile jarFile = new JarFile(resource)) {
+            Enumeration<JarEntry> entries = jarFile.entries();
+            while (entries.hasMoreElements()) {
+                String name = entries.nextElement().getName();
+                if (name.startsWith("java") && name.endsWith(".class")) {
+                    classes.add(Class.forName(name.substring(0, name.indexOf(".")).replace('/', '.')));
+                    if (count == classes.size()) {
+                        break;
+                    }
+                }
+            }
+        }
+        return classes;
+    }
+}

test/java/beans/XMLDecoder/8028054/TestConstructorFinder.java

+/*
+ * Copyright (c) 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.
+ */
+
+import com.sun.beans.finder.ConstructorFinder;
+
+import java.lang.reflect.Constructor;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/*
+ * @test
+ * @bug 8028054
+ * @summary Tests that cached constructors have synchronized access
+ * @author Sergey Malenkov
+ * @compile -XDignore.symbol.file TestConstructorFinder.java
+ * @run main TestConstructorFinder
+ */
+
+public class TestConstructorFinder {
+    public static void main(String[] args) throws Exception {
+        List<Class<?>> classes = Task.getClasses(Integer.MAX_VALUE);
+        List<Constructor> constructors = new ArrayList<>();
+        for (Class<?> type : classes) {
+            Collections.addAll(constructors, type.getConstructors());
+        }
+        Task.print("found " + constructors.size() + " constructors in " + classes.size() + " classes");
+
+        List<Task> tasks = new ArrayList<>();
+        for (int i = 0; i < 50; i++) {
+            tasks.add(new Task<Constructor>(constructors) {
+                @Override
+                protected void process(Constructor constructor) throws NoSuchMethodException {
+                    ConstructorFinder.findConstructor(constructor.getDeclaringClass(), constructor.getParameterTypes());
+                }
+            });
+        }
+        int alarm = 0;
+        while (true) {
+            int alive = 0;
+            int working = 0;
+            for (Task task : tasks) {
+                if (task.isWorking()) {
+                    working++;
+                    alive++;
+                } else if (task.isAlive()) {
+                    alive++;
+                }
+            }
+            if (alive == 0) {
+                break;
+            }
+            Task.print(working + " out of " + alive + " threads are working");
+            if ((working == 0) && (++alarm == 10)) {
+                Task.print("DEADLOCK DETECTED");
+                System.exit(100);
+            }
+            Thread.sleep(1000);
+        }
+    }
+}

test/java/beans/XMLDecoder/8028054/TestMethodFinder.java

+/*
+ * Copyright (c) 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.
+ */
+
+import com.sun.beans.finder.MethodFinder;
+
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/*
+ * @test
+ * @bug 8028054
+ * @summary Tests that cached methods have synchronized access
+ * @author Sergey Malenkov
+ * @compile -XDignore.symbol.file TestMethodFinder.java
+ * @run main TestMethodFinder
+ */
+
+public class TestMethodFinder {
+    public static void main(String[] args) throws Exception {
+        List<Class<?>> classes = Task.getClasses(4000);
+        List<Method> methods = new ArrayList<>();
+        for (Class<?> type : classes) {
+            Collections.addAll(methods, type.getMethods());
+        }
+        Task.print("found " + methods.size() + " methods in " + classes.size() + " classes");
+
+        List<Task> tasks = new ArrayList<>();
+        for (int i = 0; i < 50; i++) {
+            tasks.add(new Task<Method>(methods) {
+                @Override
+                protected void process(Method method) throws NoSuchMethodException {
+                    MethodFinder.findMethod(method.getDeclaringClass(), method.getName(), method.getParameterTypes());
+                }
+            });
+        }
+        int alarm = 0;
+        while (true) {
+            int alive = 0;
+            int working = 0;
+            for (Task task : tasks) {
+                if (task.isWorking()) {
+                    working++;
+                    alive++;
+                } else if (task.isAlive()) {
+                    alive++;
+                }
+            }
+            if (alive == 0) {
+                break;
+            }
+            Task.print(working + " out of " + alive + " threads are working");
+            if ((working == 0) && (++alarm == 10)) {
+                Task.print("DEADLOCK DETECTED");
+                System.exit(100);
+            }
+            Thread.sleep(1000);
+        }
+    }
+}