7079254: Toolkit eventListener leaks memory

Reviewed-by: serb, art

src/share/classes/java/awt/Component.java

@@ -1671,6 +1671,15 @@ public abstract class Component implements ImageObserver, MenuContainer,
         /* do nothing */
     }
 
+    /*
+     * Delete references from LightweithDispatcher of a heavyweight parent
+     */
+    void clearLightweightDispatcherOnRemove(Component removedComponent) {
+        if (parent != null) {
+            parent.clearLightweightDispatcherOnRemove(removedComponent);
+        }
+    }
+
     /**
      * @deprecated As of JDK version 1.1,
      * replaced by <code>setVisible(boolean)</code>.
@@ -6974,6 +6983,8 @@ public abstract class Component implements ImageObserver, MenuContainer,
         }
 
         synchronized (getTreeLock()) {
+            clearLightweightDispatcherOnRemove(this);
+
             if (isFocusOwner() && KeyboardFocusManager.isAutoFocusTransferEnabledFor(this)) {
                 transferFocus(true);
             }

src/share/classes/java/awt/Container.java

@@ -3306,6 +3306,16 @@ public class Container extends Component {
         }
     }
 
+    @Override
+    void clearLightweightDispatcherOnRemove(Component removedComponent) {
+        if (dispatcher != null) {
+            dispatcher.removeReferences(removedComponent);
+        } else {
+            //It is a Lightweight Container, should clear parent`s Dispatcher
+            super.clearLightweightDispatcherOnRemove(removedComponent);
+        }
+    }
+
     final Container getTraversalRoot() {
         if (isFocusCycleRoot()) {
             return findTraversalRoot();
@@ -4411,6 +4421,7 @@ class LightweightDispatcher implements java.io.Serializable, AWTEventListener {
         //System.out.println("Disposing lw dispatcher");
         stopListeningForOtherDrags();
         mouseEventTarget = null;
+        targetLastEntered = null;
     }
 
     /**
@@ -4502,6 +4513,7 @@ class LightweightDispatcher implements java.io.Serializable, AWTEventListener {
     // MOUSE_CLICKED.
     if (!isMouseGrab(e) && id != MouseEvent.MOUSE_CLICKED) {
             mouseEventTarget = (mouseOver != nativeContainer) ? mouseOver: null;
+            isCleaned = false;
         }
 
         if (mouseEventTarget != null) {
@@ -4545,10 +4557,14 @@ class LightweightDispatcher implements java.io.Serializable, AWTEventListener {
             retargetMouseEvent(mouseOver, id, e);
         break;
             }
-            //Consuming of wheel events is implemented in "retargetMouseEvent".
-            if (id != MouseEvent.MOUSE_WHEEL) {
-                e.consume();
-            }
+        //Consuming of wheel events is implemented in "retargetMouseEvent".
+        if (id != MouseEvent.MOUSE_WHEEL) {
+            e.consume();
+        }
+    } else if (isCleaned && id != MouseEvent.MOUSE_WHEEL) {
+        //After mouseEventTarget was removed and cleaned should consume all events
+        //until new mouseEventTarget is found
+        e.consume();
     }
     return e.isConsumed();
     }
@@ -4891,6 +4907,11 @@ class LightweightDispatcher implements java.io.Serializable, AWTEventListener {
      */
     private transient Component targetLastEntered;
 
+    /**
+     * Indicates whether {@code mouseEventTarget} was removed and nulled
+     */
+    private transient boolean isCleaned;
+
     /**
      * Is the mouse over the native container
      */
@@ -4925,4 +4946,14 @@ class LightweightDispatcher implements java.io.Serializable, AWTEventListener {
         AWTEvent.MOUSE_EVENT_MASK |
         AWTEvent.MOUSE_MOTION_EVENT_MASK |
         AWTEvent.MOUSE_WHEEL_EVENT_MASK;
+
+    void removeReferences(Component removedComponent) {
+        if (mouseEventTarget == removedComponent) {
+            isCleaned = true;
+            mouseEventTarget = null;
+        }
+        if (targetLastEntered == removedComponent) {
+            targetLastEntered = null;
+        }
+    }
 }

test/java/awt/LightweightDispatcher/LWDispatcherMemoryLeakTest.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.awt.AWTException;
+import java.awt.FlowLayout;
+import java.awt.Robot;
+import java.lang.ref.Reference;
+import java.lang.ref.WeakReference;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import javax.swing.JButton;
+import javax.swing.JFrame;
+import javax.swing.JPanel;
+import javax.swing.SwingUtilities;
+import test.java.awt.regtesthelpers.Util;
+
+/*
+ @test
+ @bug 7079254
+ @summary Toolkit eventListener leaks memory
+ @library ../regtesthelpers
+ @build Util
+ @compile LWDispatcherMemoryLeakTest.java
+ @run main/othervm -Xmx10M LWDispatcherMemoryLeakTest
+ */
+public class LWDispatcherMemoryLeakTest {
+
+    private static JFrame frame;
+    private static WeakReference<JButton> button;
+    private static WeakReference<JPanel> p;
+
+    public static void init() throws Throwable {
+        SwingUtilities.invokeAndWait(new Runnable() {
+            @Override
+            public void run() {
+                frame = new JFrame();
+                frame.setLayout(new FlowLayout());
+                button = new WeakReference<JButton>(new JButton("Text"));
+                p = new WeakReference<JPanel>(new JPanel(new FlowLayout()));
+                p.get().add(button.get());
+                frame.add(p.get());
+
+                frame.setBounds(500, 400, 200, 200);
+                frame.setVisible(true);
+            }
+        });
+
+        Util.waitTillShown(button.get());
+        Util.clickOnComp(button.get(), new Robot());
+
+        SwingUtilities.invokeAndWait(new Runnable() {
+            @Override
+            public void run() {
+                frame.remove(p.get());
+            }
+        });
+
+        Util.waitForIdle(null);
+        assertGC();
+    }
+
+    public static void assertGC() throws Throwable {
+        List<byte[]> alloc = new ArrayList<byte[]>();
+        int size = 10 * 1024;
+        while (true) {
+            try {
+                alloc.add(new byte[size]);
+            } catch (OutOfMemoryError err) {
+                break;
+            }
+        }
+        alloc = null;
+        if (button.get() != null) {
+            throw new Exception("Test failed: JButton was not collected");
+        }
+    }
+
+    public static void main(String args[]) throws Throwable {
+        init();
+    }
+}