6892340: Part of the CR 6741890 should be forwardported

Reviewed-by: malenkov

jdk/src/windows/classes/sun/awt/shell/Win32ShellFolder2.java

@@ -524,7 +524,7 @@ final class Win32ShellFolder2 extends ShellFolder {
     // NOTE: this method uses COM and must be called on the 'COM thread'. See ComInvoker for the details
     private static native int compareIDs(long pParentIShellFolder, long pidl1, long pidl2);
 
-    private Boolean cachedIsFileSystem;
+    private volatile Boolean cachedIsFileSystem;
 
     /**
      * @return Whether this is a file system shell folder
@@ -759,7 +759,7 @@ final class Win32ShellFolder2 extends ShellFolder {
         }, InterruptedException.class);
     }
 
-    private Boolean cachedIsLink;
+    private volatile Boolean cachedIsLink;
 
     /**
      * @return Whether this shell folder is a link

jdk/test/javax/swing/JFileChooser/6741890/bug6741890.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright 2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/* @test
+   @bug 6741890
+   @summary Deadlock in Win32ShellFolderManager2
+   @author Pavel Porvatov
+   @run main bug6741890
+*/
+
+import sun.awt.shell.ShellFolder;
+
+import java.io.File;
+import java.lang.reflect.Field;
+import java.util.concurrent.Callable;
+
+public class bug6741890 {
+    /**
+     * This mux is used to prevent NPE in the isLink and isFileSystem methods
+     */
+    private static final Object mux = new Object();
+
+    private static final int COUNT = 100000;
+
+    public static void main(String[] args) throws Exception {
+        String tmpDir = System.getProperty("java.io.tmpdir");
+
+        if (tmpDir.length() == 0) { //'java.io.tmpdir' isn't guaranteed to be defined
+            tmpDir = System.getProperty("user.home");
+        }
+
+        final ShellFolder tmpFile = ShellFolder.getShellFolder(new File(tmpDir));
+
+        System.out.println("Temp directory: " + tmpDir);
+
+        System.out.println("Stress test was run");
+
+        Thread thread = new Thread() {
+            public void run() {
+                while (!isInterrupted()) {
+                    ShellFolder.invoke(new Callable<Void>() {
+                        public Void call() throws Exception {
+                            synchronized (mux) {
+                                tmpFile.isFileSystem();
+                                tmpFile.isLink();
+                            }
+
+                            return null;
+                        }
+                    });
+                }
+            }
+        };
+
+        thread.start();
+
+        for (int i = 0; i < COUNT; i++) {
+            synchronized (mux) {
+                clearField(tmpFile, "cachedIsLink");
+                clearField(tmpFile, "cachedIsFileSystem");
+            }
+
+            tmpFile.isFileSystem();
+            tmpFile.isLink();
+        }
+
+        thread.interrupt();
+        thread.join();
+
+        System.out.println("Test passed successfully");
+    }
+
+    private static void clearField(Object o, String fieldName) throws Exception {
+        Field field = o.getClass().getDeclaredField(fieldName);
+
+        field.setAccessible(true);
+
+        field.set(o, null);
+    }
+}