--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/6910618/Test.java	Tue Feb 09 01:31:13 2010 -0800
@@ -0,0 +1,74 @@
+/*
+ * Copyright 2010 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 6910605
+ * @summary C2: NullPointerException/ClassCaseException is thrown when C2 with DeoptimizeALot is used
+ *
+ * @run main/othervm -Xmx64m -XX:+IgnoreUnrecognizedVMOptions -XX:+DeoptimizeALot -XX:+DoEscapeAnalysis -Xbatch -XX:InlineSmallCode=2000 Test
+ *
+ */
+
+/*
+ * Added InlineSmallCode=2000 to guaranty inlining of StringBuilder::append() to allow scalar replace StringBuilder object.
+ *
+ * original test: gc/gctests/StringGC
+ */
+
+public class Test {
+        private final String toAdd = "0123456789abcdef";
+        private int maxLength;
+        private static final int numberOfThreads = 8;
+
+        private class StringAdder extends Thread {
+                private String s;
+
+                public void test() {
+                        s = s + toAdd;
+                }
+                public void run() {
+                        do {
+                                test();
+                        } while (s.length() < maxLength);
+                 }
+        }
+
+        public void test() throws InterruptedException {
+                maxLength = toAdd.length() * 15000/ numberOfThreads;
+                StringAdder[] sa = new StringAdder[numberOfThreads];
+                for (int i = 0; i < numberOfThreads; i++) {
+                        sa[i] = new StringAdder();
+                        sa[i].start();
+                }
+                for (int i = 0; i < numberOfThreads; i++) {
+                        sa[i].join();
+                }
+        }
+
+        public static void main(String[] args) throws InterruptedException {
+                Test t = new Test();
+                t.test();
+        }
+}