8006506: Add test for redefining methods in backtraces to java/lang/instrument tests
Reviewed-by: sspitsyn, coleenp
diff --git a/test/java/lang/instrument/RedefineMethodInBacktraceApp.java b/test/java/lang/instrument/RedefineMethodInBacktraceApp.java
new file mode 100644
index 0000000..a4ad088
--- /dev/null
+++ b/test/java/lang/instrument/RedefineMethodInBacktraceApp.java
@@ -0,0 +1,111 @@
+/*
+ * 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.io.File;
+import java.io.FileInputStream;
+import java.io.InputStream;
+import java.lang.instrument.ClassDefinition;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+/**
+ * When an exception is thrown, the JVM collects just enough information
+ * about the stack trace to be able to create a full fledged stack trace
+ * (StackTraceElement[]). The backtrace contains this information and the
+ * JVM must make sure that the data in the backtrace is still usable after
+ * a class redefinition.
+ *
+ * After the PermGen removal there was a bug when the last reference to a Method
+ * was in the backtrace. The class of the method was kept alive, because of the
+ * mirror stored in the backtrace, but the old versions of the redefined method
+ * could be freed, since class redefinition didn't know about the backtraces.
+ */
+public class RedefineMethodInBacktraceApp {
+ public static void main(String args[]) throws Exception {
+ System.out.println("Hello from RedefineMethodInBacktraceApp!");
+
+ new RedefineMethodInBacktraceApp().doTest();
+
+ System.exit(0);
+ }
+
+ private void doTest() throws Exception {
+ doMethodInBacktraceTest();
+ }
+
+ private void doMethodInBacktraceTest() throws Exception {
+ Throwable t = getThrowableFromMethodToRedefine();
+
+ doRedefine(RedefineMethodInBacktraceTarget.class);
+
+ doClassUnloading();
+
+ touchRedefinedMethodInBacktrace(t);
+ }
+
+ private static Throwable getThrowableFromMethodToRedefine() throws Exception {
+ Class<RedefineMethodInBacktraceTarget> c =
+ RedefineMethodInBacktraceTarget.class;
+ Method method = c.getMethod("methodToRedefine");
+
+ Throwable thrownFromMethodToRedefine = null;
+ try {
+ method.invoke(null);
+ } catch (InvocationTargetException e) {
+ thrownFromMethodToRedefine = e.getCause();
+ if (!(thrownFromMethodToRedefine instanceof RuntimeException)) {
+ throw e;
+ }
+ }
+ method = null;
+ c = null;
+
+ return thrownFromMethodToRedefine;
+ }
+
+ private static void doClassUnloading() {
+ // This will clean out old, unused redefined methods.
+ System.gc();
+ }
+
+ private static void touchRedefinedMethodInBacktrace(Throwable throwable) {
+ // Make sure that we can convert the backtrace, which is referring to
+ // the redefined method, to a StrackTraceElement[] without crashing.
+ throwable.getStackTrace();
+ }
+
+ private static void doRedefine(Class<?> clazz) throws Exception {
+ // Load the second version of this class.
+ File f = new File(clazz.getName() + ".class");
+ System.out.println("Reading test class from " + f.getAbsolutePath());
+ InputStream redefineStream = new FileInputStream(f);
+
+ byte[] redefineBuffer = NamedBuffer.loadBufferFromStream(redefineStream);
+
+ ClassDefinition redefineParamBlock = new ClassDefinition(
+ clazz, redefineBuffer);
+
+ RedefineMethodInBacktraceAgent.getInstrumentation().redefineClasses(
+ new ClassDefinition[] {redefineParamBlock});
+ }
+}