8046246: the constantPoolCacheOopDesc::adjust_method_entries() used in...

8046246: the constantPoolCacheOopDesc::adjust_method_entries() used in RedefineClasses does not scale
Summary: add new test java/lang/instrument/ManyMethodsBenchmarkAgent.java
Reviewed-by: coleenp, dcubed

test/java/lang/instrument/ManyMethodsBenchmarkAgent.java

+/*
+ * Copyright (c) 2015, 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.
+ */
+
+/**
+ * @test
+ * @bug 8046246
+ * @summary Tests and benchmarks the JVMTI RedefineClasses when a
+ *          single class (and its parent) contains many methods.
+ *
+ * @run build ManyMethodsBenchmarkApp ManyMethodsBenchmarkAgent
+ * @run shell MakeJAR3.sh ManyMethodsBenchmarkAgent 'Can-Retransform-Classes: true'
+ * @run main/othervm -javaagent:ManyMethodsBenchmarkAgent.jar ManyMethodsBenchmarkApp
+ */
+import java.lang.instrument.*;
+
+public class ManyMethodsBenchmarkAgent
+{
+    public  static boolean fail = false;
+    public  static boolean completed = false;
+    private static  Instrumentation instrumentation;
+
+    public static void
+    premain(    String agentArgs,
+                Instrumentation instrumentation) {
+        System.out.println("ManyMethodsBenchmarkAgent started");
+        ManyMethodsBenchmarkAgent.instrumentation = instrumentation;
+        System.out.println("ManyMethodsBenchmarkAgent finished");
+    }
+
+    static void instr() {
+        System.out.println("ManyMethodsBenchmarkAgent.instr started");
+
+        Class[] allClasses = instrumentation.getAllLoadedClasses();
+
+        for (int i = 0; i < allClasses.length; i++) {
+            Class klass = allClasses[i];
+            String name = klass.getName();
+            if (!name.equals("Base")) {
+                continue;
+            }
+            System.err.println("Instrumenting the class: " + klass);
+
+            try {
+                instrumentation.retransformClasses(klass);
+            } catch (Throwable e) {
+                System.err.println("Error: bad return from retransform: " + klass);
+                System.err.println("  ERROR: " + e);
+                fail = true;
+            }
+        }
+        completed = true;
+        System.out.println("ManyMethodsBenchmarkAgent.instr finished");
+    }
+
+}

test/java/lang/instrument/ManyMethodsBenchmarkApp.java

+/*
+ * Copyright 2015 Google 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 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.FileWriter;
+import java.io.PrintStream;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Type;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.Arrays;
+import java.util.List;
+import javax.tools.JavaCompiler;
+import javax.tools.StandardJavaFileManager;
+import javax.tools.ToolProvider;
+
+/**
+ * A manual benchmark of the JVMTI RedefineClasses when a
+ * single class (and its parent) contains many methods.
+ */
+public class ManyMethodsBenchmarkApp {
+     // Limit is 64k but we can not put such many as the CP limit is 32k.
+     // In practice, it means a real limit is much lower (less than 22000).
+    static final int METHOD_COUNT = 20000;
+
+    static Class<?> loadClassInNewClassLoader(String className) throws Exception {
+        URL[] urls = { new File(".").toURI().toURL() };
+        URLClassLoader ucl = new URLClassLoader(urls, null);
+        Class<?> klazz = Class.forName(className, true, ucl);
+        return klazz;
+    }
+
+    static void benchmarkClassOperations(String className) throws Exception {
+        Class<?> klazz = loadClassInNewClassLoader(className);
+
+        Method[] methods = klazz.getDeclaredMethods();
+        if (methods.length != METHOD_COUNT) {
+            throw new AssertionError("unexpected method count: " + methods.length +
+                                     " expected: " + METHOD_COUNT);
+        }
+
+        methods = klazz.getMethods();
+        // returned methods includes those inherited from Object
+        int objectMethodSlop = 100;
+        if (methods.length <= METHOD_COUNT ||
+            methods.length >= METHOD_COUNT + objectMethodSlop) {
+            throw new AssertionError("unexpected method count: " + methods.length);
+        }
+
+        // Invoke methods to make them appear in the constant pool cache
+        Object obj = klazz.newInstance();
+        Object[] args = new Object[0];
+        for (Method m: methods) {
+            try {
+                Class<?>[] types = m.getParameterTypes();
+                String     name  = m.getName();
+             // System.out.println("method: " + name + "; argno: " + types.length);
+                if (types.length == 0 && name.length() == 2 && name.startsWith("f")) {
+                    m.invoke(obj, args);
+                }
+            } catch (InvocationTargetException ex) {
+                ex.printStackTrace();
+            }
+        }
+    }
+
+    public static void main(String[] args) throws Exception {
+        System.out.println("test started: ManyMethodsBenchmarkApp");
+
+        // Create source files with many methods
+        File base = new File("Base.java");
+        try (FileWriter fw = new FileWriter(base)) {
+            fw.write("public class Base {\n");
+            final int L = 10;
+            // Each of the first L methods makes calls to its own chunk of METHOD_COUNT/L methods
+            for (int k = 0; k < L; k++) {
+                fw.write("    public void f" + k + "() {\n");
+                int shift = (k == 0) ? L : 0;
+                for (int i = (k * (METHOD_COUNT/L)) + shift; i < (k + 1) * METHOD_COUNT/L; i++) {
+                    fw.write("        f" + i + "();\n");
+                }
+                fw.write("    }\n");
+            }
+
+            // The rest of (METHOD_COUNT - L) methods have empty body
+            for (int i = L; i < METHOD_COUNT; i++) {
+                fw.write("    public static void f" + i + "() {}\n");
+            }
+            fw.write("}\n");
+        }
+
+        // Compile the generated source files.
+        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
+        List<File> files = Arrays.asList(new File[] { base });
+        try (StandardJavaFileManager fileManager =
+             compiler.getStandardFileManager(null, null, null)) {
+            compiler.getTask(null, fileManager, null, null, null,
+                fileManager.getJavaFileObjectsFromFiles(files))
+                .call();
+        }
+
+        benchmarkClassOperations("Base");
+
+        ManyMethodsBenchmarkAgent.instr();
+
+        // Cleanup
+        base.delete();
+        new File("Base.class").delete();
+        if (!ManyMethodsBenchmarkAgent.completed) {
+            throw new Exception("ERROR: ManyMethodsBenchmarkAgent did not complete.");
+        }
+
+        if (ManyMethodsBenchmarkAgent.fail) {
+            throw new Exception("ERROR: ManyMethodsBenchmarkAgent failed.");
+        } else {
+            System.out.println("ManyMethodsBenchmarkAgent succeeded.");
+        }
+        System.out.println("test finished: ManyMethodsBenchmarkApp");
+    }
+}