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/*
* 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");
}
}
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