/*
* Copyright (c) 2008, 2010, 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.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.reflect.Method;
import java.net.URI;
import java.util.Arrays;
import java.util.Vector;
import javax.tools.Diagnostic;
import javax.tools.DiagnosticCollector;
import javax.tools.FileObject;
import javax.tools.ForwardingJavaFileManager;
import javax.tools.JavaCompiler;
import javax.tools.JavaCompiler.CompilationTask;
import javax.tools.JavaFileManager;
import javax.tools.JavaFileObject;
import javax.tools.JavaFileObject.Kind;
import javax.tools.SimpleJavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;
/*
* @test SortMethodsTest
* @bug 6925573
* @summary verify that class loading does not need quadratic time with regard to the number of class
methods.
* @run main SortMethodsTest
* @author volker.simonis@gmail.com
*/
public class SortMethodsTest {
static String createClass(String name, int nrOfMethods) {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
pw.println("public class " + name + "{");
for (int i = 0; i < nrOfMethods; i++) {
pw.println(" public void m" + i + "() {}");
}
pw.println(" public static String sayHello() {");
pw.println(" return \"Hello from class \" + " + name +
".class.getName() + \" with \" + " + name +
".class.getDeclaredMethods().length + \" methods\";");
pw.println(" }");
pw.println("}");
pw.close();
return sw.toString();
}
public static void main(String args[]) {
JavaCompiler comp = ToolProvider.getSystemJavaCompiler();
DiagnosticCollector<JavaFileObject> diags = new DiagnosticCollector<JavaFileObject>();
final String cName = new String("ManyMethodsClass");
Vector<Long> results = new Vector<Long>();
for (int i = 6; i < 600000; i*=10) {
String klass = createClass(cName, i);
JavaMemoryFileObject file = new JavaMemoryFileObject(cName, klass);
MemoryFileManager mfm = new MemoryFileManager(comp.getStandardFileManager(diags, null, null), file);
CompilationTask task = comp.getTask(null, mfm, diags, null, null, Arrays.asList(file));
if (task.call()) {
try {
MemoryClassLoader mcl = new MemoryClassLoader(file);
long start = System.nanoTime();
Class<? extends Object> c = Class.forName(cName, true, mcl);
long end = System.nanoTime();
results.add(end - start);
Method m = c.getDeclaredMethod("sayHello", new Class[0]);
String ret = (String)m.invoke(null, new Object[0]);
System.out.println(ret + " (loaded and resloved in " + (end - start) + "ns)");
} catch (Exception e) {
System.err.println(e);
}
}
else {
System.out.println(klass);
System.out.println();
for (Diagnostic diag : diags.getDiagnostics()) {
System.out.println(diag.getCode() + "\n" + diag.getKind() + "\n" + diag.getPosition());
System.out.println(diag.getSource() + "\n" + diag.getMessage(null));
}
}
}
long lastRatio = 0;
for (int i = 2; i < results.size(); i++) {
long normalized1 = Math.max(results.get(i-1) - results.get(0), 1);
long normalized2 = Math.max(results.get(i) - results.get(0), 1);
long ratio = normalized2/normalized1;
lastRatio = ratio;
System.out.println("10 x more methods requires " + ratio + " x more time");
}
// The following is just vague estimation but seems to work on current x86_64 and sparcv9 machines
if (lastRatio > 80) {
throw new RuntimeException("ATTENTION: it seems that class loading needs quadratic time with regard to the number of class methods!!!");
}
}
}
class JavaMemoryFileObject extends SimpleJavaFileObject {
private final String code;
private ByteArrayOutputStream byteCode;
JavaMemoryFileObject(String name, String code) {
super(URI.create("string:///" + name.replace('.','/') + Kind.SOURCE.extension), Kind.SOURCE);
this.code = code;
}
@Override
public CharSequence getCharContent(boolean ignoreEncodingErrors) {
return code;
}
@Override
public OutputStream openOutputStream() {
byteCode = new ByteArrayOutputStream();
return byteCode;
}
byte[] getByteCode() {
return byteCode.toByteArray();
}
}
class MemoryClassLoader extends ClassLoader {
private final JavaMemoryFileObject jfo;
public MemoryClassLoader(JavaMemoryFileObject jfo) {
this.jfo = jfo;
}
public Class findClass(String name) {
byte[] b = jfo.getByteCode();
return defineClass(name, b, 0, b.length);
}
}
class MemoryFileManager extends ForwardingJavaFileManager<JavaFileManager> {
private final JavaFileObject jfo;
public MemoryFileManager(StandardJavaFileManager jfm, JavaFileObject jfo) {
super(jfm);
this.jfo = jfo;
}
@Override
public FileObject getFileForInput(Location location, String packageName,
String relativeName) throws IOException {
return jfo;
}
@Override
public JavaFileObject getJavaFileForOutput(Location location, String qualifiedName,
Kind kind, FileObject outputFile) throws IOException {
return jfo;
}
}