| /* |
| * 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; |
| } |
| |
| } |