Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * 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;

   }

 }