1 /*

     2  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 import java.io.ByteArrayOutputStream;

    26 import java.io.IOException;

    27 import java.io.OutputStream;

    28 import java.io.PrintWriter;

    29 import java.io.StringWriter;

    30 

    31 import java.lang.reflect.Method;

    32 import java.net.URI;

    33 import java.util.Arrays;

    34 import java.util.Vector;

    35 

    36 import javax.tools.Diagnostic;

    37 import javax.tools.DiagnosticCollector;

    38 import javax.tools.FileObject;

    39 import javax.tools.ForwardingJavaFileManager;

    40 import javax.tools.JavaCompiler;

    41 import javax.tools.JavaCompiler.CompilationTask;

    42 import javax.tools.JavaFileManager;

    43 import javax.tools.JavaFileObject;

    44 import javax.tools.JavaFileObject.Kind;

    45 import javax.tools.SimpleJavaFileObject;

    46 import javax.tools.StandardJavaFileManager;

    47 import javax.tools.ToolProvider;

    48 

    49 /*

    50  * @ignore 6959423

    51  * @test SortMethodsTest

    52  * @bug 6925573

    53  * @summary verify that class loading does not need quadratic time with regard to the number of class

    54 methods.

    55  * @run main SortMethodsTest

    56  * @author volker.simonis@gmail.com

    57 */

    58 

    59 public class SortMethodsTest {

    60 

    61   static String createClass(String name, int nrOfMethods) {

    62     StringWriter sw = new StringWriter();

    63     PrintWriter pw = new PrintWriter(sw);

    64     pw.println("public class " + name + "{");

    65     for (int i = 0; i < nrOfMethods; i++) {

    66       pw.println("  public void m" + i + "() {}");

    67     }

    68     pw.println("  public static String sayHello() {");

    69     pw.println("    return \"Hello from class \" + " + name +

    70                ".class.getName() + \" with \" + " + name +

    71                ".class.getDeclaredMethods().length + \" methods\";");

    72     pw.println("  }");

    73     pw.println("}");

    74     pw.close();

    75     return sw.toString();

    76   }

    77 

    78   public static void main(String args[]) {

    79 

    80     JavaCompiler comp = ToolProvider.getSystemJavaCompiler();

    81     DiagnosticCollector<JavaFileObject> diags = new DiagnosticCollector<JavaFileObject>();

    82     final String cName = new String("ManyMethodsClass");

    83     Vector<Long> results = new Vector<Long>();

    84 

    85     for (int i = 6; i < 600000; i*=10) {

    86       String klass =  createClass(cName, i);

    87       JavaMemoryFileObject file = new JavaMemoryFileObject(cName, klass);

    88       MemoryFileManager mfm = new MemoryFileManager(comp.getStandardFileManager(diags, null, null), file);

    89       CompilationTask task = comp.getTask(null, mfm, diags, null, null, Arrays.asList(file));

    90 

    91       if (task.call()) {

    92         try {

    93           MemoryClassLoader mcl = new MemoryClassLoader(file);

    94           long start = System.nanoTime();

    95           Class<? extends Object> c = Class.forName(cName, true, mcl);

    96           long end = System.nanoTime();

    97           results.add(end - start);

    98           Method m = c.getDeclaredMethod("sayHello", new Class[0]);

    99           String ret = (String)m.invoke(null, new Object[0]);

   100           System.out.println(ret + " (loaded and resloved in " + (end - start) + "ns)");

   101         } catch (Exception e) {

   102           System.err.println(e);

   103         }

   104       }

   105       else {

   106         System.out.println(klass);

   107         System.out.println();

   108         for (Diagnostic diag : diags.getDiagnostics()) {

   109           System.out.println(diag.getCode() + "\n" + diag.getKind() + "\n" + diag.getPosition());

   110           System.out.println(diag.getSource() + "\n" + diag.getMessage(null));

   111         }

   112       }

   113     }

   114 

   115     long lastRatio = 0;

   116     for (int i = 2; i < results.size(); i++) {

   117       long normalized1 = Math.max(results.get(i-1) - results.get(0), 1);

   118       long normalized2 = Math.max(results.get(i) - results.get(0), 1);

   119       long ratio = normalized2/normalized1;

   120       lastRatio = ratio;

   121       System.out.println("10 x more methods requires " + ratio + " x more time");

   122     }

   123     // The following is just vague estimation but seems to work on current x86_64 and sparcv9 machines

   124     if (lastRatio > 80) {

   125       throw new RuntimeException("ATTENTION: it seems that class loading needs quadratic time with regard to the number of class methods!!!");

   126     }

   127   }

   128 }

   129 

   130 class JavaMemoryFileObject extends SimpleJavaFileObject {

   131 

   132   private final String code;

   133   private ByteArrayOutputStream byteCode;

   134 

   135   JavaMemoryFileObject(String name, String code) {

   136     super(URI.create("string:///" + name.replace('.','/') + Kind.SOURCE.extension), Kind.SOURCE);

   137     this.code = code;

   138   }

   139 

   140   @Override

   141   public CharSequence getCharContent(boolean ignoreEncodingErrors) {

   142     return code;

   143   }

   144 

   145   @Override

   146   public OutputStream openOutputStream() {

   147     byteCode = new ByteArrayOutputStream();

   148     return byteCode;

   149   }

   150 

   151   byte[] getByteCode() {

   152     return byteCode.toByteArray();

   153    }

   154 }

   155 

   156 class MemoryClassLoader extends ClassLoader {

   157 

   158   private final JavaMemoryFileObject jfo;

   159 

   160   public MemoryClassLoader(JavaMemoryFileObject jfo) {

   161     this.jfo = jfo;

   162   }

   163 

   164   public Class findClass(String name) {

   165     byte[] b = jfo.getByteCode();

   166     return defineClass(name, b, 0, b.length);

   167   }

   168 }

   169 

   170 class MemoryFileManager extends ForwardingJavaFileManager<JavaFileManager> {

   171 

   172   private final JavaFileObject jfo;

   173 

   174   public MemoryFileManager(StandardJavaFileManager jfm, JavaFileObject jfo) {

   175     super(jfm);

   176     this.jfo = jfo;

   177   }

   178 

   179   @Override

   180   public FileObject getFileForInput(Location location, String packageName,

   181                                     String relativeName) throws IOException {

   182     return jfo;

   183   }

   184 

   185   @Override

   186   public JavaFileObject getJavaFileForOutput(Location location, String qualifiedName,

   187                                              Kind kind, FileObject outputFile) throws IOException {

   188     return jfo;

   189   }

   190 

   191 }