1 /*
   2  * Copyright (c) 2015, 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 package utils;
  24 
  25 /**
  26  * Garbage producer that creates classes loaded with GeneratingClassLoader.
  27  *
  28  * Note: this class is not thread-safe.
  29  */
  30 class GeneratedClassProducer {
  31 
  32     private int number;
  33     private String className;
  34     private StringBuilder sb = new StringBuilder();
  35     private int minPerClassLoader = 50;
  36     private int maxPerClassLoader = 150;
  37     private int count;
  38     private GeneratingClassLoader loader = new GeneratingClassLoader();
  39 
  40     GeneratedClassProducer() {
  41         this(GeneratingClassLoader.DEFAULT_CLASSNAME);
  42     }
  43 
  44     GeneratedClassProducer(String className) {
  45         this.className = className;
  46     }
  47 
  48     String getNewName() {
  49         sb.delete(0, sb.length());
  50         sb.append("Class");
  51         sb.append(number);
  52         int n = loader.getNameLength() - sb.length();
  53         for (int i = 0; i < n; ++i) {
  54             sb.append('_');
  55         }
  56         return sb.toString();
  57     }
  58 
  59     Class create(long memory) {
  60         try {
  61             if (number++ > maxPerClassLoader || loader == null) {
  62                 loader = new GeneratingClassLoader(className);
  63                 count = 50;
  64                 number = 0;
  65             }
  66             return loader.loadClass(getNewName());
  67         } catch (ClassNotFoundException e) {
  68             throw new RuntimeException(e);
  69         }
  70     }
  71 }