1 /*
   2  * Copyright (c) 2019, 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 import sun.hotspot.WhiteBox;
  25 
  26 import java.lang.reflect.Method;
  27 import java.util.HashMap;
  28 
  29 public class TestJIT {
  30 
  31     private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
  32 
  33     static void doSomething() {
  34         HashMap<String,String> map = new HashMap<>();
  35         for (int i=0; i<400; i++) {
  36             // Call these methods so that the class/field/method references used
  37             // by these methods are resolved. This allows C2 to compile more code.
  38             String x = "Hello" + i;
  39             map.put(x, x);
  40             map.get(x);
  41         }
  42     }
  43 
  44     static public void main(String[] args) throws NoSuchMethodException {
  45         Method put_method = HashMap.class.getDeclaredMethod("put", Object.class, Object.class);
  46         Method get_method = HashMap.class.getDeclaredMethod("get", Object.class);
  47         Method test_method = TestJIT.class.getDeclaredMethod("doSomething");
  48 
  49         doSomething();
  50 
  51         // 4 == CompilerWhiteBoxTest.COMP_LEVEL_FULL_OPTIMIZATION => C2
  52         WHITE_BOX.enqueueMethodForCompilation(get_method, 4);
  53         WHITE_BOX.enqueueMethodForCompilation(put_method, 4);
  54         WHITE_BOX.enqueueMethodForCompilation(test_method, 4);
  55 
  56         // Try to start dynamic dumping while the above compilations are still in progesss
  57         System.exit(0);
  58     }
  59 }