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 }