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 

    24 import java.lang.ref.WeakReference;

    25 

    26 public class SafepointTestMain {

    27     public static class B {

    28         static int count = 0;

    29         public static volatile boolean stop = false;

    30         static void localSleep(int time) {

    31           try{

    32             Thread.currentThread().sleep(time);

    33           } catch(InterruptedException ie) {

    34           }

    35         }

    36 

    37         public static void infinite() {

    38             while (!stop) { count++; }

    39         }

    40     }

    41 

    42     public static byte[] garbage;

    43     public static volatile WeakReference<Object> weakref;

    44 

    45     public static void createweakref() {

    46         Object o = new Object();

    47         weakref = new WeakReference<>(o);

    48     }

    49 

    50     public static void main(String[] args) throws Exception {

    51         // Run function in separate thread to force compilation and pint safepoint

    52         // message for compiled method

    53         new Thread() {

    54             public void run() {

    55                 B.infinite();

    56             }

    57         }.start();

    58         B.localSleep(1000);

    59         // Cause several safepoints to run GC while the compiled method is running,

    60         // to see safepoint messages

    61         for (int i = 0; i < 2; i++) {

    62             createweakref();

    63             while(weakref.get() != null) {

    64                 garbage = new byte[8192];

    65                 System.gc();

    66             }

    67         }

    68         B.stop = true;

    69     }

    70 }