1 /*

     2  * Copyright (c) 2018, Red Hat, Inc. All rights reserved.

     3  *

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

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

     6  * published by the Free Software Foundation.

     7  *

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

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

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

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

    12  * accompanied this code).

    13  *

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

    15  * 2 along with this work; if not, write to the Free Software Foundation,

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

    17  *

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

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

    20  * questions.

    21  *

    22  */

    23 

    24 /*

    25  * @test TestRefprocSanity

    26  * @summary Test that null references/referents work fine

    27  * @key gc

    28  * @requires vm.gc.Shenandoah

    29  *

    30  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -Xms1g                                                             TestRefprocSanity

    31  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -Xms1g -XX:+ShenandoahVerify                                       TestRefprocSanity

    32  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -Xms1g                       -XX:ShenandoahGCHeuristics=aggressive TestRefprocSanity

    33  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -Xms1g -XX:+ShenandoahVerify -XX:ShenandoahGCHeuristics=traversal  TestRefprocSanity

    34  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -Xms1g                       -XX:ShenandoahGCHeuristics=traversal  TestRefprocSanity

    35  */

    36 

    37 import java.lang.ref.*;

    38 

    39 public class TestRefprocSanity {

    40 

    41     static final long TARGET_MB = Long.getLong("target", 10_000); // 10 Gb allocation

    42     static final int WINDOW = 10_000;

    43 

    44     static final Reference<MyObject>[] refs = new Reference[WINDOW];

    45 

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

    47         long count = TARGET_MB * 1024 * 1024 / 32;

    48         int rIdx = 0;

    49 

    50         ReferenceQueue rq = new ReferenceQueue();

    51 

    52         for (int c = 0; c < WINDOW; c++) {

    53             refs[c] = select(c, new MyObject(c), rq);

    54         }

    55 

    56         for (int c = 0; c < count; c++) {

    57             verifyRefAt(rIdx);

    58             refs[rIdx] = select(c, new MyObject(rIdx), rq);

    59 

    60             rIdx++;

    61             if (rIdx >= WINDOW) {

    62                 rIdx = 0;

    63             }

    64             while (rq.poll() != null); // drain

    65         }

    66     }

    67 

    68     static Reference<MyObject> select(int v, MyObject ext, ReferenceQueue rq) {

    69         switch (v % 10) {

    70             case 0:  return new SoftReference<MyObject>(null);

    71             case 1:  return new SoftReference<MyObject>(null, rq);

    72             case 2:  return new SoftReference<MyObject>(ext);

    73             case 3:  return new SoftReference<MyObject>(ext, rq);

    74             case 4:  return new WeakReference<MyObject>(null);

    75             case 5:  return new WeakReference<MyObject>(null, rq);

    76             case 6:  return new WeakReference<MyObject>(ext);

    77             case 7:  return new WeakReference<MyObject>(ext, rq);

    78             case 8:  return new PhantomReference<MyObject>(null, rq);

    79             case 9:  return new PhantomReference<MyObject>(ext, rq);

    80             default: throw new IllegalStateException();

    81         }

    82     }

    83 

    84     static void verifyRefAt(int idx) {

    85         Reference<MyObject> ref = refs[idx];

    86         MyObject mo = ref.get();

    87         if (mo != null && mo.x != idx) {

    88             throw new IllegalStateException("Referent tag is incorrect: " + mo.x + ", should be " + idx);

    89         }

    90     }

    91 

    92     static class MyObject {

    93         final int x;

    94 

    95         public MyObject(int x) {

    96             this.x = x;

    97         }

    98     }

    99 

   100 }