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  *
  29  * @run main/othervm -Xmx1g -Xms1g -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC                                                             TestRefprocSanity
  30  * @run main/othervm -Xmx1g -Xms1g -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+ShenandoahVerify                                       TestRefprocSanity
  31  * @run main/othervm -Xmx1g -Xms1g -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC                       -XX:ShenandoahGCHeuristics=aggressive TestRefprocSanity
  32  *
  33  * @run main/othervm -Xmx1g -Xms1g -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=traversal                              TestRefprocSanity
  34  * @run main/othervm -Xmx1g -Xms1g -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=traversal -XX:+ShenandoahVerify        TestRefprocSanity
  35  * @run main/othervm -Xmx1g -Xms1g -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=traversal -XX:ShenandoahGCHeuristics=aggressive TestRefprocSanity
  36  */
  37 
  38 import java.lang.ref.*;
  39 
  40 public class TestRefprocSanity {
  41 
  42     static final long TARGET_MB = Long.getLong("target", 10_000); // 10 Gb allocation
  43     static final int WINDOW = 10_000;
  44 
  45     static final Reference<MyObject>[] refs = new Reference[WINDOW];
  46 
  47     public static void main(String[] args) throws Exception {
  48         long count = TARGET_MB * 1024 * 1024 / 32;
  49         int rIdx = 0;
  50 
  51         ReferenceQueue rq = new ReferenceQueue();
  52 
  53         for (int c = 0; c < WINDOW; c++) {
  54             refs[c] = select(c, new MyObject(c), rq);
  55         }
  56 
  57         for (int c = 0; c < count; c++) {
  58             verifyRefAt(rIdx);
  59             refs[rIdx] = select(c, new MyObject(rIdx), rq);
  60 
  61             rIdx++;
  62             if (rIdx >= WINDOW) {
  63                 rIdx = 0;
  64             }
  65             while (rq.poll() != null); // drain
  66         }
  67     }
  68 
  69     static Reference<MyObject> select(int v, MyObject ext, ReferenceQueue rq) {
  70         switch (v % 10) {
  71             case 0:  return new SoftReference<MyObject>(null);
  72             case 1:  return new SoftReference<MyObject>(null, rq);
  73             case 2:  return new SoftReference<MyObject>(ext);
  74             case 3:  return new SoftReference<MyObject>(ext, rq);
  75             case 4:  return new WeakReference<MyObject>(null);
  76             case 5:  return new WeakReference<MyObject>(null, rq);
  77             case 6:  return new WeakReference<MyObject>(ext);
  78             case 7:  return new WeakReference<MyObject>(ext, rq);
  79             case 8:  return new PhantomReference<MyObject>(null, rq);
  80             case 9:  return new PhantomReference<MyObject>(ext, rq);
  81             default: throw new IllegalStateException();
  82         }
  83     }
  84 
  85     static void verifyRefAt(int idx) {
  86         Reference<MyObject> ref = refs[idx];
  87         MyObject mo = ref.get();
  88         if (mo != null && mo.x != idx) {
  89             throw new IllegalStateException("Referent tag is incorrect: " + mo.x + ", should be " + idx);
  90         }
  91     }
  92 
  93     static class MyObject {
  94         final int x;
  95 
  96         public MyObject(int x) {
  97             this.x = x;
  98         }
  99     }
 100 
 101 }