test/runtime/jni/ReturnJNIWeak/ReturnJNIWeak.java

Fri, 10 May 2019 18:50:40 +0000

author
phh
date
Fri, 10 May 2019 18:50:40 +0000
changeset 9671
e86bc9786d83
permissions
-rw-r--r--

8223664: Add jtreg tests for 8223528, backport to jdk8u of 8176100
Summary: Add hotspot/test/runtime/jni directory with two tests for 8176100
Reviewed-by: kbarrett, coleenp, tschatzl

     1 /*
     2  * Copyright (c) 2017, 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  */
    24 public final class ReturnJNIWeak {
    25     static {
    26         System.loadLibrary("ReturnJNIWeak");
    27     }
    29     private static final class TestObject {
    30         public final int value;
    32         public TestObject(int value) {
    33             this.value = value;
    34         }
    35     }
    37     private static volatile TestObject testObject = null;
    39     private static native void registerObject(Object o);
    40     private static native void unregisterObject();
    41     private static native Object getObject();
    43     // Create the test object and record it both strongly and weakly.
    44     private static void remember(int value) {
    45         TestObject o = new TestObject(value);
    46         registerObject(o);
    47         testObject = o;
    48     }
    50     // Remove both strong and weak references to the current test object.
    51     private static void forget() {
    52         unregisterObject();
    53         testObject = null;
    54     }
    56     // Verify the weakly recorded object
    57     private static void checkValue(int value) throws Exception {
    58         Object o = getObject();
    59         if (o == null) {
    60             throw new RuntimeException("Weak reference unexpectedly null");
    61         }
    62         TestObject t = (TestObject)o;
    63         if (t.value != value) {
    64             throw new RuntimeException("Incorrect value");
    65         }
    66     }
    68     // Verify we can create a weak reference and get it back.
    69     private static void testSanity() throws Exception {
    70         System.out.println("running testSanity");
    71         int value = 5;
    72         try {
    73             remember(value);
    74             checkValue(value);
    75         } finally {
    76             forget();
    77         }
    78     }
    80     // Verify weak ref value survives across collection if strong ref exists.
    81     private static void testSurvival() throws Exception {
    82         System.out.println("running testSurvival");
    83         int value = 10;
    84         try {
    85             remember(value);
    86             checkValue(value);
    87             System.gc();
    88             // Verify weak ref still has expected value.
    89             checkValue(value);
    90         } finally {
    91             forget();
    92         }
    93     }
    95     // Verify weak ref cleared if no strong ref exists.
    96     private static void testClear() throws Exception {
    97         System.out.println("running testClear");
    98         int value = 15;
    99         try {
   100             remember(value);
   101             checkValue(value);
   102             // Verify still good.
   103             checkValue(value);
   104             // Drop reference.
   105             testObject = null;
   106             System.gc();
   107             // Verify weak ref cleared as expected.
   108             Object recorded = getObject();
   109             if (recorded != null) {
   110                 throw new RuntimeException("expected clear");
   111             }
   112         } finally {
   113             forget();
   114         }
   115     }
   117     public static void main(String[] args) throws Exception {
   118         testSanity();
   119         testSurvival();
   120         testClear();
   121     }
   122 }

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