1 /*
   2  * Copyright (c) 2017, 2018, 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 
  25 /*
  26  * @test
  27  * @key stress gc randomness
  28  *
  29  * @summary converted from VM Testbase gc/gctests/PhantomReference/phantom002.
  30  * VM Testbase keywords: [gc, stress, stressopt, nonconcurrent]
  31  * VM Testbase readme:
  32  * DESCRIPTION
  33  *     The test checks that Garbage Collector correctly works with
  34  *     PhantomReferences. It also checks that no unexpected exceptions and errors
  35  *     are thrown or the JVM is not crashed.
  36  *     The test starts a number of threads. Each thread run tests for some time
  37  *     or serveral iterations.  See javadoc StressOptions for configuration.
  38  *     First of all each thread defines what type to check (there are 11 types
  39  *     totally). As soon as the type is defined, a PhantomRefence is created that
  40  *     refers to an array of tested type and is registered with in a queue. A
  41  *     PhantomRefence for NonbranchyTree and Referent calsses does not refer to
  42  *     arrays, but to instances of the classes.
  43  *     After that a thread performs next checks for the reference:
  44  *         1. The reference is in queue after GC is provoked with
  45  *            Algorithms.eatMemory() method (a single thread eats the memory).
  46  *         2. reference.get() returns null.
  47  *         3. queue.poll() returns the reference that was created.
  48  *         4. queue.poll() again returns null.
  49  *         5. If the checked type is class (Referent), then it must be finalized,
  50  *            since the reference is already enqueued.
  51  *         6. reference.clear() does not throw any exception.
  52  *     The test extends ThreadedGCTest and implements GarbageProducerAware and
  53  *     MemoryStrategyAware interfaces. The corresponding javadoc documentation
  54  *     for additional test configuration.
  55  *
  56  * @library /vmTestbase
  57  *          /test/lib
  58  * @run driver jdk.test.lib.FileInstaller . .
  59  * @run main/othervm gc.gctests.PhantomReference.phantom001.phantom001 -ms high
  60  */
  61