1 /*
   2  * Copyright (c) 2019, 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 package gc.g1;
  25 
  26 /* @test
  27  * @bug 8218880
  28  * @summary Test that issuing a periodic collection while the GC locker is
  29  * held does not crash the VM.
  30  * @key gc
  31  * @requires vm.gc.G1
  32  * @modules java.base
  33  * @run main/othervm/native
  34  *    -Xbootclasspath/a:.
  35  *    -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
  36  *    -XX:+UseG1GC -XX:G1PeriodicGCInterval=100
  37  *    -XX:+G1PeriodicGCInvokesConcurrent
  38  *    -Xlog:gc,gc+periodic=debug
  39  *    gc.g1.TestPeriodicCollectionJNI
  40  * @run main/othervm/native
  41  *    -Xbootclasspath/a:.
  42  *    -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
  43  *    -XX:+UseG1GC -XX:G1PeriodicGCInterval=100
  44  *    -XX:-G1PeriodicGCInvokesConcurrent
  45  *    -Xlog:gc,gc+periodic=debug
  46  *    gc.g1.TestPeriodicCollectionJNI
  47  */
  48 
  49 public class TestPeriodicCollectionJNI {
  50     static { System.loadLibrary("TestPeriodicCollectionJNI"); }
  51 
  52     private static native boolean blockInNative(byte[] array);
  53     private static native void unblock();
  54 
  55     public static void block() {
  56         if (!blockInNative(new byte[0])) {
  57             throw new RuntimeException("failed to acquire lock to dummy object");
  58         }
  59     }
  60 
  61     public static void main(String[] args) throws InterruptedException {
  62         long timeout = 2000;
  63         long startTime = System.currentTimeMillis();
  64 
  65         // start CS locker thread
  66         BlockInNative blocker = new BlockInNative();
  67         blocker.start();
  68 
  69         try {
  70             // check timeout to success deadlocking
  71             while (System.currentTimeMillis() < startTime + timeout) {
  72                 System.out.println("Sleeping to let periodic GC trigger...");
  73                 Thread.sleep(200);
  74             }
  75         } finally {
  76             unblock();
  77         }
  78     }
  79 }
  80 
  81 class BlockInNative extends Thread {
  82 
  83     public void run() {
  84         TestPeriodicCollectionJNI.block();
  85     }
  86 
  87     native void unlock();
  88 }
  89