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  */

    23 

    24 /**

    25  * @test

    26  * @bug 8167108

    27  * @summary Stress test java.lang.Thread.countStackFrames() at thread exit.

    28  * @run main/othervm -Xlog:thread+smr=debug CountStackFramesAtExit

    29  */

    30 

    31 import java.util.concurrent.CountDownLatch;

    32 

    33 public class CountStackFramesAtExit extends Thread {

    34     final static int N_THREADS = 32;

    35     final static int N_LATE_CALLS = 1000;

    36 

    37     public CountDownLatch exitSyncObj = new CountDownLatch(1);

    38     public CountDownLatch startSyncObj = new CountDownLatch(1);

    39 

    40     @Override

    41     public void run() {

    42         // Tell main thread we have started.

    43         startSyncObj.countDown();

    44         try {

    45             // Wait for main thread to interrupt us so we

    46             // can race to exit.

    47             exitSyncObj.await();

    48         } catch (InterruptedException e) {

    49             // ignore because we expect one

    50         }

    51     }

    52 

    53     public static void main(String[] args) {

    54         CountStackFramesAtExit threads[] = new CountStackFramesAtExit[N_THREADS];

    55 

    56         for (int i = 0; i < N_THREADS; i++ ) {

    57             threads[i] = new CountStackFramesAtExit();

    58             int late_count = 1;

    59             threads[i].start();

    60             try {

    61                 // Wait for the worker thread to get going.

    62                 threads[i].startSyncObj.await();

    63 

    64                 // This interrupt() call will break the worker out of

    65                 // the exitSyncObj.await() call and the countStackFrames()

    66                 // calls will come in during thread exit.

    67                 threads[i].interrupt();

    68                 for (; late_count <= N_LATE_CALLS; late_count++) {

    69                     try {

    70                         threads[i].countStackFrames();

    71                     } catch (IllegalThreadStateException itse) {

    72                         // ignore because we expect it

    73                     }

    74 

    75                     if (!threads[i].isAlive()) {

    76                         // Done with Thread.countStackFrames() calls since

    77                         // thread is not alive.

    78                         break;

    79                     }

    80                 }

    81             } catch (InterruptedException e) {

    82                 throw new Error("Unexpected: " + e);

    83             }

    84 

    85             System.out.println("INFO: thread #" + i + ": made " + late_count +

    86                                " late calls to java.lang.Thread.countStackFrames()");

    87             System.out.println("INFO: thread #" + i + ": N_LATE_CALLS==" +

    88                                N_LATE_CALLS + " value is " +

    89                                ((late_count >= N_LATE_CALLS) ? "NOT " : "") +

    90                                "large enough to cause a Thread.countStackFrames() " +

    91                                "call after thread exit.");

    92 

    93             try {

    94                 threads[i].join();

    95             } catch (InterruptedException e) {

    96                 throw new Error("Unexpected: " + e);

    97             }

    98             threads[i].countStackFrames();

    99             if (threads[i].isAlive()) {

   100                 throw new Error("Expected !Thread.isAlive() after thread #" +

   101                                 i + " has been join()'ed");

   102             }

   103         }

   104 

   105         String cmd = System.getProperty("sun.java.command");

   106         if (cmd != null && !cmd.startsWith("com.sun.javatest.regtest.agent.MainWrapper")) {

   107             // Exit with success in a non-JavaTest environment:

   108             System.exit(0);

   109         }

   110     }

   111 }