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 }