1 /*
   2  * Copyright (c) 2015, 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 jdk.testlibrary.management;
  25 
  26 import java.lang.management.ManagementFactory;
  27 import java.lang.management.ThreadInfo;
  28 import java.lang.management.ThreadMXBean;
  29 
  30 /**
  31  * A few utility methods to use ThreadMXBean.
  32  */
  33 public final class ThreadMXBeanTool {
  34 
  35     /**
  36      * Waits until {@link Thread} is in the certain {@link Thread.State}
  37      * and blocking on {@code object}.
  38      *
  39      * @param state The thread state
  40      * @param object The object to block on
  41      */
  42     public static void waitUntilBlockingOnObject(Thread thread, Thread.State state, Object object)
  43         throws InterruptedException {
  44         String want = object == null ? null : object.getClass().getName() + '@'
  45                 + Integer.toHexString(System.identityHashCode(object));
  46         ThreadMXBean tmx = ManagementFactory.getThreadMXBean();
  47         while (thread.isAlive()) {
  48             ThreadInfo ti = tmx.getThreadInfo(thread.getId());
  49             if (ti.getThreadState() == state
  50                     && (want == null || want.equals(ti.getLockName()))) {
  51                 return;
  52             }
  53             Thread.sleep(1);
  54         }
  55     }
  56 
  57     /**
  58      * Waits until {@link Thread} is in native.
  59      */
  60     public static void waitUntilInNative(Thread thread) throws InterruptedException {
  61         ThreadMXBean tmx = ManagementFactory.getThreadMXBean();
  62         while (thread.isAlive()) {
  63             ThreadInfo ti = tmx.getThreadInfo(thread.getId());
  64             if (ti.isInNative()) {
  65                 return;
  66             }
  67             Thread.sleep(1);
  68         }
  69     }
  70 
  71 }
  72