1 /*
   2  * Copyright (c) 2007, 2010, 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 #include "precompiled.hpp"
  26 #include "memory/allocation.inline.hpp"
  27 #include "runtime/jniPeriodicChecker.hpp"
  28 #include "runtime/task.hpp"
  29 
  30 
  31 // --------------------------------------------------------
  32 // Class to aid in periodic checking under CheckJNICalls
  33 class JniPeriodicCheckerTask : public PeriodicTask {
  34   public:
  35      JniPeriodicCheckerTask(int interval_time) : PeriodicTask(interval_time) {}
  36      void task() { os::run_periodic_checks(); }
  37      static void engage();
  38      static void disengage();
  39 };
  40 
  41 
  42 //----------------------------------------------------------
  43 // Implementation of JniPeriodicChecker
  44 
  45 JniPeriodicCheckerTask*              JniPeriodicChecker::_task   = NULL;
  46 
  47 /*
  48  * The engage() method is called at initialization time via
  49  * Thread::create_vm() to initialize the JniPeriodicChecker and
  50  * register it with the WatcherThread as a periodic task.
  51  */
  52 void JniPeriodicChecker::engage() {
  53   if (CheckJNICalls && !is_active()) {
  54     // start up the periodic task
  55     _task = new JniPeriodicCheckerTask(10);
  56     _task->enroll();
  57   }
  58 }
  59 
  60 
  61 /*
  62  * the disengage() method is responsible for deactivating the periodic
  63  * task. This  method is called from before_exit() in java.cpp and is only called
  64  * after the WatcherThread has been stopped.
  65  */
  66 void JniPeriodicChecker::disengage() {
  67   if (CheckJNICalls && is_active()) {
  68     // remove JniPeriodicChecker
  69     _task->disenroll();
  70     delete _task;
  71     _task = NULL;
  72   }
  73 }
  74 
  75 void jniPeriodicChecker_exit() {
  76   if (!CheckJNICalls) return;
  77 }