Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "memory/allocation.hpp"

 #include "runtime/init.hpp"

 #include "runtime/task.hpp"

 #include "runtime/thread.inline.hpp"

 #include "runtime/timer.hpp"

 #ifdef TARGET_OS_FAMILY_linux

 # include "os_linux.inline.hpp"

 #endif

 #ifdef TARGET_OS_FAMILY_solaris

 # include "os_solaris.inline.hpp"

 #endif

 #ifdef TARGET_OS_FAMILY_windows

 # include "os_windows.inline.hpp"

 #endif

 #ifdef TARGET_OS_FAMILY_bsd

 # include "os_bsd.inline.hpp"

 #endif

 int PeriodicTask::_num_tasks = 0;

 PeriodicTask* PeriodicTask::_tasks[PeriodicTask::max_tasks];

 #ifndef PRODUCT

 elapsedTimer PeriodicTask::_timer;

 int PeriodicTask::_intervalHistogram[PeriodicTask::max_interval];

 int PeriodicTask::_ticks;

 void PeriodicTask::print_intervals() {

   if (ProfilerCheckIntervals) {

     for (int i = 0; i < PeriodicTask::max_interval; i++) {

       int n = _intervalHistogram[i];

       if (n > 0) tty->print_cr("%3d: %5d (%4.1f%%)", i, n, 100.0 * n / _ticks);

     }

   }

 }

 #endif

 void PeriodicTask::real_time_tick(int delay_time) {

 #ifndef PRODUCT

   if (ProfilerCheckIntervals) {

     _ticks++;

     _timer.stop();

     int ms = (int)(_timer.seconds() * 1000.0);

     _timer.reset();

     _timer.start();

     if (ms >= PeriodicTask::max_interval) ms = PeriodicTask::max_interval - 1;

     _intervalHistogram[ms]++;

   }

 #endif

   {

     MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);

     int orig_num_tasks = _num_tasks;

     for(int index = 0; index < _num_tasks; index++) {

       _tasks[index]->execute_if_pending(delay_time);

       if (_num_tasks < orig_num_tasks) { // task dis-enrolled itself

         index--;  // re-do current slot as it has changed

         orig_num_tasks = _num_tasks;

       }

     }

   }

 }

 int PeriodicTask::time_to_wait() {

   MutexLockerEx ml(PeriodicTask_lock->owned_by_self() ?

                      NULL : PeriodicTask_lock, Mutex::_no_safepoint_check_flag);

   if (_num_tasks == 0) {

     return 0; // sleep until shutdown or a task is enrolled

   }

   int delay = _tasks[0]->time_to_next_interval();

   for (int index = 1; index < _num_tasks; index++) {

     delay = MIN2(delay, _tasks[index]->time_to_next_interval());

   }

   return delay;

 }

 PeriodicTask::PeriodicTask(size_t interval_time) :

   _counter(0), _interval((int) interval_time) {

   // Sanity check the interval time

   assert(_interval >= PeriodicTask::min_interval &&

          _interval <= PeriodicTask::max_interval &&

          _interval %  PeriodicTask::interval_gran == 0,

               "improper PeriodicTask interval time");

 }

 PeriodicTask::~PeriodicTask() {

   disenroll();

 }

 /* enroll could be called from a JavaThread, so we have to check for

  * safepoint when taking the lock to avoid deadlocking */

 void PeriodicTask::enroll() {

   MutexLockerEx ml(PeriodicTask_lock->owned_by_self() ?

                      NULL : PeriodicTask_lock);

   if (_num_tasks == PeriodicTask::max_tasks) {

     fatal("Overflow in PeriodicTask table");

   }

   _tasks[_num_tasks++] = this;

   WatcherThread* thread = WatcherThread::watcher_thread();

   if (thread) {

     thread->unpark();

   } else {

     WatcherThread::start();

   }

 }

 /* disenroll could be called from a JavaThread, so we have to check for

  * safepoint when taking the lock to avoid deadlocking */

 void PeriodicTask::disenroll() {

   MutexLockerEx ml(PeriodicTask_lock->owned_by_self() ?

                      NULL : PeriodicTask_lock);

   int index;

   for(index = 0; index < _num_tasks && _tasks[index] != this; index++)

     ;

   if (index == _num_tasks) {

     return;

   }

   _num_tasks--;

   for (; index < _num_tasks; index++) {

     _tasks[index] = _tasks[index+1];

   }

 }