task.cpp revision 1472:c18cbe5936b8
1/* 2 * Copyright (c) 1997, 2008, 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 "incls/_precompiled.incl" 26# include "incls/_task.cpp.incl" 27 28int PeriodicTask::_num_tasks = 0; 29PeriodicTask* PeriodicTask::_tasks[PeriodicTask::max_tasks]; 30#ifndef PRODUCT 31elapsedTimer PeriodicTask::_timer; 32int PeriodicTask::_intervalHistogram[PeriodicTask::max_interval]; 33int PeriodicTask::_ticks; 34 35void PeriodicTask::print_intervals() { 36 if (ProfilerCheckIntervals) { 37 for (int i = 0; i < PeriodicTask::max_interval; i++) { 38 int n = _intervalHistogram[i]; 39 if (n > 0) tty->print_cr("%3d: %5d (%4.1f%%)", i, n, 100.0 * n / _ticks); 40 } 41 } 42} 43#endif 44 45void PeriodicTask::real_time_tick(size_t delay_time) { 46#ifndef PRODUCT 47 if (ProfilerCheckIntervals) { 48 _ticks++; 49 _timer.stop(); 50 int ms = (int)(_timer.seconds() * 1000.0); 51 _timer.reset(); 52 _timer.start(); 53 if (ms >= PeriodicTask::max_interval) ms = PeriodicTask::max_interval - 1; 54 _intervalHistogram[ms]++; 55 } 56#endif 57 int orig_num_tasks = _num_tasks; 58 for(int index = 0; index < _num_tasks; index++) { 59 _tasks[index]->execute_if_pending(delay_time); 60 if (_num_tasks < orig_num_tasks) { // task dis-enrolled itself 61 index--; // re-do current slot as it has changed 62 orig_num_tasks = _num_tasks; 63 } 64 } 65} 66 67 68PeriodicTask::PeriodicTask(size_t interval_time) : 69 _counter(0), _interval(interval_time) { 70 // Sanity check the interval time 71 assert(_interval >= PeriodicTask::min_interval && 72 _interval <= PeriodicTask::max_interval && 73 _interval % PeriodicTask::interval_gran == 0, 74 "improper PeriodicTask interval time"); 75} 76 77PeriodicTask::~PeriodicTask() { 78 if (is_enrolled()) 79 disenroll(); 80} 81 82bool PeriodicTask::is_enrolled() const { 83 for(int index = 0; index < _num_tasks; index++) 84 if (_tasks[index] == this) return true; 85 return false; 86} 87 88void PeriodicTask::enroll() { 89 assert(WatcherThread::watcher_thread() == NULL, "dynamic enrollment of tasks not yet supported"); 90 91 if (_num_tasks == PeriodicTask::max_tasks) 92 fatal("Overflow in PeriodicTask table"); 93 _tasks[_num_tasks++] = this; 94} 95 96void PeriodicTask::disenroll() { 97 assert(WatcherThread::watcher_thread() == NULL || 98 Thread::current() == WatcherThread::watcher_thread(), 99 "dynamic disenrollment currently only handled from WatcherThread from within task() method"); 100 101 int index; 102 for(index = 0; index < _num_tasks && _tasks[index] != this; index++); 103 if (index == _num_tasks) return; 104 _num_tasks--; 105 for (; index < _num_tasks; index++) { 106 _tasks[index] = _tasks[index+1]; 107 } 108} 109