Mercurial > hg > truffle
view src/share/vm/runtime/task.hpp @ 7432:0b3d19153cc6
8001028: Improve GC option handling
Summary: If there are not enough native resources to create the ReferenceHandler or Finalizer Java threads, the VM will attempt to throw an OOME before the java.lang.Class class has been initialized. This can result in assertion failures and other crashes. Move the initialization of the java.lang.Class class to just before the initialization of the java.lang.ref.Finalizer class.
Reviewed-by: jwilhelm, dholmes, coleenp
author | johnc |
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date | Wed, 12 Dec 2012 12:07:32 -0800 |
parents | c284cf4781f0 |
children |
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/* * Copyright (c) 1997, 2012, 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. * */ #ifndef SHARE_VM_RUNTIME_TASK_HPP #define SHARE_VM_RUNTIME_TASK_HPP #include "utilities/top.hpp" // A PeriodicTask has the sole purpose of executing its task // function with regular intervals. // Usage: // PeriodicTask pf(10); // pf.enroll(); // ... // pf.disenroll(); class PeriodicTask: public CHeapObj<mtInternal> { public: // Useful constants. // The interval constants are used to ensure the declared interval // is appropriate; it must be between min_interval and max_interval, // and have a granularity of interval_gran (all in millis). enum { max_tasks = 10, // Max number of periodic tasks in system interval_gran = 10, min_interval = 10, max_interval = 10000 }; static int num_tasks() { return _num_tasks; } private: int _counter; const int _interval; static int _num_tasks; static PeriodicTask* _tasks[PeriodicTask::max_tasks]; static void real_time_tick(int delay_time); #ifndef PRODUCT static elapsedTimer _timer; // measures time between ticks static int _ticks; // total number of ticks static int _intervalHistogram[max_interval]; // to check spacing of timer interrupts public: static void print_intervals(); #endif // Only the WatcherThread can cause us to execute PeriodicTasks friend class WatcherThread; public: PeriodicTask(size_t interval_time); // interval is in milliseconds of elapsed time ~PeriodicTask(); // Make the task active // For dynamic enrollment at the time T, the task will execute somewhere // between T and T + interval_time. void enroll(); // Make the task deactive void disenroll(); void execute_if_pending(int delay_time) { // make sure we don't overflow jlong tmp = (jlong) _counter + (jlong) delay_time; if (tmp >= (jlong) _interval) { _counter = 0; task(); } else { _counter += delay_time; } } // Returns how long (time in milliseconds) before the next time we should // execute this task. int time_to_next_interval() const { assert(_interval > _counter, "task counter greater than interval?"); return _interval - _counter; } // Calculate when the next periodic task will fire. // Called by the WatcherThread's run method. static int time_to_wait(); // The task to perform at each period virtual void task() = 0; }; #endif // SHARE_VM_RUNTIME_TASK_HPP