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src/share/vm/runtime/task.cpp@2b42b31e7928 (annotated)

src/share/vm/runtime/task.cpp

Fri, 21 Nov 2008 08:09:11 -0800

author

coleenp

date

Fri, 21 Nov 2008 08:09:11 -0800

changeset 882

2b42b31e7928

parent 791

1ee8caae33af

child 1907

c18cbe5936b8

permissions

-rw-r--r--

6676175: BigApps crash JVM Client VM (build 10.0-b22, mixed mode, sharing) with SIGSEGV (0xb)
Summary: Add test for biased locking epoch before walking own thread stack in case of rare race
Reviewed-by: phh, never

duke@435	1	/*
xdono@631	2	* Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
duke@435	19	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435	20	* CA 95054 USA or visit www.sun.com if you need additional information or
duke@435	21	* have any questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
duke@435	25	# include "incls/_precompiled.incl"
duke@435	26	# include "incls/_task.cpp.incl"
duke@435	27
duke@435	28	int PeriodicTask::_num_tasks = 0;
duke@435	29	PeriodicTask* PeriodicTask::_tasks[PeriodicTask::max_tasks];
duke@435	30	#ifndef PRODUCT
duke@435	31	elapsedTimer PeriodicTask::_timer;
duke@435	32	int PeriodicTask::_intervalHistogram[PeriodicTask::max_interval];
duke@435	33	int PeriodicTask::_ticks;
duke@435	34
duke@435	35	void PeriodicTask::print_intervals() {
duke@435	36	if (ProfilerCheckIntervals) {
duke@435	37	for (int i = 0; i < PeriodicTask::max_interval; i++) {
duke@435	38	int n = _intervalHistogram[i];
duke@435	39	if (n > 0) tty->print_cr("%3d: %5d (%4.1f%%)", i, n, 100.0 * n / _ticks);
duke@435	40	}
duke@435	41	}
duke@435	42	}
duke@435	43	#endif
duke@435	44
duke@435	45	void PeriodicTask::real_time_tick(size_t delay_time) {
duke@435	46	#ifndef PRODUCT
duke@435	47	if (ProfilerCheckIntervals) {
duke@435	48	_ticks++;
duke@435	49	_timer.stop();
duke@435	50	int ms = (int)(_timer.seconds() * 1000.0);
duke@435	51	_timer.reset();
duke@435	52	_timer.start();
duke@435	53	if (ms >= PeriodicTask::max_interval) ms = PeriodicTask::max_interval - 1;
duke@435	54	_intervalHistogram[ms]++;
duke@435	55	}
duke@435	56	#endif
duke@435	57	int orig_num_tasks = _num_tasks;
duke@435	58	for(int index = 0; index < _num_tasks; index++) {
duke@435	59	_tasks[index]->execute_if_pending(delay_time);
duke@435	60	if (_num_tasks < orig_num_tasks) { // task dis-enrolled itself
duke@435	61	index--; // re-do current slot as it has changed
duke@435	62	orig_num_tasks = _num_tasks;
duke@435	63	}
duke@435	64	}
duke@435	65	}
duke@435	66
duke@435	67
duke@435	68	PeriodicTask::PeriodicTask(size_t interval_time) :
duke@435	69	_counter(0), _interval(interval_time) {
duke@435	70	// Sanity check the interval time
duke@435	71	assert(_interval >= PeriodicTask::min_interval &&
duke@435	72	_interval <= PeriodicTask::max_interval &&
duke@435	73	_interval % PeriodicTask::interval_gran == 0,
duke@435	74	"improper PeriodicTask interval time");
duke@435	75	}
duke@435	76
duke@435	77	PeriodicTask::~PeriodicTask() {
duke@435	78	if (is_enrolled())
duke@435	79	disenroll();
duke@435	80	}
duke@435	81
duke@435	82	bool PeriodicTask::is_enrolled() const {
duke@435	83	for(int index = 0; index < _num_tasks; index++)
duke@435	84	if (_tasks[index] == this) return true;
duke@435	85	return false;
duke@435	86	}
duke@435	87
duke@435	88	void PeriodicTask::enroll() {
duke@435	89	assert(WatcherThread::watcher_thread() == NULL, "dynamic enrollment of tasks not yet supported");
duke@435	90
duke@435	91	if (_num_tasks == PeriodicTask::max_tasks)
duke@435	92	fatal("Overflow in PeriodicTask table");
duke@435	93	_tasks[_num_tasks++] = this;
duke@435	94	}
duke@435	95
duke@435	96	void PeriodicTask::disenroll() {
duke@435	97	assert(WatcherThread::watcher_thread() == NULL ||
duke@435	98	Thread::current() == WatcherThread::watcher_thread(),
duke@435	99	"dynamic disenrollment currently only handled from WatcherThread from within task() method");
duke@435	100
duke@435	101	int index;
duke@435	102	for(index = 0; index < _num_tasks && _tasks[index] != this; index++);
duke@435	103	if (index == _num_tasks) return;
duke@435	104	_num_tasks--;
duke@435	105	for (; index < _num_tasks; index++) {
duke@435	106	_tasks[index] = _tasks[index+1];
duke@435	107	}
duke@435	108	}