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src/share/vm/gc_implementation/parallelScavenge/gcTaskThread.cpp@4dfb2df418f2 (annotated)

src/share/vm/gc_implementation/parallelScavenge/gcTaskThread.cpp

Thu, 22 Sep 2011 10:57:37 -0700

author

johnc

date

Thu, 22 Sep 2011 10:57:37 -0700

changeset 3175

4dfb2df418f2

parent 2314

f95d63e2154a

child 3294

bca17e38de00

permissions

-rw-r--r--

6484982: G1: process references during evacuation pauses
Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate.
Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp

duke@435	1
duke@435	2	/*
stefank@2314	3	* Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435	4	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	5	*
duke@435	6	* This code is free software; you can redistribute it and/or modify it
duke@435	7	* under the terms of the GNU General Public License version 2 only, as
duke@435	8	* published by the Free Software Foundation.
duke@435	9	*
duke@435	10	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	13	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	14	* accompanied this code).
duke@435	15	*
duke@435	16	* You should have received a copy of the GNU General Public License version
duke@435	17	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	18	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	19	*
trims@1907	20	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907	21	* or visit www.oracle.com if you need additional information or have any
trims@1907	22	* questions.
duke@435	23	*
duke@435	24	*/
duke@435	25
stefank@2314	26	#include "precompiled.hpp"
stefank@2314	27	#include "gc_implementation/parallelScavenge/gcTaskManager.hpp"
stefank@2314	28	#include "gc_implementation/parallelScavenge/gcTaskThread.hpp"
stefank@2314	29	#include "memory/allocation.hpp"
stefank@2314	30	#include "memory/allocation.inline.hpp"
stefank@2314	31	#include "memory/resourceArea.hpp"
stefank@2314	32	#include "runtime/handles.hpp"
stefank@2314	33	#include "runtime/handles.inline.hpp"
stefank@2314	34	#include "runtime/os.hpp"
stefank@2314	35	#include "runtime/thread.hpp"
duke@435	36
duke@435	37	GCTaskThread::GCTaskThread(GCTaskManager* manager,
duke@435	38	uint which,
duke@435	39	uint processor_id) :
duke@435	40	_manager(manager),
duke@435	41	_processor_id(processor_id),
duke@435	42	_time_stamps(NULL),
duke@435	43	_time_stamp_index(0)
duke@435	44	{
duke@435	45	if (!os::create_thread(this, os::pgc_thread))
duke@435	46	vm_exit_out_of_memory(0, "Cannot create GC thread. Out of system resources.");
duke@435	47
duke@435	48	if (PrintGCTaskTimeStamps) {
duke@435	49	_time_stamps = NEW_C_HEAP_ARRAY(GCTaskTimeStamp, GCTaskTimeStampEntries );
duke@435	50
duke@435	51	guarantee(_time_stamps != NULL, "Sanity");
duke@435	52	}
duke@435	53	set_id(which);
duke@435	54	set_name("GC task thread#%d (ParallelGC)", which);
duke@435	55	}
duke@435	56
duke@435	57	GCTaskThread::~GCTaskThread() {
duke@435	58	if (_time_stamps != NULL) {
duke@435	59	FREE_C_HEAP_ARRAY(GCTaskTimeStamp, _time_stamps);
duke@435	60	}
duke@435	61	}
duke@435	62
duke@435	63	void GCTaskThread::start() {
duke@435	64	os::start_thread(this);
duke@435	65	}
duke@435	66
duke@435	67	GCTaskTimeStamp* GCTaskThread::time_stamp_at(uint index) {
duke@435	68	guarantee(index < GCTaskTimeStampEntries, "increase GCTaskTimeStampEntries");
duke@435	69
duke@435	70	return &(_time_stamps[index]);
duke@435	71	}
duke@435	72
duke@435	73	void GCTaskThread::print_task_time_stamps() {
duke@435	74	assert(PrintGCTaskTimeStamps, "Sanity");
duke@435	75	assert(_time_stamps != NULL, "Sanity (Probably set PrintGCTaskTimeStamps late)");
duke@435	76
duke@435	77	tty->print_cr("GC-Thread %u entries: %d", id(), _time_stamp_index);
duke@435	78	for(uint i=0; i<_time_stamp_index; i++) {
duke@435	79	GCTaskTimeStamp* time_stamp = time_stamp_at(i);
duke@435	80	tty->print_cr("\t[ %s " INT64_FORMAT " " INT64_FORMAT " ]",
duke@435	81	time_stamp->name(),
duke@435	82	time_stamp->entry_time(),
duke@435	83	time_stamp->exit_time());
duke@435	84	}
duke@435	85
duke@435	86	// Reset after dumping the data
duke@435	87	_time_stamp_index = 0;
duke@435	88	}
duke@435	89
duke@435	90	void GCTaskThread::print_on(outputStream* st) const {
duke@435	91	st->print("\"%s\" ", name());
duke@435	92	Thread::print_on(st);
duke@435	93	st->cr();
duke@435	94	}
duke@435	95
duke@435	96	void GCTaskThread::run() {
duke@435	97	// Set up the thread for stack overflow support
duke@435	98	this->record_stack_base_and_size();
duke@435	99	this->initialize_thread_local_storage();
duke@435	100	// Bind yourself to your processor.
duke@435	101	if (processor_id() != GCTaskManager::sentinel_worker()) {
duke@435	102	if (TraceGCTaskThread) {
duke@435	103	tty->print_cr("GCTaskThread::run: "
duke@435	104	" binding to processor %u", processor_id());
duke@435	105	}
duke@435	106	if (!os::bind_to_processor(processor_id())) {
duke@435	107	DEBUG_ONLY(
duke@435	108	warning("Couldn't bind GCTaskThread %u to processor %u",
duke@435	109	which(), processor_id());
duke@435	110	)
duke@435	111	}
duke@435	112	}
duke@435	113	// Part of thread setup.
duke@435	114	// ??? Are these set up once here to make subsequent ones fast?
duke@435	115	HandleMark hm_outer;
duke@435	116	ResourceMark rm_outer;
duke@435	117
duke@435	118	TimeStamp timer;
duke@435	119
duke@435	120	for (;/* ever */;) {
duke@435	121	// These are so we can flush the resources allocated in the inner loop.
duke@435	122	HandleMark hm_inner;
duke@435	123	ResourceMark rm_inner;
duke@435	124	for (; /* break */; ) {
duke@435	125	// This will block until there is a task to be gotten.
duke@435	126	GCTask* task = manager()->get_task(which());
duke@435	127
duke@435	128	// In case the update is costly
duke@435	129	if (PrintGCTaskTimeStamps) {
duke@435	130	timer.update();
duke@435	131	}
duke@435	132
duke@435	133	jlong entry_time = timer.ticks();
duke@435	134	char* name = task->name();
duke@435	135
duke@435	136	task->do_it(manager(), which());
duke@435	137	manager()->note_completion(which());
duke@435	138
duke@435	139	if (PrintGCTaskTimeStamps) {
duke@435	140	assert(_time_stamps != NULL, "Sanity (PrintGCTaskTimeStamps set late?)");
duke@435	141
duke@435	142	timer.update();
duke@435	143
duke@435	144	GCTaskTimeStamp* time_stamp = time_stamp_at(_time_stamp_index++);
duke@435	145
duke@435	146	time_stamp->set_name(name);
duke@435	147	time_stamp->set_entry_time(entry_time);
duke@435	148	time_stamp->set_exit_time(timer.ticks());
duke@435	149	}
duke@435	150
duke@435	151	// Check if we should release our inner resources.
duke@435	152	if (manager()->should_release_resources(which())) {
duke@435	153	manager()->note_release(which());
duke@435	154	break;
duke@435	155	}
duke@435	156	}
duke@435	157	}
duke@435	158	}