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src/share/vm/memory/referencePolicy.cpp@5134fa1cfe63 (annotated)

src/share/vm/memory/referencePolicy.cpp

Thu, 24 Mar 2011 15:47:01 -0700

author

ysr

date

Thu, 24 Mar 2011 15:47:01 -0700

changeset 2710

5134fa1cfe63

parent 2314

f95d63e2154a

child 3188

d1bdeef3e3e2

permissions

-rw-r--r--

7029036: Card-table verification hangs with all framework collectors, except G1, even before the first GC
Summary: When verifying clean card ranges, use memory-range-bounded iteration over oops of objects overlapping that range, thus avoiding the otherwise quadratic worst-case cost of scanning large object arrays.
Reviewed-by: jmasa, jwilhelm, tonyp

duke@435	1	/*
stefank@2314	2	* Copyright (c) 2000, 2010, Oracle and/or its affiliates. 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	*
trims@1907	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907	20	* or visit www.oracle.com if you need additional information or have any
trims@1907	21	* questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
stefank@2314	25	#include "precompiled.hpp"
stefank@2314	26	#include "classfile/javaClasses.hpp"
stefank@2314	27	#include "memory/referencePolicy.hpp"
stefank@2314	28	#include "memory/universe.hpp"
stefank@2314	29	#include "runtime/arguments.hpp"
stefank@2314	30	#include "runtime/globals.hpp"
duke@435	31
duke@435	32	LRUCurrentHeapPolicy::LRUCurrentHeapPolicy() {
ysr@892	33	setup();
ysr@888	34	}
ysr@888	35
ysr@888	36	// Capture state (of-the-VM) information needed to evaluate the policy
ysr@892	37	void LRUCurrentHeapPolicy::setup() {
duke@435	38	_max_interval = (Universe::get_heap_free_at_last_gc() / M) * SoftRefLRUPolicyMSPerMB;
duke@435	39	assert(_max_interval >= 0,"Sanity check");
duke@435	40	}
duke@435	41
duke@435	42	// The oop passed in is the SoftReference object, and not
duke@435	43	// the object the SoftReference points to.
duke@435	44	bool LRUCurrentHeapPolicy::should_clear_reference(oop p) {
duke@435	45	jlong interval = java_lang_ref_SoftReference::clock() - java_lang_ref_SoftReference::timestamp(p);
duke@435	46	assert(interval >= 0, "Sanity check");
duke@435	47
duke@435	48	// The interval will be zero if the ref was accessed since the last scavenge/gc.
duke@435	49	if(interval <= _max_interval) {
duke@435	50	return false;
duke@435	51	}
duke@435	52
duke@435	53	return true;
duke@435	54	}
duke@435	55
duke@435	56	/////////////////////// MaxHeap //////////////////////
duke@435	57
duke@435	58	LRUMaxHeapPolicy::LRUMaxHeapPolicy() {
ysr@892	59	setup();
ysr@888	60	}
ysr@888	61
ysr@888	62	// Capture state (of-the-VM) information needed to evaluate the policy
ysr@892	63	void LRUMaxHeapPolicy::setup() {
duke@435	64	size_t max_heap = MaxHeapSize;
duke@435	65	max_heap -= Universe::get_heap_used_at_last_gc();
duke@435	66	max_heap /= M;
duke@435	67
duke@435	68	_max_interval = max_heap * SoftRefLRUPolicyMSPerMB;
duke@435	69	assert(_max_interval >= 0,"Sanity check");
duke@435	70	}
duke@435	71
duke@435	72	// The oop passed in is the SoftReference object, and not
duke@435	73	// the object the SoftReference points to.
duke@435	74	bool LRUMaxHeapPolicy::should_clear_reference(oop p) {
duke@435	75	jlong interval = java_lang_ref_SoftReference::clock() - java_lang_ref_SoftReference::timestamp(p);
duke@435	76	assert(interval >= 0, "Sanity check");
duke@435	77
duke@435	78	// The interval will be zero if the ref was accessed since the last scavenge/gc.
duke@435	79	if(interval <= _max_interval) {
duke@435	80	return false;
duke@435	81	}
duke@435	82
duke@435	83	return true;
duke@435	84	}