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src/share/vm/memory/referencePolicy.cpp@0bfd3fb24150 (annotated)

src/share/vm/memory/referencePolicy.cpp

Tue, 13 Apr 2010 13:52:10 -0700

author

jmasa

date

Tue, 13 Apr 2010 13:52:10 -0700

changeset 1822

0bfd3fb24150

parent 905

ad8c8ca4ab0f

child 1907

c18cbe5936b8

permissions

-rw-r--r--

6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
Summary: Ensure a full GC that clears SoftReferences before throwing an out-of-memory
Reviewed-by: ysr, jcoomes

duke@435	1	/*
xdono@905	2	* Copyright 2000-2008 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/_referencePolicy.cpp.incl"
duke@435	27
duke@435	28	LRUCurrentHeapPolicy::LRUCurrentHeapPolicy() {
ysr@892	29	setup();
ysr@888	30	}
ysr@888	31
ysr@888	32	// Capture state (of-the-VM) information needed to evaluate the policy
ysr@892	33	void LRUCurrentHeapPolicy::setup() {
duke@435	34	_max_interval = (Universe::get_heap_free_at_last_gc() / M) * SoftRefLRUPolicyMSPerMB;
duke@435	35	assert(_max_interval >= 0,"Sanity check");
duke@435	36	}
duke@435	37
duke@435	38	// The oop passed in is the SoftReference object, and not
duke@435	39	// the object the SoftReference points to.
duke@435	40	bool LRUCurrentHeapPolicy::should_clear_reference(oop p) {
duke@435	41	jlong interval = java_lang_ref_SoftReference::clock() - java_lang_ref_SoftReference::timestamp(p);
duke@435	42	assert(interval >= 0, "Sanity check");
duke@435	43
duke@435	44	// The interval will be zero if the ref was accessed since the last scavenge/gc.
duke@435	45	if(interval <= _max_interval) {
duke@435	46	return false;
duke@435	47	}
duke@435	48
duke@435	49	return true;
duke@435	50	}
duke@435	51
duke@435	52	/////////////////////// MaxHeap //////////////////////
duke@435	53
duke@435	54	LRUMaxHeapPolicy::LRUMaxHeapPolicy() {
ysr@892	55	setup();
ysr@888	56	}
ysr@888	57
ysr@888	58	// Capture state (of-the-VM) information needed to evaluate the policy
ysr@892	59	void LRUMaxHeapPolicy::setup() {
duke@435	60	size_t max_heap = MaxHeapSize;
duke@435	61	max_heap -= Universe::get_heap_used_at_last_gc();
duke@435	62	max_heap /= M;
duke@435	63
duke@435	64	_max_interval = max_heap * SoftRefLRUPolicyMSPerMB;
duke@435	65	assert(_max_interval >= 0,"Sanity check");
duke@435	66	}
duke@435	67
duke@435	68	// The oop passed in is the SoftReference object, and not
duke@435	69	// the object the SoftReference points to.
duke@435	70	bool LRUMaxHeapPolicy::should_clear_reference(oop p) {
duke@435	71	jlong interval = java_lang_ref_SoftReference::clock() - java_lang_ref_SoftReference::timestamp(p);
duke@435	72	assert(interval >= 0, "Sanity check");
duke@435	73
duke@435	74	// The interval will be zero if the ref was accessed since the last scavenge/gc.
duke@435	75	if(interval <= _max_interval) {
duke@435	76	return false;
duke@435	77	}
duke@435	78
duke@435	79	return true;
duke@435	80	}