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src/share/vm/oops/markOop.inline.hpp@710a3c8b516e (annotated)

src/share/vm/oops/markOop.inline.hpp

Tue, 08 Aug 2017 15:57:29 +0800

author

aoqi

date

Tue, 08 Aug 2017 15:57:29 +0800

changeset 6876

710a3c8b516e

parent 4037

da91efe96a93

parent 0

f90c822e73f8

permissions

-rw-r--r--

merge

aoqi@0	1	/*
aoqi@0	2	* Copyright (c) 2006, 2012, Oracle and/or its affiliates. All rights reserved.
aoqi@0	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0	4	*
aoqi@0	5	* This code is free software; you can redistribute it and/or modify it
aoqi@0	6	* under the terms of the GNU General Public License version 2 only, as
aoqi@0	7	* published by the Free Software Foundation.
aoqi@0	8	*
aoqi@0	9	* This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
aoqi@0	12	* version 2 for more details (a copy is included in the LICENSE file that
aoqi@0	13	* accompanied this code).
aoqi@0	14	*
aoqi@0	15	* You should have received a copy of the GNU General Public License version
aoqi@0	16	* 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0	18	*
aoqi@0	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0	20	* or visit www.oracle.com if you need additional information or have any
aoqi@0	21	* questions.
aoqi@0	22	*
aoqi@0	23	*/
aoqi@0	24
aoqi@0	25	#ifndef SHARE_VM_OOPS_MARKOOP_INLINE_HPP
aoqi@0	26	#define SHARE_VM_OOPS_MARKOOP_INLINE_HPP
aoqi@0	27
aoqi@0	28	#include "oops/klass.hpp"
aoqi@0	29	#include "oops/markOop.hpp"
aoqi@0	30	#include "runtime/globals.hpp"
aoqi@0	31
aoqi@0	32	// Should this header be preserved during GC (when biased locking is enabled)?
aoqi@0	33	inline bool markOopDesc::must_be_preserved_with_bias(oop obj_containing_mark) const {
aoqi@0	34	assert(UseBiasedLocking, "unexpected");
aoqi@0	35	if (has_bias_pattern()) {
aoqi@0	36	// Will reset bias at end of collection
aoqi@0	37	// Mark words of biased and currently locked objects are preserved separately
aoqi@0	38	return false;
aoqi@0	39	}
aoqi@0	40	markOop prototype_header = prototype_for_object(obj_containing_mark);
aoqi@0	41	if (prototype_header->has_bias_pattern()) {
aoqi@0	42	// Individual instance which has its bias revoked; must return
aoqi@0	43	// true for correctness
aoqi@0	44	return true;
aoqi@0	45	}
aoqi@0	46	return (!is_unlocked() || !has_no_hash());
aoqi@0	47	}
aoqi@0	48
aoqi@0	49	// Should this header be preserved during GC?
aoqi@0	50	inline bool markOopDesc::must_be_preserved(oop obj_containing_mark) const {
aoqi@0	51	if (!UseBiasedLocking)
aoqi@0	52	return (!is_unlocked() || !has_no_hash());
aoqi@0	53	return must_be_preserved_with_bias(obj_containing_mark);
aoqi@0	54	}
aoqi@0	55
aoqi@0	56	// Should this header be preserved in the case of a promotion failure
aoqi@0	57	// during scavenge (when biased locking is enabled)?
aoqi@0	58	inline bool markOopDesc::must_be_preserved_with_bias_for_promotion_failure(oop obj_containing_mark) const {
aoqi@0	59	assert(UseBiasedLocking, "unexpected");
aoqi@0	60	// We don't explicitly save off the mark words of biased and
aoqi@0	61	// currently-locked objects during scavenges, so if during a
aoqi@0	62	// promotion failure we encounter either a biased mark word or a
aoqi@0	63	// klass which still has a biasable prototype header, we have to
aoqi@0	64	// preserve the mark word. This results in oversaving, but promotion
aoqi@0	65	// failures are rare, and this avoids adding more complex logic to
aoqi@0	66	// the scavengers to call new variants of
aoqi@0	67	// BiasedLocking::preserve_marks() / restore_marks() in the middle
aoqi@0	68	// of a scavenge when a promotion failure has first been detected.
aoqi@0	69	if (has_bias_pattern() ||
aoqi@0	70	prototype_for_object(obj_containing_mark)->has_bias_pattern()) {
aoqi@0	71	return true;
aoqi@0	72	}
aoqi@0	73	return (!is_unlocked() || !has_no_hash());
aoqi@0	74	}
aoqi@0	75
aoqi@0	76	// Should this header be preserved in the case of a promotion failure
aoqi@0	77	// during scavenge?
aoqi@0	78	inline bool markOopDesc::must_be_preserved_for_promotion_failure(oop obj_containing_mark) const {
aoqi@0	79	if (!UseBiasedLocking)
aoqi@0	80	return (!is_unlocked() || !has_no_hash());
aoqi@0	81	return must_be_preserved_with_bias_for_promotion_failure(obj_containing_mark);
aoqi@0	82	}
aoqi@0	83
aoqi@0	84
aoqi@0	85	// Same as must_be_preserved_with_bias_for_promotion_failure() except that
aoqi@0	86	// it takes a Klass* argument, instead of the object of which this is the mark word.
aoqi@0	87	inline bool markOopDesc::must_be_preserved_with_bias_for_cms_scavenge(Klass* klass_of_obj_containing_mark) const {
aoqi@0	88	assert(UseBiasedLocking, "unexpected");
aoqi@0	89	// CMS scavenges preserve mark words in similar fashion to promotion failures; see above
aoqi@0	90	if (has_bias_pattern() ||
aoqi@0	91	klass_of_obj_containing_mark->prototype_header()->has_bias_pattern()) {
aoqi@0	92	return true;
aoqi@0	93	}
aoqi@0	94	return (!is_unlocked() || !has_no_hash());
aoqi@0	95	}
aoqi@0	96
aoqi@0	97	// Same as must_be_preserved_for_promotion_failure() except that
aoqi@0	98	// it takes a Klass* argument, instead of the object of which this is the mark word.
aoqi@0	99	inline bool markOopDesc::must_be_preserved_for_cms_scavenge(Klass* klass_of_obj_containing_mark) const {
aoqi@0	100	if (!UseBiasedLocking)
aoqi@0	101	return (!is_unlocked() || !has_no_hash());
aoqi@0	102	return must_be_preserved_with_bias_for_cms_scavenge(klass_of_obj_containing_mark);
aoqi@0	103	}
aoqi@0	104
aoqi@0	105	inline markOop markOopDesc::prototype_for_object(oop obj) {
aoqi@0	106	#ifdef ASSERT
aoqi@0	107	markOop prototype_header = obj->klass()->prototype_header();
aoqi@0	108	assert(prototype_header == prototype() || prototype_header->has_bias_pattern(), "corrupt prototype header");
aoqi@0	109	#endif
aoqi@0	110	return obj->klass()->prototype_header();
aoqi@0	111	}
aoqi@0	112
aoqi@0	113	#endif // SHARE_VM_OOPS_MARKOOP_INLINE_HPP