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src/share/vm/gc_implementation/parallelScavenge/psPromotionLAB.cpp@c18cbe5936b8 (annotated)

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

Thu, 27 May 2010 19:08:38 -0700

author

trims

date

Thu, 27 May 2010 19:08:38 -0700

changeset 1907

c18cbe5936b8

parent 631

d1605aabd0a1

child 2314

f95d63e2154a

permissions

-rw-r--r--

6941466: Oracle rebranding changes for Hotspot repositories
Summary: Change all the Sun copyrights to Oracle copyright
Reviewed-by: ohair

duke@435	1	/*
trims@1907	2	* Copyright (c) 2002, 2008, 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
duke@435	25	#include "incls/_precompiled.incl"
duke@435	26	#include "incls/_psPromotionLAB.cpp.incl"
duke@435	27
coleenp@548	28	size_t PSPromotionLAB::filler_header_size;
duke@435	29
duke@435	30	// This is the shared initialization code. It sets up the basic pointers,
duke@435	31	// and allows enough extra space for a filler object. We call a virtual
duke@435	32	// method, "lab_is_valid()" to handle the different asserts the old/young
duke@435	33	// labs require.
duke@435	34	void PSPromotionLAB::initialize(MemRegion lab) {
duke@435	35	assert(lab_is_valid(lab), "Sanity");
duke@435	36
duke@435	37	HeapWord* bottom = lab.start();
duke@435	38	HeapWord* end = lab.end();
duke@435	39
duke@435	40	set_bottom(bottom);
duke@435	41	set_end(end);
duke@435	42	set_top(bottom);
duke@435	43
coleenp@548	44	// Initialize after VM starts up because header_size depends on compressed
coleenp@548	45	// oops.
coleenp@548	46	filler_header_size = align_object_size(typeArrayOopDesc::header_size(T_INT));
coleenp@548	47
duke@435	48	// We can be initialized to a zero size!
duke@435	49	if (free() > 0) {
duke@435	50	if (ZapUnusedHeapArea) {
duke@435	51	debug_only(Copy::fill_to_words(top(), free()/HeapWordSize, badHeapWord));
duke@435	52	}
duke@435	53
duke@435	54	// NOTE! We need to allow space for a filler object.
duke@435	55	assert(lab.word_size() >= filler_header_size, "lab is too small");
duke@435	56	end = end - filler_header_size;
duke@435	57	set_end(end);
duke@435	58
duke@435	59	_state = needs_flush;
duke@435	60	} else {
duke@435	61	_state = zero_size;
duke@435	62	}
duke@435	63
duke@435	64	assert(this->top() <= this->end(), "pointers out of order");
duke@435	65	}
duke@435	66
duke@435	67	// Fill all remaining lab space with an unreachable object.
duke@435	68	// The goal is to leave a contiguous parseable span of objects.
duke@435	69	void PSPromotionLAB::flush() {
duke@435	70	assert(_state != flushed, "Attempt to flush PLAB twice");
duke@435	71	assert(top() <= end(), "pointers out of order");
duke@435	72
duke@435	73	// If we were initialized to a zero sized lab, there is
duke@435	74	// nothing to flush
duke@435	75	if (_state == zero_size)
duke@435	76	return;
duke@435	77
duke@435	78	// PLAB's never allocate the last aligned_header_size
duke@435	79	// so they can always fill with an array.
duke@435	80	HeapWord* tlab_end = end() + filler_header_size;
duke@435	81	typeArrayOop filler_oop = (typeArrayOop) top();
duke@435	82	filler_oop->set_mark(markOopDesc::prototype());
duke@435	83	filler_oop->set_klass(Universe::intArrayKlassObj());
duke@435	84	const size_t array_length =
duke@435	85	pointer_delta(tlab_end, top()) - typeArrayOopDesc::header_size(T_INT);
duke@435	86	assert( (array_length * (HeapWordSize/sizeof(jint))) < (size_t)max_jint, "array too big in PSPromotionLAB");
duke@435	87	filler_oop->set_length((int)(array_length * (HeapWordSize/sizeof(jint))));
duke@435	88
duke@435	89	#ifdef ASSERT
duke@435	90	// Note that we actually DO NOT want to use the aligned header size!
duke@435	91	HeapWord* elt_words = ((HeapWord*)filler_oop) + typeArrayOopDesc::header_size(T_INT);
duke@435	92	Copy::fill_to_words(elt_words, array_length, 0xDEAABABE);
duke@435	93	#endif
duke@435	94
duke@435	95	set_bottom(NULL);
duke@435	96	set_end(NULL);
duke@435	97	set_top(NULL);
duke@435	98
duke@435	99	_state = flushed;
duke@435	100	}
duke@435	101
duke@435	102	bool PSPromotionLAB::unallocate_object(oop obj) {
duke@435	103	assert(Universe::heap()->is_in(obj), "Object outside heap");
duke@435	104
duke@435	105	if (contains(obj)) {
duke@435	106	HeapWord* object_end = (HeapWord*)obj + obj->size();
duke@435	107	assert(object_end <= top(), "Object crosses promotion LAB boundary");
duke@435	108
duke@435	109	if (object_end == top()) {
duke@435	110	set_top((HeapWord*)obj);
duke@435	111	return true;
duke@435	112	}
duke@435	113	}
duke@435	114
duke@435	115	return false;
duke@435	116	}
duke@435	117
duke@435	118	// Fill all remaining lab space with an unreachable object.
duke@435	119	// The goal is to leave a contiguous parseable span of objects.
duke@435	120	void PSOldPromotionLAB::flush() {
duke@435	121	assert(_state != flushed, "Attempt to flush PLAB twice");
duke@435	122	assert(top() <= end(), "pointers out of order");
duke@435	123
duke@435	124	if (_state == zero_size)
duke@435	125	return;
duke@435	126
duke@435	127	HeapWord* obj = top();
duke@435	128
duke@435	129	PSPromotionLAB::flush();
duke@435	130
duke@435	131	assert(_start_array != NULL, "Sanity");
duke@435	132
duke@435	133	_start_array->allocate_block(obj);
duke@435	134	}
duke@435	135
duke@435	136	#ifdef ASSERT
duke@435	137
duke@435	138	bool PSYoungPromotionLAB::lab_is_valid(MemRegion lab) {
duke@435	139	ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435	140	assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
duke@435	141
duke@435	142	MutableSpace* to_space = heap->young_gen()->to_space();
duke@435	143	MemRegion used = to_space->used_region();
duke@435	144	if (used.contains(lab)) {
duke@435	145	return true;
duke@435	146	}
duke@435	147
duke@435	148	return false;
duke@435	149	}
duke@435	150
duke@435	151	bool PSOldPromotionLAB::lab_is_valid(MemRegion lab) {
duke@435	152	ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435	153	assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
duke@435	154	assert(_start_array->covered_region().contains(lab), "Sanity");
duke@435	155
duke@435	156	PSOldGen* old_gen = heap->old_gen();
duke@435	157	MemRegion used = old_gen->object_space()->used_region();
duke@435	158
duke@435	159	if (used.contains(lab)) {
duke@435	160	return true;
duke@435	161	}
duke@435	162
duke@435	163	return false;
duke@435	164	}
duke@435	165
duke@435	166	#endif /* ASSERT */