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src/share/vm/gc_implementation/parallelScavenge/objectStartArray.cpp@5534bd30c151 (annotated)

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

Thu, 30 May 2013 13:04:51 -0700

author

jcoomes

date

Thu, 30 May 2013 13:04:51 -0700

changeset 5201

5534bd30c151

parent 4993

746b070f5022

child 6198

55fb97c4c58d

permissions

-rw-r--r--

6725714: par compact - add a table to speed up bitmap searches
Reviewed-by: jmasa, tschatzl

duke@435	1	/*
coleenp@4037	2	* Copyright (c) 2001, 2012, 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 "gc_implementation/parallelScavenge/objectStartArray.hpp"
stefank@2314	27	#include "memory/allocation.inline.hpp"
stefank@2314	28	#include "memory/cardTableModRefBS.hpp"
stefank@2314	29	#include "oops/oop.inline.hpp"
stefank@2314	30	#include "runtime/java.hpp"
zgu@3900	31	#include "services/memTracker.hpp"
duke@435	32
duke@435	33	void ObjectStartArray::initialize(MemRegion reserved_region) {
duke@435	34	// We're based on the assumption that we use the same
duke@435	35	// size blocks as the card table.
duke@435	36	assert((int)block_size == (int)CardTableModRefBS::card_size, "Sanity");
duke@435	37	assert((int)block_size <= 512, "block_size must be less than or equal to 512");
duke@435	38
duke@435	39	// Calculate how much space must be reserved
duke@435	40	_reserved_region = reserved_region;
duke@435	41
duke@435	42	size_t bytes_to_reserve = reserved_region.word_size() / block_size_in_words;
duke@435	43	assert(bytes_to_reserve > 0, "Sanity");
duke@435	44
duke@435	45	bytes_to_reserve =
duke@435	46	align_size_up(bytes_to_reserve, os::vm_allocation_granularity());
duke@435	47
duke@435	48	// Do not use large-pages for the backing store. The one large page region
duke@435	49	// will be used for the heap proper.
duke@435	50	ReservedSpace backing_store(bytes_to_reserve);
duke@435	51	if (!backing_store.is_reserved()) {
duke@435	52	vm_exit_during_initialization("Could not reserve space for ObjectStartArray");
duke@435	53	}
zgu@3900	54	MemTracker::record_virtual_memory_type((address)backing_store.base(), mtGC);
duke@435	55
duke@435	56	// We do not commit any memory initially
duke@435	57	if (!_virtual_space.initialize(backing_store, 0)) {
duke@435	58	vm_exit_during_initialization("Could not commit space for ObjectStartArray");
duke@435	59	}
duke@435	60
duke@435	61	_raw_base = (jbyte*)_virtual_space.low_boundary();
zgu@3900	62
duke@435	63	if (_raw_base == NULL) {
duke@435	64	vm_exit_during_initialization("Could not get raw_base address");
duke@435	65	}
duke@435	66
zgu@3900	67	MemTracker::record_virtual_memory_type((address)_raw_base, mtGC);
zgu@3900	68
zgu@3900	69
duke@435	70	_offset_base = _raw_base - (size_t(reserved_region.start()) >> block_shift);
duke@435	71
duke@435	72	_covered_region.set_start(reserved_region.start());
duke@435	73	_covered_region.set_word_size(0);
duke@435	74
duke@435	75	_blocks_region.set_start((HeapWord*)_raw_base);
duke@435	76	_blocks_region.set_word_size(0);
duke@435	77	}
duke@435	78
duke@435	79	void ObjectStartArray::set_covered_region(MemRegion mr) {
duke@435	80	assert(_reserved_region.contains(mr), "MemRegion outside of reserved space");
duke@435	81	assert(_reserved_region.start() == mr.start(), "Attempt to move covered region");
duke@435	82
duke@435	83	HeapWord* low_bound = mr.start();
duke@435	84	HeapWord* high_bound = mr.end();
duke@435	85	assert((uintptr_t(low_bound) & (block_size - 1)) == 0, "heap must start at block boundary");
duke@435	86	assert((uintptr_t(high_bound) & (block_size - 1)) == 0, "heap must end at block boundary");
duke@435	87
duke@435	88	size_t requested_blocks_size_in_bytes = mr.word_size() / block_size_in_words;
duke@435	89
duke@435	90	// Only commit memory in page sized chunks
duke@435	91	requested_blocks_size_in_bytes =
duke@435	92	align_size_up(requested_blocks_size_in_bytes, os::vm_page_size());
duke@435	93
duke@435	94	_covered_region = mr;
duke@435	95
duke@435	96	size_t current_blocks_size_in_bytes = _blocks_region.byte_size();
duke@435	97
duke@435	98	if (requested_blocks_size_in_bytes > current_blocks_size_in_bytes) {
duke@435	99	// Expand
duke@435	100	size_t expand_by = requested_blocks_size_in_bytes - current_blocks_size_in_bytes;
duke@435	101	if (!_virtual_space.expand_by(expand_by)) {
ccheung@4993	102	vm_exit_out_of_memory(expand_by, OOM_MMAP_ERROR, "object start array expansion");
duke@435	103	}
duke@435	104	// Clear *only* the newly allocated region
duke@435	105	memset(_blocks_region.end(), clean_block, expand_by);
duke@435	106	}
duke@435	107
duke@435	108	if (requested_blocks_size_in_bytes < current_blocks_size_in_bytes) {
duke@435	109	// Shrink
duke@435	110	size_t shrink_by = current_blocks_size_in_bytes - requested_blocks_size_in_bytes;
duke@435	111	_virtual_space.shrink_by(shrink_by);
duke@435	112	}
duke@435	113
duke@435	114	_blocks_region.set_word_size(requested_blocks_size_in_bytes / sizeof(HeapWord));
duke@435	115
duke@435	116	assert(requested_blocks_size_in_bytes % sizeof(HeapWord) == 0, "Block table not expanded in word sized increment");
duke@435	117	assert(requested_blocks_size_in_bytes == _blocks_region.byte_size(), "Sanity");
duke@435	118	assert(block_for_addr(low_bound) == &_raw_base[0], "Checking start of map");
duke@435	119	assert(block_for_addr(high_bound-1) <= &_raw_base[_blocks_region.byte_size()-1], "Checking end of map");
duke@435	120	}
duke@435	121
duke@435	122	void ObjectStartArray::reset() {
duke@435	123	memset(_blocks_region.start(), clean_block, _blocks_region.byte_size());
duke@435	124	}
duke@435	125
duke@435	126
duke@435	127	bool ObjectStartArray::object_starts_in_range(HeapWord* start_addr,
duke@435	128	HeapWord* end_addr) const {
duke@435	129	assert(start_addr <= end_addr, "range is wrong");
duke@435	130	if (start_addr > end_addr) {
duke@435	131	return false;
duke@435	132	}
duke@435	133
duke@435	134	jbyte* start_block = block_for_addr(start_addr);
duke@435	135	jbyte* end_block = block_for_addr(end_addr);
duke@435	136
duke@435	137	for (jbyte* block = start_block; block <= end_block; block++) {
duke@435	138	if (*block != clean_block) {
duke@435	139	return true;
duke@435	140	}
duke@435	141	}
duke@435	142	// No object starts in this slice; verify this using
coleenp@4037	143	// more traditional methods: Note that no object can
coleenp@4037	144	// start before the start_addr.
coleenp@4037	145	assert(end_addr == start_addr ||
coleenp@4037	146	object_start(end_addr - 1) <= start_addr,
duke@435	147	"Oops an object does start in this slice?");
duke@435	148	return false;
duke@435	149	}