Tue, 08 Aug 2017 15:57:29 +0800
merge
1 /*
2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
25 #include "precompiled.hpp"
26 #include "gc_implementation/parallelScavenge/objectStartArray.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "memory/cardTableModRefBS.hpp"
29 #include "oops/oop.inline.hpp"
30 #include "runtime/java.hpp"
31 #include "services/memTracker.hpp"
33 void ObjectStartArray::initialize(MemRegion reserved_region) {
34 // We're based on the assumption that we use the same
35 // size blocks as the card table.
36 assert((int)block_size == (int)CardTableModRefBS::card_size, "Sanity");
37 assert((int)block_size <= 512, "block_size must be less than or equal to 512");
39 // Calculate how much space must be reserved
40 _reserved_region = reserved_region;
42 size_t bytes_to_reserve = reserved_region.word_size() / block_size_in_words;
43 assert(bytes_to_reserve > 0, "Sanity");
45 bytes_to_reserve =
46 align_size_up(bytes_to_reserve, os::vm_allocation_granularity());
48 // Do not use large-pages for the backing store. The one large page region
49 // will be used for the heap proper.
50 ReservedSpace backing_store(bytes_to_reserve);
51 if (!backing_store.is_reserved()) {
52 vm_exit_during_initialization("Could not reserve space for ObjectStartArray");
53 }
54 MemTracker::record_virtual_memory_type((address)backing_store.base(), mtGC);
56 // We do not commit any memory initially
57 if (!_virtual_space.initialize(backing_store, 0)) {
58 vm_exit_during_initialization("Could not commit space for ObjectStartArray");
59 }
61 _raw_base = (jbyte*)_virtual_space.low_boundary();
63 if (_raw_base == NULL) {
64 vm_exit_during_initialization("Could not get raw_base address");
65 }
67 MemTracker::record_virtual_memory_type((address)_raw_base, mtGC);
70 _offset_base = _raw_base - (size_t(reserved_region.start()) >> block_shift);
72 _covered_region.set_start(reserved_region.start());
73 _covered_region.set_word_size(0);
75 _blocks_region.set_start((HeapWord*)_raw_base);
76 _blocks_region.set_word_size(0);
77 }
79 void ObjectStartArray::set_covered_region(MemRegion mr) {
80 assert(_reserved_region.contains(mr), "MemRegion outside of reserved space");
81 assert(_reserved_region.start() == mr.start(), "Attempt to move covered region");
83 HeapWord* low_bound = mr.start();
84 HeapWord* high_bound = mr.end();
85 assert((uintptr_t(low_bound) & (block_size - 1)) == 0, "heap must start at block boundary");
86 assert((uintptr_t(high_bound) & (block_size - 1)) == 0, "heap must end at block boundary");
88 size_t requested_blocks_size_in_bytes = mr.word_size() / block_size_in_words;
90 // Only commit memory in page sized chunks
91 requested_blocks_size_in_bytes =
92 align_size_up(requested_blocks_size_in_bytes, os::vm_page_size());
94 _covered_region = mr;
96 size_t current_blocks_size_in_bytes = _blocks_region.byte_size();
98 if (requested_blocks_size_in_bytes > current_blocks_size_in_bytes) {
99 // Expand
100 size_t expand_by = requested_blocks_size_in_bytes - current_blocks_size_in_bytes;
101 if (!_virtual_space.expand_by(expand_by)) {
102 vm_exit_out_of_memory(expand_by, OOM_MMAP_ERROR, "object start array expansion");
103 }
104 // Clear *only* the newly allocated region
105 memset(_blocks_region.end(), clean_block, expand_by);
106 }
108 if (requested_blocks_size_in_bytes < current_blocks_size_in_bytes) {
109 // Shrink
110 size_t shrink_by = current_blocks_size_in_bytes - requested_blocks_size_in_bytes;
111 _virtual_space.shrink_by(shrink_by);
112 }
114 _blocks_region.set_word_size(requested_blocks_size_in_bytes / sizeof(HeapWord));
116 assert(requested_blocks_size_in_bytes % sizeof(HeapWord) == 0, "Block table not expanded in word sized increment");
117 assert(requested_blocks_size_in_bytes == _blocks_region.byte_size(), "Sanity");
118 assert(block_for_addr(low_bound) == &_raw_base[0], "Checking start of map");
119 assert(block_for_addr(high_bound-1) <= &_raw_base[_blocks_region.byte_size()-1], "Checking end of map");
120 }
122 void ObjectStartArray::reset() {
123 memset(_blocks_region.start(), clean_block, _blocks_region.byte_size());
124 }
127 bool ObjectStartArray::object_starts_in_range(HeapWord* start_addr,
128 HeapWord* end_addr) const {
129 assert(start_addr <= end_addr, "range is wrong");
130 if (start_addr > end_addr) {
131 return false;
132 }
134 jbyte* start_block = block_for_addr(start_addr);
135 jbyte* end_block = block_for_addr(end_addr);
137 for (jbyte* block = start_block; block <= end_block; block++) {
138 if (*block != clean_block) {
139 return true;
140 }
141 }
143 return false;
144 }