1 /*
2 * Copyright (c) 2001, 2015, 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 */
24
25 #ifndef SHARE_VM_GC_G1_G1BLOCKOFFSETTABLE_INLINE_HPP
26 #define SHARE_VM_GC_G1_G1BLOCKOFFSETTABLE_INLINE_HPP
27
28 #include "gc/g1/g1BlockOffsetTable.hpp"
29 #include "gc/g1/heapRegion.hpp"
30 #include "gc/shared/memset_with_concurrent_readers.hpp"
31 #include "gc/shared/space.hpp"
32
33 inline HeapWord* G1BlockOffsetTablePart::block_start(const void* addr) {
34 if (addr >= _space->bottom() && addr < _space->end()) {
35 HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1);
36 return forward_to_block_containing_addr(q, addr);
37 } else {
38 return NULL;
39 }
40 }
41
42 inline HeapWord* G1BlockOffsetTablePart::block_start_const(const void* addr) const {
43 if (addr >= _space->bottom() && addr < _space->end()) {
44 HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1);
45 HeapWord* n = q + block_size(q);
46 return forward_to_block_containing_addr_const(q, n, addr);
47 } else {
48 return NULL;
49 }
50 }
51
52 u_char G1BlockOffsetTable::offset_array(size_t index) const {
53 check_index(index, "index out of range");
54 return _offset_array[index];
55 }
56
57 void G1BlockOffsetTable::set_offset_array(size_t index, u_char offset) {
58 check_index(index, "index out of range");
59 set_offset_array_raw(index, offset);
60 }
61
62 void G1BlockOffsetTable::set_offset_array(size_t index, HeapWord* high, HeapWord* low) {
63 check_index(index, "index out of range");
64 assert(high >= low, "addresses out of order");
65 size_t offset = pointer_delta(high, low);
66 check_offset(offset, "offset too large");
67 set_offset_array(index, (u_char)offset);
68 }
69
70 void G1BlockOffsetTable::set_offset_array(size_t left, size_t right, u_char offset) {
71 check_index(right, "right index out of range");
72 assert(left <= right, "indexes out of order");
73 size_t num_cards = right - left + 1;
74 memset_with_concurrent_readers(&_offset_array[left], offset, num_cards);
75 }
76
77 // Variant of index_for that does not check the index for validity.
78 inline size_t G1BlockOffsetTable::index_for_raw(const void* p) const {
79 return pointer_delta((char*)p, _reserved.start(), sizeof(char)) >> LogN;
80 }
81
82 inline size_t G1BlockOffsetTable::index_for(const void* p) const {
83 char* pc = (char*)p;
84 assert(pc >= (char*)_reserved.start() &&
85 pc < (char*)_reserved.end(),
86 "p (" PTR_FORMAT ") not in reserved [" PTR_FORMAT ", " PTR_FORMAT ")",
87 p2i(p), p2i(_reserved.start()), p2i(_reserved.end()));
88 size_t result = index_for_raw(p);
89 check_index(result, "bad index from address");
90 return result;
91 }
92
93 inline HeapWord* G1BlockOffsetTable::address_for_index(size_t index) const {
94 check_index(index, "index out of range");
95 HeapWord* result = address_for_index_raw(index);
96 assert(result >= _reserved.start() && result < _reserved.end(),
97 "bad address from index result " PTR_FORMAT
98 " _reserved.start() " PTR_FORMAT " _reserved.end() " PTR_FORMAT,
99 p2i(result), p2i(_reserved.start()), p2i(_reserved.end()));
100 return result;
101 }
102
103 inline size_t G1BlockOffsetTablePart::block_size(const HeapWord* p) const {
104 return _space->block_size(p);
105 }
106
107 inline HeapWord* G1BlockOffsetTablePart::block_at_or_preceding(const void* addr,
108 bool has_max_index,
109 size_t max_index) const {
110 assert(_bot->offset_array(0) == 0, "objects can't cross covered areas");
111 size_t index = _bot->index_for(addr);
112 // We must make sure that the offset table entry we use is valid. If
113 // "addr" is past the end, start at the last known one and go forward.
114 if (has_max_index) {
115 index = MIN2(index, max_index);
116 }
117 HeapWord* q = _bot->address_for_index(index);
118
119 uint offset = _bot->offset_array(index); // Extend u_char to uint.
120 while (offset >= N_words) {
121 // The excess of the offset from N_words indicates a power of Base
122 // to go back by.
123 size_t n_cards_back = BlockOffsetArray::entry_to_cards_back(offset);
124 q -= (N_words * n_cards_back);
125 index -= n_cards_back;
126 offset = _bot->offset_array(index);
127 }
128 assert(offset < N_words, "offset too large");
129 q -= offset;
130 return q;
131 }
132
133 inline HeapWord* G1BlockOffsetTablePart::forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n,
134 const void* addr) const {
135 if (addr >= _space->top()) return _space->top();
136 while (n <= addr) {
137 q = n;
138 oop obj = oop(q);
139 if (obj->klass_or_null() == NULL) {
140 return q;
141 }
142 n += block_size(q);
143 }
144 assert(q <= n, "wrong order for q and addr");
145 assert(addr < n, "wrong order for addr and n");
146 return q;
147 }
148
149 inline HeapWord* G1BlockOffsetTablePart::forward_to_block_containing_addr(HeapWord* q,
150 const void* addr) {
151 if (oop(q)->klass_or_null() == NULL) {
152 return q;
153 }
154 HeapWord* n = q + block_size(q);
155 // In the normal case, where the query "addr" is a card boundary, and the
156 // offset table chunks are the same size as cards, the block starting at
157 // "q" will contain addr, so the test below will fail, and we'll fall
158 // through quickly.
159 if (n <= addr) {
160 q = forward_to_block_containing_addr_slow(q, n, addr);
161 }
162 assert(q <= addr, "wrong order for current and arg");
163 return q;
164 }
165
166 #endif // SHARE_VM_GC_G1_G1BLOCKOFFSETTABLE_INLINE_HPP