1/*
2 * Copyright (c) 2016, 2017, 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#ifndef SHARE_GC_Z_ZBITMAP_INLINE_HPP
25#define SHARE_GC_Z_ZBITMAP_INLINE_HPP
26
27#include "gc/z/zBitMap.hpp"
28#include "runtime/atomic.hpp"
29#include "utilities/bitMap.inline.hpp"
30#include "utilities/debug.hpp"
31
32inline ZBitMap::ZBitMap(idx_t size_in_bits) :
33 CHeapBitMap(size_in_bits, mtGC, false /* clear */) {}
34
35inline BitMap::bm_word_t ZBitMap::bit_mask_pair(idx_t bit) {
36 assert(bit_in_word(bit) < BitsPerWord - 1, "Invalid bit index");
37 return (bm_word_t)3 << bit_in_word(bit);
38}
39
40inline bool ZBitMap::par_set_bit_pair_finalizable(idx_t bit, bool& inc_live) {
41 inc_live = par_set_bit(bit);
42 return inc_live;
43}
44
45inline bool ZBitMap::par_set_bit_pair_strong(idx_t bit, bool& inc_live) {
46 verify_index(bit);
47 volatile bm_word_t* const addr = word_addr(bit);
48 const bm_word_t pair_mask = bit_mask_pair(bit);
49 bm_word_t old_val = *addr;
50
51 do {
52 const bm_word_t new_val = old_val | pair_mask;
53 if (new_val == old_val) {
54 // Someone else beat us to it
55 inc_live = false;
56 return false;
57 }
58 const bm_word_t cur_val = Atomic::cmpxchg(new_val, addr, old_val);
59 if (cur_val == old_val) {
60 // Success
61 const bm_word_t marked_mask = bit_mask(bit);
62 inc_live = !(old_val & marked_mask);
63 return true;
64 }
65
66 // The value changed, retry
67 old_val = cur_val;
68 } while (true);
69}
70
71inline bool ZBitMap::par_set_bit_pair(idx_t bit, bool finalizable, bool& inc_live) {
72 if (finalizable) {
73 return par_set_bit_pair_finalizable(bit, inc_live);
74 } else {
75 return par_set_bit_pair_strong(bit, inc_live);
76 }
77}
78
79#endif // SHARE_GC_Z_ZBITMAP_INLINE_HPP
80