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
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23 */
24
25 #ifndef SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP
26 #define SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP
27
28 #include "gc/shared/barrierSet.hpp"
29 #include "gc/shared/cardTableModRefBS.inline.hpp"
30 #include "utilities/align.hpp"
31
32 // Inline functions of BarrierSet, which de-virtualize certain
33 // performance-critical calls when the barrier is the most common
34 // card-table kind.
35
36 inline bool BarrierSet::devirtualize_reference_writes() const {
37 switch (kind()) {
38 case CardTableForRS:
39 case CardTableExtension:
40 return true;
41 default:
42 return false;
43 }
44 }
45
46 template <class T> void BarrierSet::write_ref_field_pre(T* field, oop new_val) {
47 if (devirtualize_reference_writes()) {
48 barrier_set_cast<CardTableModRefBS>(this)->inline_write_ref_field_pre(field, new_val);
49 } else {
50 write_ref_field_pre_work(field, new_val);
51 }
52 }
53
54 void BarrierSet::write_ref_field(void* field, oop new_val, bool release) {
55 if (devirtualize_reference_writes()) {
56 barrier_set_cast<CardTableModRefBS>(this)->inline_write_ref_field(field, new_val, release);
57 } else {
58 write_ref_field_work(field, new_val, release);
59 }
60 }
61
62 // count is number of array elements being written
63 void BarrierSet::write_ref_array(HeapWord* start, size_t count) {
64 assert(count <= (size_t)max_intx, "count too large");
65 HeapWord* end = (HeapWord*)((char*)start + (count*heapOopSize));
66 // In the case of compressed oops, start and end may potentially be misaligned;
67 // so we need to conservatively align the first downward (this is not
68 // strictly necessary for current uses, but a case of good hygiene and,
69 // if you will, aesthetics) and the second upward (this is essential for
70 // current uses) to a HeapWord boundary, so we mark all cards overlapping
71 // this write. If this evolves in the future to calling a
72 // logging barrier of narrow oop granularity, like the pre-barrier for G1
73 // (mentioned here merely by way of example), we will need to change this
74 // interface, so it is "exactly precise" (if i may be allowed the adverbial
75 // redundancy for emphasis) and does not include narrow oop slots not
76 // included in the original write interval.
77 HeapWord* aligned_start = align_down(start, HeapWordSize);
78 HeapWord* aligned_end = align_up (end, HeapWordSize);
79 // If compressed oops were not being used, these should already be aligned
80 assert(UseCompressedOops || (aligned_start == start && aligned_end == end),
81 "Expected heap word alignment of start and end");
82 write_ref_array_work(MemRegion(aligned_start, aligned_end));
83 }
84
85
86 inline void BarrierSet::write_region(MemRegion mr) {
87 if (devirtualize_reference_writes()) {
88 barrier_set_cast<CardTableModRefBS>(this)->inline_write_region(mr);
89 } else {
90 write_region_work(mr);
91 }
92 }
93
94 #endif // SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP