1 /*
2 * Copyright (c) 2016, 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_SHARED_MODREFBARRIERSET_INLINE_HPP
26 #define SHARE_VM_GC_SHARED_MODREFBARRIERSET_INLINE_HPP
27
28 #include "gc/shared/modRefBarrierSet.hpp"
29 #include "oops/oop.hpp"
30
31 // count is number of array elements being written
32 void ModRefBarrierSet::write_ref_array(HeapWord* start, size_t count) {
33 assert(count <= (size_t)max_intx, "count too large");
34 HeapWord* end = (HeapWord*)((char*)start + (count*heapOopSize));
35 // In the case of compressed oops, start and end may potentially be misaligned;
36 // so we need to conservatively align the first downward (this is not
37 // strictly necessary for current uses, but a case of good hygiene and,
38 // if you will, aesthetics) and the second upward (this is essential for
39 // current uses) to a HeapWord boundary, so we mark all cards overlapping
40 // this write. If this evolves in the future to calling a
41 // logging barrier of narrow oop granularity, like the pre-barrier for G1
42 // (mentioned here merely by way of example), we will need to change this
43 // interface, so it is "exactly precise" (if i may be allowed the adverbial
44 // redundancy for emphasis) and does not include narrow oop slots not
45 // included in the original write interval.
46 HeapWord* aligned_start = (HeapWord*)align_size_down((uintptr_t)start, HeapWordSize);
47 HeapWord* aligned_end = (HeapWord*)align_size_up ((uintptr_t)end, HeapWordSize);
48 // If compressed oops were not being used, these should already be aligned
49 assert(UseCompressedOops || (aligned_start == start && aligned_end == end),
50 "Expected heap word alignment of start and end");
51 write_ref_array_region(MemRegion(aligned_start, aligned_end));
52 }
53
54 template <DecoratorSet decorators, typename BarrierSetT>
55 inline void ModRefBarrierSet::AccessBarrier<decorators, BarrierSetT>::
56 oop_store(void* addr, oop value) {
57 if (!DecoratorTest<decorators>::HAS_ACCESS_ON_HEAP || DecoratorTest<decorators>::HAS_ACCESS_WEAK) {
58 Basic::oop_store(addr, value);
59 } else {
60 BarrierSetT *bs = barrier_set_cast<BarrierSetT>(barrier_set());
61 bs->BarrierSetT::template write_ref_field_pre<decorators>(addr);
62 Basic::oop_store(addr, value);
63 bs->BarrierSetT::template write_ref_field_post<decorators>(addr, value);
64 }
65 }
66
67 template <DecoratorSet decorators, typename BarrierSetT>
68 inline void ModRefBarrierSet::AccessBarrier<decorators, BarrierSetT>::
69 oop_store_at(Klass* base, ptrdiff_t offset, oop value) {
70 BarrierSetT *bs = barrier_set_cast<BarrierSetT>(barrier_set());
71 bs->BarrierSetT::klass_update_barrier_set_pre(base, (oop*)Basic::field_addr(base, offset));
72 Basic::oop_store(Basic::field_addr(base, offset), value);
73 bs->BarrierSetT::klass_update_barrier_set(base, (oop*)Basic::field_addr(base, offset), value);
74 }
75
76 template <DecoratorSet decorators, typename BarrierSetT>
77 inline oop ModRefBarrierSet::AccessBarrier<decorators, BarrierSetT>::
78 oop_cas(oop new_value, void* addr, oop compare_value) {
79 if (!DecoratorTest<decorators>::HAS_ACCESS_ON_HEAP || DecoratorTest<decorators>::HAS_ACCESS_WEAK) {
80 return Basic::oop_cas(new_value, addr, compare_value);
81 } else {
82 BarrierSetT *bs = barrier_set_cast<BarrierSetT>(barrier_set());
83 bs->BarrierSetT::template write_ref_field_pre<decorators>(addr);
84 oop result = Basic::oop_cas(new_value, addr, compare_value);
85 if (result == compare_value) {
86 bs->BarrierSetT::template write_ref_field_post<decorators>(addr, new_value);
87 }
88 return result;
89 }
90 }
91
92 template <DecoratorSet decorators, typename BarrierSetT>
93 inline oop ModRefBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_swap(oop new_value, void* addr) {
94 if (!DecoratorTest<decorators>::HAS_ACCESS_ON_HEAP || DecoratorTest<decorators>::HAS_ACCESS_WEAK) {
95 return Basic::oop_swap(new_value, addr);
96 } else {
97 BarrierSetT *bs = barrier_set_cast<BarrierSetT>(barrier_set());
98 bs->BarrierSetT::template write_ref_field_pre<decorators>(addr);
99 oop result = Basic::oop_swap(new_value, addr);
100 bs->BarrierSetT::template write_ref_field_post<decorators>(addr, new_value);
101 return result;
102 }
103 }
104
105 template <DecoratorSet decorators, typename BarrierSetT>
106 template <typename T>
107 inline bool ModRefBarrierSet::AccessBarrier<decorators, BarrierSetT>::
108 oop_copy(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length) {
109 BarrierSetT *bs = barrier_set_cast<BarrierSetT>(barrier_set());
110
111 if (DecoratorTest<decorators>::HAS_DEST_COVARIANT) {
112 // Optimized case
113 bs->BarrierSetT::write_ref_array_pre(dst, (int)length,
114 DecoratorTest<decorators>::HAS_DEST_NOT_INITIALIZED);
115 Basic::template oop_copy<T>(src_obj, dst_obj, src, dst, length);
116 bs->BarrierSetT::write_ref_array((HeapWord*)dst, length);
117 } else {
118 Klass* bound = bound_for_array((oop)dst_obj);
119 T* from = src;
120 T* end = from + length;
121 for (T* p = dst; from < end; from++, p++) {
122 // XXX this is going to be slow.
123 T element = *from;
124 // even slower now
125 bool element_is_null = oopDesc::is_null(element);
126 oop new_val = element_is_null ? oop(NULL)
127 : oopDesc::decode_heap_oop_not_null(element);
128 if (element_is_null || is_bounded_by(new_val, bound)) {
129 bs->BarrierSetT::template write_ref_field_pre<decorators>((void*)p);
130 *p = element;
131 } else {
132 // We must do a barrier to cover the partial copy.
133 const size_t pd = pointer_delta(p, dst, (size_t)heapOopSize);
134 // pointer delta is scaled to number of elements (length field in
135 // objArrayOop) which we assume is 32 bit.
136 assert(pd == (size_t)(int)pd, "length field overflow");
137 bs->BarrierSetT::write_ref_array((HeapWord*)dst, pd);
138 return false;
139 }
140 }
141 bs->BarrierSetT::write_ref_array((HeapWord*)dst, length);
142 }
143 return true;
144 }
145
146 template <DecoratorSet decorators, typename BarrierSetT>
147 inline void ModRefBarrierSet::AccessBarrier<decorators, BarrierSetT>::
148 clone(oop src, oop dst, size_t size) {
149 Basic::clone(src, dst, size);
150 BarrierSetT *bs = barrier_set_cast<BarrierSetT>(barrier_set());
151 bs->BarrierSetT::write_region(MemRegion((HeapWord*)(void*)dst, size));
152 }
153
154 #endif // SHARE_VM_GC_SHARED_MODREFBARRIERSET_INLINE_HPP