1 /*
2 * Copyright (c) 2000, 2023, 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_GC_SHARED_MODREFBARRIERSET_HPP
26 #define SHARE_GC_SHARED_MODREFBARRIERSET_HPP
27
28 #include "gc/shared/barrierSet.hpp"
29 #include "memory/memRegion.hpp"
30
31 class Klass;
32
33 class ModRefBarrierSet: public BarrierSet {
34 protected:
35 ModRefBarrierSet(BarrierSetAssembler* barrier_set_assembler,
36 BarrierSetC1* barrier_set_c1,
37 BarrierSetC2* barrier_set_c2,
38 const BarrierSet::FakeRtti& fake_rtti)
39 : BarrierSet(barrier_set_assembler,
40 barrier_set_c1,
41 barrier_set_c2,
42 nullptr /* barrier_set_nmethod */,
43 nullptr /* barrier_set_stack_chunk */,
44 fake_rtti.add_tag(BarrierSet::ModRef)) { }
45 ~ModRefBarrierSet() { }
46
47 public:
48 template <DecoratorSet decorators, typename T>
49 inline void write_ref_field_pre(T* addr) {}
50
51 template <DecoratorSet decorators, typename T>
52 inline void write_ref_field_post(T *addr) {}
53
54 // Causes all refs in "mr" to be assumed to be modified (by this JavaThread).
55 virtual void write_region(MemRegion mr) = 0;
56 // Causes all refs in "mr" to be assumed to be modified by the given JavaThread.
57 virtual void write_region(JavaThread* thread, MemRegion mr) = 0;
58
59 // Operations on arrays, or general regions (e.g., for "clone") may be
60 // optimized by some barriers.
61
62 // Below length is the # array elements being written
63 virtual void write_ref_array_pre(oop* dst, size_t length,
64 bool dest_uninitialized) {}
65 virtual void write_ref_array_pre(narrowOop* dst, size_t length,
66 bool dest_uninitialized) {}
67 // Below count is the # array elements being written, starting
68 // at the address "start", which may not necessarily be HeapWord-aligned
69 inline void write_ref_array(HeapWord* start, size_t count);
70
71 // The ModRef abstraction introduces pre and post barriers
72 template <DecoratorSet decorators, typename BarrierSetT>
73 class AccessBarrier: public BarrierSet::AccessBarrier<decorators, BarrierSetT> {
74 typedef BarrierSet::AccessBarrier<decorators, BarrierSetT> Raw;
75
76 public:
77 template <typename T>
78 static void oop_store_in_heap(T* addr, oop value);
79 template <typename T>
80 static oop oop_atomic_cmpxchg_in_heap(T* addr, oop compare_value, oop new_value);
81 template <typename T>
82 static oop oop_atomic_xchg_in_heap(T* addr, oop new_value);
83
84 template <typename T>
85 static bool oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
86 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
87 size_t length);
88
89 static void clone_in_heap(oop src, oop dst, size_t size);
90
91 static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
92 oop_store_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), value);
93 }
94
95 static oop oop_atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, oop new_value) {
96 return oop_atomic_xchg_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), new_value);
97 }
98
99 static oop oop_atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, oop compare_value, oop new_value) {
100 return oop_atomic_cmpxchg_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), compare_value, new_value);
101 }
102 };
103 };
104
105 template<>
106 struct BarrierSet::GetName<ModRefBarrierSet> {
107 static const BarrierSet::Name value = BarrierSet::ModRef;
108 };
109
110 #endif // SHARE_GC_SHARED_MODREFBARRIERSET_HPP