1 /*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef ART_RUNTIME_GC_COLLECTOR_SEMI_SPACE_INL_H_
18 #define ART_RUNTIME_GC_COLLECTOR_SEMI_SPACE_INL_H_
19
20 #include "semi_space.h"
21
22 #include "gc/accounting/heap_bitmap.h"
23 #include "mirror/object-inl.h"
24
25 namespace art {
26 namespace gc {
27 namespace collector {
28
29 class BitmapSetSlowPathVisitor {
30 public:
BitmapSetSlowPathVisitor(SemiSpace * semi_space)31 explicit BitmapSetSlowPathVisitor(SemiSpace* semi_space) : semi_space_(semi_space) {
32 }
33
operator()34 void operator()(const mirror::Object* obj) const {
35 CHECK(!semi_space_->to_space_->HasAddress(obj)) << "Marking " << obj << " in to_space_";
36 // Marking a large object, make sure its aligned as a sanity check.
37 CHECK(IsAligned<kPageSize>(obj));
38 }
39
40 private:
41 SemiSpace* const semi_space_;
42 };
43
GetForwardingAddressInFromSpace(mirror::Object * obj)44 inline mirror::Object* SemiSpace::GetForwardingAddressInFromSpace(mirror::Object* obj) const {
45 DCHECK(from_space_->HasAddress(obj));
46 LockWord lock_word = obj->GetLockWord(false);
47 if (lock_word.GetState() != LockWord::kForwardingAddress) {
48 return nullptr;
49 }
50 return reinterpret_cast<mirror::Object*>(lock_word.ForwardingAddress());
51 }
52
53 // Used to mark and copy objects. Any newly-marked objects who are in the from space Get moved to
54 // the to-space and have their forward address updated. Objects which have been newly marked are
55 // pushed on the mark stack.
56 template<bool kPoisonReferences>
MarkObject(mirror::ObjectReference<kPoisonReferences,mirror::Object> * obj_ptr)57 inline void SemiSpace::MarkObject(
58 mirror::ObjectReference<kPoisonReferences, mirror::Object>* obj_ptr) {
59 mirror::Object* obj = obj_ptr->AsMirrorPtr();
60 if (obj == nullptr) {
61 return;
62 }
63 if (from_space_->HasAddress(obj)) {
64 mirror::Object* forward_address = GetForwardingAddressInFromSpace(obj);
65 // If the object has already been moved, return the new forward address.
66 if (UNLIKELY(forward_address == nullptr)) {
67 forward_address = MarkNonForwardedObject(obj);
68 DCHECK(forward_address != nullptr);
69 // Make sure to only update the forwarding address AFTER you copy the object so that the
70 // monitor word doesn't Get stomped over.
71 obj->SetLockWord(
72 LockWord::FromForwardingAddress(reinterpret_cast<size_t>(forward_address)), false);
73 // Push the object onto the mark stack for later processing.
74 MarkStackPush(forward_address);
75 }
76 obj_ptr->Assign(forward_address);
77 } else if (!collect_from_space_only_ && !immune_region_.ContainsObject(obj)) {
78 BitmapSetSlowPathVisitor visitor(this);
79 if (!mark_bitmap_->Set(obj, visitor)) {
80 // This object was not previously marked.
81 MarkStackPush(obj);
82 }
83 }
84 }
85
86 } // namespace collector
87 } // namespace gc
88 } // namespace art
89
90 #endif // ART_RUNTIME_GC_COLLECTOR_SEMI_SPACE_INL_H_
91