1 /*
2 * Copyright (C) 2011 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 #include "space.h"
18
19 #include "base/logging.h"
20 #include "gc/accounting/heap_bitmap.h"
21 #include "gc/accounting/space_bitmap-inl.h"
22 #include "runtime.h"
23 #include "thread-inl.h"
24
25 namespace art {
26 namespace gc {
27 namespace space {
28
Space(const std::string & name,GcRetentionPolicy gc_retention_policy)29 Space::Space(const std::string& name, GcRetentionPolicy gc_retention_policy)
30 : name_(name), gc_retention_policy_(gc_retention_policy) { }
31
Dump(std::ostream & os) const32 void Space::Dump(std::ostream& os) const {
33 os << GetName() << ":" << GetGcRetentionPolicy();
34 }
35
operator <<(std::ostream & os,const Space & space)36 std::ostream& operator<<(std::ostream& os, const Space& space) {
37 space.Dump(os);
38 return os;
39 }
40
AsDlMallocSpace()41 DlMallocSpace* Space::AsDlMallocSpace() {
42 UNIMPLEMENTED(FATAL) << "Unreachable";
43 UNREACHABLE();
44 }
45
AsRosAllocSpace()46 RosAllocSpace* Space::AsRosAllocSpace() {
47 UNIMPLEMENTED(FATAL) << "Unreachable";
48 UNREACHABLE();
49 }
50
AsZygoteSpace()51 ZygoteSpace* Space::AsZygoteSpace() {
52 UNIMPLEMENTED(FATAL) << "Unreachable";
53 UNREACHABLE();
54 }
55
AsBumpPointerSpace()56 BumpPointerSpace* Space::AsBumpPointerSpace() {
57 UNIMPLEMENTED(FATAL) << "Unreachable";
58 UNREACHABLE();
59 }
60
AsRegionSpace()61 RegionSpace* Space::AsRegionSpace() {
62 LOG(FATAL) << "Unreachable";
63 return nullptr;
64 }
65
AsAllocSpace()66 AllocSpace* Space::AsAllocSpace() {
67 UNIMPLEMENTED(FATAL) << "Unreachable";
68 UNREACHABLE();
69 }
70
AsContinuousMemMapAllocSpace()71 ContinuousMemMapAllocSpace* Space::AsContinuousMemMapAllocSpace() {
72 UNIMPLEMENTED(FATAL) << "Unreachable";
73 UNREACHABLE();
74 }
75
DiscontinuousSpace(const std::string & name,GcRetentionPolicy gc_retention_policy)76 DiscontinuousSpace::DiscontinuousSpace(const std::string& name,
77 GcRetentionPolicy gc_retention_policy) :
78 Space(name, gc_retention_policy) {
79 // TODO: Fix this if we ever support objects not in the low 32 bit.
80 const size_t capacity = static_cast<size_t>(std::numeric_limits<uint32_t>::max());
81 live_bitmap_.reset(accounting::LargeObjectBitmap::Create("large live objects", nullptr,
82 capacity));
83 CHECK(live_bitmap_.get() != nullptr);
84 mark_bitmap_.reset(accounting::LargeObjectBitmap::Create("large marked objects", nullptr,
85 capacity));
86 CHECK(mark_bitmap_.get() != nullptr);
87 }
88
Sweep(bool swap_bitmaps)89 collector::ObjectBytePair ContinuousMemMapAllocSpace::Sweep(bool swap_bitmaps) {
90 accounting::ContinuousSpaceBitmap* live_bitmap = GetLiveBitmap();
91 accounting::ContinuousSpaceBitmap* mark_bitmap = GetMarkBitmap();
92 // If the bitmaps are bound then sweeping this space clearly won't do anything.
93 if (live_bitmap == mark_bitmap) {
94 return collector::ObjectBytePair(0, 0);
95 }
96 SweepCallbackContext scc(swap_bitmaps, this);
97 if (swap_bitmaps) {
98 std::swap(live_bitmap, mark_bitmap);
99 }
100 // Bitmaps are pre-swapped for optimization which enables sweeping with the heap unlocked.
101 accounting::ContinuousSpaceBitmap::SweepWalk(
102 *live_bitmap, *mark_bitmap, reinterpret_cast<uintptr_t>(Begin()),
103 reinterpret_cast<uintptr_t>(End()), GetSweepCallback(), reinterpret_cast<void*>(&scc));
104 return scc.freed;
105 }
106
107 // Returns the old mark bitmap.
BindLiveToMarkBitmap()108 void ContinuousMemMapAllocSpace::BindLiveToMarkBitmap() {
109 CHECK(!HasBoundBitmaps());
110 accounting::ContinuousSpaceBitmap* live_bitmap = GetLiveBitmap();
111 if (live_bitmap != mark_bitmap_.get()) {
112 accounting::ContinuousSpaceBitmap* mark_bitmap = mark_bitmap_.release();
113 Runtime::Current()->GetHeap()->GetMarkBitmap()->ReplaceBitmap(mark_bitmap, live_bitmap);
114 temp_bitmap_.reset(mark_bitmap);
115 mark_bitmap_.reset(live_bitmap);
116 }
117 }
118
HasBoundBitmaps() const119 bool ContinuousMemMapAllocSpace::HasBoundBitmaps() const {
120 return temp_bitmap_.get() != nullptr;
121 }
122
UnBindBitmaps()123 void ContinuousMemMapAllocSpace::UnBindBitmaps() {
124 CHECK(HasBoundBitmaps());
125 // At this point, the temp_bitmap holds our old mark bitmap.
126 accounting::ContinuousSpaceBitmap* new_bitmap = temp_bitmap_.release();
127 Runtime::Current()->GetHeap()->GetMarkBitmap()->ReplaceBitmap(mark_bitmap_.get(), new_bitmap);
128 CHECK_EQ(mark_bitmap_.release(), live_bitmap_.get());
129 mark_bitmap_.reset(new_bitmap);
130 DCHECK(temp_bitmap_.get() == nullptr);
131 }
132
SwapBitmaps()133 void ContinuousMemMapAllocSpace::SwapBitmaps() {
134 live_bitmap_.swap(mark_bitmap_);
135 // Swap names to get more descriptive diagnostics.
136 std::string temp_name(live_bitmap_->GetName());
137 live_bitmap_->SetName(mark_bitmap_->GetName());
138 mark_bitmap_->SetName(temp_name);
139 }
140
SweepCallbackContext(bool swap_bitmaps_in,space::Space * space_in)141 AllocSpace::SweepCallbackContext::SweepCallbackContext(bool swap_bitmaps_in, space::Space* space_in)
142 : swap_bitmaps(swap_bitmaps_in), space(space_in), self(Thread::Current()) {
143 }
144
145 } // namespace space
146 } // namespace gc
147 } // namespace art
148