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 LOG(FATAL) << "Unreachable";
43 return nullptr;
44 }
45
AsRosAllocSpace()46 RosAllocSpace* Space::AsRosAllocSpace() {
47 LOG(FATAL) << "Unreachable";
48 return nullptr;
49 }
50
AsZygoteSpace()51 ZygoteSpace* Space::AsZygoteSpace() {
52 LOG(FATAL) << "Unreachable";
53 return nullptr;
54 }
55
AsBumpPointerSpace()56 BumpPointerSpace* Space::AsBumpPointerSpace() {
57 LOG(FATAL) << "Unreachable";
58 return nullptr;
59 }
60
AsAllocSpace()61 AllocSpace* Space::AsAllocSpace() {
62 LOG(FATAL) << "Unimplemented";
63 return nullptr;
64 }
65
AsContinuousMemMapAllocSpace()66 ContinuousMemMapAllocSpace* Space::AsContinuousMemMapAllocSpace() {
67 LOG(FATAL) << "Unimplemented";
68 return nullptr;
69 }
70
DiscontinuousSpace(const std::string & name,GcRetentionPolicy gc_retention_policy)71 DiscontinuousSpace::DiscontinuousSpace(const std::string& name,
72 GcRetentionPolicy gc_retention_policy) :
73 Space(name, gc_retention_policy) {
74 // TODO: Fix this if we ever support objects not in the low 32 bit.
75 const size_t capacity = static_cast<size_t>(std::numeric_limits<uint32_t>::max());
76 live_bitmap_.reset(accounting::LargeObjectBitmap::Create("large live objects", nullptr,
77 capacity));
78 CHECK(live_bitmap_.get() != nullptr);
79 mark_bitmap_.reset(accounting::LargeObjectBitmap::Create("large marked objects", nullptr,
80 capacity));
81 CHECK(mark_bitmap_.get() != nullptr);
82 }
83
Sweep(bool swap_bitmaps)84 collector::ObjectBytePair ContinuousMemMapAllocSpace::Sweep(bool swap_bitmaps) {
85 accounting::ContinuousSpaceBitmap* live_bitmap = GetLiveBitmap();
86 accounting::ContinuousSpaceBitmap* mark_bitmap = GetMarkBitmap();
87 // If the bitmaps are bound then sweeping this space clearly won't do anything.
88 if (live_bitmap == mark_bitmap) {
89 return collector::ObjectBytePair(0, 0);
90 }
91 SweepCallbackContext scc(swap_bitmaps, this);
92 if (swap_bitmaps) {
93 std::swap(live_bitmap, mark_bitmap);
94 }
95 // Bitmaps are pre-swapped for optimization which enables sweeping with the heap unlocked.
96 accounting::ContinuousSpaceBitmap::SweepWalk(
97 *live_bitmap, *mark_bitmap, reinterpret_cast<uintptr_t>(Begin()),
98 reinterpret_cast<uintptr_t>(End()), GetSweepCallback(), reinterpret_cast<void*>(&scc));
99 return scc.freed;
100 }
101
102 // Returns the old mark bitmap.
BindLiveToMarkBitmap()103 void ContinuousMemMapAllocSpace::BindLiveToMarkBitmap() {
104 CHECK(!HasBoundBitmaps());
105 accounting::ContinuousSpaceBitmap* live_bitmap = GetLiveBitmap();
106 if (live_bitmap != mark_bitmap_.get()) {
107 accounting::ContinuousSpaceBitmap* mark_bitmap = mark_bitmap_.release();
108 Runtime::Current()->GetHeap()->GetMarkBitmap()->ReplaceBitmap(mark_bitmap, live_bitmap);
109 temp_bitmap_.reset(mark_bitmap);
110 mark_bitmap_.reset(live_bitmap);
111 }
112 }
113
HasBoundBitmaps() const114 bool ContinuousMemMapAllocSpace::HasBoundBitmaps() const {
115 return temp_bitmap_.get() != nullptr;
116 }
117
UnBindBitmaps()118 void ContinuousMemMapAllocSpace::UnBindBitmaps() {
119 CHECK(HasBoundBitmaps());
120 // At this point, the temp_bitmap holds our old mark bitmap.
121 accounting::ContinuousSpaceBitmap* new_bitmap = temp_bitmap_.release();
122 Runtime::Current()->GetHeap()->GetMarkBitmap()->ReplaceBitmap(mark_bitmap_.get(), new_bitmap);
123 CHECK_EQ(mark_bitmap_.release(), live_bitmap_.get());
124 mark_bitmap_.reset(new_bitmap);
125 DCHECK(temp_bitmap_.get() == nullptr);
126 }
127
SwapBitmaps()128 void ContinuousMemMapAllocSpace::SwapBitmaps() {
129 live_bitmap_.swap(mark_bitmap_);
130 // Swap names to get more descriptive diagnostics.
131 std::string temp_name(live_bitmap_->GetName());
132 live_bitmap_->SetName(mark_bitmap_->GetName());
133 mark_bitmap_->SetName(temp_name);
134 }
135
SweepCallbackContext(bool swap_bitmaps,space::Space * space)136 AllocSpace::SweepCallbackContext::SweepCallbackContext(bool swap_bitmaps, space::Space* space)
137 : swap_bitmaps(swap_bitmaps), space(space), self(Thread::Current()) {
138 }
139
140 } // namespace space
141 } // namespace gc
142 } // namespace art
143