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 <android-base/logging.h>
20
21 #include "base/macros.h"
22 #include "gc/accounting/heap_bitmap.h"
23 #include "gc/accounting/space_bitmap-inl.h"
24 #include "gc/heap.h"
25 #include "runtime.h"
26 #include "thread-current-inl.h"
27
28 namespace art {
29 namespace gc {
30 namespace space {
31
Space(const std::string & name,GcRetentionPolicy gc_retention_policy)32 Space::Space(const std::string& name, GcRetentionPolicy gc_retention_policy)
33 : name_(name), gc_retention_policy_(gc_retention_policy) { }
34
Dump(std::ostream & os) const35 void Space::Dump(std::ostream& os) const {
36 os << GetName() << ":" << GetGcRetentionPolicy();
37 }
38
operator <<(std::ostream & os,const Space & space)39 std::ostream& operator<<(std::ostream& os, const Space& space) {
40 space.Dump(os);
41 return os;
42 }
43
AsDlMallocSpace()44 DlMallocSpace* Space::AsDlMallocSpace() {
45 UNIMPLEMENTED(FATAL) << "Unreachable";
46 UNREACHABLE();
47 }
48
AsRosAllocSpace()49 RosAllocSpace* Space::AsRosAllocSpace() {
50 UNIMPLEMENTED(FATAL) << "Unreachable";
51 UNREACHABLE();
52 }
53
AsZygoteSpace()54 ZygoteSpace* Space::AsZygoteSpace() {
55 UNIMPLEMENTED(FATAL) << "Unreachable";
56 UNREACHABLE();
57 }
58
AsBumpPointerSpace()59 BumpPointerSpace* Space::AsBumpPointerSpace() {
60 UNIMPLEMENTED(FATAL) << "Unreachable";
61 UNREACHABLE();
62 }
63
AsRegionSpace()64 RegionSpace* Space::AsRegionSpace() {
65 LOG(FATAL) << "Unreachable";
66 UNREACHABLE();
67 }
68
AsAllocSpace()69 AllocSpace* Space::AsAllocSpace() {
70 UNIMPLEMENTED(FATAL) << "Unreachable";
71 UNREACHABLE();
72 }
73
AsContinuousMemMapAllocSpace()74 ContinuousMemMapAllocSpace* Space::AsContinuousMemMapAllocSpace() {
75 UNIMPLEMENTED(FATAL) << "Unreachable";
76 UNREACHABLE();
77 }
78
DiscontinuousSpace(const std::string & name,GcRetentionPolicy gc_retention_policy)79 DiscontinuousSpace::DiscontinuousSpace(const std::string& name,
80 GcRetentionPolicy gc_retention_policy) :
81 Space(name, gc_retention_policy) {
82 // TODO: Fix this if we ever support objects not in the low 32 bit.
83 const size_t capacity = static_cast<size_t>(std::numeric_limits<uint32_t>::max());
84 live_bitmap_ = accounting::LargeObjectBitmap::Create("large live objects", nullptr, capacity);
85 CHECK(live_bitmap_.IsValid());
86 mark_bitmap_ = accounting::LargeObjectBitmap::Create("large marked objects", nullptr, capacity);
87 CHECK(mark_bitmap_.IsValid());
88 }
89
Sweep(bool swap_bitmaps)90 collector::ObjectBytePair ContinuousMemMapAllocSpace::Sweep(bool swap_bitmaps) {
91 accounting::ContinuousSpaceBitmap* live_bitmap = GetLiveBitmap();
92 accounting::ContinuousSpaceBitmap* mark_bitmap = GetMarkBitmap();
93 // If the bitmaps are bound then sweeping this space clearly won't do anything.
94 if (live_bitmap == mark_bitmap) {
95 return collector::ObjectBytePair(0, 0);
96 }
97 SweepCallbackContext scc(swap_bitmaps, this);
98 if (swap_bitmaps) {
99 std::swap(live_bitmap, mark_bitmap);
100 }
101 // Bitmaps are pre-swapped for optimization which enables sweeping with the heap unlocked.
102 accounting::ContinuousSpaceBitmap::SweepWalk(
103 *live_bitmap, *mark_bitmap, reinterpret_cast<uintptr_t>(Begin()),
104 reinterpret_cast<uintptr_t>(End()), GetSweepCallback(), reinterpret_cast<void*>(&scc));
105 return scc.freed;
106 }
107
BindLiveToMarkBitmap()108 void ContinuousMemMapAllocSpace::BindLiveToMarkBitmap() {
109 CHECK(!HasBoundBitmaps());
110 temp_bitmap_ = std::move(mark_bitmap_);
111 mark_bitmap_.CopyView(live_bitmap_);
112 }
113
HasBoundBitmaps()114 bool ContinuousSpace::HasBoundBitmaps() {
115 DCHECK(GetLiveBitmap() != nullptr);
116 DCHECK(GetMarkBitmap() != nullptr);
117 // Check if the bitmaps are pointing to the same underlying data.
118 return GetLiveBitmap()->Begin() == GetMarkBitmap()->Begin();
119 }
120
UnBindBitmaps()121 void ContinuousMemMapAllocSpace::UnBindBitmaps() {
122 CHECK(HasBoundBitmaps());
123 // At this point, `temp_bitmap_` holds our old mark bitmap.
124 mark_bitmap_ = std::move(temp_bitmap_);
125 }
126
SwapBitmaps()127 void ContinuousMemMapAllocSpace::SwapBitmaps() {
128 CHECK(!HasBoundBitmaps());
129 std::swap(live_bitmap_, mark_bitmap_);
130 // Preserve 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_in,space::Space * space_in)136 AllocSpace::SweepCallbackContext::SweepCallbackContext(bool swap_bitmaps_in, space::Space* space_in)
137 : swap_bitmaps(swap_bitmaps_in), space(space_in), self(Thread::Current()) {
138 }
139
140 } // namespace space
141 } // namespace gc
142 } // namespace art
143