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
25namespace art {
26namespace gc {
27namespace space {
28
29Space::Space(const std::string& name, GcRetentionPolicy gc_retention_policy)
30    : name_(name), gc_retention_policy_(gc_retention_policy) { }
31
32void Space::Dump(std::ostream& os) const {
33  os << GetName() << ":" << GetGcRetentionPolicy();
34}
35
36std::ostream& operator<<(std::ostream& os, const Space& space) {
37  space.Dump(os);
38  return os;
39}
40
41DlMallocSpace* Space::AsDlMallocSpace() {
42  UNIMPLEMENTED(FATAL) << "Unreachable";
43  UNREACHABLE();
44}
45
46RosAllocSpace* Space::AsRosAllocSpace() {
47  UNIMPLEMENTED(FATAL) << "Unreachable";
48  UNREACHABLE();
49}
50
51ZygoteSpace* Space::AsZygoteSpace() {
52  UNIMPLEMENTED(FATAL) << "Unreachable";
53  UNREACHABLE();
54}
55
56BumpPointerSpace* Space::AsBumpPointerSpace() {
57  UNIMPLEMENTED(FATAL) << "Unreachable";
58  UNREACHABLE();
59}
60
61RegionSpace* Space::AsRegionSpace() {
62  LOG(FATAL) << "Unreachable";
63  return nullptr;
64}
65
66AllocSpace* Space::AsAllocSpace() {
67  UNIMPLEMENTED(FATAL) << "Unreachable";
68  UNREACHABLE();
69}
70
71ContinuousMemMapAllocSpace* Space::AsContinuousMemMapAllocSpace() {
72  UNIMPLEMENTED(FATAL) << "Unreachable";
73  UNREACHABLE();
74}
75
76DiscontinuousSpace::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
89collector::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.
108void 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
119bool ContinuousMemMapAllocSpace::HasBoundBitmaps() const {
120  return temp_bitmap_.get() != nullptr;
121}
122
123void 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
133void 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
141AllocSpace::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