1 /*
2  * Copyright (C) 2012 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 "gc/heap.h"
18 #include "gc/space/large_object_space.h"
19 #include "gc/space/space-inl.h"
20 #include "sticky_mark_sweep.h"
21 #include "thread-inl.h"
22 
23 namespace art {
24 namespace gc {
25 namespace collector {
26 
StickyMarkSweep(Heap * heap,bool is_concurrent,const std::string & name_prefix)27 StickyMarkSweep::StickyMarkSweep(Heap* heap, bool is_concurrent, const std::string& name_prefix)
28     : PartialMarkSweep(heap, is_concurrent,
29                        name_prefix.empty() ? "sticky " : name_prefix) {
30   cumulative_timings_.SetName(GetName());
31 }
32 
BindBitmaps()33 void StickyMarkSweep::BindBitmaps() {
34   PartialMarkSweep::BindBitmaps();
35   WriterMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
36   // For sticky GC, we want to bind the bitmaps of all spaces as the allocation stack lets us
37   // know what was allocated since the last GC. A side-effect of binding the allocation space mark
38   // and live bitmap is that marking the objects will place them in the live bitmap.
39   for (const auto& space : GetHeap()->GetContinuousSpaces()) {
40     if (space->IsContinuousMemMapAllocSpace() &&
41         space->GetGcRetentionPolicy() == space::kGcRetentionPolicyAlwaysCollect) {
42       DCHECK(space->IsContinuousMemMapAllocSpace());
43       space->AsContinuousMemMapAllocSpace()->BindLiveToMarkBitmap();
44     }
45   }
46   for (const auto& space : GetHeap()->GetDiscontinuousSpaces()) {
47     CHECK(space->IsLargeObjectSpace());
48     space->AsLargeObjectSpace()->CopyLiveToMarked();
49   }
50 }
51 
MarkReachableObjects()52 void StickyMarkSweep::MarkReachableObjects() {
53   // All reachable objects must be referenced by a root or a dirty card, so we can clear the mark
54   // stack here since all objects in the mark stack will Get scanned by the card scanning anyways.
55   // TODO: Not put these objects in the mark stack in the first place.
56   mark_stack_->Reset();
57   RecursiveMarkDirtyObjects(false, accounting::CardTable::kCardDirty - 1);
58 }
59 
Sweep(bool swap_bitmaps)60 void StickyMarkSweep::Sweep(bool swap_bitmaps) {
61   UNUSED(swap_bitmaps);
62   SweepArray(GetHeap()->GetLiveStack(), false);
63 }
64 
65 }  // namespace collector
66 }  // namespace gc
67 }  // namespace art
68