1 /*
2  * Copyright (C) 2015 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 "bitmap-inl.h"
18 
19 #include <sys/mman.h>  // For the PROT_* and MAP_* constants.
20 
21 #include "base/bit_utils.h"
22 #include "base/mem_map.h"
23 #include "card_table.h"
24 #include "gc/collector/mark_compact.h"
25 #include "jit/jit_memory_region.h"
26 
27 namespace art HIDDEN {
28 namespace gc {
29 namespace accounting {
30 
CreateFromMemMap(MemMap && mem_map,size_t num_bits)31 Bitmap* Bitmap::CreateFromMemMap(MemMap&& mem_map, size_t num_bits) {
32   CHECK(mem_map.IsValid());
33   return new Bitmap(std::move(mem_map), num_bits);
34 }
35 
Bitmap(MemMap && mem_map,size_t num_bits)36 Bitmap::Bitmap(MemMap&& mem_map, size_t num_bits)
37     : mem_map_(std::move(mem_map)),
38       bitmap_begin_(reinterpret_cast<uintptr_t*>(mem_map_.Begin())),
39       bitmap_numbits_(num_bits) {
40   CHECK(bitmap_begin_ != nullptr);
41   CHECK_NE(num_bits, 0U);
42 }
43 
~Bitmap()44 Bitmap::~Bitmap() {
45   // Destroys member MemMap.
46 }
47 
AllocateMemMap(const std::string & name,size_t num_bits)48 MemMap Bitmap::AllocateMemMap(const std::string& name, size_t num_bits) {
49   const size_t bitmap_size = RoundUp(
50       RoundUp(num_bits, kBitsPerBitmapWord) / kBitsPerBitmapWord * sizeof(uintptr_t), gPageSize);
51   std::string error_msg;
52   MemMap mem_map = MemMap::MapAnonymous(name.c_str(),
53                                         bitmap_size,
54                                         PROT_READ | PROT_WRITE,
55                                         /*low_4gb=*/ false,
56                                         &error_msg);
57   if (UNLIKELY(!mem_map.IsValid())) {
58     LOG(ERROR) << "Failed to allocate bitmap " << name << ": " << error_msg;
59   }
60   return mem_map;
61 }
62 
Create(const std::string & name,size_t num_bits)63 Bitmap* Bitmap::Create(const std::string& name, size_t num_bits) {
64   MemMap mem_map = AllocateMemMap(name, num_bits);
65   if (UNLIKELY(!mem_map.IsValid())) {
66     return nullptr;
67   }
68   return CreateFromMemMap(std::move(mem_map), num_bits);
69 }
70 
Clear()71 void Bitmap::Clear() {
72   if (bitmap_begin_ != nullptr) {
73     mem_map_.MadviseDontNeedAndZero();
74   }
75 }
76 
CopyFrom(Bitmap * source_bitmap)77 void Bitmap::CopyFrom(Bitmap* source_bitmap) {
78   DCHECK_EQ(BitmapSize(), source_bitmap->BitmapSize());
79   std::copy(source_bitmap->Begin(),
80             source_bitmap->Begin() + BitmapSize() / kBitsPerBitmapWord, Begin());
81 }
82 
83 template<size_t kAlignment>
Create(const std::string & name,uintptr_t cover_begin,uintptr_t cover_end)84 MemoryRangeBitmap<kAlignment>* MemoryRangeBitmap<kAlignment>::Create(
85     const std::string& name, uintptr_t cover_begin, uintptr_t cover_end) {
86   CHECK_ALIGNED(cover_begin, kAlignment);
87   CHECK_ALIGNED(cover_end, kAlignment);
88   const size_t num_bits = (cover_end - cover_begin) / kAlignment;
89   MemMap mem_map = Bitmap::AllocateMemMap(name, num_bits);
90   CHECK(mem_map.IsValid());
91   return CreateFromMemMap(std::move(mem_map), cover_begin, num_bits);
92 }
93 
94 template<size_t kAlignment>
CreateFromMemMap(MemMap && mem_map,uintptr_t begin,size_t num_bits)95 MemoryRangeBitmap<kAlignment>* MemoryRangeBitmap<kAlignment>::CreateFromMemMap(
96     MemMap&& mem_map, uintptr_t begin, size_t num_bits) {
97   return new MemoryRangeBitmap(std::move(mem_map), begin, num_bits);
98 }
99 
100 template class MemoryRangeBitmap<CardTable::kCardSize>;
101 template class MemoryRangeBitmap<jit::kJitCodeAccountingBytes>;
102 template class MemoryRangeBitmap<collector::MarkCompact::kAlignment>;
103 
104 }  // namespace accounting
105 }  // namespace gc
106 }  // namespace art
107 
108