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