image_space.h revision 95a935415d44903b28326424beb4db5c013ef089 
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#ifndef ART_RUNTIME_GC_SPACE_IMAGE_SPACE_H_
18#define ART_RUNTIME_GC_SPACE_IMAGE_SPACE_H_
19
20#include "gc/accounting/space_bitmap.h"
21#include "runtime.h"
22#include "space.h"
23
24namespace art {
25
26class OatFile;
27
28namespace gc {
29namespace space {
30
31// An image space is a space backed with a memory mapped image.
32class ImageSpace : public MemMapSpace {
33 public:
34  SpaceType GetType() const {
35    return kSpaceTypeImageSpace;
36  }
37
38  // Create a Space from an image file for a specified instruction
39  // set. Cannot be used for future allocation or collected.
40  //
41  // Create also opens the OatFile associated with the image file so
42  // that it be contiguously allocated with the image before the
43  // creation of the alloc space. The ReleaseOatFile will later be
44  // used to transfer ownership of the OatFile to the ClassLinker when
45  // it is initialized.
46  static ImageSpace* Create(const char* image, InstructionSet image_isa, std::string* error_msg)
47      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
48
49  // Reads the image header from the specified image location for the
50  // instruction set image_isa or dies trying.
51  static ImageHeader* ReadImageHeaderOrDie(const char* image_location,
52                                           InstructionSet image_isa);
53
54  // Reads the image header from the specified image location for the
55  // instruction set image_isa. Returns nullptr on failure, with
56  // reason in error_msg.
57  static ImageHeader* ReadImageHeader(const char* image_location,
58                                      InstructionSet image_isa,
59                                      std::string* error_msg);
60
61  // Give access to the OatFile.
62  const OatFile* GetOatFile() const;
63
64  // Releases the OatFile from the ImageSpace so it can be transfer to
65  // the caller, presumably the ClassLinker.
66  OatFile* ReleaseOatFile()
67      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
68
69  void VerifyImageAllocations()
70      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
71
72  const ImageHeader& GetImageHeader() const {
73    return *reinterpret_cast<ImageHeader*>(Begin());
74  }
75
76  // Actual filename where image was loaded from.
77  // For example: /data/dalvik-cache/arm/system@framework@boot.art
78  const std::string GetImageFilename() const {
79    return GetName();
80  }
81
82  // Symbolic location for image.
83  // For example: /system/framework/boot.art
84  const std::string GetImageLocation() const {
85    return image_location_;
86  }
87
88  accounting::ContinuousSpaceBitmap* GetLiveBitmap() const OVERRIDE {
89    return live_bitmap_.get();
90  }
91
92  accounting::ContinuousSpaceBitmap* GetMarkBitmap() const OVERRIDE {
93    // ImageSpaces have the same bitmap for both live and marked. This helps reduce the number of
94    // special cases to test against.
95    return live_bitmap_.get();
96  }
97
98  void Dump(std::ostream& os) const;
99
100  // Sweeping image spaces is a NOP.
101  void Sweep(bool /* swap_bitmaps */, size_t* /* freed_objects */, size_t* /* freed_bytes */) {
102  }
103
104  bool CanMoveObjects() const OVERRIDE {
105    return false;
106  }
107
108  // Returns the filename of the image corresponding to
109  // requested image_location, or the filename where a new image
110  // should be written if one doesn't exist. Looks for a generated
111  // image in the specified location and then in the dalvik-cache.
112  //
113  // Returns true if an image was found, false otherwise.
114  static bool FindImageFilename(const char* image_location,
115                                InstructionSet image_isa,
116                                std::string* system_location,
117                                bool* has_system,
118                                std::string* data_location,
119                                bool* dalvik_cache_exists,
120                                bool* has_data,
121                                bool *is_global_cache);
122
123 private:
124  // Tries to initialize an ImageSpace from the given image path,
125  // returning NULL on error.
126  //
127  // If validate_oat_file is false (for /system), do not verify that
128  // image's OatFile is up-to-date relative to its DexFile
129  // inputs. Otherwise (for /data), validate the inputs and generate
130  // the OatFile in /data/dalvik-cache if necessary.
131  static ImageSpace* Init(const char* image_filename, const char* image_location,
132                          bool validate_oat_file, std::string* error_msg)
133      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
134
135  OatFile* OpenOatFile(const char* image, std::string* error_msg) const
136      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
137
138  bool ValidateOatFile(std::string* error_msg) const
139      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
140
141  friend class Space;
142
143  static Atomic<uint32_t> bitmap_index_;
144
145  std::unique_ptr<accounting::ContinuousSpaceBitmap> live_bitmap_;
146
147  ImageSpace(const std::string& name, const char* image_location,
148             MemMap* mem_map, accounting::ContinuousSpaceBitmap* live_bitmap);
149
150  // The OatFile associated with the image during early startup to
151  // reserve space contiguous to the image. It is later released to
152  // the ClassLinker during it's initialization.
153  std::unique_ptr<OatFile> oat_file_;
154
155  const std::string image_location_;
156
157  DISALLOW_COPY_AND_ASSIGN(ImageSpace);
158};
159
160}  // namespace space
161}  // namespace gc
162}  // namespace art
163
164#endif  // ART_RUNTIME_GC_SPACE_IMAGE_SPACE_H_
165