image_space.h revision 2afe49450f2e018f18b5de45428b9174bfd6f196 
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)
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.
51  static ImageHeader* ReadImageHeaderOrDie(const char* image_location,
52                                           InstructionSet image_isa);
53
54  // Releases the OatFile from the ImageSpace so it can be transfer to
55  // the caller, presumably the ClassLinker.
56  OatFile* ReleaseOatFile()
57      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
58
59  void VerifyImageAllocations()
60      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
61
62  const ImageHeader& GetImageHeader() const {
63    return *reinterpret_cast<ImageHeader*>(Begin());
64  }
65
66  // Actual filename where image was loaded from.
67  // For example: /data/dalvik-cache/arm/system@framework@boot.art
68  const std::string GetImageFilename() const {
69    return GetName();
70  }
71
72  // Symbolic location for image.
73  // For example: /system/framework/boot.art
74  const std::string GetImageLocation() const {
75    return image_location_;
76  }
77
78  accounting::ContinuousSpaceBitmap* GetLiveBitmap() const OVERRIDE {
79    return live_bitmap_.get();
80  }
81
82  accounting::ContinuousSpaceBitmap* GetMarkBitmap() const OVERRIDE {
83    // ImageSpaces have the same bitmap for both live and marked. This helps reduce the number of
84    // special cases to test against.
85    return live_bitmap_.get();
86  }
87
88  void Dump(std::ostream& os) const;
89
90  // Sweeping image spaces is a NOP.
91  void Sweep(bool /* swap_bitmaps */, size_t* /* freed_objects */, size_t* /* freed_bytes */) {
92  }
93
94  bool CanMoveObjects() const OVERRIDE {
95    return false;
96  }
97
98 private:
99  // Tries to initialize an ImageSpace from the given image path,
100  // returning NULL on error.
101  //
102  // If validate_oat_file is false (for /system), do not verify that
103  // image's OatFile is up-to-date relative to its DexFile
104  // inputs. Otherwise (for /data), validate the inputs and generate
105  // the OatFile in /data/dalvik-cache if necessary.
106  static ImageSpace* Init(const char* image_filename, const char* image_location,
107                          bool validate_oat_file, std::string* error_msg)
108      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
109
110  // Returns the filename of the image corresponding to
111  // requested image_location, or the filename where a new image
112  // should be written if one doesn't exist. Looks for a generated
113  // image in the specified location and then in the dalvik-cache.
114  //
115  // Returns true if an image was found, false otherwise.
116  static bool FindImageFilename(const char* image_location,
117                                InstructionSet image_isa,
118                                std::string* location,
119                                bool* is_system);
120
121  OatFile* OpenOatFile(const char* image, std::string* error_msg) const
122      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
123
124  bool ValidateOatFile(std::string* error_msg) const
125      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
126
127  friend class Space;
128
129  static Atomic<uint32_t> bitmap_index_;
130
131  UniquePtr<accounting::ContinuousSpaceBitmap> live_bitmap_;
132
133  ImageSpace(const std::string& name, const char* image_location,
134             MemMap* mem_map, accounting::ContinuousSpaceBitmap* live_bitmap);
135
136  // The OatFile associated with the image during early startup to
137  // reserve space contiguous to the image. It is later released to
138  // the ClassLinker during it's initialization.
139  UniquePtr<OatFile> oat_file_;
140
141  const std::string image_location_;
142
143  DISALLOW_COPY_AND_ASSIGN(ImageSpace);
144};
145
146}  // namespace space
147}  // namespace gc
148}  // namespace art
149
150#endif  // ART_RUNTIME_GC_SPACE_IMAGE_SPACE_H_
151