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 
24 namespace art {
25 
26 class OatFile;
27 
28 namespace gc {
29 namespace space {
30 
31 // An image space is a space backed with a memory mapped image.
32 class ImageSpace : public MemMapSpace {
33  public:
GetType()34   SpaceType GetType() const {
35     return kSpaceTypeImageSpace;
36   }
37 
38   // Create a boot image 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* CreateBootImage(const char* image,
47                                      InstructionSet image_isa,
48                                      bool secondary_image,
49                                      std::string* error_msg)
50       SHARED_REQUIRES(Locks::mutator_lock_);
51 
52   // Try to open an existing app image space.
53   static ImageSpace* CreateFromAppImage(const char* image,
54                                         const OatFile* oat_file,
55                                         std::string* error_msg)
56       SHARED_REQUIRES(Locks::mutator_lock_);
57 
58   // Reads the image header from the specified image location for the
59   // instruction set image_isa or dies trying.
60   static ImageHeader* ReadImageHeaderOrDie(const char* image_location,
61                                            InstructionSet image_isa);
62 
63   // Reads the image header from the specified image location for the
64   // instruction set image_isa. Returns null on failure, with
65   // reason in error_msg.
66   static ImageHeader* ReadImageHeader(const char* image_location,
67                                       InstructionSet image_isa,
68                                       std::string* error_msg);
69 
70   // Give access to the OatFile.
71   const OatFile* GetOatFile() const;
72 
73   // Releases the OatFile from the ImageSpace so it can be transfer to
74   // the caller, presumably the OatFileManager.
75   std::unique_ptr<const OatFile> ReleaseOatFile();
76 
77   void VerifyImageAllocations()
78       SHARED_REQUIRES(Locks::mutator_lock_);
79 
GetImageHeader()80   const ImageHeader& GetImageHeader() const {
81     return *reinterpret_cast<ImageHeader*>(Begin());
82   }
83 
84   // Actual filename where image was loaded from.
85   // For example: /data/dalvik-cache/arm/system@framework@boot.art
GetImageFilename()86   const std::string GetImageFilename() const {
87     return GetName();
88   }
89 
90   // Symbolic location for image.
91   // For example: /system/framework/boot.art
GetImageLocation()92   const std::string GetImageLocation() const {
93     return image_location_;
94   }
95 
GetLiveBitmap()96   accounting::ContinuousSpaceBitmap* GetLiveBitmap() const OVERRIDE {
97     return live_bitmap_.get();
98   }
99 
GetMarkBitmap()100   accounting::ContinuousSpaceBitmap* GetMarkBitmap() const OVERRIDE {
101     // ImageSpaces have the same bitmap for both live and marked. This helps reduce the number of
102     // special cases to test against.
103     return live_bitmap_.get();
104   }
105 
106   void Dump(std::ostream& os) const;
107 
108   // Sweeping image spaces is a NOP.
Sweep(bool,size_t *,size_t *)109   void Sweep(bool /* swap_bitmaps */, size_t* /* freed_objects */, size_t* /* freed_bytes */) {
110   }
111 
CanMoveObjects()112   bool CanMoveObjects() const OVERRIDE {
113     return false;
114   }
115 
116   // Returns the filename of the image corresponding to
117   // requested image_location, or the filename where a new image
118   // should be written if one doesn't exist. Looks for a generated
119   // image in the specified location and then in the dalvik-cache.
120   //
121   // Returns true if an image was found, false otherwise.
122   static bool FindImageFilename(const char* image_location,
123                                 InstructionSet image_isa,
124                                 std::string* system_location,
125                                 bool* has_system,
126                                 std::string* data_location,
127                                 bool* dalvik_cache_exists,
128                                 bool* has_data,
129                                 bool *is_global_cache);
130 
131   // Use the input image filename to adapt the names in the given boot classpath to establish
132   // complete locations for secondary images.
133   static void CreateMultiImageLocations(const std::string& input_image_file_name,
134                                         const std::string& boot_classpath,
135                                         std::vector<std::string>* image_filenames);
136 
137   // Return the end of the image which includes non-heap objects such as ArtMethods and ArtFields.
GetImageEnd()138   uint8_t* GetImageEnd() const {
139     return Begin() + GetImageHeader().GetImageSize();
140   }
141 
142   // Return the start of the associated oat file.
GetOatFileBegin()143   uint8_t* GetOatFileBegin() const {
144     return GetImageHeader().GetOatFileBegin();
145   }
146 
147   // Return the end of the associated oat file.
GetOatFileEnd()148   uint8_t* GetOatFileEnd() const {
149     return GetImageHeader().GetOatFileEnd();
150   }
151 
152   void DumpSections(std::ostream& os) const;
153 
154  protected:
155   // Tries to initialize an ImageSpace from the given image path, returning null on error.
156   //
157   // If validate_oat_file is false (for /system), do not verify that image's OatFile is up-to-date
158   // relative to its DexFile inputs. Otherwise (for /data), validate the inputs and generate the
159   // OatFile in /data/dalvik-cache if necessary. If the oat_file is null, it uses the oat file from
160   // the image.
161   static ImageSpace* Init(const char* image_filename,
162                           const char* image_location,
163                           bool validate_oat_file,
164                           const OatFile* oat_file,
165                           std::string* error_msg)
166       SHARED_REQUIRES(Locks::mutator_lock_);
167 
168   OatFile* OpenOatFile(const char* image, std::string* error_msg) const
169       SHARED_REQUIRES(Locks::mutator_lock_);
170 
171   bool ValidateOatFile(std::string* error_msg) const
172       SHARED_REQUIRES(Locks::mutator_lock_);
173 
174   friend class Space;
175 
176   static Atomic<uint32_t> bitmap_index_;
177 
178   std::unique_ptr<accounting::ContinuousSpaceBitmap> live_bitmap_;
179 
180   ImageSpace(const std::string& name,
181              const char* image_location,
182              MemMap* mem_map,
183              accounting::ContinuousSpaceBitmap* live_bitmap,
184              uint8_t* end);
185 
186   // The OatFile associated with the image during early startup to
187   // reserve space contiguous to the image. It is later released to
188   // the ClassLinker during it's initialization.
189   std::unique_ptr<OatFile> oat_file_;
190 
191   // There are times when we need to find the boot image oat file. As
192   // we release ownership during startup, keep a non-owned reference.
193   const OatFile* oat_file_non_owned_;
194 
195   const std::string image_location_;
196 
197  private:
198   DISALLOW_COPY_AND_ASSIGN(ImageSpace);
199 };
200 
201 }  // namespace space
202 }  // namespace gc
203 }  // namespace art
204 
205 #endif  // ART_RUNTIME_GC_SPACE_IMAGE_SPACE_H_
206