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 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 
GetImageHeader()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
GetImageFilename()78   const std::string GetImageFilename() const {
79     return GetName();
80   }
81 
82   // Symbolic location for image.
83   // For example: /system/framework/boot.art
GetImageLocation()84   const std::string GetImageLocation() const {
85     return image_location_;
86   }
87 
GetLiveBitmap()88   accounting::ContinuousSpaceBitmap* GetLiveBitmap() const OVERRIDE {
89     return live_bitmap_.get();
90   }
91 
GetMarkBitmap()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.
Sweep(bool,size_t *,size_t *)101   void Sweep(bool /* swap_bitmaps */, size_t* /* freed_objects */, size_t* /* freed_bytes */) {
102   }
103 
CanMoveObjects()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