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_COMPILER_IMAGE_WRITER_H_ 18 #define ART_COMPILER_IMAGE_WRITER_H_ 19 20 #include <stdint.h> 21 #include <valgrind.h> 22 23 #include <cstddef> 24 #include <memory> 25 #include <set> 26 #include <string> 27 #include <ostream> 28 29 #include "base/bit_utils.h" 30 #include "base/macros.h" 31 #include "driver/compiler_driver.h" 32 #include "gc/space/space.h" 33 #include "lock_word.h" 34 #include "mem_map.h" 35 #include "oat_file.h" 36 #include "mirror/dex_cache.h" 37 #include "os.h" 38 #include "safe_map.h" 39 #include "utils.h" 40 41 namespace art { 42 43 // Write a Space built during compilation for use during execution. 44 class ImageWriter FINAL { 45 public: ImageWriter(const CompilerDriver & compiler_driver,uintptr_t image_begin,bool compile_pic)46 ImageWriter(const CompilerDriver& compiler_driver, uintptr_t image_begin, 47 bool compile_pic) 48 : compiler_driver_(compiler_driver), image_begin_(reinterpret_cast<uint8_t*>(image_begin)), 49 image_end_(0), image_objects_offset_begin_(0), image_roots_address_(0), oat_file_(nullptr), 50 oat_data_begin_(nullptr), interpreter_to_interpreter_bridge_offset_(0), 51 interpreter_to_compiled_code_bridge_offset_(0), jni_dlsym_lookup_offset_(0), 52 quick_generic_jni_trampoline_offset_(0), 53 quick_imt_conflict_trampoline_offset_(0), quick_resolution_trampoline_offset_(0), 54 quick_to_interpreter_bridge_offset_(0), compile_pic_(compile_pic), 55 target_ptr_size_(InstructionSetPointerSize(compiler_driver_.GetInstructionSet())), 56 bin_slot_sizes_(), bin_slot_previous_sizes_(), bin_slot_count_(), 57 intern_table_bytes_(0u), dirty_methods_(0u), clean_methods_(0u) { 58 CHECK_NE(image_begin, 0U); 59 std::fill(image_methods_, image_methods_ + arraysize(image_methods_), nullptr); 60 } 61 ~ImageWriter()62 ~ImageWriter() { 63 } 64 65 bool PrepareImageAddressSpace(); 66 IsImageAddressSpaceReady()67 bool IsImageAddressSpaceReady() const { 68 return image_roots_address_ != 0u; 69 } 70 71 template <typename T> GetImageAddress(T * object)72 T* GetImageAddress(T* object) const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 73 return object == nullptr ? nullptr : 74 reinterpret_cast<T*>(image_begin_ + GetImageOffset(object)); 75 } 76 77 ArtMethod* GetImageMethodAddress(ArtMethod* method) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 78 GetDexCacheArrayElementImageAddress(const DexFile * dex_file,uint32_t offset)79 mirror::HeapReference<mirror::Object>* GetDexCacheArrayElementImageAddress( 80 const DexFile* dex_file, uint32_t offset) const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 81 auto it = dex_cache_array_starts_.find(dex_file); 82 DCHECK(it != dex_cache_array_starts_.end()); 83 return reinterpret_cast<mirror::HeapReference<mirror::Object>*>( 84 image_begin_ + RoundUp(sizeof(ImageHeader), kObjectAlignment) + it->second + offset); 85 } 86 87 uint8_t* GetOatFileBegin() const; 88 89 bool Write(const std::string& image_filename, const std::string& oat_filename, 90 const std::string& oat_location) 91 LOCKS_EXCLUDED(Locks::mutator_lock_); 92 GetOatDataBegin()93 uintptr_t GetOatDataBegin() { 94 return reinterpret_cast<uintptr_t>(oat_data_begin_); 95 } 96 97 private: 98 bool AllocMemory(); 99 100 // Mark the objects defined in this space in the given live bitmap. 101 void RecordImageAllocations() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 102 103 // Classify different kinds of bins that objects end up getting packed into during image writing. 104 enum Bin { 105 // Dex cache arrays have a special slot for PC-relative addressing. Since they are 106 // huge, and as such their dirtiness is not important for the clean/dirty separation, 107 // we arbitrarily keep them at the beginning. 108 kBinDexCacheArray, // Object arrays belonging to dex cache. 109 // Likely-clean: 110 kBinString, // [String] Almost always immutable (except for obj header). 111 kBinArtMethodsManagedInitialized, // [ArtMethod] Not-native, and initialized. Unlikely to dirty 112 // Unknown mix of clean/dirty: 113 kBinRegular, 114 // Likely-dirty: 115 // All classes get their own bins since their fields often dirty 116 kBinClassInitializedFinalStatics, // Class initializers have been run, no non-final statics 117 kBinClassInitialized, // Class initializers have been run 118 kBinClassVerified, // Class verified, but initializers haven't been run 119 // Add more bins here if we add more segregation code. 120 // Non mirror fields must be below. 121 // ArtFields should be always clean. 122 kBinArtField, 123 // If the class is initialized, then the ArtMethods are probably clean. 124 kBinArtMethodClean, 125 // ArtMethods may be dirty if the class has native methods or a declaring class that isn't 126 // initialized. 127 kBinArtMethodDirty, 128 kBinSize, 129 // Number of bins which are for mirror objects. 130 kBinMirrorCount = kBinArtField, 131 }; 132 133 friend std::ostream& operator<<(std::ostream& stream, const Bin& bin); 134 135 static constexpr size_t kBinBits = MinimumBitsToStore<uint32_t>(kBinMirrorCount - 1); 136 // uint32 = typeof(lockword_) 137 // Subtract read barrier bits since we want these to remain 0, or else it may result in DCHECK 138 // failures due to invalid read barrier bits during object field reads. 139 static const size_t kBinShift = BitSizeOf<uint32_t>() - kBinBits - 140 LockWord::kReadBarrierStateSize; 141 // 111000.....0 142 static const size_t kBinMask = ((static_cast<size_t>(1) << kBinBits) - 1) << kBinShift; 143 144 // We use the lock word to store the bin # and bin index of the object in the image. 145 // 146 // The struct size must be exactly sizeof(LockWord), currently 32-bits, since this will end up 147 // stored in the lock word bit-for-bit when object forwarding addresses are being calculated. 148 struct BinSlot { 149 explicit BinSlot(uint32_t lockword); 150 BinSlot(Bin bin, uint32_t index); 151 152 // The bin an object belongs to, i.e. regular, class/verified, class/initialized, etc. 153 Bin GetBin() const; 154 // The offset in bytes from the beginning of the bin. Aligned to object size. 155 uint32_t GetIndex() const; 156 // Pack into a single uint32_t, for storing into a lock word. Uint32ValueBinSlot157 uint32_t Uint32Value() const { return lockword_; } 158 // Comparison operator for map support 159 bool operator<(const BinSlot& other) const { return lockword_ < other.lockword_; } 160 161 private: 162 // Must be the same size as LockWord, any larger and we would truncate the data. 163 const uint32_t lockword_; 164 }; 165 166 // We use the lock word to store the offset of the object in the image. 167 void AssignImageOffset(mirror::Object* object, BinSlot bin_slot) 168 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 169 void SetImageOffset(mirror::Object* object, size_t offset) 170 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 171 bool IsImageOffsetAssigned(mirror::Object* object) const 172 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 173 size_t GetImageOffset(mirror::Object* object) const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 174 void UpdateImageOffset(mirror::Object* obj, uintptr_t offset) 175 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 176 177 void PrepareDexCacheArraySlots() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 178 void AssignImageBinSlot(mirror::Object* object) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 179 void SetImageBinSlot(mirror::Object* object, BinSlot bin_slot) 180 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 181 bool IsImageBinSlotAssigned(mirror::Object* object) const 182 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 183 BinSlot GetImageBinSlot(mirror::Object* object) const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 184 185 void AddMethodPointerArray(mirror::PointerArray* arr) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 186 GetImageAddressCallback(void * writer,mirror::Object * obj)187 static void* GetImageAddressCallback(void* writer, mirror::Object* obj) 188 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 189 return reinterpret_cast<ImageWriter*>(writer)->GetImageAddress(obj); 190 } 191 GetLocalAddress(mirror::Object * object)192 mirror::Object* GetLocalAddress(mirror::Object* object) const 193 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 194 size_t offset = GetImageOffset(object); 195 uint8_t* dst = image_->Begin() + offset; 196 return reinterpret_cast<mirror::Object*>(dst); 197 } 198 GetOatAddress(uint32_t offset)199 const uint8_t* GetOatAddress(uint32_t offset) const { 200 // With Quick, code is within the OatFile, as there are all in one 201 // .o ELF object. 202 DCHECK_LT(offset, oat_file_->Size()); 203 DCHECK(oat_data_begin_ != nullptr); 204 return offset == 0u ? nullptr : oat_data_begin_ + offset; 205 } 206 IsArtMethodBin(Bin bin)207 static bool IsArtMethodBin(Bin bin) { 208 return bin == kBinArtMethodClean || bin == kBinArtMethodDirty; 209 } 210 211 // Returns true if the class was in the original requested image classes list. 212 bool IsImageClass(mirror::Class* klass) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 213 214 // Debug aid that list of requested image classes. 215 void DumpImageClasses(); 216 217 // Preinitializes some otherwise lazy fields (such as Class name) to avoid runtime image dirtying. 218 void ComputeLazyFieldsForImageClasses() 219 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 220 static bool ComputeLazyFieldsForClassesVisitor(mirror::Class* klass, void* arg) 221 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 222 223 // Wire dex cache resolved strings to strings in the image to avoid runtime resolution. 224 void ComputeEagerResolvedStrings() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 225 static void ComputeEagerResolvedStringsCallback(mirror::Object* obj, void* arg) 226 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 227 228 // Remove unwanted classes from various roots. 229 void PruneNonImageClasses() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 230 static bool NonImageClassesVisitor(mirror::Class* c, void* arg) 231 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 232 233 // Verify unwanted classes removed. 234 void CheckNonImageClassesRemoved() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 235 static void CheckNonImageClassesRemovedCallback(mirror::Object* obj, void* arg) 236 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 237 238 // Lays out where the image objects will be at runtime. 239 void CalculateNewObjectOffsets() 240 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 241 void CreateHeader(size_t oat_loaded_size, size_t oat_data_offset) 242 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 243 mirror::ObjectArray<mirror::Object>* CreateImageRoots() const 244 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 245 void CalculateObjectBinSlots(mirror::Object* obj) 246 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 247 void UnbinObjectsIntoOffset(mirror::Object* obj) 248 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 249 250 void WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) 251 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 252 void WalkFieldsInOrder(mirror::Object* obj) 253 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 254 static void WalkFieldsCallback(mirror::Object* obj, void* arg) 255 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 256 static void UnbinObjectsIntoOffsetCallback(mirror::Object* obj, void* arg) 257 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 258 259 // Creates the contiguous image in memory and adjusts pointers. 260 void CopyAndFixupNativeData() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 261 void CopyAndFixupObjects() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 262 static void CopyAndFixupObjectsCallback(mirror::Object* obj, void* arg) 263 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 264 void CopyAndFixupObject(mirror::Object* obj) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 265 void CopyAndFixupMethod(ArtMethod* orig, ArtMethod* copy) 266 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 267 void FixupClass(mirror::Class* orig, mirror::Class* copy) 268 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 269 void FixupObject(mirror::Object* orig, mirror::Object* copy) 270 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 271 void FixupPointerArray(mirror::Object* dst, mirror::PointerArray* arr, mirror::Class* klass, 272 Bin array_type) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 273 274 // Get quick code for non-resolution/imt_conflict/abstract method. 275 const uint8_t* GetQuickCode(ArtMethod* method, bool* quick_is_interpreted) 276 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 277 278 const uint8_t* GetQuickEntryPoint(ArtMethod* method) 279 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 280 281 // Patches references in OatFile to expect runtime addresses. 282 void SetOatChecksumFromElfFile(File* elf_file); 283 284 // Calculate the sum total of the bin slot sizes in [0, up_to). Defaults to all bins. 285 size_t GetBinSizeSum(Bin up_to = kBinSize) const; 286 287 // Return true if a method is likely to be dirtied at runtime. 288 bool WillMethodBeDirty(ArtMethod* m) const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 289 290 // Assign the offset for an ArtMethod. 291 void AssignMethodOffset(ArtMethod* method, Bin bin) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 292 293 const CompilerDriver& compiler_driver_; 294 295 // Beginning target image address for the output image. 296 uint8_t* image_begin_; 297 298 // Offset to the free space in image_. 299 size_t image_end_; 300 301 // Offset from image_begin_ to where the first object is in image_. 302 size_t image_objects_offset_begin_; 303 304 // The image roots address in the image. 305 uint32_t image_roots_address_; 306 307 // oat file with code for this image 308 OatFile* oat_file_; 309 310 // Memory mapped for generating the image. 311 std::unique_ptr<MemMap> image_; 312 313 // Indexes, lengths for dex cache arrays (objects are inside of the image so that they don't 314 // move). 315 struct DexCacheArrayLocation { 316 size_t offset_; 317 size_t length_; 318 Bin bin_type_; 319 }; 320 SafeMap<mirror::Object*, DexCacheArrayLocation> dex_cache_array_indexes_; 321 322 // Pointer arrays that need to be updated. Since these are only some int and long arrays, we need 323 // to keep track. These include vtable arrays, iftable arrays, and dex caches. 324 std::unordered_map<mirror::PointerArray*, Bin> pointer_arrays_; 325 326 // The start offsets of the dex cache arrays. 327 SafeMap<const DexFile*, size_t> dex_cache_array_starts_; 328 329 // Saved hash codes. We use these to restore lockwords which were temporarily used to have 330 // forwarding addresses as well as copying over hash codes. 331 std::unordered_map<mirror::Object*, uint32_t> saved_hashcode_map_; 332 333 // Beginning target oat address for the pointers from the output image to its oat file. 334 const uint8_t* oat_data_begin_; 335 336 // Image bitmap which lets us know where the objects inside of the image reside. 337 std::unique_ptr<gc::accounting::ContinuousSpaceBitmap> image_bitmap_; 338 339 // Offset from oat_data_begin_ to the stubs. 340 uint32_t interpreter_to_interpreter_bridge_offset_; 341 uint32_t interpreter_to_compiled_code_bridge_offset_; 342 uint32_t jni_dlsym_lookup_offset_; 343 uint32_t quick_generic_jni_trampoline_offset_; 344 uint32_t quick_imt_conflict_trampoline_offset_; 345 uint32_t quick_resolution_trampoline_offset_; 346 uint32_t quick_to_interpreter_bridge_offset_; 347 const bool compile_pic_; 348 349 // Size of pointers on the target architecture. 350 size_t target_ptr_size_; 351 352 // Bin slot tracking for dirty object packing 353 size_t bin_slot_sizes_[kBinSize]; // Number of bytes in a bin 354 size_t bin_slot_previous_sizes_[kBinSize]; // Number of bytes in previous bins. 355 size_t bin_slot_count_[kBinSize]; // Number of objects in a bin 356 357 // Cached size of the intern table for when we allocate memory. 358 size_t intern_table_bytes_; 359 360 // ArtField, ArtMethod relocating map. These are allocated as array of structs but we want to 361 // have one entry per art field for convenience. ArtFields are placed right after the end of the 362 // image objects (aka sum of bin_slot_sizes_). ArtMethods are placed right after the ArtFields. 363 struct NativeObjectReloc { 364 uintptr_t offset; 365 Bin bin_type; 366 }; 367 std::unordered_map<void*, NativeObjectReloc> native_object_reloc_; 368 369 // Runtime ArtMethods which aren't reachable from any Class but need to be copied into the image. 370 ArtMethod* image_methods_[ImageHeader::kImageMethodsCount]; 371 372 // Counters for measurements, used for logging only. 373 uint64_t dirty_methods_; 374 uint64_t clean_methods_; 375 376 friend class FixupClassVisitor; 377 friend class FixupRootVisitor; 378 friend class FixupVisitor; 379 DISALLOW_COPY_AND_ASSIGN(ImageWriter); 380 }; 381 382 } // namespace art 383 384 #endif // ART_COMPILER_IMAGE_WRITER_H_ 385