/* * Copyright (C) 2011 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef ART_RUNTIME_MIRROR_DEX_CACHE_H_ #define ART_RUNTIME_MIRROR_DEX_CACHE_H_ #include "array.h" #include "base/bit_utils.h" #include "dex_file_types.h" #include "object.h" #include "object_array.h" namespace art { class ArtField; class ArtMethod; struct DexCacheOffsets; class DexFile; class ImageWriter; union JValue; class LinearAlloc; class Thread; namespace mirror { class CallSite; class Class; class MethodType; class String; template struct PACKED(8) DexCachePair { GcRoot object; uint32_t index; // The array is initially [ {0,0}, {0,0}, {0,0} ... ] // We maintain the invariant that once a dex cache entry is populated, // the pointer is always non-0 // Any given entry would thus be: // {non-0, non-0} OR {0,0} // // It's generally sufficiently enough then to check if the // lookup index matches the stored index (for a >0 lookup index) // because if it's true the pointer is also non-null. // // For the 0th entry which is a special case, the value is either // {0,0} (initial state) or {non-0, 0} which indicates // that a valid object is stored at that index for a dex section id of 0. // // As an optimization, we want to avoid branching on the object pointer since // it's always non-null if the id branch succeeds (except for the 0th id). // Set the initial state for the 0th entry to be {0,1} which is guaranteed to fail // the lookup id == stored id branch. DexCachePair(ObjPtr object, uint32_t index) : object(object), index(index) {} DexCachePair() : index(0) {} DexCachePair(const DexCachePair&) = default; DexCachePair& operator=(const DexCachePair&) = default; static void Initialize(std::atomic>* dex_cache) { DexCachePair first_elem; first_elem.object = GcRoot(nullptr); first_elem.index = InvalidIndexForSlot(0); dex_cache[0].store(first_elem, std::memory_order_relaxed); } static uint32_t InvalidIndexForSlot(uint32_t slot) { // Since the cache size is a power of two, 0 will always map to slot 0. // Use 1 for slot 0 and 0 for all other slots. return (slot == 0) ? 1u : 0u; } T* GetObjectForIndex(uint32_t idx) REQUIRES_SHARED(Locks::mutator_lock_) { if (idx != index) { return nullptr; } DCHECK(!object.IsNull()); return object.Read(); } }; template struct PACKED(2 * __SIZEOF_POINTER__) NativeDexCachePair { T* object; size_t index; // This is similar to DexCachePair except that we're storing a native pointer // instead of a GC root. See DexCachePair for the details. NativeDexCachePair(T* object, uint32_t index) : object(object), index(index) {} NativeDexCachePair() : object(nullptr), index(0u) { } NativeDexCachePair(const NativeDexCachePair&) = default; NativeDexCachePair& operator=(const NativeDexCachePair&) = default; static void Initialize(std::atomic>* dex_cache, PointerSize pointer_size); static uint32_t InvalidIndexForSlot(uint32_t slot) { // Since the cache size is a power of two, 0 will always map to slot 0. // Use 1 for slot 0 and 0 for all other slots. return (slot == 0) ? 1u : 0u; } T* GetObjectForIndex(uint32_t idx) REQUIRES_SHARED(Locks::mutator_lock_) { if (idx != index) { return nullptr; } DCHECK(object != nullptr); return object; } }; using TypeDexCachePair = DexCachePair; using TypeDexCacheType = std::atomic; using StringDexCachePair = DexCachePair; using StringDexCacheType = std::atomic; using FieldDexCachePair = NativeDexCachePair; using FieldDexCacheType = std::atomic; using MethodDexCachePair = NativeDexCachePair; using MethodDexCacheType = std::atomic; using MethodTypeDexCachePair = DexCachePair; using MethodTypeDexCacheType = std::atomic; // C++ mirror of java.lang.DexCache. class MANAGED DexCache FINAL : public Object { public: // Size of java.lang.DexCache.class. static uint32_t ClassSize(PointerSize pointer_size); // Size of type dex cache. Needs to be a power of 2 for entrypoint assumptions to hold. static constexpr size_t kDexCacheTypeCacheSize = 1024; static_assert(IsPowerOfTwo(kDexCacheTypeCacheSize), "Type dex cache size is not a power of 2."); // Size of string dex cache. Needs to be a power of 2 for entrypoint assumptions to hold. static constexpr size_t kDexCacheStringCacheSize = 1024; static_assert(IsPowerOfTwo(kDexCacheStringCacheSize), "String dex cache size is not a power of 2."); // Size of field dex cache. Needs to be a power of 2 for entrypoint assumptions to hold. static constexpr size_t kDexCacheFieldCacheSize = 1024; static_assert(IsPowerOfTwo(kDexCacheFieldCacheSize), "Field dex cache size is not a power of 2."); // Size of method dex cache. Needs to be a power of 2 for entrypoint assumptions to hold. static constexpr size_t kDexCacheMethodCacheSize = 1024; static_assert(IsPowerOfTwo(kDexCacheMethodCacheSize), "Method dex cache size is not a power of 2."); // Size of method type dex cache. Needs to be a power of 2 for entrypoint assumptions // to hold. static constexpr size_t kDexCacheMethodTypeCacheSize = 1024; static_assert(IsPowerOfTwo(kDexCacheMethodTypeCacheSize), "MethodType dex cache size is not a power of 2."); static constexpr size_t StaticTypeSize() { return kDexCacheTypeCacheSize; } static constexpr size_t StaticStringSize() { return kDexCacheStringCacheSize; } static constexpr size_t StaticArtFieldSize() { return kDexCacheFieldCacheSize; } static constexpr size_t StaticMethodSize() { return kDexCacheMethodCacheSize; } static constexpr size_t StaticMethodTypeSize() { return kDexCacheMethodTypeCacheSize; } // Size of an instance of java.lang.DexCache not including referenced values. static constexpr uint32_t InstanceSize() { return sizeof(DexCache); } static void InitializeDexCache(Thread* self, ObjPtr dex_cache, ObjPtr location, const DexFile* dex_file, LinearAlloc* linear_alloc, PointerSize image_pointer_size) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(Locks::dex_lock_); template void FixupStrings(StringDexCacheType* dest, const Visitor& visitor) REQUIRES_SHARED(Locks::mutator_lock_); template void FixupResolvedTypes(TypeDexCacheType* dest, const Visitor& visitor) REQUIRES_SHARED(Locks::mutator_lock_); template void FixupResolvedMethodTypes(MethodTypeDexCacheType* dest, const Visitor& visitor) REQUIRES_SHARED(Locks::mutator_lock_); template void FixupResolvedCallSites(GcRoot* dest, const Visitor& visitor) REQUIRES_SHARED(Locks::mutator_lock_); String* GetLocation() REQUIRES_SHARED(Locks::mutator_lock_) { return GetFieldObject(OFFSET_OF_OBJECT_MEMBER(DexCache, location_)); } static MemberOffset StringsOffset() { return OFFSET_OF_OBJECT_MEMBER(DexCache, strings_); } static MemberOffset ResolvedTypesOffset() { return OFFSET_OF_OBJECT_MEMBER(DexCache, resolved_types_); } static MemberOffset ResolvedFieldsOffset() { return OFFSET_OF_OBJECT_MEMBER(DexCache, resolved_fields_); } static MemberOffset ResolvedMethodsOffset() { return OFFSET_OF_OBJECT_MEMBER(DexCache, resolved_methods_); } static MemberOffset ResolvedMethodTypesOffset() { return OFFSET_OF_OBJECT_MEMBER(DexCache, resolved_method_types_); } static MemberOffset ResolvedCallSitesOffset() { return OFFSET_OF_OBJECT_MEMBER(DexCache, resolved_call_sites_); } static MemberOffset NumStringsOffset() { return OFFSET_OF_OBJECT_MEMBER(DexCache, num_strings_); } static MemberOffset NumResolvedTypesOffset() { return OFFSET_OF_OBJECT_MEMBER(DexCache, num_resolved_types_); } static MemberOffset NumResolvedFieldsOffset() { return OFFSET_OF_OBJECT_MEMBER(DexCache, num_resolved_fields_); } static MemberOffset NumResolvedMethodsOffset() { return OFFSET_OF_OBJECT_MEMBER(DexCache, num_resolved_methods_); } static MemberOffset NumResolvedMethodTypesOffset() { return OFFSET_OF_OBJECT_MEMBER(DexCache, num_resolved_method_types_); } static MemberOffset NumResolvedCallSitesOffset() { return OFFSET_OF_OBJECT_MEMBER(DexCache, num_resolved_call_sites_); } String* GetResolvedString(dex::StringIndex string_idx) ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_); void SetResolvedString(dex::StringIndex string_idx, ObjPtr resolved) ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_); // Clear a string for a string_idx, used to undo string intern transactions to make sure // the string isn't kept live. void ClearString(dex::StringIndex string_idx) REQUIRES_SHARED(Locks::mutator_lock_); Class* GetResolvedType(dex::TypeIndex type_idx) REQUIRES_SHARED(Locks::mutator_lock_); void SetResolvedType(dex::TypeIndex type_idx, ObjPtr resolved) REQUIRES_SHARED(Locks::mutator_lock_); void ClearResolvedType(dex::TypeIndex type_idx) REQUIRES_SHARED(Locks::mutator_lock_); ALWAYS_INLINE ArtMethod* GetResolvedMethod(uint32_t method_idx, PointerSize ptr_size) REQUIRES_SHARED(Locks::mutator_lock_); ALWAYS_INLINE void SetResolvedMethod(uint32_t method_idx, ArtMethod* resolved, PointerSize ptr_size) REQUIRES_SHARED(Locks::mutator_lock_); ALWAYS_INLINE void ClearResolvedMethod(uint32_t method_idx, PointerSize ptr_size) REQUIRES_SHARED(Locks::mutator_lock_); // Pointer sized variant, used for patching. ALWAYS_INLINE ArtField* GetResolvedField(uint32_t idx, PointerSize ptr_size) REQUIRES_SHARED(Locks::mutator_lock_); // Pointer sized variant, used for patching. ALWAYS_INLINE void SetResolvedField(uint32_t idx, ArtField* field, PointerSize ptr_size) REQUIRES_SHARED(Locks::mutator_lock_); ALWAYS_INLINE void ClearResolvedField(uint32_t idx, PointerSize ptr_size) REQUIRES_SHARED(Locks::mutator_lock_); MethodType* GetResolvedMethodType(uint32_t proto_idx) REQUIRES_SHARED(Locks::mutator_lock_); void SetResolvedMethodType(uint32_t proto_idx, MethodType* resolved) REQUIRES_SHARED(Locks::mutator_lock_); CallSite* GetResolvedCallSite(uint32_t call_site_idx) REQUIRES_SHARED(Locks::mutator_lock_); // Attempts to bind |call_site_idx| to the call site |resolved|. The // caller must use the return value in place of |resolved|. This is // because multiple threads can invoke the bootstrap method each // producing a call site, but the method handle invocation on the // call site must be on a common agreed value. CallSite* SetResolvedCallSite(uint32_t call_site_idx, CallSite* resolved) WARN_UNUSED REQUIRES_SHARED(Locks::mutator_lock_); StringDexCacheType* GetStrings() ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { return GetFieldPtr64(StringsOffset()); } void SetStrings(StringDexCacheType* strings) ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { SetFieldPtr(StringsOffset(), strings); } TypeDexCacheType* GetResolvedTypes() ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { return GetFieldPtr(ResolvedTypesOffset()); } void SetResolvedTypes(TypeDexCacheType* resolved_types) ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { SetFieldPtr(ResolvedTypesOffset(), resolved_types); } MethodDexCacheType* GetResolvedMethods() ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { return GetFieldPtr(ResolvedMethodsOffset()); } void SetResolvedMethods(MethodDexCacheType* resolved_methods) ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { SetFieldPtr(ResolvedMethodsOffset(), resolved_methods); } FieldDexCacheType* GetResolvedFields() ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { return GetFieldPtr(ResolvedFieldsOffset()); } void SetResolvedFields(FieldDexCacheType* resolved_fields) ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { SetFieldPtr(ResolvedFieldsOffset(), resolved_fields); } MethodTypeDexCacheType* GetResolvedMethodTypes() ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { return GetFieldPtr64(ResolvedMethodTypesOffset()); } void SetResolvedMethodTypes(MethodTypeDexCacheType* resolved_method_types) ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { SetFieldPtr(ResolvedMethodTypesOffset(), resolved_method_types); } GcRoot* GetResolvedCallSites() ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { return GetFieldPtr*>(ResolvedCallSitesOffset()); } void SetResolvedCallSites(GcRoot* resolved_call_sites) ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { SetFieldPtr(ResolvedCallSitesOffset(), resolved_call_sites); } size_t NumStrings() REQUIRES_SHARED(Locks::mutator_lock_) { return GetField32(NumStringsOffset()); } size_t NumResolvedTypes() REQUIRES_SHARED(Locks::mutator_lock_) { return GetField32(NumResolvedTypesOffset()); } size_t NumResolvedMethods() REQUIRES_SHARED(Locks::mutator_lock_) { return GetField32(NumResolvedMethodsOffset()); } size_t NumResolvedFields() REQUIRES_SHARED(Locks::mutator_lock_) { return GetField32(NumResolvedFieldsOffset()); } size_t NumResolvedMethodTypes() REQUIRES_SHARED(Locks::mutator_lock_) { return GetField32(NumResolvedMethodTypesOffset()); } size_t NumResolvedCallSites() REQUIRES_SHARED(Locks::mutator_lock_) { return GetField32(NumResolvedCallSitesOffset()); } const DexFile* GetDexFile() ALWAYS_INLINE REQUIRES_SHARED(Locks::mutator_lock_) { return GetFieldPtr(OFFSET_OF_OBJECT_MEMBER(DexCache, dex_file_)); } void SetDexFile(const DexFile* dex_file) REQUIRES_SHARED(Locks::mutator_lock_) { SetFieldPtr(OFFSET_OF_OBJECT_MEMBER(DexCache, dex_file_), dex_file); } void SetLocation(ObjPtr location) REQUIRES_SHARED(Locks::mutator_lock_); // NOTE: Get/SetElementPtrSize() are intended for working with ArtMethod** and ArtField** // provided by GetResolvedMethods/Fields() and ArtMethod::GetDexCacheResolvedMethods(), // so they need to be public. template static PtrType GetElementPtrSize(PtrType* ptr_array, size_t idx, PointerSize ptr_size); template static void SetElementPtrSize(PtrType* ptr_array, size_t idx, PtrType ptr, PointerSize ptr_size); template static NativeDexCachePair GetNativePairPtrSize(std::atomic>* pair_array, size_t idx, PointerSize ptr_size); template static void SetNativePairPtrSize(std::atomic>* pair_array, size_t idx, NativeDexCachePair pair, PointerSize ptr_size); uint32_t StringSlotIndex(dex::StringIndex string_idx) REQUIRES_SHARED(Locks::mutator_lock_); uint32_t TypeSlotIndex(dex::TypeIndex type_idx) REQUIRES_SHARED(Locks::mutator_lock_); uint32_t FieldSlotIndex(uint32_t field_idx) REQUIRES_SHARED(Locks::mutator_lock_); uint32_t MethodSlotIndex(uint32_t method_idx) REQUIRES_SHARED(Locks::mutator_lock_); uint32_t MethodTypeSlotIndex(uint32_t proto_idx) REQUIRES_SHARED(Locks::mutator_lock_); private: void Init(const DexFile* dex_file, ObjPtr location, StringDexCacheType* strings, uint32_t num_strings, TypeDexCacheType* resolved_types, uint32_t num_resolved_types, MethodDexCacheType* resolved_methods, uint32_t num_resolved_methods, FieldDexCacheType* resolved_fields, uint32_t num_resolved_fields, MethodTypeDexCacheType* resolved_method_types, uint32_t num_resolved_method_types, GcRoot* resolved_call_sites, uint32_t num_resolved_call_sites) REQUIRES_SHARED(Locks::mutator_lock_); // std::pair<> is not trivially copyable and as such it is unsuitable for atomic operations, // so we use a custom pair class for loading and storing the NativeDexCachePair<>. template struct PACKED(2 * sizeof(IntType)) ConversionPair { ConversionPair(IntType f, IntType s) : first(f), second(s) { } ConversionPair(const ConversionPair&) = default; ConversionPair& operator=(const ConversionPair&) = default; IntType first; IntType second; }; using ConversionPair32 = ConversionPair; using ConversionPair64 = ConversionPair; // Visit instance fields of the dex cache as well as its associated arrays. template void VisitReferences(ObjPtr klass, const Visitor& visitor) REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(Locks::heap_bitmap_lock_); // Due to lack of 16-byte atomics support, we use hand-crafted routines. #if defined(__aarch64__) // 16-byte atomics are supported on aarch64. ALWAYS_INLINE static ConversionPair64 AtomicLoadRelaxed16B( std::atomic* target) { return target->load(std::memory_order_relaxed); } ALWAYS_INLINE static void AtomicStoreRelease16B( std::atomic* target, ConversionPair64 value) { target->store(value, std::memory_order_release); } #elif defined(__x86_64__) ALWAYS_INLINE static ConversionPair64 AtomicLoadRelaxed16B( std::atomic* target) { uint64_t first, second; __asm__ __volatile__( "lock cmpxchg16b (%2)" : "=&a"(first), "=&d"(second) : "r"(target), "a"(0), "d"(0), "b"(0), "c"(0) : "cc"); return ConversionPair64(first, second); } ALWAYS_INLINE static void AtomicStoreRelease16B( std::atomic* target, ConversionPair64 value) { uint64_t first, second; __asm__ __volatile__ ( "movq (%2), %%rax\n\t" "movq 8(%2), %%rdx\n\t" "1:\n\t" "lock cmpxchg16b (%2)\n\t" "jnz 1b" : "=&a"(first), "=&d"(second) : "r"(target), "b"(value.first), "c"(value.second) : "cc"); } #else static ConversionPair64 AtomicLoadRelaxed16B(std::atomic* target); static void AtomicStoreRelease16B(std::atomic* target, ConversionPair64 value); #endif HeapReference location_; // Number of elements in the call_sites_ array. Note that this appears here // because of our packing logic for 32 bit fields. uint32_t num_resolved_call_sites_; uint64_t dex_file_; // const DexFile* uint64_t resolved_call_sites_; // GcRoot* array with num_resolved_call_sites_ // elements. uint64_t resolved_fields_; // std::atomic*, array with // num_resolved_fields_ elements. uint64_t resolved_method_types_; // std::atomic* array with // num_resolved_method_types_ elements. uint64_t resolved_methods_; // ArtMethod*, array with num_resolved_methods_ elements. uint64_t resolved_types_; // TypeDexCacheType*, array with num_resolved_types_ elements. uint64_t strings_; // std::atomic*, array with num_strings_ // elements. uint32_t num_resolved_fields_; // Number of elements in the resolved_fields_ array. uint32_t num_resolved_method_types_; // Number of elements in the resolved_method_types_ array. uint32_t num_resolved_methods_; // Number of elements in the resolved_methods_ array. uint32_t num_resolved_types_; // Number of elements in the resolved_types_ array. uint32_t num_strings_; // Number of elements in the strings_ array. friend struct art::DexCacheOffsets; // for verifying offset information friend class Object; // For VisitReferences DISALLOW_IMPLICIT_CONSTRUCTORS(DexCache); }; } // namespace mirror } // namespace art #endif // ART_RUNTIME_MIRROR_DEX_CACHE_H_