// Copyright 2012 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef V8_API_H_ #define V8_API_H_ #include "src/v8.h" #include "include/v8-testing.h" #include "src/contexts.h" #include "src/factory.h" #include "src/isolate.h" #include "src/list-inl.h" namespace v8 { // Constants used in the implementation of the API. The most natural thing // would usually be to place these with the classes that use them, but // we want to keep them out of v8.h because it is an externally // visible file. class Consts { public: enum TemplateType { FUNCTION_TEMPLATE = 0, OBJECT_TEMPLATE = 1 }; }; // Utilities for working with neander-objects, primitive // env-independent JSObjects used by the api. class NeanderObject { public: explicit NeanderObject(v8::internal::Isolate* isolate, int size); explicit inline NeanderObject(v8::internal::Handle obj); explicit inline NeanderObject(v8::internal::Object* obj); inline v8::internal::Object* get(int index); inline void set(int index, v8::internal::Object* value); inline v8::internal::Handle value() { return value_; } int size(); private: v8::internal::Handle value_; }; // Utilities for working with neander-arrays, a simple extensible // array abstraction built on neander-objects. class NeanderArray { public: explicit NeanderArray(v8::internal::Isolate* isolate); explicit inline NeanderArray(v8::internal::Handle obj); inline v8::internal::Handle value() { return obj_.value(); } void add(v8::internal::Handle value); int length(); v8::internal::Object* get(int index); // Change the value at an index to undefined value. If the index is // out of bounds, the request is ignored. Returns the old value. void set(int index, v8::internal::Object* value); private: NeanderObject obj_; }; NeanderObject::NeanderObject(v8::internal::Handle obj) : value_(v8::internal::Handle::cast(obj)) { } NeanderObject::NeanderObject(v8::internal::Object* obj) : value_(v8::internal::Handle( v8::internal::JSObject::cast(obj))) { } NeanderArray::NeanderArray(v8::internal::Handle obj) : obj_(obj) { } v8::internal::Object* NeanderObject::get(int offset) { DCHECK(value()->HasFastObjectElements()); return v8::internal::FixedArray::cast(value()->elements())->get(offset); } void NeanderObject::set(int offset, v8::internal::Object* value) { DCHECK(value_->HasFastObjectElements()); v8::internal::FixedArray::cast(value_->elements())->set(offset, value); } template inline T ToCData(v8::internal::Object* obj) { STATIC_ASSERT(sizeof(T) == sizeof(v8::internal::Address)); return reinterpret_cast( reinterpret_cast( v8::internal::Foreign::cast(obj)->foreign_address())); } template inline v8::internal::Handle FromCData( v8::internal::Isolate* isolate, T obj) { STATIC_ASSERT(sizeof(T) == sizeof(v8::internal::Address)); return isolate->factory()->NewForeign( reinterpret_cast(reinterpret_cast(obj))); } class ApiFunction { public: explicit ApiFunction(v8::internal::Address addr) : addr_(addr) { } v8::internal::Address address() { return addr_; } private: v8::internal::Address addr_; }; class RegisteredExtension { public: explicit RegisteredExtension(Extension* extension); static void Register(RegisteredExtension* that); static void UnregisterAll(); Extension* extension() { return extension_; } RegisteredExtension* next() { return next_; } static RegisteredExtension* first_extension() { return first_extension_; } private: Extension* extension_; RegisteredExtension* next_; static RegisteredExtension* first_extension_; }; #define OPEN_HANDLE_LIST(V) \ V(Template, TemplateInfo) \ V(FunctionTemplate, FunctionTemplateInfo) \ V(ObjectTemplate, ObjectTemplateInfo) \ V(Signature, SignatureInfo) \ V(AccessorSignature, FunctionTemplateInfo) \ V(TypeSwitch, TypeSwitchInfo) \ V(Data, Object) \ V(RegExp, JSRegExp) \ V(Object, JSObject) \ V(Array, JSArray) \ V(ArrayBuffer, JSArrayBuffer) \ V(ArrayBufferView, JSArrayBufferView) \ V(TypedArray, JSTypedArray) \ V(Uint8Array, JSTypedArray) \ V(Uint8ClampedArray, JSTypedArray) \ V(Int8Array, JSTypedArray) \ V(Uint16Array, JSTypedArray) \ V(Int16Array, JSTypedArray) \ V(Uint32Array, JSTypedArray) \ V(Int32Array, JSTypedArray) \ V(Float32Array, JSTypedArray) \ V(Float64Array, JSTypedArray) \ V(DataView, JSDataView) \ V(Name, Name) \ V(String, String) \ V(Symbol, Symbol) \ V(Script, JSFunction) \ V(UnboundScript, SharedFunctionInfo) \ V(Function, JSFunction) \ V(Message, JSMessageObject) \ V(Context, Context) \ V(External, Object) \ V(StackTrace, JSArray) \ V(StackFrame, JSObject) \ V(DeclaredAccessorDescriptor, DeclaredAccessorDescriptor) class Utils { public: static inline bool ApiCheck(bool condition, const char* location, const char* message) { if (!condition) Utils::ReportApiFailure(location, message); return condition; } static Local ToFunctionTemplate(NeanderObject obj); static Local ToObjectTemplate(NeanderObject obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocalUint8Array( v8::internal::Handle obj); static inline Local ToLocalUint8ClampedArray( v8::internal::Handle obj); static inline Local ToLocalInt8Array( v8::internal::Handle obj); static inline Local ToLocalUint16Array( v8::internal::Handle obj); static inline Local ToLocalInt16Array( v8::internal::Handle obj); static inline Local ToLocalUint32Array( v8::internal::Handle obj); static inline Local ToLocalInt32Array( v8::internal::Handle obj); static inline Local ToLocalFloat32Array( v8::internal::Handle obj); static inline Local ToLocalFloat64Array( v8::internal::Handle obj); static inline Local MessageToLocal( v8::internal::Handle obj); static inline Local StackTraceToLocal( v8::internal::Handle obj); static inline Local StackFrameToLocal( v8::internal::Handle obj); static inline Local NumberToLocal( v8::internal::Handle obj); static inline Local IntegerToLocal( v8::internal::Handle obj); static inline Local Uint32ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local AccessorSignatureToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); static inline Local ExternalToLocal( v8::internal::Handle obj); static inline Local ToLocal( v8::internal::Handle obj); #define DECLARE_OPEN_HANDLE(From, To) \ static inline v8::internal::Handle \ OpenHandle(const From* that, bool allow_empty_handle = false); OPEN_HANDLE_LIST(DECLARE_OPEN_HANDLE) #undef DECLARE_OPEN_HANDLE template static inline Local Convert(v8::internal::Handle obj) { DCHECK(obj.is_null() || !obj->IsTheHole()); return Local(reinterpret_cast(obj.location())); } template static inline v8::internal::Handle OpenPersistent( const v8::Persistent& persistent) { return v8::internal::Handle( reinterpret_cast(persistent.val_)); } template static inline v8::internal::Handle OpenPersistent( v8::Persistent* persistent) { return OpenPersistent(*persistent); } template static inline v8::internal::Handle OpenHandle(v8::Local handle) { return OpenHandle(*handle); } private: static void ReportApiFailure(const char* location, const char* message); }; template v8::internal::Handle v8::internal::Handle::EscapeFrom( v8::EscapableHandleScope* scope) { v8::internal::Handle handle; if (!is_null()) { handle = *this; } return Utils::OpenHandle(*scope->Escape(Utils::ToLocal(handle)), true); } template inline T* ToApi(v8::internal::Handle obj) { return reinterpret_cast(obj.location()); } template inline v8::Local ToApiHandle( v8::internal::Handle obj) { return Utils::Convert(obj); } // Implementations of ToLocal #define MAKE_TO_LOCAL(Name, From, To) \ Local Utils::Name(v8::internal::Handle obj) { \ return Convert(obj); \ } #define MAKE_TO_LOCAL_TYPED_ARRAY(Type, typeName, TYPE, ctype, size) \ Local Utils::ToLocal##Type##Array( \ v8::internal::Handle obj) { \ DCHECK(obj->type() == kExternal##Type##Array); \ return Convert(obj); \ } MAKE_TO_LOCAL(ToLocal, Context, Context) MAKE_TO_LOCAL(ToLocal, Object, Value) MAKE_TO_LOCAL(ToLocal, JSFunction, Function) MAKE_TO_LOCAL(ToLocal, Name, Name) MAKE_TO_LOCAL(ToLocal, String, String) MAKE_TO_LOCAL(ToLocal, Symbol, Symbol) MAKE_TO_LOCAL(ToLocal, JSRegExp, RegExp) MAKE_TO_LOCAL(ToLocal, JSObject, Object) MAKE_TO_LOCAL(ToLocal, JSArray, Array) MAKE_TO_LOCAL(ToLocal, JSArrayBuffer, ArrayBuffer) MAKE_TO_LOCAL(ToLocal, JSArrayBufferView, ArrayBufferView) MAKE_TO_LOCAL(ToLocal, JSDataView, DataView) MAKE_TO_LOCAL(ToLocal, JSTypedArray, TypedArray) TYPED_ARRAYS(MAKE_TO_LOCAL_TYPED_ARRAY) MAKE_TO_LOCAL(ToLocal, FunctionTemplateInfo, FunctionTemplate) MAKE_TO_LOCAL(ToLocal, ObjectTemplateInfo, ObjectTemplate) MAKE_TO_LOCAL(ToLocal, SignatureInfo, Signature) MAKE_TO_LOCAL(AccessorSignatureToLocal, FunctionTemplateInfo, AccessorSignature) MAKE_TO_LOCAL(ToLocal, TypeSwitchInfo, TypeSwitch) MAKE_TO_LOCAL(MessageToLocal, Object, Message) MAKE_TO_LOCAL(StackTraceToLocal, JSArray, StackTrace) MAKE_TO_LOCAL(StackFrameToLocal, JSObject, StackFrame) MAKE_TO_LOCAL(NumberToLocal, Object, Number) MAKE_TO_LOCAL(IntegerToLocal, Object, Integer) MAKE_TO_LOCAL(Uint32ToLocal, Object, Uint32) MAKE_TO_LOCAL(ExternalToLocal, JSObject, External) MAKE_TO_LOCAL(ToLocal, DeclaredAccessorDescriptor, DeclaredAccessorDescriptor) #undef MAKE_TO_LOCAL_TYPED_ARRAY #undef MAKE_TO_LOCAL // Implementations of OpenHandle #define MAKE_OPEN_HANDLE(From, To) \ v8::internal::Handle Utils::OpenHandle( \ const v8::From* that, bool allow_empty_handle) { \ EXTRA_CHECK(allow_empty_handle || that != NULL); \ EXTRA_CHECK(that == NULL || \ (*reinterpret_cast(that))->Is##To()); \ return v8::internal::Handle( \ reinterpret_cast(const_cast(that))); \ } OPEN_HANDLE_LIST(MAKE_OPEN_HANDLE) #undef MAKE_OPEN_HANDLE #undef OPEN_HANDLE_LIST namespace internal { // Tracks string usage to help make better decisions when // externalizing strings. // // Implementation note: internally this class only tracks fresh // strings and keeps a single use counter for them. class StringTracker { public: // Records that the given string's characters were copied to some // external buffer. If this happens often we should honor // externalization requests for the string. void RecordWrite(Handle string) { Address address = reinterpret_cast
(*string); Address top = isolate_->heap()->NewSpaceTop(); if (IsFreshString(address, top)) { IncrementUseCount(top); } } // Estimates freshness and use frequency of the given string based // on how close it is to the new space top and the recorded usage // history. inline bool IsFreshUnusedString(Handle string) { Address address = reinterpret_cast
(*string); Address top = isolate_->heap()->NewSpaceTop(); return IsFreshString(address, top) && IsUseCountLow(top); } private: StringTracker() : use_count_(0), last_top_(NULL), isolate_(NULL) { } static inline bool IsFreshString(Address string, Address top) { return top - kFreshnessLimit <= string && string <= top; } inline bool IsUseCountLow(Address top) { if (last_top_ != top) return true; return use_count_ < kUseLimit; } inline void IncrementUseCount(Address top) { if (last_top_ != top) { use_count_ = 0; last_top_ = top; } ++use_count_; } // Single use counter shared by all fresh strings. int use_count_; // Last new space top when the use count above was valid. Address last_top_; Isolate* isolate_; // How close to the new space top a fresh string has to be. static const int kFreshnessLimit = 1024; // The number of uses required to consider a string useful. static const int kUseLimit = 32; friend class Isolate; DISALLOW_COPY_AND_ASSIGN(StringTracker); }; class DeferredHandles { public: ~DeferredHandles(); private: DeferredHandles(Object** first_block_limit, Isolate* isolate) : next_(NULL), previous_(NULL), first_block_limit_(first_block_limit), isolate_(isolate) { isolate->LinkDeferredHandles(this); } void Iterate(ObjectVisitor* v); List blocks_; DeferredHandles* next_; DeferredHandles* previous_; Object** first_block_limit_; Isolate* isolate_; friend class HandleScopeImplementer; friend class Isolate; }; // This class is here in order to be able to declare it a friend of // HandleScope. Moving these methods to be members of HandleScope would be // neat in some ways, but it would expose internal implementation details in // our public header file, which is undesirable. // // An isolate has a single instance of this class to hold the current thread's // data. In multithreaded V8 programs this data is copied in and out of storage // so that the currently executing thread always has its own copy of this // data. class HandleScopeImplementer { public: explicit HandleScopeImplementer(Isolate* isolate) : isolate_(isolate), blocks_(0), entered_contexts_(0), saved_contexts_(0), spare_(NULL), call_depth_(0), last_handle_before_deferred_block_(NULL) { } ~HandleScopeImplementer() { DeleteArray(spare_); } // Threading support for handle data. static int ArchiveSpacePerThread(); char* RestoreThread(char* from); char* ArchiveThread(char* to); void FreeThreadResources(); // Garbage collection support. void Iterate(v8::internal::ObjectVisitor* v); static char* Iterate(v8::internal::ObjectVisitor* v, char* data); inline internal::Object** GetSpareOrNewBlock(); inline void DeleteExtensions(internal::Object** prev_limit); inline void IncrementCallDepth() {call_depth_++;} inline void DecrementCallDepth() {call_depth_--;} inline bool CallDepthIsZero() { return call_depth_ == 0; } inline void EnterContext(Handle context); inline void LeaveContext(); inline bool LastEnteredContextWas(Handle context); // Returns the last entered context or an empty handle if no // contexts have been entered. inline Handle LastEnteredContext(); inline void SaveContext(Context* context); inline Context* RestoreContext(); inline bool HasSavedContexts(); inline List* blocks() { return &blocks_; } Isolate* isolate() const { return isolate_; } void ReturnBlock(Object** block) { DCHECK(block != NULL); if (spare_ != NULL) DeleteArray(spare_); spare_ = block; } private: void ResetAfterArchive() { blocks_.Initialize(0); entered_contexts_.Initialize(0); saved_contexts_.Initialize(0); spare_ = NULL; last_handle_before_deferred_block_ = NULL; call_depth_ = 0; } void Free() { DCHECK(blocks_.length() == 0); DCHECK(entered_contexts_.length() == 0); DCHECK(saved_contexts_.length() == 0); blocks_.Free(); entered_contexts_.Free(); saved_contexts_.Free(); if (spare_ != NULL) { DeleteArray(spare_); spare_ = NULL; } DCHECK(call_depth_ == 0); } void BeginDeferredScope(); DeferredHandles* Detach(Object** prev_limit); Isolate* isolate_; List blocks_; // Used as a stack to keep track of entered contexts. List entered_contexts_; // Used as a stack to keep track of saved contexts. List saved_contexts_; Object** spare_; int call_depth_; Object** last_handle_before_deferred_block_; // This is only used for threading support. HandleScopeData handle_scope_data_; void IterateThis(ObjectVisitor* v); char* RestoreThreadHelper(char* from); char* ArchiveThreadHelper(char* to); friend class DeferredHandles; friend class DeferredHandleScope; DISALLOW_COPY_AND_ASSIGN(HandleScopeImplementer); }; const int kHandleBlockSize = v8::internal::KB - 2; // fit in one page void HandleScopeImplementer::SaveContext(Context* context) { saved_contexts_.Add(context); } Context* HandleScopeImplementer::RestoreContext() { return saved_contexts_.RemoveLast(); } bool HandleScopeImplementer::HasSavedContexts() { return !saved_contexts_.is_empty(); } void HandleScopeImplementer::EnterContext(Handle context) { entered_contexts_.Add(*context); } void HandleScopeImplementer::LeaveContext() { entered_contexts_.RemoveLast(); } bool HandleScopeImplementer::LastEnteredContextWas(Handle context) { return !entered_contexts_.is_empty() && entered_contexts_.last() == *context; } Handle HandleScopeImplementer::LastEnteredContext() { if (entered_contexts_.is_empty()) return Handle::null(); return Handle(entered_contexts_.last()); } // If there's a spare block, use it for growing the current scope. internal::Object** HandleScopeImplementer::GetSpareOrNewBlock() { internal::Object** block = (spare_ != NULL) ? spare_ : NewArray(kHandleBlockSize); spare_ = NULL; return block; } void HandleScopeImplementer::DeleteExtensions(internal::Object** prev_limit) { while (!blocks_.is_empty()) { internal::Object** block_start = blocks_.last(); internal::Object** block_limit = block_start + kHandleBlockSize; #ifdef DEBUG // SealHandleScope may make the prev_limit to point inside the block. if (block_start <= prev_limit && prev_limit <= block_limit) { #ifdef ENABLE_HANDLE_ZAPPING internal::HandleScope::ZapRange(prev_limit, block_limit); #endif break; } #else if (prev_limit == block_limit) break; #endif blocks_.RemoveLast(); #ifdef ENABLE_HANDLE_ZAPPING internal::HandleScope::ZapRange(block_start, block_limit); #endif if (spare_ != NULL) { DeleteArray(spare_); } spare_ = block_start; } DCHECK((blocks_.is_empty() && prev_limit == NULL) || (!blocks_.is_empty() && prev_limit != NULL)); } // Interceptor functions called from generated inline caches to notify // CPU profiler that external callbacks are invoked. void InvokeAccessorGetterCallback( v8::Local property, const v8::PropertyCallbackInfo& info, v8::AccessorNameGetterCallback getter); void InvokeFunctionCallback(const v8::FunctionCallbackInfo& info, v8::FunctionCallback callback); class Testing { public: static v8::Testing::StressType stress_type() { return stress_type_; } static void set_stress_type(v8::Testing::StressType stress_type) { stress_type_ = stress_type; } private: static v8::Testing::StressType stress_type_; }; } } // namespace v8::internal #endif // V8_API_H_