src/api.h

   1 // Copyright 2008 the V8 project authors. All rights reserved.
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   3 // modification, are permitted provided that the following conditions are
   4 // met:
   5 //
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   7 //       notice, this list of conditions and the following disclaimer.
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   9 //       copyright notice, this list of conditions and the following
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  11 //       with the distribution.
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  14 //       from this software without specific prior written permission.
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  27
  28 #ifndef V8_API_H_
  29 #define V8_API_H_
  30
  31 #include "apiutils.h"
  32 #include "factory.h"
  33
  34 namespace v8 {
  35
  36 // Constants used in the implementation of the API.  The most natural thing
  37 // would usually be to place these with the classes that use them, but
  38 // we want to keep them out of v8.h because it is an externally
  39 // visible file.
  40 class Consts {
  41  public:
  42   enum TemplateType {
  43     FUNCTION_TEMPLATE = 0,
  44     OBJECT_TEMPLATE = 1
  45   };
  46 };
  47
  48
  49 // Utilities for working with neander-objects, primitive
  50 // env-independent JSObjects used by the api.
  51 class NeanderObject {
  52  public:
  53   explicit NeanderObject(int size);
  54   inline NeanderObject(v8::internal::Handle<v8::internal::Object> obj);
  55   inline NeanderObject(v8::internal::Object* obj);
  56   inline v8::internal::Object* get(int index);
  57   inline void set(int index, v8::internal::Object* value);
  58   inline v8::internal::Handle<v8::internal::JSObject> value() { return value_; }
  59   int size();
  60  private:
  61   v8::internal::Handle<v8::internal::JSObject> value_;
  62 };
  63
  64
  65 // Utilities for working with neander-arrays, a simple extensible
  66 // array abstraction built on neander-objects.
  67 class NeanderArray {
  68  public:
  69   NeanderArray();
  70   inline NeanderArray(v8::internal::Handle<v8::internal::Object> obj);
  71   inline v8::internal::Handle<v8::internal::JSObject> value() {
  72     return obj_.value();
  73   }
  74
  75   void add(v8::internal::Handle<v8::internal::Object> value);
  76
  77   int length();
  78
  79   v8::internal::Object* get(int index);
  80   // Change the value at an index to undefined value. If the index is
  81   // out of bounds, the request is ignored. Returns the old value.
  82   void set(int index, v8::internal::Object* value);
  83  private:
  84   NeanderObject obj_;
  85 };
  86
  87
  88 NeanderObject::NeanderObject(v8::internal::Handle<v8::internal::Object> obj)
  89     : value_(v8::internal::Handle<v8::internal::JSObject>::cast(obj)) { }
  90
  91
  92 NeanderObject::NeanderObject(v8::internal::Object* obj)
  93     : value_(v8::internal::Handle<v8::internal::JSObject>(
  94         v8::internal::JSObject::cast(obj))) { }
  95
  96
  97 NeanderArray::NeanderArray(v8::internal::Handle<v8::internal::Object> obj)
  98     : obj_(obj) { }
  99
 100
 101 v8::internal::Object* NeanderObject::get(int offset) {
 102   ASSERT(value()->HasFastElements());
 103   return v8::internal::FixedArray::cast(value()->elements())->get(offset);
 104 }
 105
 106
 107 void NeanderObject::set(int offset, v8::internal::Object* value) {
 108   ASSERT(value_->HasFastElements());
 109   v8::internal::FixedArray::cast(value_->elements())->set(offset, value);
 110 }
 111
 112
 113 template <typename T> static inline T ToCData(v8::internal::Object* obj) {
 114   STATIC_ASSERT(sizeof(T) == sizeof(v8::internal::Address));
 115   return reinterpret_cast<T>(
 116       reinterpret_cast<intptr_t>(v8::internal::Proxy::cast(obj)->proxy()));
 117 }
 118
 119
 120 template <typename T>
 121 static inline v8::internal::Handle<v8::internal::Object> FromCData(T obj) {
 122   STATIC_ASSERT(sizeof(T) == sizeof(v8::internal::Address));
 123   return v8::internal::Factory::NewProxy(
 124       reinterpret_cast<v8::internal::Address>(reinterpret_cast<intptr_t>(obj)));
 125 }
 126
 127
 128 class ApiFunction {
 129  public:
 130   explicit ApiFunction(v8::internal::Address addr) : addr_(addr) { }
 131   v8::internal::Address address() { return addr_; }
 132  private:
 133   v8::internal::Address addr_;
 134 };
 135
 136
 137 enum ExtensionTraversalState {
 138   UNVISITED, VISITED, INSTALLED
 139 };
 140
 141
 142 class RegisteredExtension {
 143  public:
 144   explicit RegisteredExtension(Extension* extension);
 145   static void Register(RegisteredExtension* that);
 146   Extension* extension() { return extension_; }
 147   RegisteredExtension* next() { return next_; }
 148   RegisteredExtension* next_auto() { return next_auto_; }
 149   ExtensionTraversalState state() { return state_; }
 150   void set_state(ExtensionTraversalState value) { state_ = value; }
 151   static RegisteredExtension* first_extension() { return first_extension_; }
 152  private:
 153   Extension* extension_;
 154   RegisteredExtension* next_;
 155   RegisteredExtension* next_auto_;
 156   ExtensionTraversalState state_;
 157   static RegisteredExtension* first_extension_;
 158   static RegisteredExtension* first_auto_extension_;
 159 };
 160
 161
 162 class Utils {
 163  public:
 164   static bool ReportApiFailure(const char* location, const char* message);
 165
 166   static Local<FunctionTemplate> ToFunctionTemplate(NeanderObject obj);
 167   static Local<ObjectTemplate> ToObjectTemplate(NeanderObject obj);
 168
 169   static inline Local<Context> ToLocal(
 170       v8::internal::Handle<v8::internal::Context> obj);
 171   static inline Local<Value> ToLocal(
 172       v8::internal::Handle<v8::internal::Object> obj);
 173   static inline Local<Function> ToLocal(
 174       v8::internal::Handle<v8::internal::JSFunction> obj);
 175   static inline Local<String> ToLocal(
 176       v8::internal::Handle<v8::internal::String> obj);
 177   static inline Local<RegExp> ToLocal(
 178       v8::internal::Handle<v8::internal::JSRegExp> obj);
 179   static inline Local<Object> ToLocal(
 180       v8::internal::Handle<v8::internal::JSObject> obj);
 181   static inline Local<Array> ToLocal(
 182       v8::internal::Handle<v8::internal::JSArray> obj);
 183   static inline Local<External> ToLocal(
 184       v8::internal::Handle<v8::internal::Proxy> obj);
 185   static inline Local<Message> MessageToLocal(
 186       v8::internal::Handle<v8::internal::Object> obj);
 187   static inline Local<StackTrace> StackTraceToLocal(
 188       v8::internal::Handle<v8::internal::JSArray> obj);
 189   static inline Local<StackFrame> StackFrameToLocal(
 190       v8::internal::Handle<v8::internal::JSObject> obj);
 191   static inline Local<Number> NumberToLocal(
 192       v8::internal::Handle<v8::internal::Object> obj);
 193   static inline Local<Integer> IntegerToLocal(
 194       v8::internal::Handle<v8::internal::Object> obj);
 195   static inline Local<Uint32> Uint32ToLocal(
 196       v8::internal::Handle<v8::internal::Object> obj);
 197   static inline Local<FunctionTemplate> ToLocal(
 198       v8::internal::Handle<v8::internal::FunctionTemplateInfo> obj);
 199   static inline Local<ObjectTemplate> ToLocal(
 200       v8::internal::Handle<v8::internal::ObjectTemplateInfo> obj);
 201   static inline Local<Signature> ToLocal(
 202       v8::internal::Handle<v8::internal::SignatureInfo> obj);
 203   static inline Local<TypeSwitch> ToLocal(
 204       v8::internal::Handle<v8::internal::TypeSwitchInfo> obj);
 205
 206   static inline v8::internal::Handle<v8::internal::TemplateInfo>
 207       OpenHandle(const Template* that);
 208   static inline v8::internal::Handle<v8::internal::FunctionTemplateInfo>
 209       OpenHandle(const FunctionTemplate* that);
 210   static inline v8::internal::Handle<v8::internal::ObjectTemplateInfo>
 211       OpenHandle(const ObjectTemplate* that);
 212   static inline v8::internal::Handle<v8::internal::Object>
 213       OpenHandle(const Data* data);
 214   static inline v8::internal::Handle<v8::internal::JSRegExp>
 215       OpenHandle(const RegExp* data);
 216   static inline v8::internal::Handle<v8::internal::JSObject>
 217       OpenHandle(const v8::Object* data);
 218   static inline v8::internal::Handle<v8::internal::JSArray>
 219       OpenHandle(const v8::Array* data);
 220   static inline v8::internal::Handle<v8::internal::String>
 221       OpenHandle(const String* data);
 222   static inline v8::internal::Handle<v8::internal::Object>
 223       OpenHandle(const Script* data);
 224   static inline v8::internal::Handle<v8::internal::JSFunction>
 225       OpenHandle(const Function* data);
 226   static inline v8::internal::Handle<v8::internal::JSObject>
 227       OpenHandle(const Message* message);
 228   static inline v8::internal::Handle<v8::internal::JSArray>
 229       OpenHandle(const StackTrace* stack_trace);
 230   static inline v8::internal::Handle<v8::internal::JSObject>
 231       OpenHandle(const StackFrame* stack_frame);
 232   static inline v8::internal::Handle<v8::internal::Context>
 233       OpenHandle(const v8::Context* context);
 234   static inline v8::internal::Handle<v8::internal::SignatureInfo>
 235       OpenHandle(const v8::Signature* sig);
 236   static inline v8::internal::Handle<v8::internal::TypeSwitchInfo>
 237       OpenHandle(const v8::TypeSwitch* that);
 238   static inline v8::internal::Handle<v8::internal::Proxy>
 239       OpenHandle(const v8::External* that);
 240 };
 241
 242
 243 template <class T>
 244 static inline T* ToApi(v8::internal::Handle<v8::internal::Object> obj) {
 245   return reinterpret_cast<T*>(obj.location());
 246 }
 247
 248
 249 template <class T>
 250 v8::internal::Handle<T> v8::internal::Handle<T>::EscapeFrom(
 251     v8::HandleScope* scope) {
 252   v8::internal::Handle<T> handle;
 253   if (!is_null()) {
 254     handle = *this;
 255   }
 256   return Utils::OpenHandle(*scope->Close(Utils::ToLocal(handle)));
 257 }
 258
 259
 260 // Implementations of ToLocal
 261
 262 #define MAKE_TO_LOCAL(Name, From, To)                                       \
 263   Local<v8::To> Utils::Name(v8::internal::Handle<v8::internal::From> obj) { \
 264     ASSERT(obj.is_null() || !obj->IsTheHole());                             \
 265     return Local<To>(reinterpret_cast<To*>(obj.location()));                \
 266   }
 267
 268 MAKE_TO_LOCAL(ToLocal, Context, Context)
 269 MAKE_TO_LOCAL(ToLocal, Object, Value)
 270 MAKE_TO_LOCAL(ToLocal, JSFunction, Function)
 271 MAKE_TO_LOCAL(ToLocal, String, String)
 272 MAKE_TO_LOCAL(ToLocal, JSRegExp, RegExp)
 273 MAKE_TO_LOCAL(ToLocal, JSObject, Object)
 274 MAKE_TO_LOCAL(ToLocal, JSArray, Array)
 275 MAKE_TO_LOCAL(ToLocal, Proxy, External)
 276 MAKE_TO_LOCAL(ToLocal, FunctionTemplateInfo, FunctionTemplate)
 277 MAKE_TO_LOCAL(ToLocal, ObjectTemplateInfo, ObjectTemplate)
 278 MAKE_TO_LOCAL(ToLocal, SignatureInfo, Signature)
 279 MAKE_TO_LOCAL(ToLocal, TypeSwitchInfo, TypeSwitch)
 280 MAKE_TO_LOCAL(MessageToLocal, Object, Message)
 281 MAKE_TO_LOCAL(StackTraceToLocal, JSArray, StackTrace)
 282 MAKE_TO_LOCAL(StackFrameToLocal, JSObject, StackFrame)
 283 MAKE_TO_LOCAL(NumberToLocal, Object, Number)
 284 MAKE_TO_LOCAL(IntegerToLocal, Object, Integer)
 285 MAKE_TO_LOCAL(Uint32ToLocal, Object, Uint32)
 286
 287 #undef MAKE_TO_LOCAL
 288
 289
 290 // Implementations of OpenHandle
 291
 292 #define MAKE_OPEN_HANDLE(From, To) \
 293   v8::internal::Handle<v8::internal::To> Utils::OpenHandle(\
 294     const v8::From* that) { \
 295     return v8::internal::Handle<v8::internal::To>( \
 296         reinterpret_cast<v8::internal::To**>(const_cast<v8::From*>(that))); \
 297   }
 298
 299 MAKE_OPEN_HANDLE(Template, TemplateInfo)
 300 MAKE_OPEN_HANDLE(FunctionTemplate, FunctionTemplateInfo)
 301 MAKE_OPEN_HANDLE(ObjectTemplate, ObjectTemplateInfo)
 302 MAKE_OPEN_HANDLE(Signature, SignatureInfo)
 303 MAKE_OPEN_HANDLE(TypeSwitch, TypeSwitchInfo)
 304 MAKE_OPEN_HANDLE(Data, Object)
 305 MAKE_OPEN_HANDLE(RegExp, JSRegExp)
 306 MAKE_OPEN_HANDLE(Object, JSObject)
 307 MAKE_OPEN_HANDLE(Array, JSArray)
 308 MAKE_OPEN_HANDLE(String, String)
 309 MAKE_OPEN_HANDLE(Script, Object)
 310 MAKE_OPEN_HANDLE(Function, JSFunction)
 311 MAKE_OPEN_HANDLE(Message, JSObject)
 312 MAKE_OPEN_HANDLE(Context, Context)
 313 MAKE_OPEN_HANDLE(External, Proxy)
 314 MAKE_OPEN_HANDLE(StackTrace, JSArray)
 315 MAKE_OPEN_HANDLE(StackFrame, JSObject)
 316
 317 #undef MAKE_OPEN_HANDLE
 318
 319
 320 namespace internal {
 321
 322 // This class is here in order to be able to declare it a friend of
 323 // HandleScope.  Moving these methods to be members of HandleScope would be
 324 // neat in some ways, but it would expose external implementation details in
 325 // our public header file, which is undesirable.
 326 //
 327 // There is a singleton instance of this class to hold the per-thread data.
 328 // For multithreaded V8 programs this data is copied in and out of storage
 329 // so that the currently executing thread always has its own copy of this
 330 // data.
 331 class HandleScopeImplementer {
 332  public:
 333
 334   HandleScopeImplementer()
 335       : blocks_(0),
 336         entered_contexts_(0),
 337         saved_contexts_(0),
 338         spare_(NULL),
 339         ignore_out_of_memory_(false),
 340         call_depth_(0) { }
 341
 342   static HandleScopeImplementer* instance();
 343
 344   // Threading support for handle data.
 345   static int ArchiveSpacePerThread();
 346   static char* RestoreThread(char* from);
 347   static char* ArchiveThread(char* to);
 348   static void FreeThreadResources();
 349
 350   // Garbage collection support.
 351   static void Iterate(v8::internal::ObjectVisitor* v);
 352   static char* Iterate(v8::internal::ObjectVisitor* v, char* data);
 353
 354
 355   inline internal::Object** GetSpareOrNewBlock();
 356   inline void DeleteExtensions(internal::Object** prev_limit);
 357
 358   inline void IncrementCallDepth() {call_depth_++;}
 359   inline void DecrementCallDepth() {call_depth_--;}
 360   inline bool CallDepthIsZero() { return call_depth_ == 0; }
 361
 362   inline void EnterContext(Handle<Object> context);
 363   inline bool LeaveLastContext();
 364
 365   // Returns the last entered context or an empty handle if no
 366   // contexts have been entered.
 367   inline Handle<Object> LastEnteredContext();
 368
 369   inline void SaveContext(Context* context);
 370   inline Context* RestoreContext();
 371   inline bool HasSavedContexts();
 372
 373   inline List<internal::Object**>* blocks() { return &blocks_; }
 374   inline bool ignore_out_of_memory() { return ignore_out_of_memory_; }
 375   inline void set_ignore_out_of_memory(bool value) {
 376     ignore_out_of_memory_ = value;
 377   }
 378
 379  private:
 380   void ResetAfterArchive() {
 381     blocks_.Initialize(0);
 382     entered_contexts_.Initialize(0);
 383     saved_contexts_.Initialize(0);
 384     spare_ = NULL;
 385     ignore_out_of_memory_ = false;
 386     call_depth_ = 0;
 387   }
 388
 389   void Free() {
 390     ASSERT(blocks_.length() == 0);
 391     ASSERT(entered_contexts_.length() == 0);
 392     ASSERT(saved_contexts_.length() == 0);
 393     blocks_.Free();
 394     entered_contexts_.Free();
 395     saved_contexts_.Free();
 396     if (spare_ != NULL) {
 397       DeleteArray(spare_);
 398       spare_ = NULL;
 399     }
 400     ASSERT(call_depth_ == 0);
 401   }
 402
 403   List<internal::Object**> blocks_;
 404   // Used as a stack to keep track of entered contexts.
 405   List<Handle<Object> > entered_contexts_;
 406   // Used as a stack to keep track of saved contexts.
 407   List<Context*> saved_contexts_;
 408   Object** spare_;
 409   bool ignore_out_of_memory_;
 410   int call_depth_;
 411   // This is only used for threading support.
 412   v8::ImplementationUtilities::HandleScopeData handle_scope_data_;
 413
 414   void IterateThis(ObjectVisitor* v);
 415   char* RestoreThreadHelper(char* from);
 416   char* ArchiveThreadHelper(char* to);
 417
 418   DISALLOW_COPY_AND_ASSIGN(HandleScopeImplementer);
 419 };
 420
 421
 422 static const int kHandleBlockSize = v8::internal::KB - 2;  // fit in one page
 423
 424
 425 void HandleScopeImplementer::SaveContext(Context* context) {
 426   saved_contexts_.Add(context);
 427 }
 428
 429
 430 Context* HandleScopeImplementer::RestoreContext() {
 431   return saved_contexts_.RemoveLast();
 432 }
 433
 434
 435 bool HandleScopeImplementer::HasSavedContexts() {
 436   return !saved_contexts_.is_empty();
 437 }
 438
 439
 440 void HandleScopeImplementer::EnterContext(Handle<Object> context) {
 441   entered_contexts_.Add(context);
 442 }
 443
 444
 445 bool HandleScopeImplementer::LeaveLastContext() {
 446   if (entered_contexts_.is_empty()) return false;
 447   entered_contexts_.RemoveLast();
 448   return true;
 449 }
 450
 451
 452 Handle<Object> HandleScopeImplementer::LastEnteredContext() {
 453   if (entered_contexts_.is_empty()) return Handle<Object>::null();
 454   return entered_contexts_.last();
 455 }
 456
 457
 458 // If there's a spare block, use it for growing the current scope.
 459 internal::Object** HandleScopeImplementer::GetSpareOrNewBlock() {
 460   internal::Object** block = (spare_ != NULL) ?
 461       spare_ :
 462       NewArray<internal::Object*>(kHandleBlockSize);
 463   spare_ = NULL;
 464   return block;
 465 }
 466
 467
 468 void HandleScopeImplementer::DeleteExtensions(internal::Object** prev_limit) {
 469   while (!blocks_.is_empty()) {
 470     internal::Object** block_start = blocks_.last();
 471     internal::Object** block_limit = block_start + kHandleBlockSize;
 472 #ifdef DEBUG
 473     // NoHandleAllocation may make the prev_limit to point inside the block.
 474     if (block_start <= prev_limit && prev_limit <= block_limit) break;
 475 #else
 476     if (prev_limit == block_limit) break;
 477 #endif
 478
 479     blocks_.RemoveLast();
 480 #ifdef DEBUG
 481     v8::ImplementationUtilities::ZapHandleRange(block_start, block_limit);
 482 #endif
 483     if (spare_ != NULL) {
 484       DeleteArray(spare_);
 485     }
 486     spare_ = block_start;
 487   }
 488   ASSERT((blocks_.is_empty() && prev_limit == NULL) ||
 489          (!blocks_.is_empty() && prev_limit != NULL));
 490 }
 491
 492 } }  // namespace v8::internal
 493
 494 #endif  // V8_API_H_