v8  4.1.0.27(io.js1.8.4)
V8 is Google's open source JavaScript engine
Handle< T > Class Template Reference

#include <v8.h>

Inheritance diagram for Handle< T >:

Public Member Functions

V8_INLINE Handle ()
 
template<class S >
V8_INLINE Handle (Handle< S > that)
 
V8_INLINE bool IsEmpty () const
 
V8_INLINE void Clear ()
 
V8_INLINE T * operator-> () const
 
V8_INLINE T * operator* () const
 
template<class S >
V8_INLINE bool operator== (const Handle< S > &that) const
 
template<class S >
V8_INLINE bool operator== (const PersistentBase< S > &that) const
 
template<class S >
V8_INLINE bool operator!= (const Handle< S > &that) const
 
template<class S >
V8_INLINE bool operator!= (const Persistent< S > &that) const
 
template<class S >
V8_INLINE Handle< S > As ()
 

Static Public Member Functions

template<class S >
static V8_INLINE Handle< T > Cast (Handle< S > that)
 
static V8_INLINE Handle< T > New (Isolate *isolate, Handle< T > that)
 
static V8_INLINE Handle< T > New (Isolate *isolate, const PersistentBase< T > &that)
 

Friends

class Utils
 
template<class F , class M >
class Persistent
 
template<class F >
class PersistentBase
 
template<class F >
class Handle
 
template<class F >
class Local
 
template<class F >
class FunctionCallbackInfo
 
template<class F >
class PropertyCallbackInfo
 
template<class F >
class internal::CustomArguments
 
class Context
 
class HandleScope
 
class Object
 
class Private
 
Handle< PrimitiveUndefined (Isolate *isolate)
 
Handle< PrimitiveNull (Isolate *isolate)
 
Handle< BooleanTrue (Isolate *isolate)
 
Handle< BooleanFalse (Isolate *isolate)
 

Detailed Description

template<class T>
class v8::Handle< T >

An object reference managed by the v8 garbage collector.

All objects returned from v8 have to be tracked by the garbage collector so that it knows that the objects are still alive. Also, because the garbage collector may move objects, it is unsafe to point directly to an object. Instead, all objects are stored in handles which are known by the garbage collector and updated whenever an object moves. Handles should always be passed by value (except in cases like out-parameters) and they should never be allocated on the heap.

There are two types of handles: local and persistent handles. Local handles are light-weight and transient and typically used in local operations. They are managed by HandleScopes. Persistent handles can be used when storing objects across several independent operations and have to be explicitly deallocated when they're no longer used.

It is safe to extract the object stored in the handle by dereferencing the handle (for instance, to extract the Object* from a Handle<Object>); the value will still be governed by a handle behind the scenes and the same rules apply to these values as to their handles.

Definition at line 107 of file v8.h.

Constructor & Destructor Documentation

V8_INLINE Handle ( )
inline

Creates an empty handle.

Definition at line 220 of file v8.h.

Referenced by Extension::GetNativeFunctionTemplate().

V8_INLINE Handle ( Handle< S >  that)
inline

Creates a handle for the contents of the specified handle. This constructor allows you to pass handles as arguments by value and to assign between handles. However, if you try to assign between incompatible handles, for instance from a Handle<String> to a Handle<Number> it will cause a compile-time error. Assigning between compatible handles, for instance assigning a Handle<String> to a variable declared as Handle<Value>, is legal because String is a subclass of Value.

This check fails when trying to convert between incompatible handles. For example, converting from a Handle<String> to a Handle<Number>.

Definition at line 232 of file v8.h.

Member Function Documentation

V8_INLINE Handle<S> As ( )
inline

Definition at line 303 of file v8.h.

static V8_INLINE Handle<T> Cast ( Handle< S >  that)
inlinestatic

Definition at line 294 of file v8.h.

V8_INLINE void Clear ( )
inline

Sets the handle to be empty. IsEmpty() will then return true.

Definition at line 250 of file v8.h.

V8_INLINE bool IsEmpty ( ) const
inline

Returns true if the handle is empty.

Definition at line 245 of file v8.h.

static V8_INLINE Handle<T> New ( Isolate isolate,
Handle< T >  that 
)
inlinestatic

Definition at line 307 of file v8.h.

static V8_INLINE Handle<T> New ( Isolate isolate,
const PersistentBase< T > &  that 
)
inlinestatic

Definition at line 310 of file v8.h.

V8_INLINE bool operator!= ( const Handle< S > &  that) const
inline

Checks whether two handles are different. Returns true if only one of the handles is empty, or if the objects to which they refer are different. The handles' references are not checked.

Definition at line 285 of file v8.h.

V8_INLINE bool operator!= ( const Persistent< S > &  that) const
inline

Definition at line 289 of file v8.h.

V8_INLINE T* operator* ( ) const
inline

Definition at line 254 of file v8.h.

V8_INLINE T* operator-> ( ) const
inline

Definition at line 252 of file v8.h.

Referenced by Context::Scope::Scope(), Script::V8_DEPRECATED(), and Context::Scope::~Scope().

V8_INLINE bool operator== ( const Handle< S > &  that) const
inline

Checks whether two handles are the same. Returns true if both are empty, or if the objects to which they refer are identical. The handles' references are not checked.

Definition at line 262 of file v8.h.

V8_INLINE bool operator== ( const PersistentBase< S > &  that) const
inline

Definition at line 270 of file v8.h.

Friends And Related Function Documentation

friend class Context
friend

Definition at line 328 of file v8.h.

Handle<Boolean> False ( Isolate isolate)
friend

Definition at line 7354 of file v8.h.

friend class FunctionCallbackInfo
friend

Definition at line 321 of file v8.h.

friend class Handle
friend

Definition at line 319 of file v8.h.

friend class HandleScope
friend

Definition at line 329 of file v8.h.

friend class internal::CustomArguments
friend

Definition at line 323 of file v8.h.

friend class Local
friend

Definition at line 320 of file v8.h.

Handle<Primitive> Null ( Isolate isolate)
friend

Definition at line 7336 of file v8.h.

friend class Object
friend

Definition at line 330 of file v8.h.

friend class Persistent
friend

Definition at line 317 of file v8.h.

friend class PersistentBase
friend

Definition at line 318 of file v8.h.

friend class Private
friend

Definition at line 331 of file v8.h.

friend class PropertyCallbackInfo
friend

Definition at line 322 of file v8.h.

Handle<Boolean> True ( Isolate isolate)
friend

Definition at line 7345 of file v8.h.

Handle<Primitive> Undefined ( Isolate isolate)
friend

Definition at line 7327 of file v8.h.

friend class Utils
friend

Definition at line 316 of file v8.h.


The documentation for this class was generated from the following file: