PersistentBase< T > Class Template Reference

#include <v8.h>

Inheritance diagram for PersistentBase< T >:

Public Member Functions
V8_INLINE void	Reset ()
template<class S >
V8_INLINE void	Reset (Isolate *isolate, const Local< S > &other)
template<class S >
V8_INLINE void	Reset (Isolate *isolate, const PersistentBase< S > &other)
V8_INLINE bool	IsEmpty () const
V8_INLINE void	Empty ()
V8_INLINE Local< T >	Get (Isolate *isolate) const
template<class S >
V8_INLINE bool	operator== (const PersistentBase< S > &that) const
template<class S >
V8_INLINE bool	operator== (const Local< S > &that) const
template<class S >
V8_INLINE bool	operator!= (const PersistentBase< S > &that) const
template<class S >
V8_INLINE bool	operator!= (const Local< S > &that) const
template<typename P >
V8_INLINE void	SetWeak (P *parameter, typename WeakCallbackInfo< P >::Callback callback, WeakCallbackType type)
V8_INLINE void	SetWeak ()
template<typename P >
V8_INLINE P *	ClearWeak ()
V8_INLINE void	ClearWeak ()
V8_INLINE void	AnnotateStrongRetainer (const char *label)
V8_INLINE void	RegisterExternalReference (Isolate *isolate) const
	V8_DEPRECATE_SOON ("Objects are always considered independent. " "Use MarkActive to avoid collecting otherwise dead weak handles.", V8_INLINE void MarkIndependent())
V8_INLINE void	MarkActive ()
	V8_DEPRECATE_SOON ("See MarkIndependent.", V8_INLINE bool IsIndependent() const)
V8_INLINE bool	IsNearDeath () const
V8_INLINE bool	IsWeak () const
V8_INLINE void	SetWrapperClassId (uint16_t class_id)
V8_INLINE uint16_t	WrapperClassId () const
	PersistentBase (const PersistentBase &other)=delete
void	operator= (const PersistentBase &)=delete
template<class S >
void	Reset (Isolate *isolate, const Local< S > &other)
template<class S >
void	Reset (Isolate *isolate, const PersistentBase< S > &other)

Friends
class	Isolate
class	Utils
template<class F >
class	Local
template<class F1 , class F2 >
class	Persistent
template<class F >
class	Global
template<class F >
class	PersistentBase
template<class F >
class	ReturnValue
template<class F1 , class F2 , class F3 >
class	PersistentValueMapBase
template<class F1 , class F2 >
class	PersistentValueVector
class	Object

Detailed Description

template<class T>
class v8::PersistentBase< T >

An object reference that is independent of any handle scope. Where a Local handle only lives as long as the HandleScope in which it was allocated, a PersistentBase handle remains valid until it is explicitly disposed using Reset().

A persistent handle contains a reference to a storage cell within the V8 engine which holds an object value and which is updated by the garbage collector whenever the object is moved. A new storage cell can be created using the constructor or PersistentBase::Reset and existing handles can be disposed using PersistentBase::Reset.

Definition at line 564 of file v8.h.

Constructor & Destructor Documentation

PersistentBase()

PersistentBase ( const PersistentBase< T > &  other )

delete

Member Function Documentation

AnnotateStrongRetainer()

void AnnotateStrongRetainer

(

const char *

label

)

Annotates the strong handle with the given label, which is then used by the heap snapshot generator as a name of the edge from the root to the handle. The function does not take ownership of the label and assumes that the label is valid as long as the handle is valid.

Definition at line 9481 of file v8.h.

ClearWeak() [1/2]

V8_INLINE P* ClearWeak

(

)

ClearWeak() [2/2]

P * ClearWeak ( )

inline

Definition at line 645 of file v8.h.

Empty()

V8_INLINE void Empty ( )

inline

Definition at line 586 of file v8.h.

Get()

V8_INLINE Local<T> Get ( Isolate *  isolate ) const

inline

Definition at line 588 of file v8.h.

References Local< T >::Local.

IsEmpty()

V8_INLINE bool IsEmpty ( ) const

inline

Definition at line 585 of file v8.h.

Referenced by PersistentBase< T >::RegisterExternalReference().

IsNearDeath()

bool IsNearDeath

Checks if the handle holds the only reference to an object.

Definition at line 9410 of file v8.h.

References Internals::GetNodeState(), Internals::kNodeStateIsNearDeathValue, and Internals::kNodeStateIsPendingValue.

IsWeak()

bool IsWeak

Returns true if the handle's reference is weak.

Definition at line 9421 of file v8.h.

References Internals::GetNodeState(), and Internals::kNodeStateIsWeakValue.

MarkActive()

void MarkActive

Marks the reference to this object as active. The scavenge garbage collection should not reclaim the objects marked as active, even if the object held by the handle is otherwise unreachable.

This bit is cleared after the each garbage collection pass.

Definition at line 9498 of file v8.h.

References Internals::kNodeIsActiveShift, and Internals::UpdateNodeFlag().

operator!=() [1/2]

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

inline

Definition at line 616 of file v8.h.

operator!=() [2/2]

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

inline

Definition at line 611 of file v8.h.

operator=()

void operator= ( const PersistentBase< T > &  )

delete

operator==() [1/2]

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

inline

Definition at line 602 of file v8.h.

operator==() [2/2]

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

inline

Definition at line 593 of file v8.h.

RegisterExternalReference()

void RegisterExternalReference

(

Isolate *

isolate

)

const

Allows the embedder to tell the v8 garbage collector that a certain object is alive. Only allowed when the embedder is asked to trace its heap by EmbedderHeapTracer.

Definition at line 9487 of file v8.h.

References PersistentBase< T >::IsEmpty().

Reset() [1/5]

void Reset

If non-empty, destroy the underlying storage cell IsEmpty() will return true after this call.

Definition at line 9430 of file v8.h.

Reset() [2/5]

V8_INLINE void Reset	(	Isolate *	isolate,
		const Local< S > &	other
	)

If non-empty, destroy the underlying storage cell and create a new one with the contents of other if other is non empty

Reset() [3/5]

void Reset	(	Isolate *	isolate,
		const Local< S > &	other
	)

Definition at line 9439 of file v8.h.

Reset() [4/5]

V8_INLINE void Reset	(	Isolate *	isolate,
		const PersistentBase< S > &	other
	)

If non-empty, destroy the underlying storage cell and create a new one with the contents of other if other is non empty

Reset() [5/5]

void Reset	(	Isolate *	isolate,
		const PersistentBase< S > &	other
	)

Definition at line 9449 of file v8.h.

SetWeak() [1/2]

void SetWeak

Turns this handle into a weak phantom handle without finalization callback. The handle will be reset automatically when the garbage collector detects that the object is no longer reachable. A related function Isolate::NumberOfPhantomHandleResetsSinceLastCall returns how many phantom handles were reset by the garbage collector.

Definition at line 9469 of file v8.h.

SetWeak() [2/2]

V8_INLINE void SetWeak	(	P *	parameter,
		typename WeakCallbackInfo< P >::Callback	callback,
		WeakCallbackType	type
	)

Install a finalization callback on this object. NOTE: There is no guarantee as to when or even if the callback is invoked. The invocation is performed solely on a best effort basis. As always, GC-based finalization should not be relied upon for any critical form of resource management!

Definition at line 9460 of file v8.h.

SetWrapperClassId()

void SetWrapperClassId

(

uint16_t

class_id

)

Assigns a wrapper class ID to the handle. See RetainedObjectInfo interface description in v8-profiler.h for details.

Definition at line 9507 of file v8.h.

References Internals::kNodeClassIdOffset.

V8_DEPRECATE_SOON() [1/2]

V8_DEPRECATE_SOON	(	"Objects are always considered independent. " "Use MarkActive to avoid collecting otherwise dead weak handles."	,
		V8_INLINE void	MarkIndependent()
	)

Marks the reference to this object independent. Garbage collector is free to ignore any object groups containing this object. Weak callback for an independent handle should not assume that it will be preceded by a global GC prologue callback or followed by a global GC epilogue callback.

V8_DEPRECATE_SOON() [2/2]

V8_DEPRECATE_SOON	(	"See MarkIndependent."	,
		V8_INLINE bool IsIndependent() const
	)

WrapperClassId()

uint16_t WrapperClassId

Returns the class ID previously assigned to this handle or 0 if no class ID was previously assigned.

Definition at line 9517 of file v8.h.

References Internals::kNodeClassIdOffset.

Friends And Related Function Documentation

Global

friend class Global

friend

Definition at line 712 of file v8.h.

Referenced by PersistentValueVector< V, Traits >::Append(), PersistentValueVector< V, Traits >::Clear(), Global< T >::Pass(), PersistentValueMapBase< K, V, Traits >::Release(), PersistentValueMapBase< K, V, Traits >::RemoveWeak(), PersistentValueMap< K, V, Traits >::Set(), and GlobalValueMap< K, V, Traits >::Set().

Isolate

friend class Isolate

friend

Definition at line 707 of file v8.h.

Local

friend class Local

friend

Definition at line 709 of file v8.h.

Object

friend class Object

friend

Definition at line 718 of file v8.h.

Persistent

friend class Persistent

friend

Definition at line 710 of file v8.h.

PersistentBase

friend class PersistentBase

friend

Definition at line 713 of file v8.h.

PersistentValueMapBase

friend class PersistentValueMapBase

friend

Definition at line 716 of file v8.h.

PersistentValueVector

friend class PersistentValueVector

friend

Definition at line 717 of file v8.h.

ReturnValue

friend class ReturnValue

friend

Definition at line 714 of file v8.h.

Utils

friend class Utils

friend

Definition at line 708 of file v8.h.

---

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

• include/v8.h