Visitor Class Reference

#include <visitor.h>

Inheritance diagram for Visitor:

Data Structures
class	Key

Public Member Functions
	Visitor (Key)
virtual	~Visitor ()=default
template<typename T >
void	Trace (const T *t)
template<typename T >
void	Trace (const Member< T > &member)
template<typename T >
void	Trace (const WeakMember< T > &weak_member)
template<typename T >
void	Trace (const T &object)
template<typename T , void(T::*)(const LivenessBroker &) method>
void	RegisterWeakCallbackMethod (const T *object)
template<typename K , typename V >
void	Trace (const EphemeronPair< K, V > &ephemeron_pair)
template<typename K , typename V >
void	TraceEphemeron (const WeakMember< K > &key, const V *value)
template<typename T >
void	TraceStrongly (const WeakMember< T > &weak_member)
template<typename T >
void	TraceWeakContainer (const T *object, WeakCallback callback, const void *data)
template<typename T >
void	RegisterMovableReference (const T **slot)
virtual void	RegisterWeakCallback (WeakCallback callback, const void *data)
virtual V8_WARN_UNUSED_RESULT bool	DeferTraceToMutatorThreadIfConcurrent (const void *parameter, TraceCallback callback, size_t deferred_size)

Protected Member Functions
virtual void	Visit (const void *self, TraceDescriptor)
virtual void	VisitWeak (const void *self, TraceDescriptor, WeakCallback, const void *weak_member)
virtual void	VisitRoot (const void *, TraceDescriptor, const SourceLocation &)
virtual void	VisitWeakRoot (const void *self, TraceDescriptor, WeakCallback, const void *weak_root, const SourceLocation &)
virtual void	VisitEphemeron (const void *key, const void *value, TraceDescriptor value_desc)
virtual void	VisitWeakContainer (const void *self, TraceDescriptor strong_desc, TraceDescriptor weak_desc, WeakCallback callback, const void *data)
virtual void	HandleMovableReference (const void **)

Friends
template<typename T , typename WeaknessPolicy , typename LocationPolicy , typename CheckingPolicy >
class	internal::BasicCrossThreadPersistent
template<typename T , typename WeaknessPolicy , typename LocationPolicy , typename CheckingPolicy >
class	internal::BasicPersistent
class	internal::ConservativeTracingVisitor
class	internal::VisitorBase

Detailed Description

Visitor passed to trace methods. All managed pointers must have called the Visitor's trace method on them.

class Foo final : public GarbageCollected<Foo> {
 public:
  void Trace(Visitor* visitor) const {
    visitor->Trace(foo_);
    visitor->Trace(weak_foo_);
  }
 private:
  Member<Foo> foo_;
  WeakMember<Foo> weak_foo_;
};

Definition at line 52 of file visitor.h.

Constructor & Destructor Documentation

Visitor()

Visitor ( Key  )

inlineexplicit

Definition at line 60 of file visitor.h.

Referenced by JSVisitor::JSVisitor().

~Visitor()

virtual ~Visitor ( )

virtualdefault

Member Function Documentation

DeferTraceToMutatorThreadIfConcurrent()

virtual V8_WARN_UNUSED_RESULT bool DeferTraceToMutatorThreadIfConcurrent ( const void *  parameter, TraceCallback  callback, size_t  deferred_size  )

inlinevirtual

Defers tracing an object from a concurrent thread to the mutator thread. Should be called by Trace methods of types that are not safe to trace concurrently.

Parameters

parameter	tells the trace callback which object was deferred.
callback	to be invoked for tracing on the mutator thread.
deferred_size	size of deferred object.

Returns

false if the object does not need to be deferred (i.e. currently traced on the mutator thread) and true otherwise (i.e. currently traced on a concurrent thread).

Definition at line 244 of file visitor.h.

HandleMovableReference()

virtual void HandleMovableReference ( const void **  )

inlineprotectedvirtual

Definition at line 262 of file visitor.h.

Referenced by Visitor::RegisterMovableReference().

RegisterMovableReference()

void RegisterMovableReference ( const T **  slot )

inline

Registers a slot containing a reference to an object allocated on a compactable space. Such references maybe be arbitrarily moved by the GC.

Parameters

slot	location of reference to object that might be moved by the GC.

Definition at line 214 of file visitor.h.

References Visitor::HandleMovableReference().

RegisterWeakCallback()

virtual void RegisterWeakCallback ( WeakCallback  callback, const void *  data  )

inlinevirtual

Registers a weak callback that is invoked during garbage collection.

Parameters

callback	to be invoked.
data	custom data that is passed to the callback.

Definition at line 229 of file visitor.h.

Referenced by Visitor::RegisterWeakCallbackMethod().

RegisterWeakCallbackMethod()

void RegisterWeakCallbackMethod ( const T *  object )

inline

Registers a weak callback method on the object of type T. See LivenessBroker for an usage example.

Parameters

object

of type T specifying a weak callback method.

Definition at line 142 of file visitor.h.

References Visitor::RegisterWeakCallback().

Trace() [1/5]

void Trace ( const EphemeronPair< K, V > &  ephemeron_pair )

inline

Trace method for EphemeronPair.

Parameters

ephemeron_pair

EphemeronPair reference weakly retaining a key object and strongly retaining a value object in case the key object is alive.

Definition at line 153 of file visitor.h.

Trace() [2/5]

void Trace ( const Member< T > &  member )

inline

Trace method for Member.

Parameters

member

Member reference retaining an object.

Definition at line 86 of file visitor.h.

References cppgc::kSentinelPointer.

Trace() [3/5]

void Trace ( const T &  object )

inline

Trace method for inlined objects that are not allocated themselves but otherwise follow managed heap layout and have a Trace() method.

Parameters

object

reference of the inlined object.

Definition at line 124 of file visitor.h.

References BasicMember< T, WeaknessTag, WriteBarrierPolicy, CheckingPolicy >::cppgc::TraceTrait.

Trace() [4/5]

void Trace ( const T *  t )

inline

Trace method for raw pointers. Prefer the versions for managed pointers.

Parameters

member

Reference retaining an object.

Definition at line 70 of file visitor.h.

References BasicMember< T, WeaknessTag, WriteBarrierPolicy, CheckingPolicy >::cppgc::TraceTrait, and Visitor::Visit().

Trace() [5/5]

void Trace ( const WeakMember< T > &  weak_member )

inline

Trace method for WeakMember.

Parameters

weak_member

WeakMember reference weakly retaining an object.

Definition at line 98 of file visitor.h.

References BasicMember< T, WeaknessTag, WriteBarrierPolicy, CheckingPolicy >::cppgc::TraceTrait, cppgc::kSentinelPointer, and Visitor::VisitWeak().

TraceEphemeron()

void TraceEphemeron ( const WeakMember< K > &  key, const V *  value  )

inline

Trace method for ephemerons. Used for tracing raw ephemeron in which the key and value are kept separately.

Parameters

key	WeakMember reference weakly retaining a key object.
value	Member reference weakly retaining a value object.

Definition at line 168 of file visitor.h.

References BasicMember< T, WeaknessTag, WriteBarrierPolicy, CheckingPolicy >::cppgc::TraceTrait, and Visitor::VisitEphemeron().

TraceStrongly()

void TraceStrongly ( const WeakMember< T > &  weak_member )

inline

Trace method that strongifies a WeakMember.

Parameters

weak_member

WeakMember reference retaining an object.

Definition at line 185 of file visitor.h.

References cppgc::kSentinelPointer.

TraceWeakContainer()

void TraceWeakContainer ( const T *  object, WeakCallback  callback, const void *  data  )

inline

Trace method for weak containers.

Parameters

object	reference of the weak container.
callback	to be invoked.
data	custom data that is passed to the callback.

Definition at line 199 of file visitor.h.

References BasicMember< T, WeaknessTag, WriteBarrierPolicy, CheckingPolicy >::cppgc::TraceTrait, and Visitor::VisitWeakContainer().

Visit()

virtual void Visit ( const void *  self, TraceDescriptor    )

inlineprotectedvirtual

Definition at line 251 of file visitor.h.

Referenced by Visitor::Trace().

VisitEphemeron()

virtual void VisitEphemeron ( const void *  key, const void *  value, TraceDescriptor  value_desc  )

inlineprotectedvirtual

Definition at line 257 of file visitor.h.

Referenced by Visitor::TraceEphemeron().

VisitRoot()

virtual void VisitRoot ( const void *  , TraceDescriptor  , const SourceLocation &    )

inlineprotectedvirtual

Definition at line 254 of file visitor.h.

VisitWeak()

virtual void VisitWeak ( const void *  self, TraceDescriptor  , WeakCallback  , const void *  weak_member  )

inlineprotectedvirtual

Definition at line 252 of file visitor.h.

Referenced by Visitor::Trace().

VisitWeakContainer()

virtual void VisitWeakContainer ( const void *  self, TraceDescriptor  strong_desc, TraceDescriptor  weak_desc, WeakCallback  callback, const void *  data  )

inlineprotectedvirtual

Definition at line 259 of file visitor.h.

Referenced by Visitor::TraceWeakContainer().

VisitWeakRoot()

virtual void VisitWeakRoot ( const void *  self, TraceDescriptor  , WeakCallback  , const void *  weak_root, const SourceLocation &    )

inlineprotectedvirtual

Definition at line 255 of file visitor.h.

Friends And Related Function Documentation

internal::BasicCrossThreadPersistent

friend class internal::BasicCrossThreadPersistent

friend

Definition at line 322 of file visitor.h.

Referenced by BasicCrossThreadPersistent< T, WeaknessPolicy, LocationPolicy, CheckingPolicy >::BasicCrossThreadPersistent(), BasicCrossThreadPersistent< T, WeaknessPolicy, LocationPolicy, CheckingPolicy >::Lock(), and BasicCrossThreadPersistent< T, WeaknessPolicy, LocationPolicy, CheckingPolicy >::To().

internal::BasicPersistent

friend class internal::BasicPersistent

friend

Definition at line 325 of file visitor.h.

Referenced by BasicPersistent< T, WeaknessPolicy, LocationPolicy, CheckingPolicy >::BasicPersistent(), and BasicPersistent< T, WeaknessPolicy, LocationPolicy, CheckingPolicy >::To().

internal::ConservativeTracingVisitor

friend class internal::ConservativeTracingVisitor

friend

Definition at line 326 of file visitor.h.

internal::VisitorBase

friend class internal::VisitorBase

friend

Definition at line 327 of file visitor.h.

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

• include/cppgc/visitor.h