v8::EmbedderHeapTracer Class Reference

#include <v8.h>

Data Structures
struct	AdvanceTracingActions

Public Types
enum	ForceCompletionAction { FORCE_COMPLETION, DO_NOT_FORCE_COMPLETION }

Public Member Functions
virtual void	RegisterV8References (const std::vector< std::pair< void *, void *> > &embedder_fields)=0
virtual void	TracePrologue ()=0
virtual bool	AdvanceTracing (double deadline_in_ms, AdvanceTracingActions actions)=0
virtual bool	IsTracingDone ()
virtual void	TraceEpilogue ()=0
virtual void	EnterFinalPause ()=0
virtual void	AbortTracing ()=0
void	FinalizeTracing ()
v8::Isolate *	isolate () const
	V8_DEPRECATE_SOON ("Use IsTracingDone", virtual size_t NumberOfWrappersToTrace() { return 0;})

Protected Attributes
v8::Isolate *	isolate_ = nullptr

Friends
class	internal::LocalEmbedderHeapTracer

Detailed Description

Interface for tracing through the embedder heap. During a v8 garbage collection, v8 collects hidden fields of all potential wrappers, and at the end of its marking phase iterates the collection and asks the embedder to trace through its heap and use reporter to report each JavaScript object reachable from any of the given wrappers.

Before the first call to the TraceWrappersFrom function TracePrologue will be called. When the garbage collection cycle is finished, TraceEpilogue will be called.

Member Function Documentation

AbortTracing()

virtual void v8::EmbedderHeapTracer::AbortTracing ( )

pure virtual

Called when tracing is aborted.

The embedder is expected to throw away all intermediate data and reset to the initial state.

AdvanceTracing()

virtual bool v8::EmbedderHeapTracer::AdvanceTracing ( double  deadline_in_ms, AdvanceTracingActions  actions  )

pure virtual

Called to to make a tracing step in the embedder.

The embedder is expected to trace its heap starting from wrappers reported by RegisterV8References method, and report back all reachable wrappers. Furthermore, the embedder is expected to stop tracing by the given deadline.

Returns true if there is still work to do.

EnterFinalPause()

virtual void v8::EmbedderHeapTracer::EnterFinalPause ( )

pure virtual

Called upon entering the final marking pause. No more incremental marking steps will follow this call.

RegisterV8References()

virtual void v8::EmbedderHeapTracer::RegisterV8References ( const std::vector< std::pair< void *, void *> > &  embedder_fields )

pure virtual

Called by v8 to register internal fields of found wrappers.

The embedder is expected to store them somewhere and trace reachable wrappers from them when called through |AdvanceTracing|.

TraceEpilogue()

virtual void v8::EmbedderHeapTracer::TraceEpilogue ( )

pure virtual

Called at the end of a GC cycle.

Note that allocation is not allowed within |TraceEpilogue|.

TracePrologue()

virtual void v8::EmbedderHeapTracer::TracePrologue ( )

pure virtual

Called at the beginning of a GC cycle.

V8_DEPRECATE_SOON()

v8::EmbedderHeapTracer::V8_DEPRECATE_SOON	(	"Use IsTracingDone"	,
		virtual size_t NumberOfWrappersToTrace() { return 0;}
	)

Returns the number of wrappers that are still to be traced by the embedder.

---

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

• v8/include/v8.h