@ -52,6 +52,66 @@ class ConvertableToTraceFormat {
virtual void AppendAsTraceFormat ( std : : string * out ) const = 0 ;
} ;
/**
* V8 Tracing controller .
*
* Can be implemented by an embedder to record trace events from V8 .
*/
class TracingController {
public :
virtual ~ TracingController ( ) = default ;
/**
* Called by TRACE_EVENT * macros , don ' t call this directly .
* The name parameter is a category group for example :
* TRACE_EVENT0 ( " v8,parse " , " V8.Parse " )
* The pointer returned points to a value with zero or more of the bits
* defined in CategoryGroupEnabledFlags .
* */
virtual const uint8_t * GetCategoryGroupEnabled ( const char * name ) {
static uint8_t no = 0 ;
return & no ;
}
/**
* Adds a trace event to the platform tracing system . This function call is
* usually the result of a TRACE_ * macro from trace_event_common . h when
* tracing and the category of the particular trace are enabled . It is not
* advisable to call this function on its own ; it is really only meant to be
* used by the trace macros . The returned handle can be used by
* UpdateTraceEventDuration to update the duration of COMPLETE events .
*/
virtual uint64_t AddTraceEvent (
char phase , const uint8_t * category_enabled_flag , const char * name ,
const char * scope , uint64_t id , uint64_t bind_id , int32_t num_args ,
const char * * arg_names , const uint8_t * arg_types ,
const uint64_t * arg_values ,
std : : unique_ptr < ConvertableToTraceFormat > * arg_convertables ,
unsigned int flags ) {
return 0 ;
}
/**
* Sets the duration field of a COMPLETE trace event . It must be called with
* the handle returned from AddTraceEvent ( ) .
* */
virtual void UpdateTraceEventDuration ( const uint8_t * category_enabled_flag ,
const char * name , uint64_t handle ) { }
class TraceStateObserver {
public :
virtual ~ TraceStateObserver ( ) = default ;
virtual void OnTraceEnabled ( ) = 0 ;
virtual void OnTraceDisabled ( ) = 0 ;
} ;
/** Adds tracing state change observer. */
virtual void AddTraceStateObserver ( TraceStateObserver * ) { }
/** Removes tracing state change observer. */
virtual void RemoveTraceStateObserver ( TraceStateObserver * ) { }
} ;
/**
* V8 Platform abstraction layer .
*
@ -135,6 +195,20 @@ class Platform {
* the epoch .
* */
virtual double MonotonicallyIncreasingTime ( ) = 0 ;
typedef void ( * StackTracePrinter ) ( ) ;
/**
* Returns a function pointer that print a stack trace of the current stack
* on invocation . Disables printing of the stack trace if nullptr .
*/
virtual StackTracePrinter GetStackTracePrinter ( ) { return nullptr ; }
/**
* Returns an instance of a v8 : : TracingController . This must be non - nullptr .
*/
virtual TracingController * GetTracingController ( ) { return nullptr ; }
// DEPRECATED methods, use TracingController interface instead.
/**
* Called by TRACE_EVENT * macros , don ' t call this directly .
@ -200,26 +274,13 @@ class Platform {
virtual void UpdateTraceEventDuration ( const uint8_t * category_enabled_flag ,
const char * name , uint64_t handle ) { }
class TraceStateObserver {
public :
virtual ~ TraceStateObserver ( ) = default ;
virtual void OnTraceEnabled ( ) = 0 ;
virtual void OnTraceDisabled ( ) = 0 ;
} ;
typedef v8 : : TracingController : : TraceStateObserver TraceStateObserver ;
/** Adds tracing state change observer. */
virtual void AddTraceStateObserver ( TraceStateObserver * ) { }
/** Removes tracing state change observer. */
virtual void RemoveTraceStateObserver ( TraceStateObserver * ) { }
typedef void ( * StackTracePrinter ) ( ) ;
/**
* Returns a function pointer that print a stack trace of the current stack
* on invocation . Disables printing of the stack trace if nullptr .
*/
virtual StackTracePrinter GetStackTracePrinter ( ) { return nullptr ; }
} ;
} // namespace v8
Matt Loring
8 years ago
Anna Henningsen