V8 Class Reference

#include <v8.h>

Static Public Member Functions
static void	SetFatalErrorHandler (FatalErrorCallback that)
static void	SetAllowCodeGenerationFromStringsCallback (AllowCodeGenerationFromStringsCallback that)
static void	IgnoreOutOfMemoryException ()
static bool	IsDead ()
static StartupData::CompressionAlgorithm	GetCompressedStartupDataAlgorithm ()
static int	GetCompressedStartupDataCount ()
static void	GetCompressedStartupData (StartupData *compressed_data)
static void	SetDecompressedStartupData (StartupData *decompressed_data)
static bool	AddMessageListener (MessageCallback that)
static void	RemoveMessageListeners (MessageCallback that)
static void	SetCaptureStackTraceForUncaughtExceptions (bool capture, int frame_limit=10, StackTrace::StackTraceOptions options=StackTrace::kOverview)
static void	SetFlagsFromString (const char *str, int length)
static void	SetFlagsFromCommandLine (int *argc, char **argv, bool remove_flags)
static const char *	GetVersion ()
static void	SetCounterFunction (CounterLookupCallback)
static void	SetCreateHistogramFunction (CreateHistogramCallback)
static void	SetAddHistogramSampleFunction (AddHistogramSampleCallback)
static void	EnableSlidingStateWindow ()
static void	SetFailedAccessCheckCallbackFunction (FailedAccessCheckCallback)
static void	AddGCPrologueCallback (GCPrologueCallback callback, GCType gc_type_filter=kGCTypeAll)
static void	RemoveGCPrologueCallback (GCPrologueCallback callback)
static void	SetGlobalGCPrologueCallback (GCCallback)
static void	AddGCEpilogueCallback (GCEpilogueCallback callback, GCType gc_type_filter=kGCTypeAll)
static void	RemoveGCEpilogueCallback (GCEpilogueCallback callback)
static void	SetGlobalGCEpilogueCallback (GCCallback)
static void	AddMemoryAllocationCallback (MemoryAllocationCallback callback, ObjectSpace space, AllocationAction action)
static void	RemoveMemoryAllocationCallback (MemoryAllocationCallback callback)
static void	AddCallCompletedCallback (CallCompletedCallback callback)
static void	RemoveCallCompletedCallback (CallCompletedCallback callback)
static void	AddObjectGroup (Persistent< Value > *objects, size_t length, RetainedObjectInfo *info=NULL)
static void	AddImplicitReferences (Persistent< Object > parent, Persistent< Value > *children, size_t length)
static bool	Initialize ()
static void	SetEntropySource (EntropySource source)
static void	SetReturnAddressLocationResolver (ReturnAddressLocationResolver return_address_resolver)
static bool	SetFunctionEntryHook (FunctionEntryHook entry_hook)
static void	SetJitCodeEventHandler (JitCodeEventOptions options, JitCodeEventHandler event_handler)
static intptr_t	AdjustAmountOfExternalAllocatedMemory (intptr_t change_in_bytes)
static void	PauseProfiler ()
static void	ResumeProfiler ()
static bool	IsProfilerPaused ()
static int	GetCurrentThreadId ()
static void	TerminateExecution (int thread_id)
static void	TerminateExecution (Isolate *isolate=NULL)
static bool	IsExecutionTerminating (Isolate *isolate=NULL)
static bool	Dispose ()
static void	GetHeapStatistics (HeapStatistics *heap_statistics)
static void	VisitExternalResources (ExternalResourceVisitor *visitor)
static void	VisitHandlesWithClassIds (PersistentHandleVisitor *visitor)
static bool	IdleNotification (int hint=1000)
static void	LowMemoryNotification ()
static int	ContextDisposedNotification ()

Friends
template<class T >
class	Handle
template<class T >
class	Local
template<class T >
class	Persistent
class	Context

Detailed Description

Container class for static utility functions.

Definition at line 3044 of file v8.h.

Member Function Documentation

AddCallCompletedCallback()

static void AddCallCompletedCallback ( CallCompletedCallback  callback )

static

Adds a callback to notify the host application when a script finished running. If a script re-enters the runtime during executing, the CallCompletedCallback is only invoked when the outer-most script execution ends. Executing scripts inside the callback do not trigger further callbacks.

AddGCEpilogueCallback()

static void AddGCEpilogueCallback ( GCEpilogueCallback  callback, GCType  gc_type_filter = kGCTypeAll  )

static

Enables the host application to receive a notification after a garbage collection. Allocations are not allowed in the callback function, you therefore cannot manipulate objects (set or delete properties for example) since it is possible such operations will result in the allocation of objects. It is possible to specify the GCType filter for your callback. But it is not possible to register the same callback function two times with different GCType filters.

AddGCPrologueCallback()

static void AddGCPrologueCallback ( GCPrologueCallback  callback, GCType  gc_type_filter = kGCTypeAll  )

static

Enables the host application to receive a notification before a garbage collection. Allocations are not allowed in the callback function, you therefore cannot manipulate objects (set or delete properties for example) since it is possible such operations will result in the allocation of objects. It is possible to specify the GCType filter for your callback. But it is not possible to register the same callback function two times with different GCType filters.

AddImplicitReferences()

static void AddImplicitReferences ( Persistent< Object >  parent, Persistent< Value > *  children, size_t  length  )

static

Allows the host application to declare implicit references between the objects: if |parent| is alive, all |children| are alive too. After each garbage collection, all implicit references are removed. It is intended to be used in the before-garbage-collection callback function.

AddMemoryAllocationCallback()

static void AddMemoryAllocationCallback ( MemoryAllocationCallback  callback, ObjectSpace  space, AllocationAction  action  )

static

Enables the host application to provide a mechanism to be notified and perform custom logging when V8 Allocates Executable Memory.

AddMessageListener()

static bool AddMessageListener ( MessageCallback  that )

static

Adds a message listener.

The same message listener can be added more than once and in that case it will be called more than once for each message.

AddObjectGroup()

static void AddObjectGroup ( Persistent< Value > *  objects, size_t  length, RetainedObjectInfo *  info = NULL  )

static

Allows the host application to group objects together. If one object in the group is alive, all objects in the group are alive. After each garbage collection, object groups are removed. It is intended to be used in the before-garbage-collection callback function, for instance to simulate DOM tree connections among JS wrapper objects. See v8-profiler.h for RetainedObjectInfo interface description.

AdjustAmountOfExternalAllocatedMemory()

static intptr_t AdjustAmountOfExternalAllocatedMemory ( intptr_t  change_in_bytes )

static

Adjusts the amount of registered external memory. Used to give V8 an indication of the amount of externally allocated memory that is kept alive by JavaScript objects. V8 uses this to decide when to perform global garbage collections. Registering externally allocated memory will trigger global garbage collections more often than otherwise in an attempt to garbage collect the JavaScript objects keeping the externally allocated memory alive.

Parameters

change_in_bytes

the change in externally allocated memory that is kept alive by JavaScript objects.

Returns

the adjusted value.

ContextDisposedNotification()

static int ContextDisposedNotification ( )

static

Optional notification that a context has been disposed. V8 uses these notifications to guide the GC heuristic. Returns the number of context disposals - including this one - since the last time V8 had a chance to clean up.

Dispose()

static bool Dispose ( )

static

Releases any resources used by v8 and stops any utility threads that may be running. Note that disposing v8 is permanent, it cannot be reinitialized.

It should generally not be necessary to dispose v8 before exiting a process, this should happen automatically. It is only necessary to use if the process needs the resources taken up by v8.

EnableSlidingStateWindow()

static void EnableSlidingStateWindow ( )

static

Enables the computation of a sliding window of states. The sliding window information is recorded in statistics counters.

GetCompressedStartupData()

static void GetCompressedStartupData ( StartupData *  compressed_data )

static

GetCompressedStartupDataAlgorithm()

static StartupData::CompressionAlgorithm GetCompressedStartupDataAlgorithm ( )

static

The following 4 functions are to be used when V8 is built with the 'compress_startup_data' flag enabled. In this case, the embedder must decompress startup data prior to initializing V8.

This is how interaction with V8 should look like: int compressed_data_count = v8::V8::GetCompressedStartupDataCount(); v8::StartupData* compressed_data = new v8::StartupData[compressed_data_count]; v8::V8::GetCompressedStartupData(compressed_data); ... decompress data (compressed_data can be updated in-place) ... v8::V8::SetDecompressedStartupData(compressed_data); ... now V8 can be initialized ... make sure the decompressed data stays valid until V8 shutdown

A helper class StartupDataDecompressor is provided. It implements the protocol of the interaction described above, and can be used in most cases instead of calling these API functions directly.

GetCompressedStartupDataCount()

static int GetCompressedStartupDataCount ( )

static

GetCurrentThreadId()

static int GetCurrentThreadId ( )

static

Retrieve the V8 thread id of the calling thread.

The thread id for a thread should only be retrieved after the V8 lock has been acquired with a Locker object with that thread.

GetHeapStatistics()

static void GetHeapStatistics ( HeapStatistics *  heap_statistics )

static

Get statistics about the heap memory usage.

GetVersion()

static const char* GetVersion ( )

static

Get the version string.

IdleNotification()

static bool IdleNotification ( int  hint = 1000 )

static

Optional notification that the embedder is idle. V8 uses the notification to reduce memory footprint. This call can be used repeatedly if the embedder remains idle. Returns true if the embedder should stop calling IdleNotification until real work has been done. This indicates that V8 has done as much cleanup as it will be able to do.

The hint argument specifies the amount of work to be done in the function on scale from 1 to 1000. There is no guarantee that the actual work will match the hint.

IgnoreOutOfMemoryException()

static void IgnoreOutOfMemoryException ( )

static

Ignore out-of-memory exceptions.

V8 running out of memory is treated as a fatal error by default. This means that the fatal error handler is called and that V8 is terminated.

IgnoreOutOfMemoryException can be used to not treat an out-of-memory situation as a fatal error. This way, the contexts that did not cause the out of memory problem might be able to continue execution.

Initialize()

static bool Initialize ( )

static

Initializes from snapshot if possible. Otherwise, attempts to initialize from scratch. This function is called implicitly if you use the API without calling it first.

IsDead()

static bool IsDead ( )

static

Check if V8 is dead and therefore unusable. This is the case after fatal errors such as out-of-memory situations.

IsExecutionTerminating()

static bool IsExecutionTerminating ( Isolate *  isolate = NULL )

static

Is V8 terminating JavaScript execution.

Returns true if JavaScript execution is currently terminating because of a call to TerminateExecution. In that case there are still JavaScript frames on the stack and the termination exception is still active.

Parameters

isolate

The isolate in which to check.

IsProfilerPaused()

static bool IsProfilerPaused ( )

static

Return whether profiler is currently paused.

LowMemoryNotification()

static void LowMemoryNotification ( )

static

Optional notification that the system is running low on memory. V8 uses these notifications to attempt to free memory.

PauseProfiler()

static void PauseProfiler ( )

static

Suspends recording of tick samples in the profiler. When the V8 profiling mode is enabled (usually via command line switches) this function suspends recording of tick samples. Profiling ticks are discarded until ResumeProfiler() is called.

See also the –prof and –prof_auto command line switches to enable V8 profiling.

RemoveCallCompletedCallback()

static void RemoveCallCompletedCallback ( CallCompletedCallback  callback )

static

Removes callback that was installed by AddCallCompletedCallback.

RemoveGCEpilogueCallback()

static void RemoveGCEpilogueCallback ( GCEpilogueCallback  callback )

static

This function removes callback which was installed by AddGCEpilogueCallback function.

RemoveGCPrologueCallback()

static void RemoveGCPrologueCallback ( GCPrologueCallback  callback )

static

This function removes callback which was installed by AddGCPrologueCallback function.

RemoveMemoryAllocationCallback()

static void RemoveMemoryAllocationCallback ( MemoryAllocationCallback  callback )

static

Removes callback that was installed by AddMemoryAllocationCallback.

RemoveMessageListeners()

static void RemoveMessageListeners ( MessageCallback  that )

static

Remove all message listeners from the specified callback function.

ResumeProfiler()

static void ResumeProfiler ( )

static

Resumes recording of tick samples in the profiler. See also PauseProfiler().

SetAddHistogramSampleFunction()

static void SetAddHistogramSampleFunction ( AddHistogramSampleCallback  )

static

SetAllowCodeGenerationFromStringsCallback()

static void SetAllowCodeGenerationFromStringsCallback ( AllowCodeGenerationFromStringsCallback  that )

static

Set the callback to invoke to check if code generation from strings should be allowed.

SetCaptureStackTraceForUncaughtExceptions()

static void SetCaptureStackTraceForUncaughtExceptions ( bool  capture, int  frame_limit = 10, StackTrace::StackTraceOptions  options = StackTrace::kOverview  )

static

Tells V8 to capture current stack trace when uncaught exception occurs and report it to the message listeners. The option is off by default.

SetCounterFunction()

static void SetCounterFunction ( CounterLookupCallback  )

static

Enables the host application to provide a mechanism for recording statistics counters.

SetCreateHistogramFunction()

static void SetCreateHistogramFunction ( CreateHistogramCallback  )

static

Enables the host application to provide a mechanism for recording histograms. The CreateHistogram function returns a histogram which will later be passed to the AddHistogramSample function.

SetDecompressedStartupData()

static void SetDecompressedStartupData ( StartupData *  decompressed_data )

static

SetEntropySource()

static void SetEntropySource ( EntropySource  source )

static

Allows the host application to provide a callback which can be used as a source of entropy for random number generators.

SetFailedAccessCheckCallbackFunction()

static void SetFailedAccessCheckCallbackFunction ( FailedAccessCheckCallback  )

static

Callback function for reporting failed access checks.

SetFatalErrorHandler()

static void SetFatalErrorHandler ( FatalErrorCallback  that )

static

Set the callback to invoke in case of fatal errors.

SetFlagsFromCommandLine()

static void SetFlagsFromCommandLine ( int *  argc, char **  argv, bool  remove_flags  )

static

Sets V8 flags from the command line.

SetFlagsFromString()

static void SetFlagsFromString ( const char *  str, int  length  )

static

Sets V8 flags from a string.

SetFunctionEntryHook()

static bool SetFunctionEntryHook ( FunctionEntryHook  entry_hook )

static

Allows the host application to provide the address of a function that's invoked on entry to every V8-generated function. Note that entry_hook is invoked at the very start of each generated function.

Parameters

entry_hook

a function that will be invoked on entry to every V8-generated function.

Returns

true on success on supported platforms, false on failure.

Note

Setting a new entry hook function when one is already active will fail.

SetGlobalGCEpilogueCallback()

static void SetGlobalGCEpilogueCallback ( GCCallback  )

static

The function is deprecated. Please use AddGCEpilogueCallback instead. Enables the host application to receive a notification after a major garbage collection. Allocations are not allowed in the callback function, you therefore cannot manipulate objects (set or delete properties for example) since it is possible such operations will result in the allocation of objects.

SetGlobalGCPrologueCallback()

static void SetGlobalGCPrologueCallback ( GCCallback  )

static

The function is deprecated. Please use AddGCPrologueCallback instead. Enables the host application to receive a notification before a garbage collection. Allocations are not allowed in the callback function, you therefore cannot manipulate objects (set or delete properties for example) since it is possible such operations will result in the allocation of objects.

SetJitCodeEventHandler()

static void SetJitCodeEventHandler ( JitCodeEventOptions  options, JitCodeEventHandler  event_handler  )

static

Allows the host application to provide the address of a function that is notified each time code is added, moved or removed.

Parameters

options	options for the JIT code event handler.
event_handler	the JIT code event handler, which will be invoked each time code is added, moved or removed.

Note

event_handler won't get notified of existent code.

since code removal notifications are not currently issued, the event_handler may get notifications of code that overlaps earlier code notifications. This happens when code areas are reused, and the earlier overlapping code areas should therefore be discarded.

the events passed to event_handler and the strings they point to are not guaranteed to live past each call. The event_handler must copy strings and other parameters it needs to keep around.

the set of events declared in JitCodeEvent::EventType is expected to grow over time, and the JitCodeEvent structure is expected to accrue new members. The event_handler function must ignore event codes it does not recognize to maintain future compatibility.

SetReturnAddressLocationResolver()

static void SetReturnAddressLocationResolver ( ReturnAddressLocationResolver  return_address_resolver )

static

Allows the host application to provide a callback that allows v8 to cooperate with a profiler that rewrites return addresses on stack.

TerminateExecution() [1/2]

static void TerminateExecution ( int  thread_id )

static

Forcefully terminate execution of a JavaScript thread. This can be used to terminate long-running scripts.

TerminateExecution should only be called when then V8 lock has been acquired with a Locker object. Therefore, in order to be able to terminate long-running threads, preemption must be enabled to allow the user of TerminateExecution to acquire the lock.

The termination is achieved by throwing an exception that is uncatchable by JavaScript exception handlers. Termination exceptions act as if they were caught by a C++ TryCatch exception handler. If forceful termination is used, any C++ TryCatch exception handler that catches an exception should check if that exception is a termination exception and immediately return if that is the case. Returning immediately in that case will continue the propagation of the termination exception if needed.

The thread id passed to TerminateExecution must have been obtained by calling GetCurrentThreadId on the thread in question.

Parameters

thread_id

The thread id of the thread to terminate.

TerminateExecution() [2/2]

static void TerminateExecution ( Isolate *  isolate = NULL )

static

Forcefully terminate the current thread of JavaScript execution in the given isolate. If no isolate is provided, the default isolate is used.

This method can be used by any thread even if that thread has not acquired the V8 lock with a Locker object.

Parameters

isolate

The isolate in which to terminate the current JS execution.

VisitExternalResources()

static void VisitExternalResources ( ExternalResourceVisitor *  visitor )

static

Iterates through all external resources referenced from current isolate heap. This method is not expected to be used except for debugging purposes and may be quite slow.

VisitHandlesWithClassIds()

static void VisitHandlesWithClassIds ( PersistentHandleVisitor *  visitor )

static

Iterates through all the persistent handles in the current isolate's heap that have class_ids.

Friends And Related Function Documentation

Context

friend class Context

friend

Definition at line 3501 of file v8.h.

Handle

friend class Handle

friend

Definition at line 3498 of file v8.h.

Referenced by Handle< T >::As(), Handle< T >::Cast(), v8::False(), Extension::GetNativeFunction(), Local< T >::Local(), v8::Null(), Persistent< T >::Persistent(), v8::True(), and v8::Undefined().

Local

friend class Local

friend

Definition at line 3499 of file v8.h.

Referenced by Local< T >::As(), Arguments::Callee(), Local< T >::Cast(), HandleScope::Close(), Arguments::Data(), AccessorInfo::Data(), String::Empty(), Object::GetInternalField(), Arguments::Holder(), AccessorInfo::Holder(), Local< T >::New(), Arguments::operator[](), Arguments::This(), and AccessorInfo::This().

Persistent

friend class Persistent

friend

Definition at line 3500 of file v8.h.

Referenced by Persistent< T >::As(), Persistent< T >::Cast(), and Persistent< T >::New().

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

• include/v8.h