blob: 42a814ad729ecd7cda4bf34974ba01e0eafa5ed0 [file] [log] [blame]
// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_ISOLATE_H_
#define V8_ISOLATE_H_
#include <queue>
#include "include/v8-debug.h"
#include "src/allocation.h"
#include "src/assert-scope.h"
#include "src/base/atomicops.h"
#include "src/builtins.h"
#include "src/contexts.h"
#include "src/date.h"
#include "src/execution.h"
#include "src/frames.h"
#include "src/global-handles.h"
#include "src/handles.h"
#include "src/hashmap.h"
#include "src/heap/heap.h"
#include "src/optimizing-compiler-thread.h"
#include "src/regexp-stack.h"
#include "src/runtime/runtime.h"
#include "src/runtime-profiler.h"
#include "src/zone.h"
namespace v8 {
namespace base {
class RandomNumberGenerator;
namespace internal {
class BasicBlockProfiler;
class Bootstrapper;
class CallInterfaceDescriptorData;
class CodeGenerator;
class CodeRange;
class CodeStubDescriptor;
class CodeTracer;
class CompilationCache;
class CompilationStatistics;
class ContextSlotCache;
class Counters;
class CpuFeatures;
class CpuProfiler;
class DeoptimizerData;
class Deserializer;
class EmptyStatement;
class ExternalCallbackScope;
class ExternalReferenceTable;
class Factory;
class FunctionInfoListener;
class HandleScopeImplementer;
class HeapProfiler;
class HStatistics;
class HTracer;
class InlineRuntimeFunctionsTable;
class InnerPointerToCodeCache;
class MaterializedObjectStore;
class CodeAgingHelper;
class RegExpStack;
class SaveContext;
class StringTracker;
class StubCache;
class SweeperThread;
class ThreadManager;
class ThreadState;
class ThreadVisitor; // Defined in v8threads.h
class UnicodeCache;
template <StateTag Tag> class VMState;
// 'void function pointer', used to roundtrip the
// ExternalReference::ExternalReferenceRedirector since we can not include
// assembler.h, where it is defined, here.
typedef void* ExternalReferenceRedirectorPointer();
class Debug;
class Debugger;
class PromiseOnStack;
#if !defined(__arm__) && V8_TARGET_ARCH_ARM || \
!defined(__aarch64__) && V8_TARGET_ARCH_ARM64 || \
!defined(__mips__) && V8_TARGET_ARCH_MIPS || \
!defined(__mips__) && V8_TARGET_ARCH_MIPS64
class Redirection;
class Simulator;
// Static indirection table for handles to constants. If a frame
// element represents a constant, the data contains an index into
// this table of handles to the actual constants.
// Static indirection table for handles to constants. If a Result
// represents a constant, the data contains an index into this table
// of handles to the actual constants.
typedef ZoneList<Handle<Object> > ZoneObjectList;
do { \
Isolate* __isolate__ = (isolate); \
if (__isolate__->has_scheduled_exception()) { \
return __isolate__->PromoteScheduledException(); \
} \
} while (false)
// Macros for MaybeHandle.
do { \
Isolate* __isolate__ = (isolate); \
if (__isolate__->has_scheduled_exception()) { \
__isolate__->PromoteScheduledException(); \
return value; \
} \
} while (false)
#define ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, dst, call, value) \
do { \
if (!(call).ToHandle(&dst)) { \
DCHECK((isolate)->has_pending_exception()); \
return value; \
} \
} while (false)
#define ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, dst, call) \
isolate, dst, call, isolate->heap()->exception())
#define ASSIGN_RETURN_ON_EXCEPTION(isolate, dst, call, T) \
ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, dst, call, MaybeHandle<T>())
#define THROW_NEW_ERROR(isolate, call, T) \
do { \
Handle<Object> __error__; \
ASSIGN_RETURN_ON_EXCEPTION(isolate, __error__, isolate->factory()->call, \
T); \
return isolate->Throw<T>(__error__); \
} while (false)
#define THROW_NEW_ERROR_RETURN_FAILURE(isolate, call) \
do { \
Handle<Object> __error__; \
isolate->factory()->call); \
return isolate->Throw(*__error__); \
} while (false)
#define RETURN_ON_EXCEPTION_VALUE(isolate, call, value) \
do { \
if ((call).is_null()) { \
DCHECK((isolate)->has_pending_exception()); \
return value; \
} \
} while (false)
#define RETURN_FAILURE_ON_EXCEPTION(isolate, call) \
RETURN_ON_EXCEPTION_VALUE(isolate, call, isolate->heap()->exception())
#define RETURN_ON_EXCEPTION(isolate, call, T) \
RETURN_ON_EXCEPTION_VALUE(isolate, call, MaybeHandle<T>())
C(Handler, handler) \
C(CEntryFP, c_entry_fp) \
C(CFunction, c_function) \
C(Context, context) \
C(PendingException, pending_exception) \
C(ExternalCaughtException, external_caught_exception) \
C(JSEntrySP, js_entry_sp)
// Platform-independent, reliable thread identifier.
class ThreadId {
// Creates an invalid ThreadId.
ThreadId() { base::NoBarrier_Store(&id_, kInvalidId); }
ThreadId& operator=(const ThreadId& other) {
base::NoBarrier_Store(&id_, base::NoBarrier_Load(&other.id_));
return *this;
// Returns ThreadId for current thread.
static ThreadId Current() { return ThreadId(GetCurrentThreadId()); }
// Returns invalid ThreadId (guaranteed not to be equal to any thread).
static ThreadId Invalid() { return ThreadId(kInvalidId); }
// Compares ThreadIds for equality.
INLINE(bool Equals(const ThreadId& other) const) {
return base::NoBarrier_Load(&id_) == base::NoBarrier_Load(&other.id_);
// Checks whether this ThreadId refers to any thread.
INLINE(bool IsValid() const) {
return base::NoBarrier_Load(&id_) != kInvalidId;
// Converts ThreadId to an integer representation
// (required for public API: V8::V8::GetCurrentThreadId).
int ToInteger() const { return static_cast<int>(base::NoBarrier_Load(&id_)); }
// Converts ThreadId to an integer representation
// (required for public API: V8::V8::TerminateExecution).
static ThreadId FromInteger(int id) { return ThreadId(id); }
static const int kInvalidId = -1;
explicit ThreadId(int id) { base::NoBarrier_Store(&id_, id); }
static int AllocateThreadId();
static int GetCurrentThreadId();
base::Atomic32 id_;
static base::Atomic32 highest_thread_id_;
friend class Isolate;
#define FIELD_ACCESSOR(type, name) \
inline void set_##name(type v) { name##_ = v; } \
inline type name() const { return name##_; }
class ThreadLocalTop BASE_EMBEDDED {
// Does early low-level initialization that does not depend on the
// isolate being present.
// Initialize the thread data.
void Initialize();
// Get the top C++ try catch handler or NULL if none are registered.
// This method is not guaranteed to return an address that can be
// used for comparison with addresses into the JS stack. If such an
// address is needed, use try_catch_handler_address.
FIELD_ACCESSOR(v8::TryCatch*, try_catch_handler)
// Get the address of the top C++ try catch handler or NULL if
// none are registered.
// This method always returns an address that can be compared to
// pointers into the JavaScript stack. When running on actual
// hardware, try_catch_handler_address and TryCatchHandler return
// the same pointer. When running on a simulator with a separate JS
// stack, try_catch_handler_address returns a JS stack address that
// corresponds to the place on the JS stack where the C++ handler
// would have been if the stack were not separate.
Address try_catch_handler_address() {
return reinterpret_cast<Address>(
void Free();
Isolate* isolate_;
// The context where the current execution method is created and for variable
// lookups.
Context* context_;
ThreadId thread_id_;
Object* pending_exception_;
bool has_pending_message_;
bool rethrowing_message_;
Object* pending_message_obj_;
Object* pending_message_script_;
int pending_message_start_pos_;
int pending_message_end_pos_;
// Use a separate value for scheduled exceptions to preserve the
// invariants that hold about pending_exception. We may want to
// unify them later.
Object* scheduled_exception_;
bool external_caught_exception_;
SaveContext* save_context_;
v8::TryCatch* catcher_;
// Stack.
Address c_entry_fp_; // the frame pointer of the top c entry frame
Address handler_; // try-blocks are chained through the stack
Address c_function_; // C function that was called at c entry.
// Throwing an exception may cause a Promise rejection. For this purpose
// we keep track of a stack of nested promises and the corresponding
// try-catch handlers.
PromiseOnStack* promise_on_stack_;
Simulator* simulator_;
Address js_entry_sp_; // the stack pointer of the bottom JS entry frame
// the external callback we're currently in
ExternalCallbackScope* external_callback_scope_;
StateTag current_vm_state_;
// Generated code scratch locations.
int32_t formal_count_;
// Call back function to report unsafe JS accesses.
v8::FailedAccessCheckCallback failed_access_check_callback_;
// Head of the list of live LookupResults.
LookupResult* top_lookup_result_;
void InitializeInternal();
v8::TryCatch* try_catch_handler_;
#if V8_TARGET_ARCH_ARM && !defined(__arm__) || \
V8_TARGET_ARCH_ARM64 && !defined(__aarch64__) || \
V8_TARGET_ARCH_MIPS && !defined(__mips__) || \
V8_TARGET_ARCH_MIPS64 && !defined(__mips__)
V(bool, simulator_initialized, false) \
V(HashMap*, simulator_i_cache, NULL) \
V(Redirection*, simulator_redirection, NULL)
#ifdef DEBUG
V(CommentStatistic, paged_space_comments_statistics, \
CommentStatistic::kMaxComments + 1) \
V(int, code_kind_statistics, Code::NUMBER_OF_KINDS)
/* SerializerDeserializer state. */ \
V(int32_t, jsregexp_static_offsets_vector, kJSRegexpStaticOffsetsVectorSize) \
V(int, bad_char_shift_table, kUC16AlphabetSize) \
V(int, good_suffix_shift_table, (kBMMaxShift + 1)) \
V(int, suffix_table, (kBMMaxShift + 1)) \
V(uint32_t, private_random_seed, 2) \
typedef List<HeapObject*> DebugObjectCache;
/* SerializerDeserializer state. */ \
V(int, serialize_partial_snapshot_cache_length, 0) \
V(int, serialize_partial_snapshot_cache_capacity, 0) \
V(Object**, serialize_partial_snapshot_cache, NULL) \
/* Assembler state. */ \
V(FatalErrorCallback, exception_behavior, NULL) \
V(LogEventCallback, event_logger, NULL) \
V(AllowCodeGenerationFromStringsCallback, allow_code_gen_callback, NULL) \
/* To distinguish the function templates, so that we can find them in the */ \
/* function cache of the native context. */ \
V(int, next_serial_number, 0) \
V(ExternalReferenceRedirectorPointer*, external_reference_redirector, NULL) \
/* Part of the state of liveedit. */ \
V(FunctionInfoListener*, active_function_info_listener, NULL) \
/* State for Relocatable. */ \
V(Relocatable*, relocatable_top, NULL) \
V(DebugObjectCache*, string_stream_debug_object_cache, NULL) \
V(Object*, string_stream_current_security_token, NULL) \
/* Serializer state. */ \
V(ExternalReferenceTable*, external_reference_table, NULL) \
V(int, pending_microtask_count, 0) \
V(bool, autorun_microtasks, true) \
V(HStatistics*, hstatistics, NULL) \
V(CompilationStatistics*, turbo_statistics, NULL) \
V(HTracer*, htracer, NULL) \
V(CodeTracer*, code_tracer, NULL) \
V(bool, fp_stubs_generated, false) \
V(int, max_available_threads, 0) \
V(uint32_t, per_isolate_assert_data, 0xFFFFFFFFu) \
V(PromiseRejectCallback, promise_reject_callback, NULL) \
#define THREAD_LOCAL_TOP_ACCESSOR(type, name) \
inline void set_##name(type v) { = v; } \
inline type name() const { return; }
class Isolate {
// These forward declarations are required to make the friend declarations in
// PerIsolateThreadData work on some older versions of gcc.
class ThreadDataTable;
class EntryStackItem;
// A thread has a PerIsolateThreadData instance for each isolate that it has
// entered. That instance is allocated when the isolate is initially entered
// and reused on subsequent entries.
class PerIsolateThreadData {
PerIsolateThreadData(Isolate* isolate, ThreadId thread_id)
: isolate_(isolate),
#if !defined(__arm__) && V8_TARGET_ARCH_ARM || \
!defined(__aarch64__) && V8_TARGET_ARCH_ARM64 || \
!defined(__mips__) && V8_TARGET_ARCH_MIPS || \
!defined(__mips__) && V8_TARGET_ARCH_MIPS64
prev_(NULL) { }
Isolate* isolate() const { return isolate_; }
ThreadId thread_id() const { return thread_id_; }
FIELD_ACCESSOR(uintptr_t, stack_limit)
FIELD_ACCESSOR(ThreadState*, thread_state)
#if !defined(__arm__) && V8_TARGET_ARCH_ARM || \
!defined(__aarch64__) && V8_TARGET_ARCH_ARM64 || \
!defined(__mips__) && V8_TARGET_ARCH_MIPS || \
!defined(__mips__) && V8_TARGET_ARCH_MIPS64
FIELD_ACCESSOR(Simulator*, simulator)
bool Matches(Isolate* isolate, ThreadId thread_id) const {
return isolate_ == isolate && thread_id_.Equals(thread_id);
Isolate* isolate_;
ThreadId thread_id_;
uintptr_t stack_limit_;
ThreadState* thread_state_;
#if !defined(__arm__) && V8_TARGET_ARCH_ARM || \
!defined(__aarch64__) && V8_TARGET_ARCH_ARM64 || \
!defined(__mips__) && V8_TARGET_ARCH_MIPS || \
!defined(__mips__) && V8_TARGET_ARCH_MIPS64
Simulator* simulator_;
PerIsolateThreadData* next_;
PerIsolateThreadData* prev_;
friend class Isolate;
friend class ThreadDataTable;
friend class EntryStackItem;
enum AddressId {
#define DECLARE_ENUM(CamelName, hacker_name) k##CamelName##Address,
static void InitializeOncePerProcess();
// Returns the PerIsolateThreadData for the current thread (or NULL if one is
// not currently set).
static PerIsolateThreadData* CurrentPerIsolateThreadData() {
return reinterpret_cast<PerIsolateThreadData*>(
// Returns the isolate inside which the current thread is running.
INLINE(static Isolate* Current()) {
DCHECK(base::NoBarrier_Load(&isolate_key_created_) == 1);
Isolate* isolate = reinterpret_cast<Isolate*>(
DCHECK(isolate != NULL);
return isolate;
INLINE(static Isolate* UncheckedCurrent()) {
DCHECK(base::NoBarrier_Load(&isolate_key_created_) == 1);
return reinterpret_cast<Isolate*>(
// Like UncheckedCurrent, but skips the check that |isolate_key_| was
// initialized. Callers have to ensure that themselves.
INLINE(static Isolate* UnsafeCurrent()) {
return reinterpret_cast<Isolate*>(
// Usually called by Init(), but can be called early e.g. to allow
// testing components that require logging but not the whole
// isolate.
// Safe to call more than once.
void InitializeLoggingAndCounters();
bool Init(Deserializer* des);
// True if at least one thread Enter'ed this isolate.
bool IsInUse() { return entry_stack_ != NULL; }
// Destroys the non-default isolates.
// Sets default isolate into "has_been_disposed" state rather then destroying,
// for legacy API reasons.
void TearDown();
static void GlobalTearDown();
// Find the PerThread for this particular (isolate, thread) combination
// If one does not yet exist, return null.
PerIsolateThreadData* FindPerThreadDataForThisThread();
// Find the PerThread for given (isolate, thread) combination
// If one does not yet exist, return null.
PerIsolateThreadData* FindPerThreadDataForThread(ThreadId thread_id);
// Returns the key used to store the pointer to the current isolate.
// Used internally for V8 threads that do not execute JavaScript but still
// are part of the domain of an isolate (like the context switcher).
static base::Thread::LocalStorageKey isolate_key() {
return isolate_key_;
// Returns the key used to store process-wide thread IDs.
static base::Thread::LocalStorageKey thread_id_key() {
return thread_id_key_;
static base::Thread::LocalStorageKey per_isolate_thread_data_key();
// Mutex for serializing access to break control structures.
base::RecursiveMutex* break_access() { return &break_access_; }
Address get_address_from_id(AddressId id);
// Access to top context (where the current function object was created).
Context* context() { return thread_local_top_.context_; }
void set_context(Context* context) {
DCHECK(context == NULL || context->IsContext());
thread_local_top_.context_ = context;
Context** context_address() { return &thread_local_top_.context_; }
THREAD_LOCAL_TOP_ACCESSOR(SaveContext*, save_context)
// Access to current thread id.
// Interface to pending exception.
Object* pending_exception() {
return thread_local_top_.pending_exception_;
void set_pending_exception(Object* exception_obj) {
thread_local_top_.pending_exception_ = exception_obj;
void clear_pending_exception() {
thread_local_top_.pending_exception_ = heap_.the_hole_value();
Object** pending_exception_address() {
return &thread_local_top_.pending_exception_;
bool has_pending_exception() {
return !thread_local_top_.pending_exception_->IsTheHole();
THREAD_LOCAL_TOP_ACCESSOR(bool, external_caught_exception)
void clear_pending_message() {
thread_local_top_.has_pending_message_ = false;
thread_local_top_.pending_message_obj_ = heap_.the_hole_value();
thread_local_top_.pending_message_script_ = heap_.the_hole_value();
v8::TryCatch* try_catch_handler() {
return thread_local_top_.try_catch_handler();
Address try_catch_handler_address() {
return thread_local_top_.try_catch_handler_address();
bool* external_caught_exception_address() {
return &thread_local_top_.external_caught_exception_;
THREAD_LOCAL_TOP_ACCESSOR(v8::TryCatch*, catcher)
Object** scheduled_exception_address() {
return &thread_local_top_.scheduled_exception_;
Address pending_message_obj_address() {
return reinterpret_cast<Address>(&thread_local_top_.pending_message_obj_);
Address has_pending_message_address() {
return reinterpret_cast<Address>(&thread_local_top_.has_pending_message_);
Address pending_message_script_address() {
return reinterpret_cast<Address>(
Object* scheduled_exception() {
return thread_local_top_.scheduled_exception_;
bool has_scheduled_exception() {
return thread_local_top_.scheduled_exception_ != heap_.the_hole_value();
void clear_scheduled_exception() {
thread_local_top_.scheduled_exception_ = heap_.the_hole_value();
bool HasExternalTryCatch();
bool IsFinallyOnTop();
bool is_catchable_by_javascript(Object* exception) {
return exception != heap()->termination_exception();
// Serializer.
void PushToPartialSnapshotCache(Object* obj);
// JS execution stack (see frames.h).
static Address c_entry_fp(ThreadLocalTop* thread) {
return thread->c_entry_fp_;
static Address handler(ThreadLocalTop* thread) { return thread->handler_; }
Address c_function() { return thread_local_top_.c_function_; }
inline Address* c_entry_fp_address() {
return &thread_local_top_.c_entry_fp_;
inline Address* handler_address() { return &thread_local_top_.handler_; }
inline Address* c_function_address() {
return &thread_local_top_.c_function_;
// Bottom JS entry.
Address js_entry_sp() {
return thread_local_top_.js_entry_sp_;
inline Address* js_entry_sp_address() {
return &thread_local_top_.js_entry_sp_;
// Generated code scratch locations.
void* formal_count_address() { return &thread_local_top_.formal_count_; }
// Returns the global object of the current context. It could be
// a builtin object, or a JS global object.
Handle<GlobalObject> global_object() {
return Handle<GlobalObject>(context()->global_object());
// Returns the global proxy object of the current context.
JSObject* global_proxy() {
return context()->global_proxy();
Handle<JSBuiltinsObject> js_builtins_object() {
return Handle<JSBuiltinsObject>(thread_local_top_.context_->builtins());
static int ArchiveSpacePerThread() { return sizeof(ThreadLocalTop); }
void FreeThreadResources() { thread_local_top_.Free(); }
// This method is called by the api after operations that may throw
// exceptions. If an exception was thrown and not handled by an external
// handler the exception is scheduled to be rethrown when we return to running
// JavaScript code. If an exception is scheduled true is returned.
bool OptionalRescheduleException(bool is_bottom_call);
// Push and pop a promise and the current try-catch handler.
void PushPromise(Handle<JSObject> promise);
void PopPromise();
Handle<Object> GetPromiseOnStackOnThrow();
class ExceptionScope {
explicit ExceptionScope(Isolate* isolate) :
// Scope currently can only be used for regular exceptions,
// not termination exception.
pending_exception_(isolate_->pending_exception(), isolate_),
{ }
~ExceptionScope() {
Isolate* isolate_;
Handle<Object> pending_exception_;
v8::TryCatch* catcher_;
void SetCaptureStackTraceForUncaughtExceptions(
bool capture,
int frame_limit,
StackTrace::StackTraceOptions options);
void PrintCurrentStackTrace(FILE* out);
void PrintStack(StringStream* accumulator);
void PrintStack(FILE* out);
Handle<String> StackTraceString();
NO_INLINE(void PushStackTraceAndDie(unsigned int magic,
Object* object,
Map* map,
unsigned int magic2));
Handle<JSArray> CaptureCurrentStackTrace(
int frame_limit,
StackTrace::StackTraceOptions options);
Handle<Object> CaptureSimpleStackTrace(Handle<JSObject> error_object,
Handle<Object> caller);
void CaptureAndSetDetailedStackTrace(Handle<JSObject> error_object);
void CaptureAndSetSimpleStackTrace(Handle<JSObject> error_object,
Handle<Object> caller);
Handle<JSArray> GetDetailedStackTrace(Handle<JSObject> error_object);
Handle<JSArray> GetDetailedFromSimpleStackTrace(
Handle<JSObject> error_object);
// Returns if the top context may access the given global object. If
// the result is false, the pending exception is guaranteed to be
// set.
bool MayNamedAccess(Handle<JSObject> receiver,
Handle<Object> key,
v8::AccessType type);
bool MayIndexedAccess(Handle<JSObject> receiver,
uint32_t index,
v8::AccessType type);
bool IsInternallyUsedPropertyName(Handle<Object> name);
bool IsInternallyUsedPropertyName(Object* name);
void SetFailedAccessCheckCallback(v8::FailedAccessCheckCallback callback);
void ReportFailedAccessCheck(Handle<JSObject> receiver, v8::AccessType type);
// Exception throwing support. The caller should use the result
// of Throw() as its return value.
Object* Throw(Object* exception, MessageLocation* location = NULL);
template <typename T>
MUST_USE_RESULT MaybeHandle<T> Throw(Handle<Object> exception,
MessageLocation* location = NULL) {
Throw(*exception, location);
return MaybeHandle<T>();
// Re-throw an exception. This involves no error reporting since
// error reporting was handled when the exception was thrown
// originally.
Object* ReThrow(Object* exception);
void ScheduleThrow(Object* exception);
// Re-set pending message, script and positions reported to the TryCatch
// back to the TLS for re-use when rethrowing.
void RestorePendingMessageFromTryCatch(v8::TryCatch* handler);
// Un-schedule an exception that was caught by a TryCatch handler.
void CancelScheduledExceptionFromTryCatch(v8::TryCatch* handler);
void ReportPendingMessages();
// Return pending location if any or unfilled structure.
MessageLocation GetMessageLocation();
Object* ThrowIllegalOperation();
// Promote a scheduled exception to pending. Asserts has_scheduled_exception.
Object* PromoteScheduledException();
void DoThrow(Object* exception, MessageLocation* location);
// Checks if exception should be reported and finds out if it's
// caught externally.
bool ShouldReportException(bool* can_be_caught_externally,
bool catchable_by_javascript);
// Attempts to compute the current source location, storing the
// result in the target out parameter.
void ComputeLocation(MessageLocation* target);
bool ComputeLocationFromStackTrace(MessageLocation* target,
Handle<Object> exception);
Handle<JSMessageObject> CreateMessage(Handle<Object> exception,
MessageLocation* location);
// Out of resource exception helpers.
Object* StackOverflow();
Object* TerminateExecution();
void CancelTerminateExecution();
void RequestInterrupt(InterruptCallback callback, void* data);
void InvokeApiInterruptCallbacks();
// Administration
void Iterate(ObjectVisitor* v);
void Iterate(ObjectVisitor* v, ThreadLocalTop* t);
char* Iterate(ObjectVisitor* v, char* t);
void IterateThread(ThreadVisitor* v, char* t);
// Returns the current native context.
Handle<Context> native_context();
// Returns the native context of the calling JavaScript code. That
// is, the native context of the top-most JavaScript frame.
Handle<Context> GetCallingNativeContext();
void RegisterTryCatchHandler(v8::TryCatch* that);
void UnregisterTryCatchHandler(v8::TryCatch* that);
char* ArchiveThread(char* to);
char* RestoreThread(char* from);
static const char* const kStackOverflowMessage;
static const int kUC16AlphabetSize = 256; // See StringSearchBase.
static const int kBMMaxShift = 250; // See StringSearchBase.
// Accessors.
#define GLOBAL_ACCESSOR(type, name, initialvalue) \
inline type name() const { \
DCHECK(OFFSET_OF(Isolate, name##_) == name##_debug_offset_); \
return name##_; \
} \
inline void set_##name(type value) { \
DCHECK(OFFSET_OF(Isolate, name##_) == name##_debug_offset_); \
name##_ = value; \
#define GLOBAL_ARRAY_ACCESSOR(type, name, length) \
inline type* name() { \
DCHECK(OFFSET_OF(Isolate, name##_) == name##_debug_offset_); \
return &(name##_)[0]; \
#define NATIVE_CONTEXT_FIELD_ACCESSOR(index, type, name) \
Handle<type> name() { \
return Handle<type>(native_context()->name(), this); \
} \
bool is_##name(type* value) { \
return native_context()->is_##name(value); \
Bootstrapper* bootstrapper() { return bootstrapper_; }
Counters* counters() {
// Call InitializeLoggingAndCounters() if logging is needed before
// the isolate is fully initialized.
DCHECK(counters_ != NULL);
return counters_;
CodeRange* code_range() { return code_range_; }
RuntimeProfiler* runtime_profiler() { return runtime_profiler_; }
CompilationCache* compilation_cache() { return compilation_cache_; }
Logger* logger() {
// Call InitializeLoggingAndCounters() if logging is needed before
// the isolate is fully initialized.
DCHECK(logger_ != NULL);
return logger_;
StackGuard* stack_guard() { return &stack_guard_; }
Heap* heap() { return &heap_; }
StatsTable* stats_table();
StubCache* stub_cache() { return stub_cache_; }
CodeAgingHelper* code_aging_helper() { return code_aging_helper_; }
DeoptimizerData* deoptimizer_data() { return deoptimizer_data_; }
ThreadLocalTop* thread_local_top() { return &thread_local_top_; }
MaterializedObjectStore* materialized_object_store() {
return materialized_object_store_;
MemoryAllocator* memory_allocator() {
return memory_allocator_;
KeyedLookupCache* keyed_lookup_cache() {
return keyed_lookup_cache_;
ContextSlotCache* context_slot_cache() {
return context_slot_cache_;
DescriptorLookupCache* descriptor_lookup_cache() {
return descriptor_lookup_cache_;
HandleScopeData* handle_scope_data() { return &handle_scope_data_; }
HandleScopeImplementer* handle_scope_implementer() {
return handle_scope_implementer_;
Zone* runtime_zone() { return &runtime_zone_; }
UnicodeCache* unicode_cache() {
return unicode_cache_;
InnerPointerToCodeCache* inner_pointer_to_code_cache() {
return inner_pointer_to_code_cache_;
GlobalHandles* global_handles() { return global_handles_; }
EternalHandles* eternal_handles() { return eternal_handles_; }
ThreadManager* thread_manager() { return thread_manager_; }
StringTracker* string_tracker() { return string_tracker_; }
unibrow::Mapping<unibrow::Ecma262UnCanonicalize>* jsregexp_uncanonicalize() {
return &jsregexp_uncanonicalize_;
unibrow::Mapping<unibrow::CanonicalizationRange>* jsregexp_canonrange() {
return &jsregexp_canonrange_;
RuntimeState* runtime_state() { return &runtime_state_; }
Builtins* builtins() { return &builtins_; }
void NotifyExtensionInstalled() {
has_installed_extensions_ = true;
bool has_installed_extensions() { return has_installed_extensions_; }
regexp_macro_assembler_canonicalize() {
return &regexp_macro_assembler_canonicalize_;
RegExpStack* regexp_stack() { return regexp_stack_; }
interp_canonicalize_mapping() {
return &interp_canonicalize_mapping_;
Debug* debug() { return debug_; }
inline bool DebuggerHasBreakPoints();
CpuProfiler* cpu_profiler() const { return cpu_profiler_; }
HeapProfiler* heap_profiler() const { return heap_profiler_; }
#ifdef DEBUG
HistogramInfo* heap_histograms() { return heap_histograms_; }
JSObject::SpillInformation* js_spill_information() {
return &js_spill_information_;
Factory* factory() { return reinterpret_cast<Factory*>(this); }
static const int kJSRegexpStaticOffsetsVectorSize = 128;
THREAD_LOCAL_TOP_ACCESSOR(ExternalCallbackScope*, external_callback_scope)
THREAD_LOCAL_TOP_ACCESSOR(StateTag, current_vm_state)
void SetData(uint32_t slot, void* data) {
DCHECK(slot < Internals::kNumIsolateDataSlots);
embedder_data_[slot] = data;
void* GetData(uint32_t slot) {
DCHECK(slot < Internals::kNumIsolateDataSlots);
return embedder_data_[slot];
THREAD_LOCAL_TOP_ACCESSOR(LookupResult*, top_lookup_result)
bool serializer_enabled() const { return serializer_enabled_; }
bool IsDead() { return has_fatal_error_; }
void SignalFatalError() { has_fatal_error_ = true; }
bool use_crankshaft() const;
bool initialized_from_snapshot() { return initialized_from_snapshot_; }
double time_millis_since_init() {
return base::OS::TimeCurrentMillis() - time_millis_at_init_;
DateCache* date_cache() {
return date_cache_;
void set_date_cache(DateCache* date_cache) {
if (date_cache != date_cache_) {
delete date_cache_;
date_cache_ = date_cache;
Map* get_initial_js_array_map(ElementsKind kind);
bool IsFastArrayConstructorPrototypeChainIntact();
CallInterfaceDescriptorData* call_descriptor_data(int index);
void IterateDeferredHandles(ObjectVisitor* visitor);
void LinkDeferredHandles(DeferredHandles* deferred_handles);
void UnlinkDeferredHandles(DeferredHandles* deferred_handles);
#ifdef DEBUG
bool IsDeferredHandle(Object** location);
#endif // DEBUG
bool concurrent_recompilation_enabled() {
// Thread is only available with flag enabled.
DCHECK(optimizing_compiler_thread_ == NULL ||
return optimizing_compiler_thread_ != NULL;
bool concurrent_osr_enabled() const {
// Thread is only available with flag enabled.
DCHECK(optimizing_compiler_thread_ == NULL ||
return optimizing_compiler_thread_ != NULL && FLAG_concurrent_osr;
OptimizingCompilerThread* optimizing_compiler_thread() {
return optimizing_compiler_thread_;
int id() const { return static_cast<int>(id_); }
HStatistics* GetHStatistics();
CompilationStatistics* GetTurboStatistics();
HTracer* GetHTracer();
CodeTracer* GetCodeTracer();
void DumpAndResetCompilationStats();
FunctionEntryHook function_entry_hook() { return function_entry_hook_; }
void set_function_entry_hook(FunctionEntryHook function_entry_hook) {
function_entry_hook_ = function_entry_hook;
void* stress_deopt_count_address() { return &stress_deopt_count_; }
inline base::RandomNumberGenerator* random_number_generator();
// Given an address occupied by a live code object, return that object.
Object* FindCodeObject(Address a);
int NextOptimizationId() {
int id = next_optimization_id_++;
if (!Smi::IsValid(next_optimization_id_)) {
next_optimization_id_ = 0;
return id;
// Get (and lazily initialize) the registry for per-isolate symbols.
Handle<JSObject> GetSymbolRegistry();
void AddCallCompletedCallback(CallCompletedCallback callback);
void RemoveCallCompletedCallback(CallCompletedCallback callback);
void FireCallCompletedCallback();
void SetPromiseRejectCallback(PromiseRejectCallback callback);
void ReportPromiseReject(Handle<JSObject> promise, Handle<Object> value,
v8::PromiseRejectEvent event);
void EnqueueMicrotask(Handle<Object> microtask);
void RunMicrotasks();
void SetUseCounterCallback(v8::Isolate::UseCounterCallback callback);
void CountUsage(v8::Isolate::UseCounterFeature feature);
BasicBlockProfiler* GetOrCreateBasicBlockProfiler();
BasicBlockProfiler* basic_block_profiler() { return basic_block_profiler_; }
static Isolate* NewForTesting() { return new Isolate(false); }
std::string GetTurboCfgFileName();
int GetNextUniqueSharedFunctionInfoId() { return next_unique_sfi_id_++; }
explicit Isolate(bool enable_serializer);
friend struct GlobalState;
friend struct InitializeGlobalState;
// These fields are accessed through the API, offsets must be kept in sync
// with v8::internal::Internals (in include/v8.h) constants. This is also
// verified in Isolate::Init() using runtime checks.
void* embedder_data_[Internals::kNumIsolateDataSlots];
Heap heap_;
// The per-process lock should be acquired before the ThreadDataTable is
// modified.
class ThreadDataTable {
PerIsolateThreadData* Lookup(Isolate* isolate, ThreadId thread_id);
void Insert(PerIsolateThreadData* data);
void Remove(PerIsolateThreadData* data);
void RemoveAllThreads(Isolate* isolate);
PerIsolateThreadData* list_;
// These items form a stack synchronously with threads Enter'ing and Exit'ing
// the Isolate. The top of the stack points to a thread which is currently
// running the Isolate. When the stack is empty, the Isolate is considered
// not entered by any thread and can be Disposed.
// If the same thread enters the Isolate more then once, the entry_count_
// is incremented rather then a new item pushed to the stack.
class EntryStackItem {
EntryStackItem(PerIsolateThreadData* previous_thread_data,
Isolate* previous_isolate,
EntryStackItem* previous_item)
: entry_count(1),
previous_item(previous_item) { }
int entry_count;
PerIsolateThreadData* previous_thread_data;
Isolate* previous_isolate;
EntryStackItem* previous_item;
static base::LazyMutex thread_data_table_mutex_;
static base::Thread::LocalStorageKey per_isolate_thread_data_key_;
static base::Thread::LocalStorageKey isolate_key_;
static base::Thread::LocalStorageKey thread_id_key_;
static ThreadDataTable* thread_data_table_;
// A global counter for all generated Isolates, might overflow.
static base::Atomic32 isolate_counter_;
static base::Atomic32 isolate_key_created_;
void Deinit();
static void SetIsolateThreadLocals(Isolate* isolate,
PerIsolateThreadData* data);
// Find the PerThread for this particular (isolate, thread) combination.
// If one does not yet exist, allocate a new one.
PerIsolateThreadData* FindOrAllocatePerThreadDataForThisThread();
// Initializes the current thread to run this Isolate.
// Not thread-safe. Multiple threads should not Enter/Exit the same isolate
// at the same time, this should be prevented using external locking.
void Enter();
// Exits the current thread. The previosuly entered Isolate is restored
// for the thread.
// Not thread-safe. Multiple threads should not Enter/Exit the same isolate
// at the same time, this should be prevented using external locking.
void Exit();
void InitializeThreadLocal();
void MarkCompactPrologue(bool is_compacting,
ThreadLocalTop* archived_thread_data);
void MarkCompactEpilogue(bool is_compacting,
ThreadLocalTop* archived_thread_data);
void FillCache();
// Propagate pending exception message to the v8::TryCatch.
// If there is no external try-catch or message was successfully propagated,
// then return true.
bool PropagatePendingExceptionToExternalTryCatch();
// Traverse prototype chain to find out whether the object is derived from
// the Error object.
bool IsErrorObject(Handle<Object> obj);
base::Atomic32 id_;
EntryStackItem* entry_stack_;
int stack_trace_nesting_level_;
StringStream* incomplete_message_;
Address isolate_addresses_[kIsolateAddressCount + 1]; // NOLINT
Bootstrapper* bootstrapper_;
RuntimeProfiler* runtime_profiler_;
CompilationCache* compilation_cache_;
Counters* counters_;
CodeRange* code_range_;
base::RecursiveMutex break_access_;
Logger* logger_;
StackGuard stack_guard_;
StatsTable* stats_table_;
StubCache* stub_cache_;
CodeAgingHelper* code_aging_helper_;
DeoptimizerData* deoptimizer_data_;
MaterializedObjectStore* materialized_object_store_;
ThreadLocalTop thread_local_top_;
bool capture_stack_trace_for_uncaught_exceptions_;
int stack_trace_for_uncaught_exceptions_frame_limit_;
StackTrace::StackTraceOptions stack_trace_for_uncaught_exceptions_options_;
MemoryAllocator* memory_allocator_;
KeyedLookupCache* keyed_lookup_cache_;
ContextSlotCache* context_slot_cache_;
DescriptorLookupCache* descriptor_lookup_cache_;
HandleScopeData handle_scope_data_;
HandleScopeImplementer* handle_scope_implementer_;
UnicodeCache* unicode_cache_;
Zone runtime_zone_;
InnerPointerToCodeCache* inner_pointer_to_code_cache_;
GlobalHandles* global_handles_;
EternalHandles* eternal_handles_;
ThreadManager* thread_manager_;
RuntimeState runtime_state_;
Builtins builtins_;
bool has_installed_extensions_;
StringTracker* string_tracker_;
unibrow::Mapping<unibrow::Ecma262UnCanonicalize> jsregexp_uncanonicalize_;
unibrow::Mapping<unibrow::CanonicalizationRange> jsregexp_canonrange_;
RegExpStack* regexp_stack_;
DateCache* date_cache_;
unibrow::Mapping<unibrow::Ecma262Canonicalize> interp_canonicalize_mapping_;
CallInterfaceDescriptorData* call_descriptor_data_;
base::RandomNumberGenerator* random_number_generator_;
// Whether the isolate has been created for snapshotting.
bool serializer_enabled_;
// True if fatal error has been signaled for this isolate.
bool has_fatal_error_;
// True if this isolate was initialized from a snapshot.
bool initialized_from_snapshot_;
// Time stamp at initialization.
double time_millis_at_init_;
#ifdef DEBUG
// A static array of histogram info for each type.
HistogramInfo heap_histograms_[LAST_TYPE + 1];
JSObject::SpillInformation js_spill_information_;
Debug* debug_;
CpuProfiler* cpu_profiler_;
HeapProfiler* heap_profiler_;
FunctionEntryHook function_entry_hook_;
typedef std::pair<InterruptCallback, void*> InterruptEntry;
std::queue<InterruptEntry> api_interrupts_queue_;
#define GLOBAL_BACKING_STORE(type, name, initialvalue) \
type name##_;
#define GLOBAL_ARRAY_BACKING_STORE(type, name, length) \
type name##_[length];
#ifdef DEBUG
// This class is huge and has a number of fields controlled by
// preprocessor defines. Make sure the offsets of these fields agree
// between compilation units.
#define ISOLATE_FIELD_OFFSET(type, name, ignored) \
static const intptr_t name##_debug_offset_;
DeferredHandles* deferred_handles_head_;
OptimizingCompilerThread* optimizing_compiler_thread_;
// Counts deopt points if deopt_every_n_times is enabled.
unsigned int stress_deopt_count_;
int next_optimization_id_;
int next_unique_sfi_id_;
// List of callbacks when a Call completes.
List<CallCompletedCallback> call_completed_callbacks_;
v8::Isolate::UseCounterCallback use_counter_callback_;
BasicBlockProfiler* basic_block_profiler_;
friend class ExecutionAccess;
friend class HandleScopeImplementer;
friend class IsolateInitializer;
friend class OptimizingCompilerThread;
friend class SweeperThread;
friend class ThreadManager;
friend class Simulator;
friend class StackGuard;
friend class ThreadId;
friend class TestMemoryAllocatorScope;
friend class TestCodeRangeScope;
friend class v8::Isolate;
friend class v8::Locker;
friend class v8::Unlocker;
class PromiseOnStack {
PromiseOnStack(StackHandler* handler, Handle<JSObject> promise,
PromiseOnStack* prev)
: handler_(handler), promise_(promise), prev_(prev) {}
StackHandler* handler() { return handler_; }
Handle<JSObject> promise() { return promise_; }
PromiseOnStack* prev() { return prev_; }
StackHandler* handler_;
Handle<JSObject> promise_;
PromiseOnStack* prev_;
// If the GCC version is 4.1.x or 4.2.x an additional field is added to the
// class as a work around for a bug in the generated code found with these
// versions of GCC. See V8 issue 122 for details.
class SaveContext BASE_EMBEDDED {
inline explicit SaveContext(Isolate* isolate);
~SaveContext() {
isolate_->set_context(context_.is_null() ? NULL : *context_);
Handle<Context> context() { return context_; }
SaveContext* prev() { return prev_; }
// Returns true if this save context is below a given JavaScript frame.
bool IsBelowFrame(JavaScriptFrame* frame) {
return (c_entry_fp_ == 0) || (c_entry_fp_ > frame->sp());
Isolate* isolate_;
Handle<Context> context_;
SaveContext* prev_;
Address c_entry_fp_;
class AssertNoContextChange BASE_EMBEDDED {
#ifdef DEBUG
explicit AssertNoContextChange(Isolate* isolate)
: isolate_(isolate),
context_(isolate->context(), isolate) { }
~AssertNoContextChange() {
DCHECK(isolate_->context() == *context_);
Isolate* isolate_;
Handle<Context> context_;
explicit AssertNoContextChange(Isolate* isolate) { }
class ExecutionAccess BASE_EMBEDDED {
explicit ExecutionAccess(Isolate* isolate) : isolate_(isolate) {
~ExecutionAccess() { Unlock(isolate_); }
static void Lock(Isolate* isolate) { isolate->break_access()->Lock(); }
static void Unlock(Isolate* isolate) { isolate->break_access()->Unlock(); }
static bool TryLock(Isolate* isolate) {
return isolate->break_access()->TryLock();
Isolate* isolate_;
// Support for checking for stack-overflows.
class StackLimitCheck BASE_EMBEDDED {
explicit StackLimitCheck(Isolate* isolate) : isolate_(isolate) { }
// Use this to check for stack-overflows in C++ code.
inline bool HasOverflowed() const {
StackGuard* stack_guard = isolate_->stack_guard();
return GetCurrentStackPosition() < stack_guard->real_climit();
// Use this to check for stack-overflow when entering runtime from JS code.
bool JsHasOverflowed() const;
Isolate* isolate_;
// Support for temporarily postponing interrupts. When the outermost
// postpone scope is left the interrupts will be re-enabled and any
// interrupts that occurred while in the scope will be taken into
// account.
class PostponeInterruptsScope BASE_EMBEDDED {
PostponeInterruptsScope(Isolate* isolate,
int intercept_mask = StackGuard::ALL_INTERRUPTS)
: stack_guard_(isolate->stack_guard()),
intercepted_flags_(0) {
~PostponeInterruptsScope() {
// Find the bottom-most scope that intercepts this interrupt.
// Return whether the interrupt has been intercepted.
bool Intercept(StackGuard::InterruptFlag flag);
StackGuard* stack_guard_;
int intercept_mask_;
int intercepted_flags_;
PostponeInterruptsScope* prev_;
friend class StackGuard;
class CodeTracer FINAL : public Malloced {
explicit CodeTracer(int isolate_id)
: file_(NULL),
scope_depth_(0) {
if (!ShouldRedirect()) {
file_ = stdout;
if (FLAG_redirect_code_traces_to == NULL) {
} else {
StrNCpy(filename_, FLAG_redirect_code_traces_to, filename_.length());
WriteChars(filename_.start(), "", 0, false);
class Scope {
explicit Scope(CodeTracer* tracer) : tracer_(tracer) { tracer->OpenFile(); }
~Scope() { tracer_->CloseFile(); }
FILE* file() const { return tracer_->file(); }
CodeTracer* tracer_;
void OpenFile() {
if (!ShouldRedirect()) {
if (file_ == NULL) {
file_ = base::OS::FOpen(filename_.start(), "a");
void CloseFile() {
if (!ShouldRedirect()) {
if (--scope_depth_ == 0) {
file_ = NULL;
FILE* file() const { return file_; }
static bool ShouldRedirect() {
return FLAG_redirect_code_traces;
EmbeddedVector<char, 128> filename_;
FILE* file_;
int scope_depth_;
} } // namespace v8::internal
#endif // V8_ISOLATE_H_