static inline void New(const FunctionCallbackInfo<Value>& args) {

Environment* env = Environment::GetCurrent(args);

CHECK(args.IsConstructCall());

CHECK(env->async_wrap_object_ctor_template()->HasInstance(args.This()));

CHECK(args[0]->IsUint32());

auto type = static_cast<ProviderType>(args[0].As<Uint32>()->Value());

new AsyncWrapObject(env, args.This(), type);

}

inline AsyncWrapObject(Environment* env, Local<Object> object,

ProviderType type) : AsyncWrap(env, object, type) {}

SET_NO_MEMORY_INFO()

SET_MEMORY_INFO_NAME(AsyncWrapObject)

SET_SELF_SIZE(AsyncWrapObject)

Local<Function> fn = env->async_hooks_destroy_function();

TryCatchScope try_catch(env, TryCatchScope::CatchMode::kFatal);

do {

std::vector<double> destroy_async_id_list;

destroy_async_id_list.swap(*env->destroy_async_id_list());

if (!env->can_call_into_js()) return;

for (auto async_id : destroy_async_id_list) {

// Want each callback to be cleaned up after itself, instead of cleaning

// them all up after the while() loop completes.

HandleScope scope(env->isolate());

Local<Value> async_id_value = Number::New(env->isolate(), async_id);

MaybeLocal<Value> ret = fn->Call(

env->context(), Undefined(env->isolate()), 1, &async_id_value);

if (ret.IsEmpty())

return;

}

} while (!env->destroy_async_id_list()->empty());

Local<Function> fn) {

AsyncHooks* async_hooks = env->async_hooks();

if (async_hooks->fields()[type] == 0 || !env->can_call_into_js())

return;

HandleScope handle_scope(env->isolate());

Local<Value> async_id_value = Number::New(env->isolate(), async_id);

TryCatchScope try_catch(env, TryCatchScope::CatchMode::kFatal);

USE(fn->Call(env->context(), Undefined(env->isolate()), 1, &async_id_value));

switch (provider_type()) {

#define V(PROVIDER) \

case PROVIDER_ ## PROVIDER: \

TRACE_EVENT_NESTABLE_ASYNC_BEGIN0( \

TRACING_CATEGORY_NODE1(async_hooks), \

#PROVIDER "_CALLBACK", static_cast<int64_t>(get_async_id())); \

break;

NODE_ASYNC_PROVIDER_TYPES(V)

#undef V

default:

UNREACHABLE();

}

switch (type) {

#define V(PROVIDER) \

case PROVIDER_ ## PROVIDER: \

TRACE_EVENT_NESTABLE_ASYNC_END0( \

TRACING_CATEGORY_NODE1(async_hooks), \

#PROVIDER "_CALLBACK", static_cast<int64_t>(async_id)); \

break;

NODE_ASYNC_PROVIDER_TYPES(V)

#undef V

default:

UNREACHABLE();

}

// If the user's callback failed then the after() hooks will be called at the

// end of _fatalException().

Emit(env, async_id, AsyncHooks::kAfter,

env->async_hooks_after_function());

public:

PromiseWrap(Environment* env, Local<Object> object, bool silent)

: AsyncWrap(env, object, PROVIDER_PROMISE, -1, silent) {

MakeWeak();

}

SET_NO_MEMORY_INFO()

SET_MEMORY_INFO_NAME(PromiseWrap)

SET_SELF_SIZE(PromiseWrap)

static constexpr int kIsChainedPromiseField = 1;

static constexpr int kInternalFieldCount = 2;

static PromiseWrap* New(Environment* env,

Local<Promise> promise,

PromiseWrap* parent_wrap,

bool silent);

static void getIsChainedPromise(Local<String> property,

const PropertyCallbackInfo<Value>& info);

const PropertyCallbackInfo<Value>& info) {

info.GetReturnValue().Set(

info.Holder()->GetInternalField(kIsChainedPromiseField));

Local<Value> parent) {

Local<Context> context = promise->CreationContext();

Environment* env = Environment::GetCurrent(context);

if (env == nullptr) return;

TraceEventScope trace_scope(TRACING_CATEGORY_NODE1(environment),

"EnvPromiseHook", env);

PromiseWrap* wrap = extractPromiseWrap(promise);

if (type == PromiseHookType::kInit || wrap == nullptr) {

bool silent = type != PromiseHookType::kInit;

// set parent promise's async Id as this promise's triggerAsyncId

if (parent->IsPromise()) {

// parent promise exists, current promise

// is a chained promise, so we set parent promise's id as

// current promise's triggerAsyncId

Local<Promise> parent_promise = parent.As<Promise>();

PromiseWrap* parent_wrap = extractPromiseWrap(parent_promise);

if (parent_wrap == nullptr) {

parent_wrap = PromiseWrap::New(env, parent_promise, nullptr, true);

if (parent_wrap == nullptr) return;

}

AsyncHooks::DefaultTriggerAsyncIdScope trigger_scope(parent_wrap);

wrap = PromiseWrap::New(env, promise, parent_wrap, silent);

} else {

wrap = PromiseWrap::New(env, promise, nullptr, silent);

}

}

if (wrap == nullptr) return;

if (type == PromiseHookType::kBefore) {

env->async_hooks()->push_async_ids(

wrap->get_async_id(), wrap->get_trigger_async_id());

wrap->EmitTraceEventBefore();

AsyncWrap::EmitBefore(wrap->env(), wrap->get_async_id());

} else if (type == PromiseHookType::kAfter) {

wrap->EmitTraceEventAfter(wrap->provider_type(), wrap->get_async_id());

AsyncWrap::EmitAfter(wrap->env(), wrap->get_async_id());

if (env->execution_async_id() == wrap->get_async_id()) {

// This condition might not be true if async_hooks was enabled during

// the promise callback execution.

// Popping it off the stack can be skipped in that case, because it is

// known that it would correspond to exactly one call with

// PromiseHookType::kBefore that was not witnessed by the PromiseHook.

env->async_hooks()->pop_async_id(wrap->get_async_id());

}

} else if (type == PromiseHookType::kResolve) {

AsyncWrap::EmitPromiseResolve(wrap->env(), wrap->get_async_id());

}

Environment* env = Environment::GetCurrent(args);

CHECK(args[0]->IsObject());

// All of init, before, after, destroy are supplied by async_hooks

// internally, so this should every only be called once. At which time all

// the functions should be set. Detect this by checking if init !IsEmpty().

CHECK(env->async_hooks_init_function().IsEmpty());

Local<Object> fn_obj = args[0].As<Object>();

#define SET_HOOK_FN(name) \

Local<Value> name##_v = fn_obj->Get( \

env->context(), \

FIXED_ONE_BYTE_STRING(env->isolate(), #name)).ToLocalChecked(); \

CHECK(name##_v->IsFunction()); \

env->set_async_hooks_##name##_function(name##_v.As<Function>());

SET_HOOK_FN(init);

SET_HOOK_FN(before);

SET_HOOK_FN(after);

SET_HOOK_FN(destroy);

SET_HOOK_FN(promise_resolve);

#undef SET_HOOK_FN

{

Local<FunctionTemplate> ctor =

FunctionTemplate::New(env->isolate());

ctor->SetClassName(FIXED_ONE_BYTE_STRING(env->isolate(), "PromiseWrap"));

Local<ObjectTemplate> promise_wrap_template = ctor->InstanceTemplate();

promise_wrap_template->SetInternalFieldCount(

PromiseWrap::kInternalFieldCount);

promise_wrap_template->SetAccessor(

FIXED_ONE_BYTE_STRING(env->isolate(), "isChainedPromise"),

PromiseWrap::getIsChainedPromise);

env->set_promise_wrap_template(promise_wrap_template);

}

Isolate* isolate = args.GetIsolate();

// Delay the call to `RemovePromiseHook` because we might currently be

// between the `before` and `after` calls of a Promise.

isolate->EnqueueMicrotask([](void* data) {

// The per-Isolate API provides no way of knowing whether there are multiple

// users of the PromiseHook. That hopefully goes away when V8 introduces

// a per-context API.

Isolate* isolate = static_cast<Isolate*>(data);

isolate->SetPromiseHook(nullptr);

}, static_cast<void*>(isolate));

public:

double asyncId;

Environment* env;

Persistent<Object> target;

Persistent<Object> propBag;

HandleScope scope(info.GetIsolate());

std::unique_ptr<DestroyParam> p{info.GetParameter()};

Local<Object> prop_bag = PersistentToLocal::Default(info.GetIsolate(),

p->propBag);

Local<Value> val;

if (!prop_bag->Get(p->env->context(), p->env->destroyed_string())

.ToLocal(&val)) {

return;

}

if (val->IsFalse()) {

AsyncWrap::EmitDestroy(p->env, p->asyncId);

}

// unique_ptr goes out of scope here and pointer is deleted.

CHECK(args[0]->IsObject());

CHECK(args[1]->IsNumber());

CHECK(args[2]->IsObject());

Isolate* isolate = args.GetIsolate();

DestroyParam* p = new DestroyParam();

p->asyncId = args[1].As<Number>()->Value();

p->env = Environment::GetCurrent(args);

p->target.Reset(isolate, args[0].As<Object>());

p->propBag.Reset(isolate, args[2].As<Object>());

p->target.SetWeak(p, AsyncWrap::WeakCallback, WeakCallbackType::kParameter);

AsyncWrap* wrap;

args.GetReturnValue().Set(-1);

ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());

args.GetReturnValue().Set(wrap->get_async_id());

Environment* env = Environment::GetCurrent(args);

// No need for CHECK(IsNumber()) on args because if FromJust() doesn't fail

// then the checks in push_async_ids() and pop_async_id() will.

double async_id = args[0]->NumberValue(env->context()).FromJust();

double trigger_async_id = args[1]->NumberValue(env->context()).FromJust();

env->async_hooks()->push_async_ids(async_id, trigger_async_id);

Environment* env = Environment::GetCurrent(args);

double async_id = args[0]->NumberValue(env->context()).FromJust();

args.GetReturnValue().Set(env->async_hooks()->pop_async_id(async_id));

AsyncWrap* wrap;

ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());

double execution_async_id =

args[0]->IsNumber() ? args[0].As<Number>()->Value() : -1;

wrap->AsyncReset(execution_async_id);

CHECK(args[0]->IsNumber());

AsyncWrap::EmitDestroy(

Environment::GetCurrent(args),

args[0].As<Number>()->Value());

Local<FunctionTemplate> tmpl = env->async_wrap_ctor_template();

if (tmpl.IsEmpty()) {

tmpl = env->NewFunctionTemplate(nullptr);

tmpl->SetClassName(FIXED_ONE_BYTE_STRING(env->isolate(), "AsyncWrap"));

env->SetProtoMethod(tmpl, "getAsyncId", AsyncWrap::GetAsyncId);

env->SetProtoMethod(tmpl, "asyncReset", AsyncWrap::AsyncReset);

env->set_async_wrap_ctor_template(tmpl);

}

return tmpl;

Local<Value> unused,

Local<Context> context,

void* priv) {

Environment* env = Environment::GetCurrent(context);

Isolate* isolate = env->isolate();

HandleScope scope(isolate);

env->SetMethod(target, "setupHooks", SetupHooks);

env->SetMethod(target, "pushAsyncIds", PushAsyncIds);

env->SetMethod(target, "popAsyncIds", PopAsyncIds);

env->SetMethod(target, "queueDestroyAsyncId", QueueDestroyAsyncId);

env->SetMethod(target, "enablePromiseHook", EnablePromiseHook);

env->SetMethod(target, "disablePromiseHook", DisablePromiseHook);

env->SetMethod(target, "registerDestroyHook", RegisterDestroyHook);

PropertyAttribute ReadOnlyDontDelete =

static_cast<PropertyAttribute>(ReadOnly | DontDelete);

#define FORCE_SET_TARGET_FIELD(obj, str, field) \

(obj)->DefineOwnProperty(context, \

FIXED_ONE_BYTE_STRING(isolate, str), \

field, \

ReadOnlyDontDelete).FromJust()

// Attach the uint32_t[] where each slot contains the count of the number of

// callbacks waiting to be called on a particular event. It can then be

// incremented/decremented from JS quickly to communicate to C++ if there are

// any callbacks waiting to be called.

FORCE_SET_TARGET_FIELD(target,

"async_hook_fields",

env->async_hooks()->fields().GetJSArray());

// The following v8::Float64Array has 5 fields. These fields are shared in

// this way to allow JS and C++ to read/write each value as quickly as

// possible. The fields are represented as follows:

//

// kAsyncIdCounter: Maintains the state of the next unique id to be assigned.

//

// kDefaultTriggerAsyncId: Write the id of the resource responsible for a

// handle's creation just before calling the new handle's constructor.

// After the new handle is constructed kDefaultTriggerAsyncId is set back

// to -1.

FORCE_SET_TARGET_FIELD(target,

"async_id_fields",

env->async_hooks()->async_id_fields().GetJSArray());

target->Set(context,

env->async_ids_stack_string(),

env->async_hooks()->async_ids_stack().GetJSArray()).Check();

target->Set(context,

FIXED_ONE_BYTE_STRING(env->isolate(), "owner_symbol"),

env->owner_symbol()).Check();

Local<Object> constants = Object::New(isolate);

#define SET_HOOKS_CONSTANT(name) \

FORCE_SET_TARGET_FIELD( \

constants, #name, Integer::New(isolate, AsyncHooks::name));

SET_HOOKS_CONSTANT(kInit);

SET_HOOKS_CONSTANT(kBefore);

SET_HOOKS_CONSTANT(kAfter);

SET_HOOKS_CONSTANT(kDestroy);

SET_HOOKS_CONSTANT(kPromiseResolve);

SET_HOOKS_CONSTANT(kTotals);

SET_HOOKS_CONSTANT(kCheck);

SET_HOOKS_CONSTANT(kExecutionAsyncId);

SET_HOOKS_CONSTANT(kTriggerAsyncId);

SET_HOOKS_CONSTANT(kAsyncIdCounter);

SET_HOOKS_CONSTANT(kDefaultTriggerAsyncId);

SET_HOOKS_CONSTANT(kStackLength);

#undef SET_HOOKS_CONSTANT

FORCE_SET_TARGET_FIELD(target, "constants", constants);

Local<Object> async_providers = Object::New(isolate);

#define V(p) \

FORCE_SET_TARGET_FIELD( \

async_providers, #p, Integer::New(isolate, AsyncWrap::PROVIDER_ ## p));

NODE_ASYNC_PROVIDER_TYPES(V)

#undef V

FORCE_SET_TARGET_FIELD(target, "Providers", async_providers);

#undef FORCE_SET_TARGET_FIELD

env->set_async_hooks_init_function(Local<Function>());

env->set_async_hooks_before_function(Local<Function>());

env->set_async_hooks_after_function(Local<Function>());

env->set_async_hooks_destroy_function(Local<Function>());

env->set_async_hooks_promise_resolve_function(Local<Function>());

env->set_async_hooks_binding(target);

// TODO(addaleax): This block might better work as a

// AsyncWrapObject::Initialize() or AsyncWrapObject::GetConstructorTemplate()

// function.

{

auto class_name = FIXED_ONE_BYTE_STRING(env->isolate(), "AsyncWrap");

auto function_template = env->NewFunctionTemplate(AsyncWrapObject::New);

function_template->SetClassName(class_name);

function_template->Inherit(AsyncWrap::GetConstructorTemplate(env));

auto instance_template = function_template->InstanceTemplate();

instance_template->SetInternalFieldCount(1);

auto function =

function_template->GetFunction(env->context()).ToLocalChecked();

target->Set(env->context(), class_name, function).Check();

env->set_async_wrap_object_ctor_template(function_template);

}

Local<Object> object,

ProviderType provider,

double execution_async_id)

Local<Object> object,

ProviderType provider,

double execution_async_id,

bool silent)

: BaseObject(env, object),

provider_type_(provider) {

CHECK_NE(provider, PROVIDER_NONE);

CHECK_GE(object->InternalFieldCount(), 1);

// Use AsyncReset() call to execute the init() callbacks.

AsyncReset(execution_async_id, silent);

switch (provider_type()) {

#define V(PROVIDER) \

case PROVIDER_ ## PROVIDER: \

TRACE_EVENT_NESTABLE_ASYNC_END0( \

TRACING_CATEGORY_NODE1(async_hooks), \

#PROVIDER, static_cast<int64_t>(get_async_id())); \

break;

NODE_ASYNC_PROVIDER_TYPES(V)

#undef V

default:

UNREACHABLE();

}

if (env->async_hooks()->fields()[AsyncHooks::kDestroy] == 0 ||

!env->can_call_into_js()) {

return;

}

if (env->destroy_async_id_list()->empty()) {

env->SetUnrefImmediate(DestroyAsyncIdsCallback, nullptr);

}

env->destroy_async_id_list()->push_back(async_id);

if (async_id_ != -1) {

// This instance was in use before, we have already emitted an init with

// its previous async_id and need to emit a matching destroy for that

// before generating a new async_id.

EmitDestroy(env(), async_id_);

}

// Now we can assign a new async_id_ to this instance.

async_id_ =

execution_async_id == -1 ? env()->new_async_id() : execution_async_id;

trigger_async_id_ = env()->get_default_trigger_async_id();

switch (provider_type()) {

#define V(PROVIDER) \

case PROVIDER_ ## PROVIDER: \

if (*TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED( \

TRACING_CATEGORY_NODE1(async_hooks))) { \

auto data = tracing::TracedValue::Create(); \

data->SetInteger("executionAsyncId", \

static_cast<int64_t>(env()->execution_async_id())); \

data->SetInteger("triggerAsyncId", \

static_cast<int64_t>(get_trigger_async_id())); \

TRACE_EVENT_NESTABLE_ASYNC_BEGIN1( \

TRACING_CATEGORY_NODE1(async_hooks), \

#PROVIDER, static_cast<int64_t>(get_async_id()), \

"data", std::move(data)); \

} \

break;

NODE_ASYNC_PROVIDER_TYPES(V)

#undef V

default:

UNREACHABLE();

}

if (silent) return;

EmitAsyncInit(env(), object(),

env()->async_hooks()->provider_string(provider_type()),

async_id_, trigger_async_id_);

Local<Object> object,

Local<String> type,

double async_id,

double trigger_async_id) {

CHECK(!object.IsEmpty());

CHECK(!type.IsEmpty());

AsyncHooks* async_hooks = env->async_hooks();

// Nothing to execute, so can continue normally.

if (async_hooks->fields()[AsyncHooks::kInit] == 0) {

return;

}

HandleScope scope(env->isolate());

Local<Function> init_fn = env->async_hooks_init_function();

Local<Value> argv[] = {

Number::New(env->isolate(), async_id),

type,

Number::New(env->isolate(), trigger_async_id),

object,

};

TryCatchScope try_catch(env, TryCatchScope::CatchMode::kFatal);

USE(init_fn->Call(env->context(), object, arraysize(argv), argv));

int argc,

Local<Value>* argv) {

EmitTraceEventBefore();

ProviderType provider = provider_type();

async_context context { get_async_id(), get_trigger_async_id() };

MaybeLocal<Value> ret = InternalMakeCallback(

env(), object(), cb, argc, argv, context);

// This is a static call with cached values because the `this` object may

// no longer be alive at this point.

EmitTraceEventAfter(provider, context.async_id);

return ret;

EscapableHandleScope handle_scope(env->isolate());

CHECK(!obj.IsEmpty());

TryCatchScope ignore_exceptions(env);

while (true) {

Local<Value> owner;

if (!obj->Get(env->context(),

env->owner_symbol()).ToLocal(&owner) ||

!owner->IsObject()) {

return handle_scope.Escape(obj);

}

obj = owner.As<Object>();

}