// Copyright Joyent, Inc. and other Node contributors.

//

// Permission is hereby granted, free of charge, to any person obtaining a

// copy of this software and associated documentation files (the

// "Software"), to deal in the Software without restriction, including

// without limitation the rights to use, copy, modify, merge, publish,

// distribute, sublicense, and/or sell copies of the Software, and to permit

// persons to whom the Software is furnished to do so, subject to the

// following conditions:

//

// The above copyright notice and this permission notice shall be included

// in all copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN

// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,

// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR

// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE

// USE OR OTHER DEALINGS IN THE SOFTWARE.

#include "async-wrap.h"

#include "async-wrap-inl.h"

#include "env.h"

#include "env-inl.h"

#include "util.h"

#include "util-inl.h"

#include "uv.h"

#include "v8.h"

#include "v8-profiler.h"

using v8::Array;

using v8::ArrayBuffer;

using v8::Context;

using v8::Float64Array;

using v8::Function;

using v8::FunctionCallbackInfo;

using v8::HandleScope;

using v8::HeapProfiler;

using v8::Integer;

using v8::Isolate;

using v8::Local;

using v8::MaybeLocal;

using v8::Number;

using v8::Object;

using v8::RetainedObjectInfo;

using v8::Symbol;

using v8::TryCatch;

using v8::Uint32Array;

using v8::Value;

using AsyncHooks = node::Environment::AsyncHooks;

namespace node {

static const char* const provider_names[] = {

#define V(PROVIDER) \

#PROVIDER,

NODE_ASYNC_PROVIDER_TYPES(V)

#undef V

};

// Report correct information in a heapdump.

class RetainedAsyncInfo: public RetainedObjectInfo {

public:

explicit RetainedAsyncInfo(uint16_t class_id, AsyncWrap* wrap);

void Dispose() override;

bool IsEquivalent(RetainedObjectInfo* other) override;

intptr_t GetHash() override;

const char* GetLabel() override;

intptr_t GetSizeInBytes() override;

private:

const char* label_;

const AsyncWrap* wrap_;

const int length_;

};

RetainedAsyncInfo::RetainedAsyncInfo(uint16_t class_id, AsyncWrap* wrap)

: label_(provider_names[class_id - NODE_ASYNC_ID_OFFSET]),

wrap_(wrap),

length_(wrap->self_size()) {

}

void RetainedAsyncInfo::Dispose() {

delete this;

}

bool RetainedAsyncInfo::IsEquivalent(RetainedObjectInfo* other) {

return label_ == other->GetLabel() &&

wrap_ == static_cast<RetainedAsyncInfo*>(other)->wrap_;

}

intptr_t RetainedAsyncInfo::GetHash() {

return reinterpret_cast<intptr_t>(wrap_);

}

const char* RetainedAsyncInfo::GetLabel() {

return label_;

}

intptr_t RetainedAsyncInfo::GetSizeInBytes() {

return length_;

}

RetainedObjectInfo* WrapperInfo(uint16_t class_id, Local<Value> wrapper) {

// No class_id should be the provider type of NONE.

CHECK_GT(class_id, NODE_ASYNC_ID_OFFSET);

// And make sure the class_id doesn't extend past the last provider.

CHECK_LE(class_id - NODE_ASYNC_ID_OFFSET, AsyncWrap::PROVIDERS_LENGTH);

CHECK(wrapper->IsObject());

CHECK(!wrapper.IsEmpty());

Local<Object> object = wrapper.As<Object>();

CHECK_GT(object->InternalFieldCount(), 0);

AsyncWrap* wrap = Unwrap<AsyncWrap>(object);

CHECK_NE(nullptr, wrap);

return new RetainedAsyncInfo(class_id, wrap);

}

// end RetainedAsyncInfo

static void DestroyIdsCb(uv_idle_t* handle) {

uv_idle_stop(handle);

Environment* env = Environment::from_destroy_ids_idle_handle(handle);

HandleScope handle_scope(env->isolate());

Context::Scope context_scope(env->context());

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

TryCatch try_catch(env->isolate());

std::vector<double> destroy_ids_list;

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

for (auto current_id : destroy_ids_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> argv = Number::New(env->isolate(), current_id);

MaybeLocal<Value> ret = fn->Call(

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

if (ret.IsEmpty()) {

ClearFatalExceptionHandlers(env);

FatalException(env->isolate(), try_catch);

}

}

env->destroy_ids_list()->clear();

}

static void PushBackDestroyId(Environment* env, double id) {

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

return;

if (env->destroy_ids_list()->empty())

uv_idle_start(env->destroy_ids_idle_handle(), DestroyIdsCb);

env->destroy_ids_list()->push_back(id);

}

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

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

if (!args[0]->IsObject())

return env->ThrowTypeError("first argument must be an object");

// 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);

#undef SET_HOOK_FN

}

void AsyncWrap::GetAsyncId(const FunctionCallbackInfo<Value>& args) {

AsyncWrap* wrap;

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

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

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

}

void AsyncWrap::PushAsyncIds(const FunctionCallbackInfo<Value>& args) {

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

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

// then the checks in push_ids() and pop_ids() will.

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

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

env->async_hooks()->push_ids(async_id, trigger_id);

}

void AsyncWrap::PopAsyncIds(const FunctionCallbackInfo<Value>& args) {

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

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

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

}

void AsyncWrap::ClearIdStack(const FunctionCallbackInfo<Value>& args) {

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

env->async_hooks()->clear_id_stack();

}

void AsyncWrap::AsyncReset(const FunctionCallbackInfo<Value>& args) {

AsyncWrap* wrap;

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

wrap->AsyncReset();

}

void AsyncWrap::QueueDestroyId(const FunctionCallbackInfo<Value>& args) {

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

PushBackDestroyId(Environment::GetCurrent(args), args[0]->NumberValue());

}

void AsyncWrap::Initialize(Local<Object> target,

Local<Value> unused,

Local<Context> context) {

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, "clearIdStack", ClearIdStack);

env->SetMethod(target, "addIdToDestroyList", QueueDestroyId);

v8::PropertyAttribute ReadOnlyDontDelete =

static_cast<v8::PropertyAttribute>(v8::ReadOnly | v8::DontDelete);

#define FORCE_SET_TARGET_FIELD(obj, str, field) \

(obj)->ForceSet(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.

uint32_t* fields_ptr = env->async_hooks()->fields();

int fields_count = env->async_hooks()->fields_count();

Local<ArrayBuffer> fields_ab =

ArrayBuffer::New(isolate, fields_ptr, fields_count * sizeof(*fields_ptr));

FORCE_SET_TARGET_FIELD(target,

"async_hook_fields",

Uint32Array::New(fields_ab, 0, fields_count));

// 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:

//

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

//

// kInitTriggerId: 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 kInitTriggerId is set back to 0.

double* uid_fields_ptr = env->async_hooks()->uid_fields();

int uid_fields_count = env->async_hooks()->uid_fields_count();

Local<ArrayBuffer> uid_fields_ab = ArrayBuffer::New(

isolate,

uid_fields_ptr,

uid_fields_count * sizeof(*uid_fields_ptr));

FORCE_SET_TARGET_FIELD(target,

"async_uid_fields",

Float64Array::New(uid_fields_ab, 0, uid_fields_count));

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(kCurrentAsyncId);

SET_HOOKS_CONSTANT(kCurrentTriggerId);

SET_HOOKS_CONSTANT(kAsyncUidCntr);

SET_HOOKS_CONSTANT(kInitTriggerId);

#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);

// These Symbols are used throughout node so the stored values on each object

// can be accessed easily across files.

FORCE_SET_TARGET_FIELD(

target,

"async_id_symbol",

Symbol::New(isolate, FIXED_ONE_BYTE_STRING(isolate, "asyncId")));

FORCE_SET_TARGET_FIELD(

target,

"trigger_id_symbol",

Symbol::New(isolate, FIXED_ONE_BYTE_STRING(isolate, "triggerId")));

#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>());

}

void LoadAsyncWrapperInfo(Environment* env) {

HeapProfiler* heap_profiler = env->isolate()->GetHeapProfiler();

#define V(PROVIDER) \

heap_profiler->SetWrapperClassInfoProvider( \

(NODE_ASYNC_ID_OFFSET + AsyncWrap::PROVIDER_ ## PROVIDER), WrapperInfo);

NODE_ASYNC_PROVIDER_TYPES(V)

#undef V

}

AsyncWrap::AsyncWrap(Environment* env,

Local<Object> object,

ProviderType provider)

: BaseObject(env, object),

provider_type_(provider) {

CHECK_NE(provider, PROVIDER_NONE);

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

// Shift provider value over to prevent id collision.

persistent().SetWrapperClassId(NODE_ASYNC_ID_OFFSET + provider);

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

AsyncReset();

}

AsyncWrap::~AsyncWrap() {

PushBackDestroyId(env(), get_id());

}

// Generalized call for both the constructor and for handles that are pooled

// and reused over their lifetime. This way a new uid can be assigned when

// the resource is pulled out of the pool and put back into use.

void AsyncWrap::AsyncReset() {

AsyncHooks* async_hooks = env()->async_hooks();

async_id_ = env()->new_async_id();

trigger_id_ = env()->get_init_trigger_id();

// 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(), get_id()),

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

object(),

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

};

TryCatch try_catch(env()->isolate());

MaybeLocal<Value> ret = init_fn->Call(

env()->context(), object(), arraysize(argv), argv);

if (ret.IsEmpty()) {

ClearFatalExceptionHandlers(env());

FatalException(env()->isolate(), try_catch);

}

}

Local<Value> AsyncWrap::MakeCallback(const Local<Function> cb,

int argc,

Local<Value>* argv) {

CHECK(env()->context() == env()->isolate()->GetCurrentContext());

AsyncHooks* async_hooks = env()->async_hooks();

Local<Object> context = object();

Local<Object> domain;

Local<Value> uid;

bool has_domain = false;

Environment::AsyncCallbackScope callback_scope(env());

if (env()->using_domains()) {

Local<Value> domain_v = context->Get(env()->domain_string());

has_domain = domain_v->IsObject();

if (has_domain) {

domain = domain_v.As<Object>();

if (domain->Get(env()->disposed_string())->IsTrue())

return Local<Value>();

}

}

if (has_domain) {

Local<Value> enter_v = domain->Get(env()->enter_string());

if (enter_v->IsFunction()) {

if (enter_v.As<Function>()->Call(domain, 0, nullptr).IsEmpty()) {

FatalError("node::AsyncWrap::MakeCallback",

"domain enter callback threw, please report this");

}

}

}

// Want currentId() to return the correct value from the callbacks.

AsyncHooks::ExecScope exec_scope(env(), get_id(), get_trigger_id());

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

uid = Number::New(env()->isolate(), get_id());

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

TryCatch try_catch(env()->isolate());

MaybeLocal<Value> ar = fn->Call(

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

if (ar.IsEmpty()) {

ClearFatalExceptionHandlers(env());

FatalException(env()->isolate(), try_catch);

return Local<Value>();

}

}

// Finally... Get to running the user's callback.

MaybeLocal<Value> ret = cb->Call(env()->context(), context, argc, argv);

Local<Value> ret_v;

if (!ret.ToLocal(&ret_v)) {

return Local<Value>();

}

// If the callback failed then the after() hooks will be called at the end

// of _fatalException().

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

if (uid.IsEmpty())

uid = Number::New(env()->isolate(), get_id());

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

TryCatch try_catch(env()->isolate());

MaybeLocal<Value> ar = fn->Call(

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

if (ar.IsEmpty()) {

ClearFatalExceptionHandlers(env());

FatalException(env()->isolate(), try_catch);

return Local<Value>();

}

}

// The execution scope of the id and trigger_id only go this far.

exec_scope.Dispose();

if (has_domain) {

Local<Value> exit_v = domain->Get(env()->exit_string());

if (exit_v->IsFunction()) {

if (exit_v.As<Function>()->Call(domain, 0, nullptr).IsEmpty()) {

FatalError("node::AsyncWrap::MakeCallback",

"domain exit callback threw, please report this");

}

}

}

if (callback_scope.in_makecallback()) {

return ret_v;

}

Environment::TickInfo* tick_info = env()->tick_info();

if (tick_info->length() == 0) {

env()->isolate()->RunMicrotasks();

}

// Make sure the stack unwound properly. If there are nested MakeCallback's

// then it should return early and not reach this code.

CHECK_EQ(env()->current_async_id(), 0);

CHECK_EQ(env()->trigger_id(), 0);

Local<Object> process = env()->process_object();

if (tick_info->length() == 0) {

tick_info->set_index(0);

return ret_v;

}

MaybeLocal<Value> rcheck =

env()->tick_callback_function()->Call(env()->context(),

process,

0,

nullptr);

// Make sure the stack unwound properly.

CHECK_EQ(env()->current_async_id(), 0);

CHECK_EQ(env()->trigger_id(), 0);

return rcheck.IsEmpty() ? Local<Value>() : ret_v;

}

} // namespace node

NODE_MODULE_CONTEXT_AWARE_BUILTIN(async_wrap, node::AsyncWrap::Initialize)