node/src/async-wrap.cc

#include "async-wrap.h"
#include "async-wrap-inl.h"
#include "env.h"
#include "env-inl.h"
#include "util.h"
#include "util-inl.h"

#include "v8.h"
#include "v8-profiler.h"

using v8::Array;
using v8::Context;
using v8::Function;
using v8::FunctionCallbackInfo;
using v8::HandleScope;
using v8::HeapProfiler;
using v8::Integer;
using v8::Isolate;
using v8::Local;
using v8::Object;
using v8::RetainedObjectInfo;
using v8::TryCatch;
using v8::Value;

namespace node {

static const char* const provider_names[] = {
#define V(PROVIDER)                                                           \
  #PROVIDER,
  NODE_ASYNC_PROVIDER_TYPES(V)
#undef V
};


class RetainedAsyncInfo: public RetainedObjectInfo {
 public:
  explicit RetainedAsyncInfo(uint16_t class_id, AsyncWrap* wrap);

  virtual void Dispose() override;
  virtual bool IsEquivalent(RetainedObjectInfo* other) override;
  virtual intptr_t GetHash() override;
  virtual const char* GetLabel() override;
  virtual 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_NE(NODE_ASYNC_ID_OFFSET, class_id);
  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 EnableHooksJS(const FunctionCallbackInfo<Value>& args) {
  Environment* env = Environment::GetCurrent(args);
  Local<Function> init_fn = env->async_hooks_init_function();
  if (init_fn.IsEmpty() || !init_fn->IsFunction())
    return env->ThrowTypeError("init callback is not assigned to a function");
  env->async_hooks()->set_enable_callbacks(1);
}


static void DisableHooksJS(const FunctionCallbackInfo<Value>& args) {
  Environment* env = Environment::GetCurrent(args);
  env->async_hooks()->set_enable_callbacks(0);
}


static void SetupHooks(const FunctionCallbackInfo<Value>& args) {
  Environment* env = Environment::GetCurrent(args);

  if (env->async_hooks()->callbacks_enabled())
    return env->ThrowError("hooks should not be set while also enabled");

  if (!args[0]->IsFunction())
    return env->ThrowTypeError("init callback must be a function");

  env->set_async_hooks_init_function(args[0].As<Function>());

  if (args[1]->IsFunction())
    env->set_async_hooks_pre_function(args[1].As<Function>());
  if (args[2]->IsFunction())
    env->set_async_hooks_post_function(args[2].As<Function>());
  if (args[3]->IsFunction())
    env->set_async_hooks_destroy_function(args[3].As<Function>());
}


static void 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, "disable", DisableHooksJS);
  env->SetMethod(target, "enable", EnableHooksJS);

  Local<Object> async_providers = Object::New(isolate);
#define V(PROVIDER)                                                           \
  async_providers->Set(FIXED_ONE_BYTE_STRING(isolate, #PROVIDER),             \
      Integer::New(isolate, AsyncWrap::PROVIDER_ ## PROVIDER));
  NODE_ASYNC_PROVIDER_TYPES(V)
#undef V
  target->Set(FIXED_ONE_BYTE_STRING(isolate, "Providers"), async_providers);

  env->set_async_hooks_init_function(Local<Function>());
  env->set_async_hooks_pre_function(Local<Function>());
  env->set_async_hooks_post_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
}


Local<Value> AsyncWrap::MakeCallback(const Local<Function> cb,
                                      int argc,
                                      Local<Value>* argv) {
  CHECK(env()->context() == env()->isolate()->GetCurrentContext());

  Local<Function> pre_fn = env()->async_hooks_pre_function();
  Local<Function> post_fn = env()->async_hooks_post_function();
  Local<Object> context = object();
  Local<Object> process = env()->process_object();
  Local<Object> domain;
  bool has_domain = false;

  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 Undefined(env()->isolate());
    }
  }

  TryCatch try_catch(env()->isolate());
  try_catch.SetVerbose(true);

  if (has_domain) {
    Local<Value> enter_v = domain->Get(env()->enter_string());
    if (enter_v->IsFunction()) {
      enter_v.As<Function>()->Call(domain, 0, nullptr);
      if (try_catch.HasCaught())
        return Undefined(env()->isolate());
    }
  }

  if (ran_init_callback() && !pre_fn.IsEmpty()) {
    try_catch.SetVerbose(false);
    pre_fn->Call(context, 0, nullptr);
    if (try_catch.HasCaught())
      FatalError("node::AsyncWrap::MakeCallback", "pre hook threw");
    try_catch.SetVerbose(true);
  }

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

  if (try_catch.HasCaught()) {
    return Undefined(env()->isolate());
  }

  if (ran_init_callback() && !post_fn.IsEmpty()) {
    try_catch.SetVerbose(false);
    post_fn->Call(context, 0, nullptr);
    if (try_catch.HasCaught())
      FatalError("node::AsyncWrap::MakeCallback", "post hook threw");
    try_catch.SetVerbose(true);
  }

  if (has_domain) {
    Local<Value> exit_v = domain->Get(env()->exit_string());
    if (exit_v->IsFunction()) {
      exit_v.As<Function>()->Call(domain, 0, nullptr);
      if (try_catch.HasCaught())
        return Undefined(env()->isolate());
    }
  }

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

  if (tick_info->in_tick()) {
    return ret;
  }

  if (tick_info->length() == 0) {
    env()->isolate()->RunMicrotasks();
  }

  if (tick_info->length() == 0) {
    tick_info->set_index(0);
    return ret;
  }

  tick_info->set_in_tick(true);

  env()->tick_callback_function()->Call(process, 0, nullptr);

  tick_info->set_in_tick(false);

  if (try_catch.HasCaught()) {
    tick_info->set_last_threw(true);
    return Undefined(env()->isolate());
  }

  return ret;
}

}  // namespace node

NODE_MODULE_CONTEXT_AWARE_BUILTIN(async_wrap, node::Initialize)