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"

using v8::Context;
using v8::Function;
using v8::FunctionCallbackInfo;
using v8::Handle;
using v8::HandleScope;
using v8::Integer;
using v8::Isolate;
using v8::Local;
using v8::Object;
using v8::TryCatch;
using v8::Value;
using v8::kExternalUint32Array;

namespace node {

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

  CHECK(args[0]->IsObject());
  CHECK(args[1]->IsFunction());
  CHECK(args[2]->IsFunction());
  CHECK(args[3]->IsFunction());

  // Attach Fields enum from Environment::AsyncHooks.
  // Flags attached to this object are:
  // - kCallInitHook (0): Tells the AsyncWrap constructor whether it should
  //   make a call to the init JS callback. This is disabled by default, so
  //   even after setting the callbacks the flag will have to be set to
  //   non-zero to have those callbacks called. This only affects the init
  //   callback. If the init callback was called, then the pre/post callbacks
  //   will automatically be called.
  Local<Object> async_hooks_obj = args[0].As<Object>();
  Environment::AsyncHooks* async_hooks = env->async_hooks();
  async_hooks_obj->SetIndexedPropertiesToExternalArrayData(
      async_hooks->fields(),
      kExternalUint32Array,
      async_hooks->fields_count());

  env->set_async_hooks_init_function(args[1].As<Function>());
  env->set_async_hooks_pre_function(args[2].As<Function>());
  env->set_async_hooks_post_function(args[3].As<Function>());

  env->set_using_asyncwrap(true);
}


static void Initialize(Handle<Object> target,
                Handle<Value> unused,
                Handle<Context> context) {
  Environment* env = Environment::GetCurrent(context);
  Isolate* isolate = env->isolate();
  HandleScope scope(isolate);

  NODE_SET_METHOD(target, "setupHooks", SetupHooks);

  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);
}


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

  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;
  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 (has_async_queue()) {
    try_catch.SetVerbose(false);
    env()->async_hooks_pre_function()->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 (has_async_queue()) {
    try_catch.SetVerbose(false);
    env()->async_hooks_post_function()->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)