Node.js 子线程Crash 问题的排查方法

const addon = require.resolve('./build/Release/addon.node');
// this makes addon not be unloaded
require(addon);
const { Worker } = require('worker_threads');
new Worker(`require('${addon}').start();`, {eval: true});

#include "event_loop.h"
void on_close(uv_handle_t *handle){
    delete handle;
}
void cleanup(void* data){
    uv_close((uv_handle_t *)data, on_close);
}
void Start(const Napi::CallbackInfo &args){
    Napi::Env env = args.Env();
    uv_loop_t *loop;
    v8::Isolate* isolate = v8::Isolate::GetCurrent();
    napi_get_uv_event_loop(env, &loop);
    uv_prepare_t* prepare_handle = new uv_prepare_t;
    uv_prepare_init(loop, prepare_handle);
    uv_unref((uv_handle_t *)prepare_handle);
    uv_prepare_start(prepare_handle, [](uv_prepare_t *handle) {});
    node::AddEnvironmentCleanupHook(isolate, cleanup, prepare_handle);
}
Napi::Object Initialize(Napi::Env env, Napi::Object exports){
    exports.Set(Napi::String::New(env, "start"), Napi::Function::New(env, Start));
    return exports;
}
NODE_API_MODULE(NODE_GYP_MODULE_NAME, Initialize)

WorkerThreadData data(this);
  {
    Locker locker(isolate_);
    Isolate::Scope isolate_scope(isolate_);
    SealHandleScope outer_seal(isolate_);
    DeleteFnPtr<Environment, FreeEnvironment> env_;
    // 离开作用域时执行 env_.reset();
    auto cleanup_env = OnScopeLeave([&]() {
      isolate_->CancelTerminateExecution();
      env_.reset();
    });
    // 初始化子线程
    {
      HandleScope handle_scope(isolate_);
      Local<Context> context;
      {
        TryCatch try_catch(isolate_);
        context = NewContext(isolate_);
      }
      Context::Scope context_scope(context);
      {
        env_.reset(CreateEnvironment(
            data.isolate_data_.get(),
            context,
            std::move(argv_),
            std::move(exec_argv_),
            static_cast<EnvironmentFlags::Flags>(environment_flags_),
            thread_id_,
            std::move(inspector_parent_handle_)));
      }
      {
        Mutex::ScopedLock lock(mutex_);
        if (stopped_) return;
        this->env_ = env_.get();
      }
      {
        if (LoadEnvironment(env_.get(), StartExecutionCallback{}).IsEmpty())
          return;
      }
    }
    // 进入子线程事件循环
    {
      Maybe<int> exit_code = SpinEventLoop(env_.get());
      Mutex::ScopedLock lock(mutex_);
      if (exit_code_ == 0 && exit_code.IsJust()) {
        exit_code_ = exit_code.FromJust();
      }
    }
  }

void FreeEnvironment(Environment* env) {
  Isolate* isolate = env->isolate();
  Isolate::DisallowjavascriptExecutionScope disallow_js(isolate,
      Isolate::DisallowJavascriptExecutionScope::THROW_ON_FaiLURE);
  {
    HandleScope handle_scope(isolate);  // For env->context().
    Context::Scope context_scope(env->context());
    SealHandleScope seal_handle_scope(isolate);
    env->set_stopping(true);
    env->stop_sub_worker_contexts();
    // 执行 AddEnvironmentCleanupHook 回调
    env->RunCleanup();
    RunAtExit(env);
  }
  MultiIsolatePlatfORM* platform = env->isolate_data()->platform();
  if (platform != nullptr)
    platform->DrainTasks(isolate);
  // 删除 env 对象
  delete env;
}

if (!is_main_thread()) {
    for (binding::DLib& addon : loaded_addons_) {
      addon.Close();
    }
  }

uv_run(&loop_, UV_RUN_ONCE);

void CheckedUvLoopClose(uv_loop_t* loop) {
  if (uv_loop_close(loop) == 0) return;
  PrintLibuvHandleInformation(loop, stderr);
  fflush(stderr);
  // Finally, abort.
  CHECK(0 && "uv_loop_close() while having open handles");
}

int uv_loop_close(uv_loop_t* loop) {
  QUEUE* q;
  uv_handle_t* h;
  if (uv__has_active_reqs(loop))
    return UV_EBUSY;
  QUEUE_FOREACH(q, &loop->handle_queue) {
    h = QUEUE_DATA(q, uv_handle_t, handle_queue);
    if (!(h->flags & UV_HANDLE_INTERNAL))
      return UV_EBUSY;
  }
  uv__loop_close(loop);
  if (loop == default_loop_ptr)
    default_loop_ptr = NULL;
  return 0;
}