HarmonyOS鸿蒙Next中为什么我的JNI_CalculateServiceWrappedImpl::GetInstance_jni方法中，jsThis_对象第二次返回到ts层后，就编程undefine了，都是同一个指针啊

HarmonyOS鸿蒙Next中为什么我的JNI_CalculateServiceWrappedImpl::GetInstance_jni方法中，jsThis_对象第二次返回到ts层后，就编程undefine了，都是同一个指针啊

ets代码

let calculateService1 = testNapi.CalculateServiceWrapped.GetInstance();
let calculateService2 = testNapi.CalculateServiceWrapped.GetInstance();
let calculateService3 = testNapi.CalculateServiceWrapped.GetInstance();

index.d.ts

export class CalculateServiceWrapped{
  private constructor();
  public static GetInstance() : CalculateServiceWrapped;
  public calculateNum(a:Number) : Number;
}

CalculateServiceWrapped

//
// Created on 2024/10/11.
//

#include "CalculateServiceWrapped.h"
#define LOG_TAG "napi_test"
#include "hilog/log.h"

static CalculateServiceWrapped* _instance = nullptr;

CalculateServiceWrapped::CalculateServiceWrapped(){
    
}

CalculateServiceWrapped* CalculateServiceWrapped::GetInstance()
{
    if(_instance == nullptr)
    {
        _instance = new CalculateServiceWrapped();
    }
    return _instance;
}

int CalculateServiceWrapped::calculateNum(int a){
    return a * a;
}

#include "jni_calculate_service_wrapped.h"
#include "src/CalculateServiceWrapped.h"
#include <string>

static thread_local napi_ref g_ref = nullptr;
napi_env JNI_CalculateServiceWrappedImpl::env_ = nullptr;
napi_value JNI_CalculateServiceWrappedImpl::jsThis_ = nullptr;
napi_ref JNI_CalculateServiceWrappedImpl::wrapper_ = nullptr;

napi_value JNI_CalculateServiceWrappedImpl::New(napi_env env, napi_callback_info info)
{
  napi_value newTarget;
  napi_get_new_target(env, info, &newTarget);
  if (newTarget != nullptr) {
    size_t argc = 1;
    napi_value args[1];
    napi_value jsThis;
    napi_get_cb_info(env, info, &argc, args, &jsThis, nullptr);

    CalculateServiceWrapped* obj = CalculateServiceWrapped::GetInstance();

    JNI_CalculateServiceWrappedImpl::env_ = env;
    JNI_CalculateServiceWrappedImpl::jsThis_ = jsThis;
    napi_wrap(env,
              jsThis,
              reinterpret_cast<void*>(obj),
              JNI_CalculateServiceWrappedImpl::Destructor,
              nullptr,  // finalize_hint
              &JNI_CalculateServiceWrappedImpl::wrapper_);

    return jsThis;
  } else {
    size_t argc = 0;
    napi_value args[1];
    napi_get_cb_info(env, info, &argc, args, nullptr, nullptr);

    napi_value cons;
    napi_get_reference_value(env, g_ref, &cons);
    napi_value instance;
    napi_new_instance(env, cons, argc, args, &instance);

    return instance;
  }
}

void JNI_CalculateServiceWrappedImpl::Destructor(napi_env env,
                          void* nativeObject,
                          [[maybe_unused]] void* finalize_hint)
{
}

napi_value JNI_CalculateServiceWrappedImpl::getJsObject()
{
    return this->jsThis_;
}

napi_value JNI_CalculateServiceWrappedImpl::GetInstance_jni(napi_env env, napi_callback_info info)
{
    if (jsThis_ == nullptr) 
    {
        auto obj = CalculateServiceWrapped::GetInstance();

        napi_property_descriptor properties[] = {
            { "GetInstance", nullptr, JNI_CalculateServiceWrappedImpl::GetInstance_jni, nullptr, nullptr, nullptr, napi_static, nullptr },
            { "calculateNum", nullptr, JNI_CalculateServiceWrappedImpl::calculateNum_jni, nullptr, nullptr, nullptr, napi_default, nullptr }
        };

        napi_value instance = nullptr;
        napi_create_object_with_properties(env, &instance, 2, properties);
    
        JNI_CalculateServiceWrappedImpl::env_ = env;
        JNI_CalculateServiceWrappedImpl::jsThis_ = instance;

        napi_wrap(env,
                  instance,
                  reinterpret_cast<void*>(obj),
                  JNI_CalculateServiceWrappedImpl::Destructor,
                  nullptr,  // finalize_hint
                  &JNI_CalculateServiceWrappedImpl::wrapper_);
    }
    return jsThis_;
}

napi_value JNI_CalculateServiceWrappedImpl::calculateNum_jni(napi_env env, napi_callback_info info)
{
    napi_value jsThis;
    size_t argc = 1;
    napi_value args[1] = {nullptr};
    napi_get_cb_info(env, info, &argc, args, &jsThis, nullptr);

    CalculateServiceWrapped *obj;
    napi_unwrap(env, jsThis, reinterpret_cast<void**>(&obj));

    int value1 = 0;
    napi_get_value_int32(env, args[0], &value1);
    
    auto tmpSelf = (CalculateServiceWrapped*)obj;
    int result = tmpSelf->calculateNum(value1);

    napi_value object;
    napi_create_int32(env, result, &object);
    
    return object;
}

napi_value JNI_CalculateServiceWrappedImpl::Init(napi_env env, napi_value exports)
{
    napi_property_descriptor properties[] = {
        { "GetInstance", nullptr, JNI_CalculateServiceWrappedImpl::GetInstance_jni, nullptr, nullptr, nullptr, napi_static, nullptr },
        { "calculateNum", nullptr, JNI_CalculateServiceWrappedImpl::calculateNum_jni, nullptr, nullptr, nullptr, napi_default, nullptr }
    };
    
    const char* class_name = "JNI_CalculateServiceWrappedImpl";
    napi_define_class(env, class_name, strlen(class_name), JNI_CalculateServiceWrappedImpl::New, nullptr, 2, properties, &cons);
    
    napi_set_named_property(env, exports, "CalculateServiceWrapped", cons);
    return exports;
}