#ifndef MultiThreads_ProducerConsumer_H
#define MultiThreads_ProducerConsumer_H


#include <string>
#include <queue>
#include <mutex>
#include <condition_variable>


using namespace std;
// Principles of the producer-consumer model: Use buffer zones to balance the rate between production and consumption.
// Synchronization relationship 1: When the buffer is full, the producer needs to be blocked and wait. When a product
// pops up the buffer, the producer needs to be woken up for consumption. Synchronization relationship 2: When the
// buffer is empty, the consumer needs to be blocked and waited. When a product enters the buffer, the consumer needs to
// be woken up for consumption.
class ProducerConsumerQueue {
public:
    // constructor
    ProducerConsumerQueue() {}
    ProducerConsumerQueue(int queueSize) : m_maxSize(queueSize) {}
    // producer enqueue operation
    void PutElement(string element);
    // consumer dequeue operation
    string TakeElement();
private:
    // check whether the buffer queue is full
    bool isFull() { return (m_queue.size() == m_maxSize); }
    // check whether the buffer queue is empty
    bool isEmpty() { return m_queue.empty(); }
private:
    queue<string> m_queue{};         // buffer queue
    int m_maxSize{};                 // buffer queue capacity
    mutex m_mutex{};                 // the mutex is used to protect data consistency
    condition_variable m_notEmpty{}; // condition variable, which is used to indicate whether the buffer queue is empty
    condition_variable m_notFull{};  // condition variable, which is used to indicate whether the buffer queue is full
};
#endif // MultiThreads_ProducerConsumer_H

#include "ProducerConsumer.h"


void ProducerConsumerQueue::PutElement(string element) {
    unique_lock<mutex> lock(m_mutex); // add mutex


    while (isFull()) {
        // when the data buffer queue is full, the production is blocked and wakes up after consumer consumption
        // m_mutex is automatically released at the same time
        m_notFull.wait(lock);
    }
    // reacquire the lock
    // if the queue is not full
    // the product is added to the queue and the consumer is notified that the product can be consumed
    m_queue.push(element);
    m_notEmpty.notify_one();
}
string ProducerConsumerQueue::TakeElement() {
    unique_lock<mutex> lock(m_mutex); // add mutex


    while (isEmpty()) {
        // when the data buffer queue is empty, the consumption is blocked and the producer is woken up after production
        // m_mutex is automatically released at the same time
        m_notEmpty.wait(lock);
    }
    // reacquire the lock
    // if the queue is not empty, the product is ejected and the producer is notified that it is ready for production
    string element = m_queue.front();
    m_queue.pop();
    m_notFull.notify_one();
    return element;
}

/*
 * Copyright (c) 2024 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "napi/native_api.h"
#include "ProducerConsumer.h"
#include <vector>
#include <thread>

using namespace std;

// define global thread safe function
static napi_threadsafe_function tsFun = nullptr;

static constexpr int MAX_MSG_QUEUE_SIZE = 0; // indicates that the queue length is not limited
static constexpr int INITIAL_THREAD_COUNT = 1;

// context data provided by users
// data is transferred between the native method (initialization data), ExecuteFunc, and CompleteFunc
struct ContextData {
    napi_async_work asyncWork = nullptr; // async work object
    napi_deferred deferred = nullptr;    // associated object of the delay object promise
    napi_ref callbackRef = nullptr;      // reference of callback
    string args = "";                    // parameters from ArkTS --- imageName
    string result = "";                  // C++ sub-thread calculation result --- imagePath
};

// define the buffer queue and set the capacity to 1
static ProducerConsumerQueue buffQueue(1);

// defines the image path set, which is used for later search
static vector<string> imagePathVec{"sync.png", "callback.png", "promise.png", "tsf.png"};

// check the image paths based on the image name
static bool CheckImagePath(const string &imageName, const string &imagePath) {
    // separate character strings by suffix
    size_t pos = imagePath.find_first_of('.');
    if (pos == string::npos) {
        return false;
    }

    string nameTemp = imagePath.substr(0, pos);
    if (nameTemp.empty()) {
        return false;
    }

    // determine whether the image path is the target path based on whether the image names are the same
    return (imageName == nameTemp);
}

// search for image paths by image name
static string SearchImagePath(const string &imageName) {
    for (const string &imagePath : imagePathVec) {
        if (CheckImagePath(imageName, imagePath)) {
            return imagePath;
        }
    }

    return string("");
}

static void ProductElement(void *data) {
    buffQueue.PutElement(SearchImagePath(static_cast<ContextData *>(data)->args));
}

static void ConsumeElement(void *data) { static_cast<ContextData *>(data)->result = buffQueue.TakeElement(); }

static void ConsumeElementTSF(void *data) {
    static_cast<ContextData *>(data)->result = buffQueue.TakeElement();
    // bind consumer thread to the thread safe function
    (void)napi_acquire_threadsafe_function(tsFun);
    // send async task to the JS main thread EventLoop
    (void)napi_call_threadsafe_function(tsFun, data, napi_tsfn_blocking);
    // release thread reference
    (void)napi_release_threadsafe_function(tsFun, napi_tsfn_release);
}

static void DeleteContext(napi_env env, ContextData *contextData) {
    // delete callback reference
    if (contextData->callbackRef != nullptr) {
        (void)napi_delete_reference(env, contextData->callbackRef);
    }

    // delete async work
    if (contextData->asyncWork != nullptr) {
        (void)napi_delete_async_work(env, contextData->asyncWork);
    }

    // release context data
    delete contextData;
}

static void ExecuteFunc([[maybe_unused]] napi_env env, void *data) {
    // create producer thread
    thread producer(ProductElement, data);
    // the producer and consumer threads must be synchronized
    // otherwise, the complete operation is triggered to communicate with the ArkTS after the executeFunc is complete
    // the result is unpredictable
    producer.join();

    // create consumer thread
    thread consumer(ConsumeElement, data);
    consumer.join();
}

static void CompleteFuncCallBack(napi_env env, [[maybe_unused]] napi_status status, void *data) {
    // parse context data
    ContextData *contextData = static_cast<ContextData *>(data);

    napi_value callBack = nullptr;
    napi_status operStatus = napi_get_reference_value(env, contextData->callbackRef, &callBack);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // define the undefined variable, which is used in napi_call_function
    // because no other data is transferred, the variable is defined as undefined
    napi_value undefined = nullptr;
    operStatus = napi_get_undefined(env, &undefined);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // convert the calculation result of C++ sub-thread to the napi_value type
    napi_value callBackArgs = nullptr;
    operStatus = napi_create_string_utf8(env, contextData->result.c_str(), contextData->result.length(), &callBackArgs);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // call the JS callback and send the async calculation result on the Native to ArkTS application
    napi_value callBackResult = nullptr;
    (void)napi_call_function(env, undefined, callBack, 1, &callBackArgs, &callBackResult);

    // destroy data and release memory
    DeleteContext(env, contextData);
}

static void CompleteFuncPromise(napi_env env, [[maybe_unused]] napi_status status, void *data) {
    // parse context data
    ContextData *contextData = static_cast<ContextData *>(data);

    // convert the calculation result of C++ sub-thread to the napi_value type
    napi_value promiseArgs = nullptr;
    napi_status operStatus =
        napi_create_string_utf8(env, contextData->result.c_str(), contextData->result.length(), &promiseArgs);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // the deferred and promise object are associated. the result is sent to ArkTS application through this interface
    operStatus = napi_resolve_deferred(env, contextData->deferred, promiseArgs);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // destroy data and release memory
    DeleteContext(env, contextData);
}

static void CallJsFunction(napi_env env, napi_value callBack, [[maybe_unused]] void *context, void *data) {
    // parse context data
    ContextData *contextData = static_cast<ContextData *>(data);

    // define the undefined variable, which is used in napi_call_function
    // because no other data is transferred, the variable is defined as undefined
    napi_value undefined = nullptr;
    napi_status operStatus = napi_get_undefined(env, &undefined);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // convert the calculation result of C++ sub-thread to the napi_value type
    napi_value callBackArgs = nullptr;
    operStatus = napi_create_string_utf8(env, contextData->result.c_str(), contextData->result.length(), &callBackArgs);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // call the JS callback and send the async calculation result on the Native to ArkTS application
    napi_value callBackResult = nullptr;
    (void)napi_call_function(env, undefined, callBack, 1, &callBackArgs, &callBackResult);

    // destroy data and release memory
    DeleteContext(env, contextData);
}

// sync interface
static napi_value GetImagePathSync(napi_env env, napi_callback_info info) {
    size_t paraNum = 1;
    napi_value paraArray[1] = {nullptr};

    // parse parameters
    napi_status operStatus = napi_get_cb_info(env, info, ?Num, paraArray, nullptr, nullptr);
    if (operStatus != napi_ok) {
        return nullptr;
    }

    napi_valuetype paraDataType = napi_undefined;
    operStatus = napi_typeof(env, paraArray[0], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_string)) {
        return nullptr;
    }

    // convert napi_value to char *
    constexpr size_t buffSize = 100;
    char strBuff[buffSize]{}; // char buffer for imageName string
    size_t strLength = 0;
    operStatus = napi_get_value_string_utf8(env, paraArray[0], strBuff, buffSize, &strLength);
    if ((operStatus != napi_ok) || (strLength == 0)) {
        return nullptr;
    }

    // defines context data. the memory will be released in CompleteFunc
    auto contextData = new ContextData;
    contextData->args = strBuff;

    // create producer thread
    thread producer(ProductElement, static_cast<void *>(contextData));
    producer.join();

    // create consumer thread
    thread consumer(ConsumeElement, static_cast<void *>(contextData));
    consumer.join();

    // convert the result to napi_value and send it to ArkTs application
    napi_value result = nullptr;
    (void)napi_create_string_utf8(env, contextData->result.c_str(), contextData->result.length(), &result);

    // delete context data
    DeleteContext(env, contextData);
    return result;
}

// callback async interface
static napi_value GetImagePathAsyncCallBack(napi_env env, napi_callback_info info) {
    size_t paraNum = 2;
    napi_value paraArray[2] = {nullptr};

    // parse parameters
    napi_status operStatus = napi_get_cb_info(env, info, ?Num, paraArray, nullptr, nullptr);
    if (operStatus != napi_ok) {
        return nullptr;
    }

    napi_valuetype paraDataType = napi_undefined;
    operStatus = napi_typeof(env, paraArray[0], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_string)) {
        return nullptr;
    }

    operStatus = napi_typeof(env, paraArray[1], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_function)) {
        return nullptr;
    }

    // napi_value convert to char *
    constexpr size_t buffSize = 100;
    char strBuff[buffSize]{}; // char buffer for imageName string
    size_t strLength = 0;
    operStatus = napi_get_value_string_utf8(env, paraArray[0], strBuff, buffSize, &strLength);
    if ((operStatus != napi_ok) || (strLength == 0)) {
        return nullptr;
    }

    // defines context data. the memory will be released in CompleteFunc
    auto contextData = new ContextData;
    contextData->args = strBuff;
    operStatus = napi_create_reference(env, paraArray[1], 1, &contextData->callbackRef);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    // async resource
    napi_value asyncName = nullptr;
    string asyncStr = "async callback";
    operStatus = napi_create_string_utf8(env, asyncStr.c_str(), asyncStr.length(), &asyncName);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    // create async work
    operStatus = napi_create_async_work(env, nullptr, asyncName, ExecuteFunc, CompleteFuncCallBack,
                                        static_cast<void *>(contextData), &contextData->asyncWork);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    // add the async work to the queue and wait for scheduling
    operStatus = napi_queue_async_work(env, contextData->asyncWork);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
    }

    return nullptr;
}

// promise async interface
static napi_value GetImagePathAsyncPromise(napi_env env, napi_callback_info info) {
    size_t paraNum = 1;
    napi_value paraArray[1] = {nullptr};

    // parse parameters
    napi_status operStatus = napi_get_cb_info(env, info, ?Num, paraArray, nullptr, nullptr);
    if (operStatus != napi_ok) {
        return nullptr;
    }

    napi_valuetype paraDataType = napi_undefined;
    operStatus = napi_typeof(env, paraArray[0], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_string)) {
        return nullptr;
    }

    // napi_value convert to char *
    constexpr size_t buffSize = 100;
    char strBuff[buffSize]{}; // char buffer for imageName string
    size_t strLength = 0;
    operStatus = napi_get_value_string_utf8(env, paraArray[0], strBuff, buffSize, &strLength);
    if ((operStatus != napi_ok) || (strLength == 0)) {
        return nullptr;
    }

    // defines context data. the memory will be released in CompleteFunc
    auto contextData = new ContextData;
    contextData->args = strBuff;

    // async resource
    napi_value asyncName = nullptr;
    string asyncStr = "async promise";
    operStatus = napi_create_string_utf8(env, asyncStr.c_str(), asyncStr.length(), &asyncName);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    // create async work
    operStatus = napi_create_async_work(env, nullptr, asyncName, ExecuteFunc, CompleteFuncPromise,
                                        static_cast<void *>(contextData), &contextData->asyncWork);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    // add the async work to the queue and wait for scheduling
    operStatus = napi_queue_async_work(env, contextData->asyncWork);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    // create promise object
    napi_value promiseObj = nullptr;
    operStatus = napi_create_promise(env, &contextData->deferred, &promiseObj);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    return promiseObj;
}

// thread safe function async interface
static napi_value GetImagePathAsyncTSF(napi_env env, napi_callback_info info) {
    size_t paraNum = 2;
    napi_value paraArray[2] = {nullptr};

    // parse parameters
    napi_status operStatus = napi_get_cb_info(env, info, ?Num, paraArray, nullptr, nullptr);
    if (operStatus != napi_ok) {
        return nullptr;
    }

    napi_valuetype paraDataType = napi_undefined;
    operStatus = napi_typeof(env, paraArray[0], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_string)) {
        return nullptr;
    }

    operStatus = napi_typeof(env, paraArray[1], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_function)) {
        return nullptr;
    }

    // napi_value convert to char *
    constexpr size_t buffSize = 100;
    char strBuff[buffSize]{}; // char buffer for imageName string
    size_t strLength = 0;
    operStatus = napi_get_value_string_utf8(env, paraArray[0], strBuff, buffSize, &strLength);
    if ((operStatus != napi_ok) || (strLength == 0)) {
        return nullptr;
    }

    // async resource
    napi_value asyncName = nullptr;
    string asyncStr = "async napi_threadsafe_function";
    operStatus = napi_create_string_utf8(env, asyncStr.c_str(), asyncStr.length(), &asyncName);
    if (operStatus != napi_ok) {
        return nullptr;
    }

    // defines context data. the memory will be released in CompleteFunc
    auto contextData = new ContextData;
    contextData->args = strBuff;

    // create thread safe function
    if (tsFun == nullptr) {
        operStatus =
            napi_create_threadsafe_function(env, paraArray[1], nullptr, asyncName, MAX_MSG_QUEUE_SIZE,
                                            INITIAL_THREAD_COUNT, nullptr, nullptr, nullptr, CallJsFunction, &tsFun);
        if (operStatus != napi_ok) {
            DeleteContext(env, contextData);
            return nullptr;
        }
    }

    // create producer thread
    thread producer(ProductElement, static_cast<void *>(contextData));
    producer.detach(); // must be detached

    // create consumer thread
    thread consumer(ConsumeElementTSF, static_cast<void *>(contextData));
    consumer.detach();

    return nullptr;
}

EXTERN_C_START
static napi_value Init(napi_env env, napi_value exports) {
    napi_property_descriptor desc[] = {
        {"getImagePathSync", nullptr, GetImagePathSync, nullptr, nullptr, nullptr, napi_default, nullptr},
        {"getImagePathAsyncCallBack", nullptr, GetImagePathAsyncCallBack, nullptr, nullptr, nullptr, napi_default,
         nullptr},
        {"getImagePathAsyncPromise", nullptr, GetImagePathAsyncPromise, nullptr, nullptr, nullptr, napi_default,
         nullptr},
        {"getImagePathAsyncTSF", nullptr, GetImagePathAsyncTSF, nullptr, nullptr, nullptr, napi_default, nullptr}};
    napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc);
    return exports;
}
EXTERN_C_END

static napi_module demoModule = {
    .nm_version = 1,
    .nm_flags = 0,
    .nm_filename = nullptr,
    .nm_register_func = Init,
    .nm_modname = "entry",
    .nm_priv = ((void *)0),
    .reserved = {0},
};

extern "C" __attribute__((constructor)) void RegisterEntryModule(void) { napi_module_register(&demoModule); }

static void ProductElement(void *data) {
    buffQueue.PutElement(SearchImagePath(static_cast<ContextData *>(data)->args));
}

static void ConsumeElement(void *data) { static_cast<ContextData *>(data)->result = buffQueue.TakeElement(); }

static void ConsumeElementTSF(void *data) {
    static_cast<ContextData *>(data)->result = buffQueue.TakeElement();
    // bind consumer thread to the thread safe function
    (void)napi_acquire_threadsafe_function(tsFun);
    // send async task to the JS main thread EventLoop
    (void)napi_call_threadsafe_function(tsFun, data, napi_tsfn_blocking);
    // release thread reference
    (void)napi_release_threadsafe_function(tsFun, napi_tsfn_release);
}

import testNapi from 'libentry.so';
import Constants from '../../common/constants/CommonConstants';


@Entry
@Component
struct Index {
  @State imagePath: string = Constants.INIT_IMAGE_PATH;
  imageName: string = '';


  build() {
    Column() {
      ...
      // button list, prompting the user to click the button to select the target image.
      Column() {
        ...
        // multi-threads sync call button
        Button($r('app.string.sync_button_title'))
          .width(Constants.FULL_PARENT)
          .margin($r('app.float.button_common_margin'))
          .onClick(() => {
            this.imageName = Constants.SYNC_BUTTON_IMAGE;
            this.imagePath = Constants.IMAGE_ROOT_PATH + testNapi.getImagePathSync(this.imageName);
          })
      ...
      }
      ...
    }
    ...
  }
}

// export sync interface
export const getImagePathSync: (imageName: string) => string;

// context data provided by users
// data is transferred between the native method (initialization data), ExecuteFunc, and CompleteFunc
struct ContextData {
    napi_async_work asyncWork = nullptr; // async work object
    napi_deferred deferred = nullptr;    // associated object of the delay object promise
    napi_ref callbackRef = nullptr;      // reference of callback
    string args = "";                    // parameters from ArkTS --- imageName
    string result = "";                  // C++ sub-thread calculation result --- imagePath
};

static void DeleteContext(napi_env env, ContextData *contextData) {
    // delete callback reference
    if (contextData->callbackRef != nullptr) {
        (void)napi_delete_reference(env, contextData->callbackRef);
    }
    // delete async work
    if (contextData->asyncWork != nullptr) {
        (void)napi_delete_async_work(env, contextData->asyncWork);
    }
    // release context data
    delete contextData;
}

// sync interface
static napi_value GetImagePathSync(napi_env env, napi_callback_info info) {
    size_t paraNum = 1;
    napi_value paraArray[1] = {nullptr};
    // parse parameters
    napi_status operStatus = napi_get_cb_info(env, info, ?Num, paraArray, nullptr, nullptr);
    if (operStatus != napi_ok) {
        return nullptr;
    }
    napi_valuetype paraDataType = napi_undefined;
    operStatus = napi_typeof(env, paraArray[0], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_string)) {
        return nullptr;
    }
    // convert napi_value to char *
    constexpr size_t buffSize = 100;
    char strBuff[buffSize]{}; // char buffer for imageName string
    size_t strLength = 0;
    operStatus = napi_get_value_string_utf8(env, paraArray[0], strBuff, buffSize, &strLength);
    if ((operStatus != napi_ok) || (strLength == 0)) {
        return nullptr;
    }
    // defines context data. the memory will be released in CompleteFunc
    auto contextData = new ContextData;
    contextData->args = strBuff;
    // create producer thread
    thread producer(ProductElement, static_cast<void *>(contextData));
    producer.join();
    // create consumer thread
    thread consumer(ConsumeElement, static_cast<void *>(contextData));
    consumer.join();
    // convert the result to napi_value and send it to ArkTs application
    napi_value result = nullptr;
    (void)napi_create_string_utf8(env, contextData->result.c_str(), contextData->result.length(), &result);
    // delete context data
    DeleteContext(env, contextData);
    return result;
}

NAPI_EXTERN napi_status napi_create_async_work(napi_env env,
                                               napi_value async_resource,
                                               napi_value async_resource_name,
                                               napi_async_execute_callback execute,
                                               napi_async_complete_callback complete,
                                               void* data,
                                               napi_async_work* result);
參數(shù)說(shuō)明：
[in] env：傳入接口調(diào)用者的環(huán)境，包含方舟引擎等。由框架提供，默認(rèn)情況下直接傳入即可。
[in] async_resource：可選項(xiàng)，關(guān)聯(lián)async_hooks。
[in] async_resource_name：異步資源標(biāo)識(shí)符，主要用于async_hooks API暴露斷言診斷信息。
[in] execute：執(zhí)行業(yè)務(wù)邏輯計(jì)算函數(shù)，由libuv線程池調(diào)度執(zhí)行。在該函數(shù)中執(zhí)行IO、CPU密集型任務(wù)，不阻塞主線程。
[in] complete：execute回調(diào)函數(shù)執(zhí)行完成或取消后，觸發(fā)執(zhí)行該函數(shù)。此函數(shù)在EventLoop子線程中執(zhí)行。
[in] data：用戶(hù)提供的上下文數(shù)據(jù)，用于傳遞數(shù)據(jù)。
[out] result：napi_async_work*指針，用于返回當(dāng)前此處函數(shù)調(diào)用創(chuàng)建的異步工作項(xiàng)。 返回值：返回napi_ok表示轉(zhuǎn)換成功，其他值失敗。

import testNapi from 'libentry.so';
import Constants from '../../common/constants/CommonConstants';


@Entry
@Component
struct Index {
  @State imagePath: string = Constants.INIT_IMAGE_PATH;
  imageName: string = '';


  build() {
    Column() {
      ...
      // button list, prompting the user to click the button to select the target image.
      Column() {
        ...
        // multi-threads callback async button
        Button($r('app.string.async_callback_button_title'))
          .width(Constants.FULL_PARENT)
          .margin($r('app.float.button_common_margin'))
          .onClick(() => {
            this.imageName = Constants.CALLBACK_BUTTON_IMAGE;
            testNapi.getImagePathAsyncCallBack(this.imageName, (result: string) => {
              this.imagePath = Constants.IMAGE_ROOT_PATH + result;
            });
          })
      ...
      }
      ...
    }
    ...
  }
}

// export async callback interface
export const getImagePathAsyncCallBack: (imageName: string, callBack: (result: string) => void) => void;

static void ExecuteFunc([[maybe_unused]] napi_env env, void *data) {
    // create producer thread
    thread producer(ProductElement, data);
    // the producer and consumer threads must be synchronized
    // otherwise, the complete operation is triggered to communicate with the ArkTS after the executeFunc is complete
    // the result is unpredictable
    producer.join();
    // create consumer thread
    thread consumer(ConsumeElement, data);
    consumer.join();
}

static void CompleteFuncCallBack(napi_env env, [[maybe_unused]] napi_status status, void *data) {
    // parse context data
    ContextData *contextData = static_cast<ContextData *>(data);
    napi_value callBack = nullptr;
    napi_status operStatus = napi_get_reference_value(env, contextData->callbackRef, &callBack);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }
    // define the undefined variable, which is used in napi_call_function
    // because no other data is transferred, the variable is defined as undefined
    napi_value undefined = nullptr;
    operStatus = napi_get_undefined(env, &undefined);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }
    // convert the calculation result of C++ sub-thread to the napi_value type
    napi_value callBackArgs = nullptr;
    operStatus = napi_create_string_utf8(env, contextData->result.c_str(),
        contextData->result.length(), &callBackArgs);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }
    // call the JS callback and send the async calculation result on the Native to ArkTS application
    napi_value callBackResult = nullptr;
    (void)napi_call_function(env, undefined, callBack, 1, &callBackArgs, &callBackResult);
    // destroy data and release memory
    DeleteContext(env, contextData);
}

// callback async interface
static napi_value GetImagePathAsyncCallBack(napi_env env, napi_callback_info info) {
    size_t paraNum = 2;
    napi_value paraArray[2] = {nullptr};
    // parse parameters
    napi_status operStatus = napi_get_cb_info(env, info, ?Num, paraArray, nullptr, nullptr);
    if (operStatus != napi_ok) {
        return nullptr;
    }
    napi_valuetype paraDataType = napi_undefined;
    operStatus = napi_typeof(env, paraArray[0], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_string)) {
        return nullptr;
    }
    operStatus = napi_typeof(env, paraArray[1], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_function)) {
        return nullptr;
    }
    // napi_value convert to char *
    constexpr size_t buffSize = 100;
    char strBuff[buffSize]{}; // char buffer for imageName string
    size_t strLength = 0;
    operStatus = napi_get_value_string_utf8(env, paraArray[0], strBuff, buffSize, &strLength);
    if ((operStatus != napi_ok) || (strLength == 0)) {
        return nullptr;
    }
    // defines context data. the memory will be released in CompleteFunc
    auto contextData = new ContextData;
    contextData->args = strBuff;
    operStatus = napi_create_reference(env, paraArray[1], 1, &contextData->callbackRef);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }
    // async resource
    napi_value asyncName = nullptr;
    string asyncStr = "async callback";
    operStatus = napi_create_string_utf8(env, asyncStr.c_str(), asyncStr.length(), &asyncName);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }
    // create async work
    operStatus = napi_create_async_work(env, nullptr, asyncName, ExecuteFunc, CompleteFuncCallBack,
                                        static_cast<void *>(contextData), &contextData->asyncWork);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }
    // add the async work to the queue and wait for scheduling
    operStatus = napi_queue_async_work(env, contextData->asyncWork);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
    }
    return nullptr;
}

import testNapi from 'libentry.so';
import Constants from '../../common/constants/CommonConstants';


@Entry
@Component
struct Index {
  @State imagePath: string = Constants.INIT_IMAGE_PATH;
  imageName: string = '';


  build() {
    Column() {
      ...
      // button list, prompting the user to click the button to select the target image.
      Column() {
        ...
        // multi-threads promise async button
        Button($r('app.string.async_promise_button_title'))
          .width(Constants.FULL_PARENT)
          .margin($r('app.float.button_common_margin'))
          .onClick(() => {
            this.imageName = Constants.PROMISE_BUTTON_IMAGE;
            let promiseObj = testNapi.getImagePathAsyncPromise(this.imageName);
            promiseObj.then((result: string) => {
              this.imagePath = Constants.IMAGE_ROOT_PATH + result;
            })
          })
      ...
      }
      ...
    }
    ...
  }
}

// export async promise interface
export const getImagePathAsyncPromise: (imageName: string) => Promise<string>;

static void ExecuteFunc([[maybe_unused]] napi_env env, void *data) {
    // create producer thread
    thread producer(ProductElement, data);
    // the producer and consumer threads must be synchronized
    // otherwise, the complete operation is triggered to communicate with the ArkTS after the executeFunc is complete
    // the result is unpredictable
    producer.join();
    // create consumer thread
    thread consumer(ConsumeElement, data);
    consumer.join();
}

static void CompleteFuncPromise(napi_env env, [[maybe_unused]] napi_status status, void *data) {
    // parse context data
    ContextData *contextData = static_cast<ContextData *>(data);
    // convert the calculation result of C++ sub-thread to the napi_value type
    napi_value promiseArgs = nullptr;
    napi_status operStatus =
        napi_create_string_utf8(env, contextData->result.c_str(), contextData->result.length(), &promiseArgs);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }
    // the deferred and promise object are associated. the result is sent to ArkTS application through this interface
    operStatus = napi_resolve_deferred(env, contextData->deferred, promiseArgs);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }
    // destroy data and release memory
    DeleteContext(env, contextData);
}

// promise async interface
static napi_value GetImagePathAsyncPromise(napi_env env, napi_callback_info info) {
    size_t paraNum = 1;
    napi_value paraArray[1] = {nullptr};
    // parse parameters
    napi_status operStatus = napi_get_cb_info(env, info, ?Num, paraArray, nullptr, nullptr);
    if (operStatus != napi_ok) {
        return nullptr;
    }
    napi_valuetype paraDataType = napi_undefined;
    operStatus = napi_typeof(env, paraArray[0], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_string)) {
        return nullptr;
    }
    // napi_value convert to char *
    constexpr size_t buffSize = 100;
    char strBuff[buffSize]{}; // char buffer for imageName string
    size_t strLength = 0;
    operStatus = napi_get_value_string_utf8(env, paraArray[0], strBuff, buffSize, &strLength);
    if ((operStatus != napi_ok) || (strLength == 0)) {
        return nullptr;
    }
    // defines context data. the memory will be released in CompleteFunc
    auto contextData = new ContextData;
    contextData->args = strBuff;
    // async resource
    napi_value asyncName = nullptr;
    string asyncStr = "async promise";
    operStatus = napi_create_string_utf8(env, asyncStr.c_str(), asyncStr.length(), &asyncName);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }
    // create async work
    operStatus = napi_create_async_work(env, nullptr, asyncName, ExecuteFunc, CompleteFuncPromise,
                                        static_cast<void *>(contextData), &contextData->asyncWork);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }
    // add the async work to the queue and wait for scheduling
    operStatus = napi_queue_async_work(env, contextData->asyncWork);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }
    // create promise object
    napi_value promiseObj = nullptr;
    operStatus = napi_create_promise(env, &contextData->deferred, &promiseObj);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }
    return promiseObj;
}

NAPI_EXTERN napi_status napi_create_threadsafe_function(napi_env env,
                            napi_value func,
                            napi_value async_resource,
                            napi_value async_resource_name,
                            size_t max_queue_size,
                            size_t initial_thread_count,
                            void* thread_finalize_data,
                            napi_finalize thread_finalize_cb,
                            void* context,
                            napi_threadsafe_function_call_js call_js_cb,
                            napi_threadsafe_function* result);
參數(shù)說(shuō)明：
[in] env：傳入接口調(diào)用者的環(huán)境，包含方舟引擎等。由框架提供，默認(rèn)情況下直接傳入即可。
[in] func：ArkTS應(yīng)用側(cè)傳入的回調(diào)接口callback，可為空。當(dāng)該值為nullptr時(shí)，下文call_js_cb不能為nullptr。反之，亦然。兩者不可同時(shí)為空。
[in] async_resource：關(guān)聯(lián)async_hooks，可為空。
[in] async_resource_name：異步資源標(biāo)識(shí)符，主要用于async_hooks API暴露斷言診斷信息。
[in] max_queue_size：緩沖隊(duì)列容量，0表示無(wú)限制。線程安全函數(shù)實(shí)現(xiàn)實(shí)質(zhì)為生產(chǎn)者-消費(fèi)者模型。
[in] initial_thread_count：初始線程，包括將使用此函數(shù)的主線程，可為空。
[in] thread_finalize_data：傳遞給thread_finalize_cb接口的參數(shù)，可為空。
[in] thread_finalize_cb：當(dāng)線程安全函數(shù)結(jié)束釋放時(shí)的回調(diào)接口，可為空。
[in] context：附加的上下文數(shù)據(jù)，可為空。
[in] call_js_cb：子線程需要處理的線程安全回調(diào)任務(wù)，類(lèi)似于異步工作項(xiàng)中的complete回調(diào)。當(dāng)調(diào)用napi_call_threadsafe_function后，被拋到ArkTS主線程EventLoop中，等待調(diào)度執(zhí)行。當(dāng)該值為空時(shí)，系統(tǒng)將會(huì)調(diào)用默認(rèn)回調(diào)接口。
[out] result：線程安全函數(shù)對(duì)象指針。

import testNapi from 'libentry.so';
import Constants from '../../common/constants/CommonConstants';


@Entry
@Component
struct Index {
  @State imagePath: string = Constants.INIT_IMAGE_PATH;
  imageName: string = '';


  build() {
    Column() {
      ...
      // button list, prompting the user to click the button to select the target image.
      Column() {
        ...
        // multi-threads tsf async button
        Button($r('app.string.async_tsf_button_title'))
          .width(Constants.FULL_PARENT)
          .margin($r('app.float.button_common_margin'))
          .onClick(() => {
            this.imageName = Constants.TSF_BUTTON_IMAGE;
            testNapi.getImagePathAsyncTSF(this.imageName, (result: string) => {
              this.imagePath = Constants.IMAGE_ROOT_PATH + result;
            });
          })
      ...
      }
      ...
    }
    ...
  }
}

// export thread safe function interface
export const getImagePathAsyncTSF: (imageName: string, callBack: (result: string) => void) => void;

// define global thread safe function
static napi_threadsafe_function tsFun = nullptr;
static constexpr int MAX_MSG_QUEUE_SIZE = 0; // indicates that the queue length is not limited
static constexpr int INITIAL_THREAD_COUNT = 1;

static void CallJsFunction(napi_env env, napi_value callBack, [[maybe_unused]] void *context, void *data) {
    // parse context data
    ContextData *contextData = static_cast<ContextData *>(data);
    // define the undefined variable, which is used in napi_call_function
    // because no other data is transferred, the variable is defined as undefined
    napi_value undefined = nullptr;
    napi_status operStatus = napi_get_undefined(env, &undefined);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }
    // convert the calculation result of C++ sub-thread to the napi_value type
    napi_value callBackArgs = nullptr;
    operStatus = napi_create_string_utf8(env, contextData->result.c_str(), contextData->result.length(), &callBackArgs);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }
    // call the JS callback and send the async calculation result on the Native to ArkTS application
    napi_value callBackResult = nullptr;
    (void)napi_call_function(env, undefined, callBack, 1, &callBackArgs, &callBackResult);
    // destroy data and release memory
    DeleteContext(env, contextData);
}

// thread safe function async interface
static napi_value GetImagePathAsyncTSF(napi_env env, napi_callback_info info) {
    size_t paraNum = 2;
    napi_value paraArray[2] = {nullptr};
    // parse parameters
    napi_status operStatus = napi_get_cb_info(env, info, ?Num, paraArray, nullptr, nullptr);
    if (operStatus != napi_ok) {
        return nullptr;
    }
    napi_valuetype paraDataType = napi_undefined;
    operStatus = napi_typeof(env, paraArray[0], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_string)) {
        return nullptr;
    }
    operStatus = napi_typeof(env, paraArray[1], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_function)) {
        return nullptr;
    }
    // napi_value convert to char *
    constexpr size_t buffSize = 100;
    char strBuff[buffSize]{}; // char buffer for imageName string
    size_t strLength = 0;
    operStatus = napi_get_value_string_utf8(env, paraArray[0], strBuff, buffSize, &strLength);
    if ((operStatus != napi_ok) || (strLength == 0)) {
        return nullptr;
    }
    // async resource
    napi_value asyncName = nullptr;
    string asyncStr = "async napi_threadsafe_function";
    operStatus = napi_create_string_utf8(env, asyncStr.c_str(), asyncStr.length(), &asyncName);
    if (operStatus != napi_ok) {
        return nullptr;
    }
    // defines context data. the memory will be released in CompleteFunc
    auto contextData = new ContextData;
    contextData->args = strBuff;
    // create thread safe function
    if (tsFun == nullptr) {
        operStatus =
            napi_create_threadsafe_function(env, paraArray[1], nullptr, asyncName, MAX_MSG_QUEUE_SIZE,
                                            INITIAL_THREAD_COUNT, nullptr, nullptr, nullptr, CallJsFunction, &tsFun);
        if (operStatus != napi_ok) {
            DeleteContext(env, contextData);
            return nullptr;
        }
    }
    // create producer thread
    thread producer(ProductElement, static_cast<void *>(contextData));
    producer.detach(); // must be detached


    // create consumer thread
    thread consumer(ConsumeElementTSF, static_cast<void *>(contextData));
    consumer.detach();
    return nullptr;
}

//
// Created on 2025/7/2.
//
// Node APIs are not fully supported. To solve the compilation error of the interface cannot be found,
// please include "napi/native_api.h".
// 生產(chǎn)者-消費(fèi)者模型實(shí)現(xiàn) 
// 模型緩沖隊(duì)列
#ifndef MultiThreads_ProducerConsumer_H
#define MultiThreads_ProducerConsumer_H


#include <string>
#include <queue>
#include <mutex>
#include <condition_variable>


using namespace std;
// Principles of the producer-consumer model: Use buffer zones to balance the rate between production and consumption.
// Synchronization relationship 1: When the buffer is full, the producer needs to be blocked and wait. When a product
// pops up the buffer, the producer needs to be woken up for consumption. Synchronization relationship 2: When the
// buffer is empty, the consumer needs to be blocked and waited. When a product enters the buffer, the consumer needs to
// be woken up for consumption.
class ProducerConsumerQueue {
public:
    // constructor
    ProducerConsumerQueue() {}
    ProducerConsumerQueue(int queueSize) : m_maxSize(queueSize) {}
    // producer enqueue operation
    void PutElement(string element);
    // consumer dequeue operation
    string TakeElement();
private:
    // check whether the buffer queue is full
    bool isFull() { return (m_queue.size() == m_maxSize); }
    // check whether the buffer queue is empty
    bool isEmpty() { return m_queue.empty(); }
private:
    queue<string> m_queue{};         // buffer queue
    int m_maxSize{};                 // buffer queue capacity
    mutex m_mutex{};                 // the mutex is used to protect data consistency
    condition_variable m_notEmpty{}; // condition variable, which is used to indicate whether the buffer queue is empty
    condition_variable m_notFull{};  // condition variable, which is used to indicate whether the buffer queue is full
};
#endif // MultiThreads_ProducerConsumer_H

//
// Created on 2025/7/2.
//
// Node APIs are not fully supported. To solve the compilation error of the interface cannot be found,
// please include "napi/native_api.h".
// 生產(chǎn)者-消費(fèi)者模型實(shí)現(xiàn) 

#include "ProducerConsumer.h"


void ProducerConsumerQueue::PutElement(string element) {
    unique_lock<mutex> lock(m_mutex); // add mutex


    while (isFull()) {
        // when the data buffer queue is full, the production is blocked and wakes up after consumer consumption
        // m_mutex is automatically released at the same time
        m_notFull.wait(lock);
    }
    // reacquire the lock
    // if the queue is not full
    // the product is added to the queue and the consumer is notified that the product can be consumed
    m_queue.push(element);
    m_notEmpty.notify_one();
}
string ProducerConsumerQueue::TakeElement() {
    unique_lock<mutex> lock(m_mutex); // add mutex


    while (isEmpty()) {
        // when the data buffer queue is empty, the consumption is blocked and the producer is woken up after production
        // m_mutex is automatically released at the same time
        m_notEmpty.wait(lock);
    }
    // reacquire the lock
    // if the queue is not empty, the product is ejected and the producer is notified that it is ready for production
    string element = m_queue.front();
    m_queue.pop();
    m_notFull.notify_one();
    return element;
}

/*
 * Copyright (c) 2024 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "napi/native_api.h"
#include "ProducerConsumer.h"
#include <vector>
#include <thread>

using namespace std;

// define global thread safe function
static napi_threadsafe_function tsFun = nullptr;

static constexpr int MAX_MSG_QUEUE_SIZE = 0; // indicates that the queue length is not limited
static constexpr int INITIAL_THREAD_COUNT = 1;

// context data provided by users
// data is transferred between the native method (initialization data), ExecuteFunc, and CompleteFunc
struct ContextData {
    napi_async_work asyncWork = nullptr; // async work object
    napi_deferred deferred = nullptr;    // associated object of the delay object promise
    napi_ref callbackRef = nullptr;      // reference of callback
    string args = "";                    // parameters from ArkTS --- imageName
    string result = "";                  // C++ sub-thread calculation result --- imagePath
};

//定義一個(gè)靜態(tài)全局的模型緩沖隊(duì)列。由于，每次只處理一張圖片，所以將容量設(shè)定為1。
//
//定義一個(gè)靜態(tài)全局的圖片路徑集合，用于后文搜索。

// define the buffer queue and set the capacity to 1
static ProducerConsumerQueue buffQueue(1);

// defines the image path set, which is used for later search
static vector<string> imagePathVec{"sync.png", "callback.png", "promise.png", "tsf.png"};

// check the image paths based on the image name
static bool CheckImagePath(const string &imageName, const string &imagePath) {
    // separate character strings by suffix
    size_t pos = imagePath.find_first_of('.');
    if (pos == string::npos) {
        return false;
    }

    string nameTemp = imagePath.substr(0, pos);
    if (nameTemp.empty()) {
        return false;
    }

    // determine whether the image path is the target path based on whether the image names are the same
    return (imageName == nameTemp);
}

// search for image paths by image name
static string SearchImagePath(const string &imageName) {
    for (const string &imagePath : imagePathVec) {
        if (CheckImagePath(imageName, imagePath)) {
            return imagePath;
        }
    }

    return string("");
}
//生產(chǎn)者線程執(zhí)行函數(shù)
//生產(chǎn)者線程的執(zhí)行功能：通過(guò)解析上下文數(shù)據(jù)中的圖片名稱(chēng)參數(shù)，來(lái)搜索相應(yīng)的圖片路徑，并將其置入模型緩沖隊(duì)列中。
static void ProductElement(void *data) {
    buffQueue.PutElement(SearchImagePath(static_cast<ContextData *>(data)->args));
}

//消費(fèi)者線程執(zhí)行函數(shù)
//消費(fèi)者線程的執(zhí)行功能：通過(guò)從模型緩沖隊(duì)列中獲取圖片路徑的搜索結(jié)果，并將其置入上下文數(shù)據(jù)中，用以后續(xù)反饋給ArkTS應(yīng)用側(cè)。
//非線程安全函數(shù)消費(fèi)者執(zhí)行函數(shù)：
static void ConsumeElement(void *data) { static_cast<ContextData *>(data)->result = buffQueue.TakeElement(); }

//線程安全函數(shù)消費(fèi)者執(zhí)行函數(shù)：
static void ConsumeElementTSF(void *data) {
    static_cast<ContextData *>(data)->result = buffQueue.TakeElement();
    // bind consumer thread to the thread safe function
    (void)napi_acquire_threadsafe_function(tsFun);
    // send async task to the JS main thread EventLoop
    (void)napi_call_threadsafe_function(tsFun, data, napi_tsfn_blocking);
    // release thread reference
    (void)napi_release_threadsafe_function(tsFun, napi_tsfn_release);
}

static void DeleteContext(napi_env env, ContextData *contextData) {
    // delete callback reference
    if (contextData->callbackRef != nullptr) {
        (void)napi_delete_reference(env, contextData->callbackRef);
    }

    // delete async work
    if (contextData->asyncWork != nullptr) {
        (void)napi_delete_async_work(env, contextData->asyncWork);
    }

    // release context data
    delete contextData;
}

static void ExecuteFunc([[maybe_unused]] napi_env env, void *data) {
    // create producer thread
    thread producer(ProductElement, data);
    // the producer and consumer threads must be synchronized
    // otherwise, the complete operation is triggered to communicate with the ArkTS after the executeFunc is complete
    // the result is unpredictable
    producer.join();

    // create consumer thread
    thread consumer(ConsumeElement, data);
    consumer.join();
}

static void CompleteFuncCallBack(napi_env env, [[maybe_unused]] napi_status status, void *data) {
    // parse context data
    ContextData *contextData = static_cast<ContextData *>(data);

    napi_value callBack = nullptr;
    napi_status operStatus = napi_get_reference_value(env, contextData->callbackRef, &callBack);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // define the undefined variable, which is used in napi_call_function
    // because no other data is transferred, the variable is defined as undefined
    napi_value undefined = nullptr;
    operStatus = napi_get_undefined(env, &undefined);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // convert the calculation result of C++ sub-thread to the napi_value type
    napi_value callBackArgs = nullptr;
    operStatus = napi_create_string_utf8(env, contextData->result.c_str(), contextData->result.length(), &callBackArgs);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // call the JS callback and send the async calculation result on the Native to ArkTS application
    napi_value callBackResult = nullptr;
    (void)napi_call_function(env, undefined, callBack, 1, &callBackArgs, &callBackResult);

    // destroy data and release memory
    DeleteContext(env, contextData);
}

static void CompleteFuncPromise(napi_env env, [[maybe_unused]] napi_status status, void *data) {
    // parse context data
    ContextData *contextData = static_cast<ContextData *>(data);

    // convert the calculation result of C++ sub-thread to the napi_value type
    napi_value promiseArgs = nullptr;
    napi_status operStatus =
        napi_create_string_utf8(env, contextData->result.c_str(), contextData->result.length(), &promiseArgs);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // the deferred and promise object are associated. the result is sent to ArkTS application through this interface
    operStatus = napi_resolve_deferred(env, contextData->deferred, promiseArgs);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // destroy data and release memory
    DeleteContext(env, contextData);
}

static void CallJsFunction(napi_env env, napi_value callBack, [[maybe_unused]] void *context, void *data) {
    // parse context data
    ContextData *contextData = static_cast<ContextData *>(data);

    // define the undefined variable, which is used in napi_call_function
    // because no other data is transferred, the variable is defined as undefined
    napi_value undefined = nullptr;
    napi_status operStatus = napi_get_undefined(env, &undefined);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // convert the calculation result of C++ sub-thread to the napi_value type
    napi_value callBackArgs = nullptr;
    operStatus = napi_create_string_utf8(env, contextData->result.c_str(), contextData->result.length(), &callBackArgs);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return;
    }

    // call the JS callback and send the async calculation result on the Native to ArkTS application
    napi_value callBackResult = nullptr;
    (void)napi_call_function(env, undefined, callBack, 1, &callBackArgs, &callBackResult);

    // destroy data and release memory
    DeleteContext(env, contextData);
}

// sync interface
static napi_value GetImagePathSync(napi_env env, napi_callback_info info) {
    size_t paraNum = 1;
    napi_value paraArray[1] = {nullptr};

    // parse parameters
    napi_status operStatus = napi_get_cb_info(env, info, ?Num, paraArray, nullptr, nullptr);
    if (operStatus != napi_ok) {
        return nullptr;
    }

    napi_valuetype paraDataType = napi_undefined;
    operStatus = napi_typeof(env, paraArray[0], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_string)) {
        return nullptr;
    }

    // convert napi_value to char *
    constexpr size_t buffSize = 100;
    char strBuff[buffSize]{}; // char buffer for imageName string
    size_t strLength = 0;
    operStatus = napi_get_value_string_utf8(env, paraArray[0], strBuff, buffSize, &strLength);
    if ((operStatus != napi_ok) || (strLength == 0)) {
        return nullptr;
    }

    // defines context data. the memory will be released in CompleteFunc
    auto contextData = new ContextData;
    contextData->args = strBuff;

    // create producer thread
    thread producer(ProductElement, static_cast<void *>(contextData));
    producer.join();

    // create consumer thread
    thread consumer(ConsumeElement, static_cast<void *>(contextData));
    consumer.join();

    // convert the result to napi_value and send it to ArkTs application
    napi_value result = nullptr;
    (void)napi_create_string_utf8(env, contextData->result.c_str(), contextData->result.length(), &result);

    // delete context data
    DeleteContext(env, contextData);
    return result;
}

// callback async interface
static napi_value GetImagePathAsyncCallBack(napi_env env, napi_callback_info info) {
    size_t paraNum = 2;
    napi_value paraArray[2] = {nullptr};

    // parse parameters
    napi_status operStatus = napi_get_cb_info(env, info, ?Num, paraArray, nullptr, nullptr);
    if (operStatus != napi_ok) {
        return nullptr;
    }

    napi_valuetype paraDataType = napi_undefined;
    operStatus = napi_typeof(env, paraArray[0], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_string)) {
        return nullptr;
    }

    operStatus = napi_typeof(env, paraArray[1], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_function)) {
        return nullptr;
    }

    // napi_value convert to char *
    constexpr size_t buffSize = 100;
    char strBuff[buffSize]{}; // char buffer for imageName string
    size_t strLength = 0;
    operStatus = napi_get_value_string_utf8(env, paraArray[0], strBuff, buffSize, &strLength);
    if ((operStatus != napi_ok) || (strLength == 0)) {
        return nullptr;
    }

    // defines context data. the memory will be released in CompleteFunc
    auto contextData = new ContextData;
    contextData->args = strBuff;
    operStatus = napi_create_reference(env, paraArray[1], 1, &contextData->callbackRef);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    // async resource
    napi_value asyncName = nullptr;
    string asyncStr = "async callback";
    operStatus = napi_create_string_utf8(env, asyncStr.c_str(), asyncStr.length(), &asyncName);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    // create async work
    operStatus = napi_create_async_work(env, nullptr, asyncName, ExecuteFunc, CompleteFuncCallBack,
                                        static_cast<void *>(contextData), &contextData->asyncWork);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    // add the async work to the queue and wait for scheduling
    operStatus = napi_queue_async_work(env, contextData->asyncWork);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
    }

    return nullptr;
}

// promise async interface
static napi_value GetImagePathAsyncPromise(napi_env env, napi_callback_info info) {
    size_t paraNum = 1;
    napi_value paraArray[1] = {nullptr};

    // parse parameters
    napi_status operStatus = napi_get_cb_info(env, info, ?Num, paraArray, nullptr, nullptr);
    if (operStatus != napi_ok) {
        return nullptr;
    }

    napi_valuetype paraDataType = napi_undefined;
    operStatus = napi_typeof(env, paraArray[0], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_string)) {
        return nullptr;
    }

    // napi_value convert to char *
    constexpr size_t buffSize = 100;
    char strBuff[buffSize]{}; // char buffer for imageName string
    size_t strLength = 0;
    operStatus = napi_get_value_string_utf8(env, paraArray[0], strBuff, buffSize, &strLength);
    if ((operStatus != napi_ok) || (strLength == 0)) {
        return nullptr;
    }

    // defines context data. the memory will be released in CompleteFunc
    auto contextData = new ContextData;
    contextData->args = strBuff;

    // async resource
    napi_value asyncName = nullptr;
    string asyncStr = "async promise";
    operStatus = napi_create_string_utf8(env, asyncStr.c_str(), asyncStr.length(), &asyncName);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    // create async work
    operStatus = napi_create_async_work(env, nullptr, asyncName, ExecuteFunc, CompleteFuncPromise,
                                        static_cast<void *>(contextData), &contextData->asyncWork);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    // add the async work to the queue and wait for scheduling
    operStatus = napi_queue_async_work(env, contextData->asyncWork);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    // create promise object
    napi_value promiseObj = nullptr;
    operStatus = napi_create_promise(env, &contextData->deferred, &promiseObj);
    if (operStatus != napi_ok) {
        DeleteContext(env, contextData);
        return nullptr;
    }

    return promiseObj;
}

// thread safe function async interface
static napi_value GetImagePathAsyncTSF(napi_env env, napi_callback_info info) {
    size_t paraNum = 2;
    napi_value paraArray[2] = {nullptr};

    // parse parameters
    napi_status operStatus = napi_get_cb_info(env, info, ?Num, paraArray, nullptr, nullptr);
    if (operStatus != napi_ok) {
        return nullptr;
    }

    napi_valuetype paraDataType = napi_undefined;
    operStatus = napi_typeof(env, paraArray[0], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_string)) {
        return nullptr;
    }

    operStatus = napi_typeof(env, paraArray[1], ?DataType);
    if ((operStatus != napi_ok) || (paraDataType != napi_function)) {
        return nullptr;
    }

    // napi_value convert to char *
    constexpr size_t buffSize = 100;
    char strBuff[buffSize]{}; // char buffer for imageName string
    size_t strLength = 0;
    operStatus = napi_get_value_string_utf8(env, paraArray[0], strBuff, buffSize, &strLength);
    if ((operStatus != napi_ok) || (strLength == 0)) {
        return nullptr;
    }

    // async resource
    napi_value asyncName = nullptr;
    string asyncStr = "async napi_threadsafe_function";
    operStatus = napi_create_string_utf8(env, asyncStr.c_str(), asyncStr.length(), &asyncName);
    if (operStatus != napi_ok) {
        return nullptr;
    }

    // defines context data. the memory will be released in CompleteFunc
    auto contextData = new ContextData;
    contextData->args = strBuff;

    // create thread safe function
    if (tsFun == nullptr) {
        operStatus =
            napi_create_threadsafe_function(env, paraArray[1], nullptr, asyncName, MAX_MSG_QUEUE_SIZE,
                                            INITIAL_THREAD_COUNT, nullptr, nullptr, nullptr, CallJsFunction, &tsFun);
        if (operStatus != napi_ok) {
            DeleteContext(env, contextData);
            return nullptr;
        }
    }

    // create producer thread
    thread producer(ProductElement, static_cast<void *>(contextData));
    producer.detach(); // must be detached

    // create consumer thread
    thread consumer(ConsumeElementTSF, static_cast<void *>(contextData));
    consumer.detach();

    return nullptr;
}

EXTERN_C_START
static napi_value Init(napi_env env, napi_value exports) {
    napi_property_descriptor desc[] = {
        {"getImagePathSync", nullptr, GetImagePathSync, nullptr, nullptr, nullptr, napi_default, nullptr},
        {"getImagePathAsyncCallBack", nullptr, GetImagePathAsyncCallBack, nullptr, nullptr, nullptr, napi_default,
         nullptr},
        {"getImagePathAsyncPromise", nullptr, GetImagePathAsyncPromise, nullptr, nullptr, nullptr, napi_default,
         nullptr},
        {"getImagePathAsyncTSF", nullptr, GetImagePathAsyncTSF, nullptr, nullptr, nullptr, napi_default, nullptr}};
    napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc);
    return exports;
}
EXTERN_C_END

static napi_module demoModule = {
    .nm_version = 1,
    .nm_flags = 0,
    .nm_filename = nullptr,
    .nm_register_func = Init,
    .nm_modname = "entry",
    .nm_priv = ((void *)0),
    .reserved = {0},
};

extern "C" __attribute__((constructor)) void RegisterEntryModule(void) { napi_module_register(&demoModule); }