7fd5c31b创建于 2025年12月23日历史提交

Passing a Task with the Specified Priority to an ArkTS Thread from an Asynchronous Thread Using Node-API

You can use napi_call_threadsafe_function_with_priority to pass a task with a specified priority and enqueuing mode to an ArkTS thread from an asynchronous thread in a thread-safe manner. Then, the task will be processed based on its priority and enqueuing mode.

Function Description

napi_status napi_call_threadsafe_function_with_priority(napi_threadsafe_function func, void *data,
                                                        napi_task_priority priority, bool isTail);

Name	Description
func	Thread-safe function to call.
data	Data to be passed from the asynchronous thread to the main thread.
priority	Priority of the task. For details, see napi_task_priority.
isTail	Whether to add the task to the end (tail) of the task queue. The value true means to add the task to the end of the task queue; the value false means to add the task to the head of the queue.

When to Use

Pass a task to the ArkTS main thread from an asynchronous thread in a thread-safe manner. Then, the task will be processed based on its priority and enqueuing mode.

Calling an ArkTS API Asynchronously

Example

Implementation

#include "napi/native_api.h"
// ...
#include <hilog/log.h>
// ...
static constexpr int INT_ARG_2 = 2; // Input parameter index.
static constexpr int INT_ARG_12 = 12; // Input parameter index.
static constexpr int INT_ARG_15 = 15; // Input parameter index.
// ...
struct CallbackData {
    napi_threadsafe_function tsfn;
    napi_async_work work;
};
// Callback implementation in the ArkTS thread.
static void CallJs(napi_env env, napi_value jsCb, void *context, void *data)
{
    if (env == nullptr) {
        return;
    }
    napi_value resultNumber = nullptr;
    napi_value undefined = nullptr;
    napi_get_undefined(env, &undefined);
    napi_value number1 = nullptr;
    napi_create_int32(env, INT_ARG_12, &number1);
    napi_value number2 = nullptr;
    napi_create_int32(env, INT_ARG_15, &number2);
    napi_value argv[2] = {number1, number2};
    napi_call_function(env, undefined, jsCb, INT_ARG_2, argv, &resultNumber);
    int32_t res = 0;
    napi_get_value_int32(env, resultNumber, &res);
}

// Call this API in an asynchronous thread to pass a task with the specified priority and enqueuing mode to an ArkTS thread.
static void ExecuteWork(napi_env env, void *data)
{
    CallbackData *callbackData = reinterpret_cast<CallbackData *>(data);
    // The task priority is napi_priority_idle, and the task is added to the end of the task queue.
    napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_idle, true);
    napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_low, true);
    napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_high, true);
    napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_immediate, true);
    // The task priority is napi_priority_high, and the task is added to the head of the task queue.
    napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_high, false);
}

static void WorkComplete(napi_env env, napi_status status, void *data)
{
    CallbackData *callbackData = reinterpret_cast<CallbackData *>(data);
    napi_release_threadsafe_function(callbackData->tsfn, napi_tsfn_release);
    napi_delete_async_work(env, callbackData->work);
    callbackData->work = nullptr;
    callbackData->tsfn = nullptr;
}

static napi_value CallThreadSafeWithPriority(napi_env env, napi_callback_info info)
{
    CallbackData *callbackData = new CallbackData();
    size_t argc = 1;
    napi_value jsCb = nullptr;
    napi_get_cb_info(env, info, &argc, &jsCb, nullptr, nullptr);
    napi_value resourceName = nullptr;
    napi_create_string_utf8(env, "Thread-safe Function Demo", NAPI_AUTO_LENGTH, &resourceName);
    napi_create_threadsafe_function(env, jsCb, nullptr, resourceName, 0, 1, callbackData, nullptr, callbackData, CallJs,
                                    &callbackData->tsfn);
    napi_create_async_work(env, nullptr, resourceName, ExecuteWork, WorkComplete, callbackData, &callbackData->work);
    napi_queue_async_work(env, callbackData->work);
    return nullptr;
}

napi_init.cpp

// Register the module.
EXTERN_C_START
static napi_value Init(napi_env env, napi_value exports)
{
    napi_property_descriptor desc[] = {
        { "callThreadSafeWithPriority", nullptr, CallThreadSafeWithPriority, 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 nativeModule = {
    .nm_version = 1,
    .nm_flags = 0,
    .nm_filename = nullptr,
    .nm_register_func = Init,
    .nm_modname = "entry",
    .nm_priv = nullptr,
    .reserved = { 0 },
};

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

Declare the API.

// index.d.ts
export const callThreadSafeWithPriority: (cb: (a: number, b: number) => number) => void;

Index.d.ts

Configure compile settings.

Configure the CMakeLists.txt file as follows:

# the minimum version of CMake.
cmake_minimum_required(VERSION 3.5.0)
project(MyApplication3)

set(NATIVERENDER_ROOT_PATH ${CMAKE_CURRENT_SOURCE_DIR})

if(DEFINED PACKAGE_FIND_FILE)
    include(${PACKAGE_FIND_FILE})
endif()
add_definitions( "-DLOG_TAG=\"LOG_TAG\"" )
include_directories(${NATIVERENDER_ROOT_PATH}
                    ${NATIVERENDER_ROOT_PATH}/include)

add_library(entry SHARED napi_init.cpp)
target_link_libraries(entry PUBLIC libace_napi.z.so libhilog_ndk.z.so)

Import the header file of ArkTS.
```
import testNapi from 'libentry.so';
```

ArkTS sample code

// index.ets
let callback = (a: number, b: number): number => {
  console.info('result is ' + (a + b))
  return a + b;
}
testNapi.callThreadSafeWithPriority(callback);

Index.ets