1# 使用Node-API接口从异步线程向ArkTS线程投递指定优先级和入队方式的的任务 2Node-API中的napi_call_threadsafe_function_with_priority接口的功能是从异步线程向ArkTS线程投递任务，底层队列会根据任务的优先级和入队方式来处理任务。 3 4## 函数说明 5 6```cpp 7napi_status napi_call_threadsafe_function_with_priority(napi_threadsafe_function func, 8 void *data, 9 napi_task_priority priority, 10 bool isTail); 11``` 12 13| 参数 | 说明 | 14| :------------- | :----------------------------- | 15| func | 线程安全方法 | 16| data | 异步线程期望传递给主线程的数据 | 17| priority | 指定任务的优先级[napi_task_priority](napi-data-types-interfaces.md#线程安全任务优先级) | 18| isTail | 指定任务的入队方式，true代表任务从队列的尾部入队，false代表任务从队列的头部入队。 | 19 20## 场景介绍 21异步线程向ArkTS主线程投递的任务需要根据任务指定的优先级和入队方式进行处理。 22 23## 调用异步的ArkTS接口示例 24 25### 示例代码 26 27- 模块注册 28 29 ```c++ 30 // napi_init.cpp 31 #include "napi/native_api.h" 32 #include <string.h> 33 #include <stdlib.h> 34 35 static constexpr int INT_NUM_2 = 2; // int类型数值2 36 static constexpr int INT_NUM_12 = 12; // int类型数值12 37 static constexpr int INT_NUM_15 = 15; // int类型数值15 38 39 struct CallbackData { 40 napi_threadsafe_function tsfn; 41 napi_async_work work; 42 }; 43 // ArkTS线程的回调实现 44 static void CallJs(napi_env env, napi_value jsCb, void *context, void *data) { 45 if (env == nullptr) { 46 return; 47 } 48 napi_value resultNumber = nullptr; 49 napi_value undefined = nullptr; 50 napi_get_undefined(env, &undefined); 51 napi_value number1 = nullptr; 52 napi_create_int32(env, INT_NUM_12, &number1); 53 napi_value number2 = nullptr; 54 napi_create_int32(env, INT_NUM_15, &number2); 55 napi_value argv[2] = {number1, number2}; 56 napi_call_function(env, undefined, jsCb, INT_NUM_2, argv, &resultNumber); 57 int32_t res = 0; 58 napi_get_value_int32(env, resultNumber, &res); 59 } 60 61 // 异步线程中调用该接口向ArkTS线程投递指定优先级和入队方式的任务 62 static void ExecuteWork(napi_env env, void *data) { 63 CallbackData *callbackData = reinterpret_cast<CallbackData *>(data); 64 // 执行任务为napi_priority_idle优先级，入队方式为队列尾部入队 65 napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_idle, true); 66 napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_low, true); 67 napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_high, true); 68 napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_immediate, true); 69 // 执行任务为napi_priority_high优先级，入队方式为队列头部入队 70 napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_high, false); 71 } 72 73 static void WorkComplete(napi_env env, napi_status status, void *data) { 74 CallbackData *callbackData = reinterpret_cast<CallbackData *>(data); 75 napi_release_threadsafe_function(callbackData->tsfn, napi_tsfn_release); 76 napi_delete_async_work(env, callbackData->work); 77 callbackData->work = nullptr; 78 callbackData->tsfn = nullptr; 79 } 80 81 static napi_value CallThreadSafeWithPriority(napi_env env, napi_callback_info info) { 82 size_t argc = 1; 83 napi_value jsCb = nullptr; 84 CallbackData *callbackData = nullptr; 85 napi_get_cb_info(env, info, &argc, &jsCb, nullptr, reinterpret_cast<void **>(&callbackData)); 86 napi_value resourceName = nullptr; 87 napi_create_string_utf8(env, "Thread-safe Function Demo", NAPI_AUTO_LENGTH, &resourceName); 88 napi_create_threadsafe_function(env, jsCb, nullptr, resourceName, 0, 1, callbackData, nullptr, callbackData, CallJs, 89 &callbackData->tsfn); 90 napi_create_async_work(env, nullptr, resourceName, ExecuteWork, WorkComplete, callbackData, &callbackData->work); 91 napi_queue_async_work(env, callbackData->work); 92 return nullptr; 93 } 94 95 // 注册模块接口 96 EXTERN_C_START 97 static napi_value Init(napi_env env, napi_value exports) 98 { 99 CallbackData *callbackData = new CallbackData(); 100 napi_property_descriptor desc[] = { 101 { "callThreadSafeWithPriority", nullptr, CallThreadSafeWithPriority, nullptr, nullptr, nullptr, napi_default, callbackData } 102 }; 103 napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc); 104 return exports; 105 } 106 EXTERN_C_END 107 108 static napi_module nativeModule = { 109 .nm_version = 1, 110 .nm_flags = 0, 111 .nm_filename = nullptr, 112 .nm_register_func = Init, 113 .nm_modname = "entry", 114 .nm_priv = nullptr, 115 .reserved = { 0 }, 116 }; 117 118 extern "C" __attribute__((constructor)) void RegisterEntryModule() 119 { 120 napi_module_register(&nativeModule); 121 } 122 ``` 123 124- 接口声明 125 126 ```ts 127 // index.d.ts 128 export const callThreadSafeWithPriority: (cb: (a: number, b: number) => number) => void; 129 ``` 130 131- 编译配置 132 133 CMakeLists.txt文件需要按照如下配置 134 135 ``` 136 // CMakeLists.txt 137 # the minimum version of CMake. 138 cmake_minimum_required(VERSION 3.4.1) 139 project(myapplication) 140 141 set(NATIVERENDER_ROOT_PATH ${CMAKE_CURRENT_SOURCE_DIR}) 142 143 if(DEFINED PACKAGE_FIND_FILE) 144 include(${PACKAGE_FIND_FILE}) 145 endif() 146 147 include_directories(${NATIVERENDER_ROOT_PATH} 148 ${NATIVERENDER_ROOT_PATH}/include) 149 add_library(entry SHARED hello.cpp) 150 target_link_libraries(entry PUBLIC libace_napi.z.so) 151 ``` 152 153- ArkTS代码示例 154 155 ```ts 156 // index.ets 157 import testNapi from 'libentry.so' 158 159 let callback = (a: number, b: number) : number => { 160 console.info('result is ' + (a + b)) 161 return a + b; 162 } 163 testNapi.callThreadSafeWithPriority(callback); 164 ```