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 struct CallbackData { 36 napi_threadsafe_function tsfn; 37 napi_async_work work; 38 }; 39 // ArkTS线程的回调实现 40 static void CallJs(napi_env env, napi_value jsCb, void *context, void *data) { 41 if (env == nullptr) { 42 return; 43 } 44 napi_value resultNumber = nullptr; 45 napi_value undefined = nullptr; 46 napi_get_undefined(env, &undefined); 47 napi_value number1 = nullptr; 48 napi_create_int32(env, 12, &number1); 49 napi_value number2 = nullptr; 50 napi_create_int32(env, 15, &number2); 51 napi_value argv[2] = {number1, number2}; 52 napi_call_function(env, undefined, jsCb, 2, argv, &resultNumber); 53 int32_t res = 0; 54 napi_get_value_int32(env, resultNumber, &res); 55 } 56 57 // 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 58 static void ExecuteWork(napi_env env, void *data) { 59 CallbackData *callbackData = reinterpret_cast<CallbackData *>(data); 60 // 执行任务为napi_priority_idle优先级,入队方式为队列尾部入队 61 napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_idle, true); 62 napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_low, true); 63 napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_high, true); 64 napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_immediate, true); 65 // 执行任务为napi_priority_high优先级,入队方式为队列头部入队 66 napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_high, false); 67 } 68 69 static void WorkComplete(napi_env env, napi_status status, void *data) { 70 CallbackData *callbackData = reinterpret_cast<CallbackData *>(data); 71 napi_release_threadsafe_function(callbackData->tsfn, napi_tsfn_release); 72 napi_delete_async_work(env, callbackData->work); 73 callbackData->work = nullptr; 74 callbackData->tsfn = nullptr; 75 } 76 77 static napi_value CallThreadSafeWithPriority(napi_env env, napi_callback_info info) { 78 size_t argc = 1; 79 napi_value jsCb = nullptr; 80 CallbackData *callbackData = nullptr; 81 napi_get_cb_info(env, info, &argc, &jsCb, nullptr, reinterpret_cast<void **>(&callbackData)); 82 napi_value resourceName = nullptr; 83 napi_create_string_utf8(env, "Thread-safe Function Demo", NAPI_AUTO_LENGTH, &resourceName); 84 napi_create_threadsafe_function(env, jsCb, nullptr, resourceName, 0, 1, callbackData, nullptr, callbackData, CallJs, 85 &callbackData->tsfn); 86 napi_create_async_work(env, nullptr, resourceName, ExecuteWork, WorkComplete, callbackData, &callbackData->work); 87 napi_queue_async_work(env, callbackData->work); 88 return nullptr; 89 } 90 91 // 注册模块接口 92 EXTERN_C_START 93 static napi_value Init(napi_env env, napi_value exports) 94 { 95 CallbackData *callbackData = new CallbackData(); 96 napi_property_descriptor desc[] = { 97 { "callThreadSafeWithPriority", nullptr, CallThreadSafeWithPriority, nullptr, nullptr, nullptr, napi_default, callbackData } 98 }; 99 napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc); 100 return exports; 101 } 102 EXTERN_C_END 103 104 static napi_module nativeModule = { 105 .nm_version = 1, 106 .nm_flags = 0, 107 .nm_filename = nullptr, 108 .nm_register_func = Init, 109 .nm_modname = "entry", 110 .nm_priv = nullptr, 111 .reserved = { 0 }, 112 }; 113 114 extern "C" __attribute__((constructor)) void RegisterEntryModule() 115 { 116 napi_module_register(&nativeModule); 117 } 118 ``` 119 120- 接口声明 121 122 ```ts 123 // index.d.ts 124 export const callThreadSafeWithPriority: (cb: (a: number, b: number) => number) => void; 125 ``` 126 127- 编译配置 128 129 CMakeLists.txt文件需要按照如下配置 130 131 ``` 132 // CMakeLists.txt 133 # the minimum version of CMake. 134 cmake_minimum_required(VERSION 3.4.1) 135 project(myapplication) 136 137 set(NATIVERENDER_ROOT_PATH ${CMAKE_CURRENT_SOURCE_DIR}) 138 139 if(DEFINED PACKAGE_FIND_FILE) 140 include(${PACKAGE_FIND_FILE}) 141 endif() 142 143 include_directories(${NATIVERENDER_ROOT_PATH} 144 ${NATIVERENDER_ROOT_PATH}/include) 145 add_library(entry SHARED hello.cpp) 146 target_link_libraries(entry PUBLIC libace_napi.z.so) 147 ``` 148 149- ArkTS代码示例 150 151 ```ts 152 // index.ets 153 import testNapi from 'libentry.so' 154 155 let callback = (a: number, b: number) : number => { 156 console.info('result is ' + (a + b)) 157 return a + b; 158 } 159 testNapi.callThreadSafeWithPriority(callback); 160 ```