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.
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. |
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.
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;
};
static void CallJs(napi_env env, napi_value jsCb, void *context, void *data)
{
if (env == nullptr) {
return;
}
napi_handle_scope scope = nullptr;
napi_status status = napi_open_handle_scope(env, &scope);
if (status != napi_ok) {
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;
// Obtain the int32 value corresponding to resultNumber.
napi_get_value_int32(env, resultNumber, &res);
napi_close_handle_scope(env, scope);
}
// 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);
// Post a task with the specified priority napi_priority_idle and enqueue it at the tail of the queue.
napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_idle, true);
// Post a task with the specified priority napi_priority_low and enqueue it at the tail of the queue.
napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_low, true);
// Post a task with the specified priority napi_priority_high and enqueue it at the tail of the queue.
napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_high, true);
// Post a task with the specified priority napi_priority_immediate and enqueue it at the tail of the queue.
napi_call_threadsafe_function_with_priority(callbackData->tsfn, nullptr, napi_priority_immediate, true);
// Post a task with the specified priority napi_priority_high and enqueue it at the head of the 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);
if (callbackData->tsfn != nullptr) {
napi_release_threadsafe_function(callbackData->tsfn, napi_tsfn_release);
callbackData->tsfn = nullptr;
}
if (callbackData->work != nullptr) {
napi_delete_async_work(env, callbackData->work);
callbackData->work = nullptr;
}
delete callbackData;
}
static napi_value CallThreadSafeWithPriority(napi_env env, napi_callback_info info)
{
size_t argc = 1;
napi_value jsCb = nullptr;
CallbackData *callbackData = new CallbackData();
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);
if (napi_create_threadsafe_function(env, jsCb, nullptr, resourceName, 0, 1, nullptr, nullptr, nullptr, CallJs,
&callbackData->tsfn) != napi_ok) {
delete callbackData;
return nullptr;
}
// Create an async task object.
if (napi_create_async_work(env, nullptr, resourceName,
ExecuteWork, WorkComplete, callbackData, &callbackData->work) != napi_ok) {
if (callbackData->tsfn != nullptr) {
napi_release_threadsafe_function(callbackData->tsfn, napi_tsfn_release);
}
delete callbackData;
return nullptr;
}
if (napi_queue_async_work(env, callbackData->work) != napi_ok) {
if (callbackData->tsfn != nullptr) {
napi_release_threadsafe_function(callbackData->tsfn, napi_tsfn_release);
}
napi_delete_async_work(env, callbackData->work);
delete callbackData;
return nullptr;
}
return nullptr;
} Register the module.
// 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;
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);