1# Creating an ArkTs Runtime Environment Using Node-API
2
3## When to Use
4
5After creating a thread using **pthread_create**, you can use **napi_create_ark_runtime** to create an ArkTS runtime environment and load the ArkTS module in the runtime environment. To destroy an ArkTS runtime environment that is not required, use **napi_destroy_ark_runtime**.
6
7## Constraints
8
9A maximum of 16 runtime environments can be created for a process.
10
11## Example
12
131. Declare the APIs, configure compile settings, and register the module.
14
15   **Declare the APIs.**
16
17   ```ts
18   // index.d.ts
19   export const createArkRuntime: () => object;
20   ```
21
22   **Configure compile settings.**
23
24   ```
25   // CMakeLists.txt
26   # the minimum version of CMake.
27   cmake_minimum_required(VERSION 3.4.1)
28   project(MyApplication)
29
30   set(NATIVERENDER_ROOT_PATH ${CMAKE_CURRENT_SOURCE_DIR})
31
32   include_directories(${NATIVERENDER_ROOT_PATH}
33                       ${NATIVERENDER_ROOT_PATH}/include)
34   add_library(entry SHARED create_ark_runtime.cpp)
35   target_link_libraries(entry PUBLIC libace_napi.z.so libhilog_ndk.z.so)
36   ```
37
38   **Register modules.**
39
40   ```cpp
41   // create_ark_runtime.cpp
42   EXTERN_C_START
43   static napi_value Init(napi_env env, napi_value exports)
44   {
45       napi_property_descriptor desc[] = {
46           { "createArkRuntime", nullptr, CreateArkRuntime, nullptr, nullptr, nullptr, napi_default, nullptr }
47       };
48       napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc);
49       return exports;
50   }
51   EXTERN_C_END
52
53   static napi_module nativeModule = {
54       .nm_version = 1,
55       .nm_flags = 0,
56       .nm_filename = nullptr,
57       .nm_register_func = Init,
58       .nm_modname = "entry",
59       .nm_priv = nullptr,
60       .reserved = { 0 },
61   };
62
63   extern "C" __attribute__((constructor)) void RegisterQueueWorkModule()
64   {
65       napi_module_register(&nativeModule);
66   }
67   ```
68
692. Create a thread and an ArkTS runtime environment, and load the module. For details about how to load a custom module, see [Loading a Module Using Node-API](use-napi-load-module-with-info.md).
70
71   ```cpp
72   // create_ark_runtime.cpp
73   #include <pthread.h>
74
75   #include "napi/native_api.h"
76
77   static void *CreateArkRuntimeFunc(void *arg)
78   {
79       // 1. Create the ArkTS runtime environment.
80       napi_env env;
81       napi_status ret = napi_create_ark_runtime(&env);
82       if (ret != napi_ok) {
83           return nullptr;
84       }
85
86       // 2. Load custom modules.
87       napi_value objUtils;
88       ret = napi_load_module_with_info(env, "entry/src/main/ets/pages/ObjectUtils", "com.example.myapplication/entry", &objUtils);
89       if (ret != napi_ok) {
90           return nullptr;
91       }
92
93       // 3. Use the logger in ArkTS.
94       napi_value logger;
95       ret = napi_get_named_property(env, objUtils, "Logger", &logger);
96       if (ret != napi_ok) {
97           return nullptr;
98       }
99       ret = napi_call_function(env, objUtils, logger, 0, nullptr, nullptr);
100
101       // 4. Destroy the ArkTS runtime environment.
102       ret = napi_destroy_ark_runtime(&env);
103
104       return nullptr;
105   }
106
107
108   static napi_value CreateArkRuntime(napi_env env, napi_callback_info info)
109   {
110       pthread_t tid;
111       pthread_create(&tid, nullptr, CreateArkRuntimeFunc, nullptr);
112       pthread_join(tid, nullptr);
113       return nullptr;
114   }
115   ```
116
1173. Write the ArkTS code.
118
119   ```ts
120   // ObjectUtils.ets
121   export function Logger() {
122       console.log("print log");
123   }
124   ```
125
126
127