Unlocking Hybrid Power: Creating ArkTS Runtimes in Native Threads on HarmonyOSNext with Node-API

As HarmonyOS continues to advance, developers frequently encounter scenarios where they need to blend the high-performance capabilities of native C++ with the modern flexibility of ArkTS (Ark TypeScript). This integration is particularly crucial for resource-intensive or multi-threaded operations. While ArkTS efficiently drives the user interface and application logic, native modules remain essential for low-level hardware interactions and concurrent processing.

The challenge arises because ArkTS runtime environments do not automatically initialize within native C++ threads. Without an active runtime, direct invocation of ArkTS functions from native code becomes impossible. Fortunately, HarmonyOS provides a robust solution through the Node-API (NAPI). This guide explores how to manually establish an ArkTS runtime within a native C++ thread, enabling dynamic loading of ArkTS modules and seamless function calls, thus leveraging the strengths of both environments.

The Core Workflow: Bridging Native and ArkTS

To facilitate this crucial communication, a structured approach is adopted:

1. Native Module Registration: A C++ method is defined using Node-API and bound to a function responsible for creating the ArkTS runtime.
2. C++ Thread Utilization: A new pthread is initiated to host the ArkTS runtime, ensuring execution in a separate thread.
3. ArkTS Runtime Initialization: Within this dedicated thread, napi_create_ark_runtime() is invoked to set up the necessary ArkTS execution environment.
4. Dynamic ETS Module Loading: An ArkTS (ETS) module is loaded on demand using napi_load_module_with_info().
5. Function Invocation: Exported ArkTS functions, such as a custom Logger(), can then be called directly from native code via napi_call_function().
6. Resource Cleanup: Post-execution, napi_destroy_ark_runtime() is used to dismantle the ArkTS runtime, ensuring proper resource management.

This methodical pattern empowers native modules to execute ArkTS logic safely and efficiently, even in complex multi-threaded contexts.

Step-by-Step Integration Overview

Implementing this solution involves several key steps across your project:

1. API Declaration: Define the native function (e.g., createArkRuntime) in your index.d.ts file to expose it to ArkTS.
2. Native C++ Logic: In create_ark_runtime.cpp, implement the CreateArkRuntimeFunc that handles the creation, loading, execution, and destruction of the ArkTS runtime within a new thread. The CreateArkRuntime NAPI callback then spawns this thread.
3. ArkTS Invocation: From your Index.ets file, simply call the exposed native createArkRuntime() function to trigger the C++ thread and ArkTS runtime creation.
4. Parallel ArkTS Script: Create an ObjectUtil.ets (or similar) module containing the ArkTS functions (like Logger()) that your native thread will execute.
5. CMake Configuration: Update CMakeLists.txt to include your native library (entry) and link against libace_napi.z.so and libhilog_ndk.z.so to ensure NAPI functionality.

Key Advantages of This Hybrid Approach

Integrating ArkTS runtimes into native threads offers significant benefits for HarmonyOS developers:

• Precise Runtime Control: Developers gain granular control over the lifecycle of the ArkTS engine, optimizing resource allocation by initializing and destroying it exactly when needed.
• Enhanced Multithreading Support: By isolating ArkTS execution within a separate native thread, complex logic can run asynchronously without impacting the main application thread’s responsiveness.
• Seamless Interoperability: This method establishes a robust bridge between high-performance native C++ code and flexible ArkTS logic, allowing them to complement each other effectively.
• Modular and Reusable Code: ArkTS modules can be designed for specific tasks (e.g., logging, data processing) and reused across multiple native threads or contexts, fostering better code organization.
• Improved Background Performance: Resource-intensive background tasks, such as logging or telemetry, can be offloaded to ArkTS modules running in isolated runtimes, boosting overall application performance.
• Dynamic Logic Loading: The ability to load ETS modules dynamically enables more adaptable application architectures, potentially supporting plugin systems or on-the-fly feature updates.
• HarmonyOS Compliance: Utilizing official Node-API functions ensures that your implementation adheres to HarmonyOS’s runtime guidelines and resource limitations, such as the maximum of 16 runtimes per process.

Conclusion

Successfully integrating ArkTS and native C++ code on HarmonyOS through dedicated runtimes in native threads is a powerful capability. This approach grants developers precise control over ArkTS execution, enabling performance optimization, efficient background processing, and dynamic module management. Whether you’re developing system-level services or crafting high-performance applications, mastering this hybrid architecture is key to scaling efficiently within the HarmonyOS ecosystem. Remember to design your applications with the maximum limit of 16 runtime environments per process in mind for optimal stability. This technique is an invaluable addition to any HarmonyOS developer’s toolkit, empowering you to fully leverage the platform’s versatile architecture.