napi async init

napi_status napi_async_init(napi_env env,
                            napi_value async_resource,
                            napi_value async_resource_name,
                            napi_async_context* result)

• [in] env: The environment that the API is invoked under.
• [in] async_resource: Object associated with the async work that will be passed to possible async_hooks [init hooks][] and can be accessed by [async_hooks.executionAsyncResource()][].
• [in] async_resource_name: Identifier for the kind of resource that is being provided for diagnostic information exposed by the async_hooks API.
• [out] result: The initialized async context.

Returns napi_ok if the API succeeded.

The async_resource object needs to be kept alive until [napi_async_destroy][] to keep async_hooks related API acts correctly. In order to retain ABI compatibility with previous versions, napi_async_contexts are not maintaining the strong reference to the async_resource objects to avoid introducing causing memory leaks. However, if the async_resource is garbage collected by JavaScript engine before the napi_async_context was destroyed by napi_async_destroy, calling napi_async_context related APIs like [napi_open_callback_scope][] and [napi_make_callback][] can cause problems like loss of async context when using the AsyncLocalStoage API.

In order to retain ABI compatibility with previous versions, passing NULL for async_resource does not result in an error. However, this is not recommended as this will result poor results with async_hooks [init hooks][] and async_hooks.executionAsyncResource() as the resource is now required by the underlying async_hooks implementation in order to provide the linkage between async callbacks.