napi_threadsafe_function_call_mode

赋予 napi_call_threadsafe_function() 的值，以指示只要与线程安全函数关联的队列已满，调用是否应阻塞。

¥A value to be given to napi_call_threadsafe_function() to indicate whether the call should block whenever the queue associated with the thread-safe function is full.

typedef enum {
  napi_tsfn_nonblocking,
  napi_tsfn_blocking
} napi_threadsafe_function_call_mode; 拷贝