[SPDK] In spdk 19.10, Is there proper way to use spdk_thread_create with g_new_thread_fn == NULL?

Hello, All. Lately, I updated the spdk version from 19.01 to spdk 19.10. And I noticed that spdk_thread_create is slightly differnet. The scenario I want to implement is as below. 1) spdk_thread_lib_init -> reactor_start 2) (In another thread, ) spdk_thread_create, and this spdk_thread needs to be belong to the thread which is not a reactor (but to while loop) In 19.01, it is okay, but in 19.10 if I use spdk_thread_create, that spdk_thread is registered to one of reactors with given cpu_mask because g_new_thread_fn is registered in reactor_start step. If given cpu_mask does not contains cpus of reactor, that spdk_thread_create operation is failed. So, I put g_new_thread_fn == NULL between 1), 2) (because reactor_start() inits g_new_thread_fn as its own function) and it works in my environment, but, I'm not sure this is safe way to register thread without reactor. Please let me know the way how to create just thread not to a reactor, even after initializing reactors. Best, Sejun Kwon.