RGW client request

Hello everyone, I have a doubt, What I seems to understand : when a client makes a req to rgw, then the req is spawn into multiple threads and the each of the thread will have its own req_state instances, and so if I define any data structure inside req_state then there cant be any race condition right to that data structure Am I right? If not then does this mean that req_state is global to multiple threads and there is chance of race condition?