Get the thread identifier for the specified thread.
SDL_threadID SDL_GetThreadID(SDL_Thread * thread);
the thread to query
Returns the ID of the specified thread, or the ID of the current thread if
thread is NULL.
This thread identifier is as reported by the underlying operating system. If SDL is running on a platform that does not support threads the return value will always be zero.
This function is available since SDL 2.0.0.