iv_init initialises the current threads ivykis event loop.
Each thread that wants to use ivykis must call
iv_init before any other ivykis functions are called.
The very first call to
iv_init in a process must run to completion before other threads are allowed
iv_init, but subsequent calls to
iv_init can be done concurrently.
iv_deinit frees all resources allocated by ivykis in this thread, and should be
called before this thread exits.
iv_inited returns true if
iv_init has been called in this thread. After
iv_deinit is called, it will return false.