Function linuxcnc_hal_sys::hal_port_wait_readable

pub unsafe extern "C" fn hal_port_wait_readable(
    port: *mut *mut hal_port_t, 
    count: c_uint, 
    stop: *mut sig_atomic_t
)

hal_port_wait_readable spin waits on a port until it has at least count bytes available for reading, or *stop > 0