Function update_readiness 

fn update_readiness<'tcx>(
    ecx: &mut MiriInterpCx<'tcx>,
    epoll: &Epoll,
    active_events: u32,
    force_edge: bool,
    for_each_interest: impl FnOnce(&mut dyn FnMut((FdId, i32), &mut EpollEventInterest) -> InterpResult<'tcx>) -> InterpResult<'tcx>,
) -> InterpResult<'tcx>

Call this when the interests denoted by for_each_interest have their active event set changed to active_events. The list is provided indirectly via the for_each_interest closure, which will call its argument closure for each relevant interest.

Any RefCell should be released by the time for_each_interest returns since we will then be waking up threads which might require access to those RefCell.