I've been running some tests with wasip3 recently and I was running into a situation where a program would read stdin, get some data, and then stdin would be closed. The second read of stdin wouldn't get a wakeup and would get stuck forever despite stdin being closed. I'm not 100% sure what was happening but I'm highly suspect of the Notify-based synchronization here as I know historically that's a tricky primitive to work with. This applies a hammer and moves some lock scopes up a bit further to avoid dealing with trickiness and instead ensure everything proceeds in lockstep.