Re: How to prevent a mutex being _enter()ed from being _destroy()ed?

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

> Yes -- isn't that the symptom you're seeing, or did I miss something?
It's the mutex_oncpu in the while condition that crashes, not the on in the
if condition above the do.

> It doesn't really matter since (a) only one thread ever sets the
> variable, (b) there are no invariants around it, and (c) you never
> dereference it.  So, as soon as unp_gc decides it will use a
> particular socket, it should just store the pointer to that socket in
> some global unp_gc_current_socket, and when it's done (before closef),
> it should set unp_gc_current_socket to null; then in soput/sofree,
> just KASSERT(so != unp_gc_current_socket).
But couldn't the thread that KASSERTs read a stale copy that unp_gc() 
nulled out but the null value didn't make it to the right CPU/cache/whatever?