Marc,
Could we add thread-cells?
They can be easily implemented with a per-thread hash-table, that only gets initialized if accessed.
They are incredibly useful for per thread caches, and probably a lot of other things.
For instance, I have this common pattern that i see a lot:
(def errptr-cache
(make-hash-table-eq weak-keys: #t))
(def errptr-cache-mutex
(make-mutex))
(def (get-errptr)
(with-lock errptr-cache-mutex
(lambda ()
(cond
((hash-get errptr-cache (current-thread))
=> (lambda (errptr)
(errptr_clear errptr)
errptr))
(else
(let (errptr (check-ptr get-errptr (make_errptr)))
(hash-put! errptr-cache (current-thread) errptr)
errptr))))))
and I would like to eliminate both the lock and the weak table.