[Gardeners] Shared State Concurrency specification.

[Marco Monteiro]

Duncan Rose wrote:
> (let ((closure-var 0))
>    (defun some-fun ()
>      ;; do some long-running thing with closure-var
>      closure-var)
>    (defun some-other-fun ()
>      ;; do some other long-running thing with closure-var
>      closure-var))
> 
> (spawn-thread #'some-fun)
> (some-other-fun)
> 
> ... how do these threads interact with closure-var? Is there any 
> protection? Should there be? (I suppose the usual fall-back for this 
> kind of thing would be to say it's up to the programmer... the usual 
> locking schemes would probably be used, but that assumes that the 
> developer spawning the thread knows that there are dependencies between 
> these two functions).

CLOUSURE-VAR is shared state and that is why there are synchronization
mechanisms (mutex and stuff). There is no protection.

Cheers,

Marco