[slime-devel] Threads attributes

[Terje Norderhaug]

On Jun 24, 2009, at 1:16 PM, Helmut Eller wrote:
> * Terje Norderhaug [2009-06-24 02:35+0200] writes:
>
>> Where do we go from here?
>
> I'd say we should implement a backend function, say thread-attributes,
> for some Lisps. thread-attributes could just return a plist and the
> list-threads function can then figure out how to send them over the
> wire.  By default list-threads should just return everything  
> (including
> the attribute names in the first "row") and if we ever feel a need for
> filtering we can add that as optional argument.

I second that. Here is a candidate implementation that is flexible  
when it comes to the plist returned by thread-attributes. I have  
included a working tread-attributes function for openmcl.

; swank-backend.lisp

(definterface thread-attributes (thread)
   "Returns a plist of implementation-dependent attributes for the  
THREAD")

; swank.lisp

(defslimefun list-threads ()
   "Return a list ((ID NAME STATUS DESCRIPTION ...) ...) of all  
threads, with the first item in the table being a list of attribute  
names and the rest containing the corresponding attribute values  
(possibly excluding trailing null values)."
   (setq *thread-list* (all-threads))
   (loop
     with labels = NIL
     for thread in *thread-list*
     for name = (thread-name thread)
     for attributes = (thread-attributes thread)
     do (do ((plist attributes (cddr plist)))
            ((null plist))
          (unless (find (car plist) labels)
            (setf labels (nconc labels (list (car plist))))))
     collect (list* (thread-id thread)
                    (if (symbolp name) (symbol-name name) name)
                    (thread-status thread)
                    (thread-description thread)
                    (loop for label in labels
                          collect (getf attributes label)))
     into result
     finally (return (cons (append '(id name status description)
                                   labels)
                           result))))

; swank-openmcl.lisp

(defimplementation thread-attributes (thread)
   (list
    'swank::priority
    (ccl::process-priority thread)))

-- Terje Norderhaug