Cocoa-view-pane and background-process

MacOS 10.5, LW 5.1.2

Hello,

I replaced several output-panes of my application with cocoa-view-panes,
essentially to have more sophisticated drawing tools (Bezier curves,
shadows, etc.). The result is good but now I encountered a problem when I
call a lisp background process from a cocoa event-handling callback : There
is is a long delay before the process start. Here is a simple example :

(use-package '(:capi :mp :cocoa :objc))

;defines a subclass of NSview that accepts firstResponder

(define-objc-class myNSview () () (:objc-class-name "myNSview")
(:objc-superclass-name "NSView"))
(define-objc-method ("acceptsFirstResponder" objc-bool) ((self myNSview)) t)

;receives a key down event and calls the function do-something

(define-objc-method ("keyDown:" :void) ((self myNSview) (event
objc-object-pointer)) (declare (ignore event)) (do-something))

;creates a background process

(defun make-background-process (process-name &optional (priority 0))
  (let ((mailbox (make-mailbox)) process)
    (flet ((worker (mbox name)
             (with-simple-restart (abort (format nil "Abort job known as
~a." name))
               (loop for task = (mailbox-read mbox)
                     do (with-simple-restart (abort (format nil "Allow ~a to
proceed to next job." name))
                          (apply (car task) (cdr task)))))))
      (setf process (process-run-function process-name (list :priority
priority) #'worker mailbox process-name)
            (process-mailbox process) mailbox)
      process)))
(defparameter *background-process* (make-background-process "myProcess"))

;the function 'do-something simply calls capi:beep-pane in the background
process 

(defun do-something ()
  (let ((form #'(lambda () (beep-pane))))
    (process-send *background-process* (list form))))

#|
TEST => open the view and press some key : the beep comes after a few
seconds
(contain (make-instance 'cocoa-view-pane :view-class "myNSview"
:init-function #'(lambda (pane view) (declare (ignore pane)) (invoke view
"init"))))
|#

Any idea to work around ?

Thanks

-------------------------------------------------------
Denis Pousseur
70 rue de Wansijn
1180 Bruxelles, Belgium

Tel : 32 (0)2 219 31 09
Email :  denis.pousseur@gmail.com
Website : http://www.denispousseur.com
-------------------------------------------------------

Re: Cocoa-view-pane and background-process


On May 13, 2011, at 4:58 AM, Denis Pousseur wrote:

> MacOS 10.5, LW 5.1.2
> 
> Hello,
> 
> I replaced several output-panes of my application with cocoa-view-panes,
> essentially to have more sophisticated drawing tools (Bezier curves,
> shadows, etc.). The result is good but now I encountered a problem when I
> call a lisp background process from a cocoa event-handling callback : There
> is is a long delay before the process start

There is no delay with your example using LWM 6.0.1, 64-bit intel, under Mac OS X 10.6.7

This may be a LWM 5 specific issue.

However, I see you're using mailbox-read in a loop where I think you should be using mailbox-wait-for-event.
>From the docs:

"mailbox-wait-for-event is the appropriate way to wait for an event in a mailbox in an application with a graphical user interface, because it interacts correctly with the windowing system."

So you might try replacing mailbox-read with mailbox-wait-for-event in your worker loop and see if that resolves the issue.

wamest regards,

Ralph






Raffael Cavallaro
raffaelcavallaro@me.com

Re: Cocoa-view-pane and background-process

Hi Ralph,

Thanks for the suggestion. It's really better when using
mailbox-wait-for-event. But it not resolves the problem completely : there
are always some delays, even if they are completely unpredictable.
Sometimes, it seems to be related to the focus of the window (the delay can
be longer after changing the focus)... But it's not systematic.
I need now to test what's happening when the application is delivered.

Thanks again

Best regards

Denis


Le 13/05/11 17:58, « [NOM] » <[ADRESSE]> a écrit :

> 
> On May 13, 2011, at 4:58 AM, Denis Pousseur wrote:
> 
>> MacOS 10.5, LW 5.1.2
>> 
>> Hello,
>> 
>> I replaced several output-panes of my application with cocoa-view-panes,
>> essentially to have more sophisticated drawing tools (Bezier curves,
>> shadows, etc.). The result is good but now I encountered a problem when I
>> call a lisp background process from a cocoa event-handling callback : There
>> is is a long delay before the process start
> 
> There is no delay with your example using LWM 6.0.1, 64-bit intel, under Mac
> OS X 10.6.7
> 
> This may be a LWM 5 specific issue.
> 
> However, I see you're using mailbox-read in a loop where I think you should be
> using mailbox-wait-for-event.
> From the docs:
> 
> "mailbox-wait-for-event is the appropriate way to wait for an event in a
> mailbox in an application with a graphical user interface, because it
> interacts correctly with the windowing system."
> 
> So you might try replacing mailbox-read with mailbox-wait-for-event in your
> worker loop and see if that resolves the issue.
> 
> wamest regards,
> 
> Ralph
> 
> 
> 
> 
> 
> 
> Raffael Cavallaro
> raffaelcavallaro@me.com
> 
> 
> 
> 
> 

-------------------------------------------------------
Denis Pousseur
70 rue de Wansijn
1180 Bruxelles, Belgium

Tel : 32 (0)2 219 31 09
Email :  denis.pousseur@gmail.com
Website : http://www.denispousseur.com
-------------------------------------------------------