CLIM mail archive
[Prev][Next][Index][Thread]

Re: reducing time overhead of text display (in 1.1)

    Date: Mon, 20 Dec 1993 18:59 EST
    From: Daniel D Suthers <suthers+@pitt.edu>

    ----------
    In reference to my comparison of "listener":
	  Total Run Time    = 1.95 seconds
	  Ephemeral Bytes Consed =    850,176
    vs. CLIM application pane:
	  Total Run Time    = 6.73 seconds
	  Ephemeral Bytes Consed =    962,896
    Scott asks:

    > Is this a CLIM Lisp Listener, or the Lucid Lisp Listener?  If it's not a
    > Listener that's doing output recording, then those 850K bytes are pretty
    > suspicious.  If it's not a CLIM Listener, who's doing all the consing?
    > That's probably where a lot of your time is going.

    It was the Lucid lisp listener. I don't know where the consing is, will
    investigate.

Seems worthwhile, since I bet that consing is costing you 1/4 of your time even in the
non-presentation CLIM benchmark.

    ----------
    > (2) write a
    > new kind of output record that stores knows about the kind of data you
    > are presenting, and creates and caches presentations at the moment they
    > are needed (as the user is waving the mouse around), not when you are
    > doing output.  This will make mouse tracking very slightly slower, but
    > it will amortize the cost of their creation across a much greater period
    > of time.

    We already have this information in a clos object that is stored as the
    :object of the presentation, so it may not be hard, but I don't know
    CLIM well enough to know where to begin ... put that on the learning
    queue.

Seems right.

    ----------
    In reference to my macroexpansion ...
    > In the code above, what is the call to UPDATING-OUTPUT for?  It doesn't
    > supply either a unique-id or a cache-value, so that would normally mean
    > that it is the *outermost* call in redisplay.  But nothing inside it is
    > an updating output record.  And it surely doesn't add any information
    > that CLIM can use.  My advice?  If you don't need it, flush it -- it's
    > *doubling* the number of output records you are creating.

    > If you are calling REDISPLAY on (OUTPUT-RECORD DISPLAY-OBJECT) objects,
    > then I guess you'll have to keep it, but it still seems very odd that
    > there are neither lower-level calls to UPDATING-OUTPUT nor a unique-id
    > or cache-value.

    * The macro is wrapped around various kinds of display code, some of
    which is top level and some of which is not, and some of which does have
    nested presentations ... Clearly we need to specialize the macro!

    * Yes we call redisplay on (output-record display-object). This is our
    initial and incomplete attempt at incremental redisplay -- it does not
    work yet, so don't make strong inferences from the lack of cache values! 

    The displayed object is a CLOS instance (actually a mixed CLOS/LOOM
    object). Redisplay would be necessary if any of a number of slots
    (including LOOM roles) changed their values, but is not necessary for
    all changed slots. I presume this means we need to use :cache-test.

Here's a little trick that CLIM uses in a few places, this one for the edge drawing code in the
graph formatter.  This fragment generates updating-output records only when the stream is using
redisplay already.  Note the pair of tricks -- one is the conditional in the first function, and
the other is the splitting off of the helper function to avoid the consing of lexical closure
environments required by UPDATING-OUTPUT.

(defun call-arc-drawer (stream arc-drawer parent-object child-object
		        parent parent-x parent-y child child-x child-y
			arc-drawing-options)
  (declare (dynamic-extent arc-drawer))
  (if (or (stream-redisplaying-p stream)
	  (stream-current-redisplay-record stream))
      (call-arc-drawer-1 stream arc-drawer parent-object child-object
			 parent parent-x parent-y child child-x child-y
			 arc-drawing-options)
      (apply arc-drawer stream parent-object child-object
	     parent-x parent-y child-x child-y
	     arc-drawing-options)))

;; The redisplay case is split out to avoid consing a closure environment
(defun call-arc-drawer-1 (stream arc-drawer parent-object child-object
			  parent parent-x parent-y child child-x child-y
			  arc-drawing-options)
  (declare (dynamic-extent arc-drawer))
  (updating-output (stream :unique-id (list parent child)
			   :id-test #'equal
			   :cache-value (list parent-x parent-y
					      child-x child-y)
			   :cache-test #'equal)
    (apply arc-drawer stream parent-object child-object
	   parent-x parent-y child-x child-y
	   arc-drawing-options)))

    ----------
    > WITH-END-OF-PAGE-ACTION and WITH-END-OF-LINE-ACTION are not free.  
    > Hoist them out to a higher level.

    Thanks, that saved a second or two. I already had it at top level, guess
    these were just "leftovers."

    Well, that sure generated some discussion...

    --------------------------------------------------
     Dan Suthers           | LRDC, room 505A
     suthers+@pitt.edu     | 3939 O'Hara Street
     (412) 624-7036 office | University of Pittsburgh
     (412) 624-9149 fax    | Pittsburgh, PA 15260
    --------------------------------------------------
References:
Main Index | Thread Index