Posframe is slow if emacs is built using athena/lucid toolkit

[junyi-hou]

Emacs stuck for ~half second every time posframe-show is called if emacs is built with athena toolkit. However, with gtk toolkit this is not such lag.

OS: gentoo, emacs is built with flag athena which, I think, is equivilant to emacs built with --with-x-toolkit=athena.

Just thought it would be nice if it is mentioned somewhere in the readme.

[tumashu]

What is athena?

[junyi-hou]

I think it is a library emacs uses to draw stuffs in x. My understanding is that it is just an alternative to gtk.

[tumashu]

Added to NOTE，thanks!

[tumashu]

tumashu/company-posframe#2

[tumashu]

feng@debian:~/emacs/emacs$ cat configure |grep athena
                          gtk3, lucid or athena, motif, no)
	    a | at | ath | athe | athen | athena )	val=athena ;;
this option's value should be 'yes', 'no', 'lucid', 'athena', 'motif', 'gtk',
'athena' and 'lucid' are synonyms." "$LINENO" 5
    lucid | athena | motif)
/usr/athena/include
      athena | lucid ) USE_X_TOOLKIT=LUCID ;;
feng@debian:~/emacs/emacs$ 

[dgutov]

Someone should benchmark and find which low-level operation takes all this time. Maybe using M-x profiler-start.

Personally, the Lucid build looks very fast (Ubuntu 19.04/GNOME).

[rrudakov]

I use lucid build on Linux with XMonad. Profiler reports:
Memory
CPU
Hope this will help anyhow.

[dgutov]

My best guess here is that frame creation takes time. But it should only happen once.

You can wrap some key forms in posframe.el with benchmarking calls to track it:

@@ -511,57 +511,64 @@
       (posframe--mouse-banish parent-frame)
 
       ;; Create posframe
-      (setq posframe
-            (posframe--create-posframe
-             buffer
-             :font font
-             :parent-frame parent-frame
-             :left-fringe left-fringe
-             :right-fringe right-fringe
-             :internal-border-width internal-border-width
-             :internal-border-color internal-border-color
-             :foreground-color foreground-color
-             :background-color background-color
-             :keep-ratio keep-ratio
-             :respect-header-line respect-header-line
-             :respect-mode-line respect-mode-line
-             :override-parameters override-parameters))
+      (message "create %s"
+               (benchmark-elapse
+                 (setq posframe
+                       (posframe--create-posframe
+                        buffer
+                        :font font
+                        :parent-frame parent-frame
+                        :left-fringe left-fringe
+                        :right-fringe right-fringe
+                        :internal-border-width internal-border-width
+                        :internal-border-color internal-border-color
+                        :foreground-color foreground-color
+                        :background-color background-color
+                        :keep-ratio keep-ratio
+                        :respect-header-line respect-header-line
+                        :respect-mode-line respect-mode-line
+                        :override-parameters override-parameters))))
 
       ;; Insert string into the posframe buffer
       (posframe--insert-string string no-properties)
 
       ;; Set posframe's size
-      (posframe--set-frame-size
-       posframe height min-height width min-width)
 
-      ;; Move posframe
-      (posframe--set-frame-position
-       posframe
-       (posframe-run-poshandler
-        `(;All poshandlers will get info from this plist.
-          :position ,position
-          :position-info ,position-info
-          :poshandler ,poshandler
-          :font-height ,font-height
-          :font-width ,font-width
-          :posframe ,posframe
-          :posframe-width ,(frame-pixel-width posframe)
-          :posframe-height ,(frame-pixel-height posframe)
-          :posframe-buffer ,buffer
-          :parent-frame ,parent-frame
-          :parent-frame-width ,parent-frame-width
-          :parent-frame-height ,parent-frame-height
-          :parent-window ,parent-window
-          :parent-window-top ,parent-window-top
-          :parent-window-left ,parent-window-left
-          :parent-window-width ,parent-window-width
-          :parent-window-height ,parent-window-height
-          :mode-line-height ,mode-line-height
-          :minibuffer-height ,minibuffer-height
-          :header-line-height ,header-line-height
-          :x-pixel-offset ,x-pixel-offset
-          :y-pixel-offset ,y-pixel-offset))
-       parent-frame-width parent-frame-height)
+      (message "size %s"
+               (benchmark-elapse
+                 (posframe--set-frame-size
+                  posframe height min-height width min-width)))
+
+      (message "position %s"
+               (benchmark-elapse
+                 ;; Move posframe
+                 (posframe--set-frame-position
+                  posframe
+                  (posframe-run-poshandler
+                   `(;All poshandlers will get info from this plist.
+                     :position ,position
+                     :position-info ,position-info
+                     :poshandler ,poshandler
+                     :font-height ,font-height
+                     :font-width ,font-width
+                     :posframe ,posframe
+                     :posframe-width ,(frame-pixel-width posframe)
+                     :posframe-height ,(frame-pixel-height posframe)
+                     :posframe-buffer ,buffer
+                     :parent-frame ,parent-frame
+                     :parent-frame-width ,parent-frame-width
+                     :parent-frame-height ,parent-frame-height
+                     :parent-window ,parent-window
+                     :parent-window-top ,parent-window-top
+                     :parent-window-left ,parent-window-left
+                     :parent-window-width ,parent-window-width
+                     :parent-window-height ,parent-window-height
+                     :mode-line-height ,mode-line-height
+                     :minibuffer-height ,minibuffer-height
+                     :header-line-height ,header-line-height
+                     :x-pixel-offset ,x-pixel-offset
+                     :y-pixel-offset ,y-pixel-offset))
+                  parent-frame-width parent-frame-height)))
 
       ;; Delay hide posframe when timeout is a number.
       (posframe--run-timeout-timer posframe timeout)

[tumashu]

I think it is set-frame-position too slow

(posframe-show "test" :string "aaaaaaaa"
               :background-color "red")

(setq child-frame
      (with-current-buffer "test"
        posframe--frame))

(setq p nil)

(defun test ()
  (setq p (if (equal p '(10 10))
              '(100 100)
            '(10 10)))
  (set-frame-position child-frame (car p) (cadr p))
  (redraw-frame child-frame)
  (princ p))

(benchmark 1 '(test))

[tumashu]

(benchmark 5 '(test))

"Elapsed time: 1.576151s"

[tumashu]

If I use gtk version, the result is:

(benchmark 5 '(test))

"Elapsed time: 0.000332s"

[dgutov]

Okay, yes, same here. So moving is indeed slow using Lucid build. Guess company-posframe doesn't do that very often, so I didn't notice.

[tumashu]

yes, posframe have position cache,

[dgutov]

Please read this: tumashu/company-posframe#2 (comment)

Athena builds should probably benefit as much as Lucid ones.

[tumashu]

This issue should be fixed, by https://git.savannah.gnu.org/cgit/emacs.git/commit/?h=emacs-27&id=c49d379f17bcb0ce82604def2eaa04bda00bd5ec , thanks very very much for @dgutov and Martin Rudalics's hard work :-)