RE: Emacs Resource (GDI) Leak on Windows

RE: Emacs Resource (GDI) Leak on Windows

[Maguire, Andrew (GE Infra, Energy)]

Thanks very much for replying.

I am using Windows XP SP2 - I support a number of users who also have the same problem.
In the past, I am sure Windows 2000 was also affected.

I was using the prebuilt binary:
In GNU Emacs 21.2.1 (i386-msvc-nt5.1.2600)
 of 2002-03-19 on buffy
configured using `configure --with-msvc (12.00)'
Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: ENG
  locale-coding-system: iso-latin-1
  default-enable-multibyte-characters: nil

It is interesting that the development version does not appear to display the leak.
Can you confirm it with one of the released versions of Emacs?

I have the leak on Windows XP with 21.3
In GNU Emacs 21.3.1 (i386-msvc-nt5.1.2600)
 of 2003-03-28 on buffy
configured using `configure --with-msvc (12.00)'
Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: ENG
  locale-coding-system: iso-latin-1
  default-enable-multibyte-characters: t

Perhaps, if I could try the latest dev version of Emacs I could try it out locally,
in case it is somehow related to the way our machines are built.
I have never accessed devel code, not being that familiar with C, but I have been
supporting Elisp extensions for 10 years.

Thanks,
Andrew 

> -----Original Message-----
> From: Eli Zaretskii [mailto:eliz@gnu.org]
> Sent: 04 February 2006 11:32
> To: Maguire, Andrew (GE Infra, Energy)
> Cc: jasonr@gnu.org; emacs-devel@gnu.org
> Subject: Re: Emacs Resource (GDI) Leak on Windows
> 
> 
> > Date: Fri, 03 Feb 2006 15:51:06 +0000
> > From: Andrew Maguire <andrew.maguire@ps.ge.com>
> > Cc: help-gnu-emacs@gnu.org
> > 
> > This GDI leakage is still an issue - Emacs 21.2/3
> > 
> > It appears to be directly related to the display of any 
> modified fonts, 
> > italic, bold etc.
> 
> I'm not sure I can reproduce the problem with the latest development
> sources, since you didn't show any numbers in your recipe.  See below.
> 
> > For examnple,
> > 
> > 1. start up a completely plain Emacs --no-site-file.
> > 2. Run Windows Task Manager and set it to display GDI object usage.
> 
> At this point, I have 105 GDI objects showing up in the Task Manager.
> If I wait enough for the splash screen to go away, I have 108 objects.
> 
> > 3. M-x list-faces-display
> 
> As soon as I type "M-x", the number of GDI objects goes up to 118.
> After typing "list-faces-display RET", the count goes up to 119.
> 
> > 4. SCroll the buffer up and down a lot and GDI object count 
> increases.
> 
> It increases to 121 and stops there.
> 
> > 5. Make the *Faces* buffer editable and remove all lines 
> whose font is
> >     not simply a modified foreground a background colour, 
> i.e. italic
> >     bold, fixed-pitch, variable-pitch, mode-line and tool-bar.
> > 6. Repeat scrolling up and down to force redisplay of the screen
> >     and not that although the GDI count may go up by 1 or 2 
> after you
> >     stop scrolling the extra GDI resource is released 
> leaving with the
> >     same number as before.
> 
> This doesn't change the count for me.  Does that mean that the problem
> was solved, and there's no more leakage anymore?  I'm asking because
> it's not clear to me where did you see the leakage--you seem to be
> telling that whenever the fonts are not used, their GDI objects are
> released, which to me seems to mean there's no leak.
> 
> Finally, please tell what version of Windows is that.
> 
> And thanks for your report.
> 

Re: Emacs Resource (GDI) Leak on Windows

[Eli Zaretskii]

> Date: Mon, 6 Feb 2006 12:41:39 +0100
> From: "Maguire, Andrew \(GE Infra, Energy\)" <andrew.maguire@ps.ge.com>
> Cc: <jasonr@gnu.org>, <emacs-devel@gnu.org>
> 
> It is interesting that the development version does not appear to display the leak.
> Can you confirm it with one of the released versions of Emacs?

Sorry, I don't have a released version installed.  Perhaps someone
else can confirm this.

Re: [h-e-w] Emacs Resource (GDI) Leak on Windows

[Andrew Maguire]

This GDI leakage is still an issue - Emacs 21.2/3

It appears to be directly related to the display of any modified fonts, 
italic, bold etc.

For examnple,

1. start up a completely plain Emacs --no-site-file.
2. Run Windows Task Manager and set it to display GDI object usage.
3. M-x list-faces-display
4. SCroll the buffer up and down a lot and GDI object count increases.
5. Make the *Faces* buffer editable and remove all lines whose font is
    not simply a modified foreground a background colour, i.e. italic
    bold, fixed-pitch, variable-pitch, mode-line and tool-bar.
6. Repeat scrolling up and down to force redisplay of the screen
    and not that although the GDI count may go up by 1 or 2 after you
    stop scrolling the extra GDI resource is released leaving with the
    same number as before.

The GDI usage is also directly related to the font used also.
By default Emacs, uses Courier New, Regular, 10pt.
If you remove all the modified fonts above except italic.
Then you will find that GDI objects will leak if Courier New is used
but NOT if Courier is used.
It appears to be related to the method Emacs uses to generate these 
modified forms of the main font.

Courier New apears to be a TrueType font but Courier is not - whether 
that has any difference I am not sure.

I hope these observations will be able to help find a fix for this 
problem. It is a particular pain for Modes using font-lock when 
font-lock is configured to use bold and italic fonts.

As has been mentioned before in this thread, the GDI object resource is 
a strictly limited resource on Windows and when Windows approaches that 
limit the display code Windows uses to update the screen goes haywire, 
often blatting screen data in the top left portion of the screen.

Andrew Maguire

Re: Emacs Resource (GDI) Leak on Windows

[Eli Zaretskii]

> Date: Fri, 03 Feb 2006 15:51:06 +0000
> From: Andrew Maguire <andrew.maguire@ps.ge.com>
> Cc: help-gnu-emacs@gnu.org
> 
> This GDI leakage is still an issue - Emacs 21.2/3
> 
> It appears to be directly related to the display of any modified fonts, 
> italic, bold etc.

I'm not sure I can reproduce the problem with the latest development
sources, since you didn't show any numbers in your recipe.  See below.

> For examnple,
> 
> 1. start up a completely plain Emacs --no-site-file.
> 2. Run Windows Task Manager and set it to display GDI object usage.

At this point, I have 105 GDI objects showing up in the Task Manager.
If I wait enough for the splash screen to go away, I have 108 objects.

> 3. M-x list-faces-display

As soon as I type "M-x", the number of GDI objects goes up to 118.
After typing "list-faces-display RET", the count goes up to 119.

> 4. SCroll the buffer up and down a lot and GDI object count increases.

It increases to 121 and stops there.

> 5. Make the *Faces* buffer editable and remove all lines whose font is
>     not simply a modified foreground a background colour, i.e. italic
>     bold, fixed-pitch, variable-pitch, mode-line and tool-bar.
> 6. Repeat scrolling up and down to force redisplay of the screen
>     and not that although the GDI count may go up by 1 or 2 after you
>     stop scrolling the extra GDI resource is released leaving with the
>     same number as before.

This doesn't change the count for me.  Does that mean that the problem
was solved, and there's no more leakage anymore?  I'm asking because
it's not clear to me where did you see the leakage--you seem to be
telling that whenever the fonts are not used, their GDI objects are
released, which to me seems to mean there's no leak.

Finally, please tell what version of Windows is that.

And thanks for your report.