[Bug 10114] New: Wine shouldn't rewrite the registry if it hasn' t been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

Summary: Wine shouldn't rewrite the registry if it hasn't been
                    changed
           Product: Wine
           Version: CVS/GIT
          Platform: All
        OS/Version: All
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: wine-kernel
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

[birdie@localhost .wine]$ ls -l
total 400
drwxrwxr-x 2 birdie birdie   4096 2007-10-20 12:23 dosdevices
drwxrwxr-x 4 birdie birdie   4096 2007-10-20 12:23 drive_c
-rw-rw-r-- 1 birdie birdie 368887 2007-10-20 12:33 system.reg
-rw-rw-r-- 1 birdie birdie   2373 2007-10-20 12:33 userdef.reg
-rw-rw-r-- 1 birdie birdie  16422 2007-10-20 12:33 user.reg
[birdie@localhost .wine]$
[birdie@localhost .wine]$ notepad
(do nothing, just close it)
[birdie@localhost .wine]$ ls -l
total 400
drwxrwxr-x 2 birdie birdie   4096 2007-10-20 12:23 dosdevices
drwxrwxr-x 4 birdie birdie   4096 2007-10-20 12:23 drive_c
-rw-rw-r-- 1 birdie birdie 368887 2007-10-20 12:37 system.reg
-rw-rw-r-- 1 birdie birdie   2373 2007-10-20 12:37 userdef.reg
-rw-rw-r-- 1 birdie birdie  16422 2007-10-20 12:37 user.reg

All registry files got rewritten even though I haven't touched any registry
key.

I consider this behaviour being a bug.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #1 from Alexandre Julliard   2007-10-20 07:56:25 ---
The registry is not saved if it's not modified. However, some registry keys are
updated when the server starts, for things like the font cache, the CPU info,
the locale setup, etc. Some of these could probably be made volatile keys
though.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #2 from Artem S. Tashkinov   2007-10-20 08:32:41 ---
> things like the font cache, the CPU info,

the locale setup, etc.

Alexander, you may run a plain console application ten times in a row and every
time a registry will be rewritten even though nothing changes.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #3 from Artem S. Tashkinov   2007-10-20 08:35:50 ---
If we had a binary registry stored in e.g. SQLite then it would be very easy to
dump only changed registry keys. Also that will speed up wine loading and
exiting ;-)

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

Vitaliy Margolen  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID

--- Comment #4 from Vitaliy Margolen   2007-10-20 10:36:00 ---
It changed, you just didn't bother to compare old and new. Wine auto-updates
number of registry entries on each start.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #5 from Artem S. Tashkinov   2007-10-20 11:02:34 ---
Vitaliy, it's quite normal for Wine registry to grow up 10-20MB in size and
even bigger and it's insane rewriting such a big file every time when no
changes to the registry have been committed.
> It changed, you just didn't bother to compare old and new. Wine auto-updates
> number of registry entries on each start.

The bug is about the *inefficient* manner in which registry files are being
read and dumped, not about registry keys being changed.

I'm very sorry for bothering you.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #6 from Alexandre Julliard   2007-10-21 02:51:19 ---
The saving happens in the background so it doesn't really matter if it's
inefficient. The loading does delay startup a little bit, but I don't see much
evidence that it's a significant slowdown.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #7 from Austin English   2007-10-21 03:02:11 ---
Created an attachment (id=8699)
 --> (http://bugs.winehq.org/attachment.cgi?id=8699)
Bzipped registry files

I did a little test, FWIW. I ran wineprefixcreate to create a clean .wine. I
backed up all registry files, and then ran wine notepad. Backed up all registry
files as *.reg.1. Then I ran wine notepad again, backed up all registry files
as *.reg.2. I then ran a diff between *.reg and *.reg.1 as well as *.reg.1 and
*.reg.2. I bziped the folder containing all the files and attached it here. I
simply launched notepad each time and exited. I did not move the window, type
anything, etc.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #8 from Artem S. Tashkinov   2007-10-21 08:12:33 ---
Austin, I haven't understood your intentions, probably you were trying to show
me that registry is indeed changed every time when someone runs notepad.

Anyway I'd like to stress, that wineserver will rewrite the registry files no
matter what you run. You can do this simple test:

strace -f -s 300 -o /tmp/wine wine cmd

then type 'exit' or press 'Ctrl' + 'D'

(run it several times).

You will then notice that registry files are rewritten.

So actually there are two bugs here:

1) wineserver doesn't track registry modification and dumps the registry files
every time when a particular application exits

and

2) IMO, registry files should be stored in whatever SQL backend so that a) it's
not necessary to load the entire registry into memory upon start b) it's very
easy to dump modified or newly created registry keys

SQLite (library) seems to be the best solution here due to its unconfined
license, effectiveness, small size and ubiquitousness

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

Alexandre Julliard  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[e-mail]

--- Comment #9 from Alexandre Julliard   2007-10-21 12:27:57 ---
> - wineserver doesn't track registry modification and dumps the registry files
>
> every time when a particular application exits

It does track registry modifications, and it doesn't save unmodified files.
Also application exit has nothing whatsoever to do with it, registry is saved
(if modified) upon wineserver exit. There's no bug here, it's working as
designed.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

Dan Kegel  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |CLOSED

--- Comment #10 from Dan Kegel   2008-01-28 05:58:52 ---
Closing all RESOLVED INVALID older than four weeks.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

Austin English  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
            Version|CVS/GIT                     |unspecified

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #11 from Artem S. Tashkinov   2010-03-18 04:32:06 ---
Created an attachment (id=26872)
 --> (http://bugs.winehq.org/attachment.cgi?id=26872)
97 bytes executive file which does absolutely nothing, except returning 0

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

Artem S. Tashkinov  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|CLOSED                      |UNCONFIRMED
         Resolution|INVALID                     |

--- Comment #12 from Artem S. Tashkinov   2010-03-18 04:37:00 ---
Between wine invocations of the aforementioned exe file, wine still rewrites
both system and user registry files, even though this particular file doesn't
have any GUI.

diff -u system.reg.1 system.reg.2
--- system.reg.1        2010-03-18 14:29:18.000000000 +0500
+++ system.reg.2        2010-03-18 14:30:10.000000000 +0500
@@ -12128,7 +12128,7 @@
 "CommonPictures"=str(2):"%ALLUSERSPROFILE%\Pictures"
 "CommonVideo"=str(2):"%ALLUSERSPROFILE%\Videos"

-[Software\Microsoft\Windows\CurrentVersion\Fonts] 1268904555
+[Software\Microsoft\Windows\CurrentVersion\Fonts] 1268904606
@@ -14266,7 +14266,7 @@

[Software\Microsoft\Windows NT\CurrentVersion\FontMapper] 1268904477

-[Software\Microsoft\Windows NT\CurrentVersion\Fonts] 1268904555
+[Software\Microsoft\Windows NT\CurrentVersion\Fonts] 1268904606

[birdie@localhost .wine]$ diff -u user.reg.1 user.reg.2
--- user.reg.1  2010-03-18 14:29:18.000000000 +0500
+++ user.reg.2  2010-03-18 14:30:10.000000000 +0500
@@ -428,10 +428,10 @@
 "MimeType"="application/xml"
 "ProgID"="xmlfile"

-[Software\Wine\Fonts] 1268904555
+[Software\Wine\Fonts] 1268904606
 "Codepages"="1252,437"

-[Software\Wine\Fonts\External Fonts] 1268904555
+[Software\Wine\Fonts\External Fonts] 1268904606

Alexander, please, explain what's the meaning of those integers behind registry
keys names and why those integers need to be changed even though a set of fonts
in the system remains intact.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #13 from Artem S. Tashkinov   2010-03-18 04:43:27 ---
Created an attachment (id=26873)
 --> (http://bugs.winehq.org/attachment.cgi?id=26873)
nasm -f bin -o micro.exe micro.asm (the smallest windows PE executable)

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

Alexandre Julliard  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID

--- Comment #14 from Alexandre Julliard   2010-03-18 05:13:37 ---
As already mentioned, the font cache gets updated. This doesn't matter. If you
absolutely cannot live with this, you can work on making the corresponding keys
volatile.

You still haven't demonstrated a real problem, and trying to "optimize" for the
case of an empty app that does nothing isn't particularly interesting.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #15 from Artem S. Tashkinov   2010-03-18 06:40:22 ---
(In reply to comment #14)
> As already mentioned, the font cache gets updated. This doesn't matter. If you
> absolutely cannot live with this, you can work on making the corresponding keys
> volatile.

Can you please shed light on that - I'm not into Wine internals at all.
> You still haven't demonstrated a real problem, and trying to "optimize" for the
> case of an empty app that does nothing isn't particularly interesting.

Alexander, I guess 99% of Windows applications don't touch (write to) HKLM
registry hive when running, so I think this bug makes a perfect sense for e.g.
laptop users who would like to minimize disk thrashing.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

Dan Kegel  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[e-mail]

--- Comment #16 from Dan Kegel   2010-03-18 07:05:05 ---
Artem, can you measure how long the rewrite takes?
If this is an opportunity to speed up application
startup, maybe it's worth looking at.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #17 from Alexandre Julliard   2010-03-18 07:12:33 ---
Given that the rewrite happens at shutdown (and asynchronously) it's not going
to make the slightest difference for app startup times...

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #18 from Artem S. Tashkinov   2010-03-18 07:25:34 ---
> Given that the rewrite happens at shutdown (and asynchronously) it's not going
> to make the slightest difference for app startup times...

Orly?

Say we run a simple tiny application like ... notepad, after which wine server
almost instantly exits, then read my point below:

Since Wine stores registry as a text file, installing the complete, say, MS
Office 2003 plus Corel Draw X4/X5 may easily swell registry up to 50MB in size
and on a highly fragmented laptop drive, writing out such a file may easily
take ten seconds or even more.

That means a subsequent notepad run may be severely delayed until Wine server
finishes dumping the registry to a HDD.

I don't have a laptop, I don't have these applications installed and I have a
speed desktop drive (Seagate 7200.12) with almost zero fragmentation so my
results will be quite meaningless.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #19 from Dan Kegel   2010-03-18 07:48:07 ---
So you're proposing that the loop
  while sleep 10
  do
    wine cmd /c echo hi
  done
would keep a laptop drive busy if the user had installed Office?

If someone can confirm that, maybe it's worth looking at doing the
optimization,
but I'm not sure the optimization would actually help that case.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #20 from Artem S. Tashkinov   2010-03-18 07:52:39 ---
(In reply to comment #19)
> So you're proposing that the loop
>   while sleep 10
>   do
>     wine cmd /c echo hi
>   done
> would keep a laptop drive busy if the user had installed Office?

Exactly.
> If someone can confirm that, maybe it's worth looking at doing the
> optimization,
> but I'm not sure the optimization would actually help that case.

I don't care about any possible delays, I care about mass storage (which can be
e.g. cheap SSD which has a very limited number of rewrite cycles) and
efficiency.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

--- Comment #21 from Dan Kegel   2010-03-18 07:54:43 ---
Sure, any measure of waste (power consumption, cpu consumption, ...)
would be fine as a metric if it really impacts the user.

'Nuff said.  Show some measurable harm to the user and maybe it's worth fixing.

[Bug 10114] Wine shouldn't rewrite the registry if it hasn't been changed

http://bugs.winehq.org/show_bug.cgi?id=10114

Dmitry Timoshkov  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |CLOSED
          Component|kernel32                    |-unknown
           Platform|All                         |Other
         OS/Version|All                         |other

--- Comment #22 from Dmitry Timoshkov   2010-03-18 07:56:42 ---
Closing invalid.