[PATCH 1/3] winmm: Fix mciSendString command parsing on 64-bit.

Octavian Voicu octavian.voicu at gmail.com
Fri Aug 27 11:53:18 CDT 2010

On Fri, Aug 27, 2010 at 7:36 PM,  <Joerg-Cyril.Hoehle at t-systems.com> wrote:
> Octavian Voicu wrote:
>>> so binary compatibility in RC files is required
>>We don't have this right now. Native winmm.dll uses integer resource
>>ids (id 200 for core commands, [...])
>>Wine currently uses string ids
> Could you please elaborate on that? I wasn't aware of an incompatibility.

Check out this job on wine testbot:

I copied the table loading code from mci.c, but had to change the code
that loaded the tables, because in native winmm.dll, tables are
identified by an integer resource id (not a string one):

str = MAKEINTRESOURCEW(200); /* this is for CORE table I guess, as it
doesn't match any known device type */

I read somewhere that WIN98 and earlier stored tables in mmsystem.dll,
that's why all the tests fail.

If somebody would be interested, he could use resedit (free download
from www.resedit.net) to open resources in dlls (www.topdll.com has a
lot of dlls of various versions). Latest ones have versions something
like 6.1.7600.* (ie. the ones used by win7).

Anyway, compare the full log (from the testbot job 4830 linked
eralier) for tests W7PROX64 (32 bit mci) and W7PROX64 (64 bit mci).
Conclusion is that 32 bit mci uses MCI_INTEGER as return type for
MCI_STATUS, while 64 bit one uses MCI_INTEGER64.

I'll add MCI_INTEGER64 to mmddk.h (#ifdef-ed like in the ddk) and also
something like MCI_INTEGER3264 which will be MCI_INTEGER on 32 bit
systems, and MCI_INTEGER64 on 64 bit systems. Then use MCI_INTEGER3264
in winmm_res.rc & others.

>>> I don't agree here. IMO the parser should be the most agnostic possibly
>>> against the real data structures
>>Not sure if I understand exactly what you mean here
> I believe Eric envisions a parser that needs no MCI_*_PARMS at all
> because everything lies in the resource (except that the first
> DWORD_PTR is the callback).  Even MCI_RETURN need not be second (yet
> there's no known case where that happens).  It would be a major change
> from the current parser.
> It could be sketched as follows:
>  - get first token (verb)
>  - get second token (beware of quoting) ("device")
>  - find driver according to device
>    - either name of an existing alias
>    - or name of MCI driver ("waveaudio")
>    - or waveaudio!foo.wav
>    - or "all"
>    - or something else
>  - load driver's command table (may need loading driver!)
>  - parse command options according to table
> Now we know the command's numeric value and can act upon it.
> That would be much more compatible than what is in place now.
> Still, the devil lies in the details. E.g. a)
> sound
> sound notify
> are valid MCI commands. Look ma, no device!

I'll look into it, sounds like a challenge :)

> b) Sysinfo cdaudio quantity open
> need IMHO not load the cdaudio driver. It strictly operates at winmm's
> level.  Perhaps first try to identify the verb via the core table, and
> if it's a core command like MCI_SYSINFO, never load the driver?
> MCI_SYSINFO_PARMS.wDeviceType needs special treatment anyway,
> the parser is not enough.
> c) When to unload the driver?
> At some point one needs MCI_*_PARMS.  For instance, it's winmm's job
> to detect MCIERR_DUPLICATE_ALIAS.  How is it going to access the alias
> field if not via MCI_OPEN_PARMS and thus imposing that all
> MCI_*_OPEN_PARMS are congruent?  (e.g. MCI_DGV|WAVE_OPEN_PARMS).
> One could imagine backparsing the resource file to detect the position
> of the slot that defines the MCI_ALIAS element... This is just crazy.
> I've tests that prove (and a patch in my queue) that unlike the
> mciSendCommand interface, the string parser always sets an alias.  So
> at some point it must set the lpstrAlias slot.  How is it going to do
> that if not via MCI_OPEN_PARMS?

Not very familiar with this part yet, so I'll focus on getting basic
64 bit support working first, while also looking at the big picture
when possible.


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