[DSOUND] Implement a locking mechanism

[Robert Reif]

Maarten Lankhorst wrote:

>[DSOUND] Implement a locking mechanism
>
>Attempt to implement locking in dsounds mixer.
>
>Sadly horribly broken, I'm posting this in the hope someone knows what
>magic values to fill in at the first "if (lock)" .. I really have no clue.
>
>As stated before it is required to be used with previous winealsa patch.
>
>Right now it also calls Unlock with lockamount as argument, this should
>probably be changed to how much is actually written to (frag), but that
>part doesn't really matter much I think, it's more important to get the
>first Lock() right.
>  
>
You shouldn't need to make any changes to direct sound.  You just need 
to remove the flag DSDDESC_DONTNEEDPRIMARYLOCK from alsa and make the 
necessary changes in alsa.  The direct sound hardware primary buffer 
locking support is already in primary.c.