__dri2ParseEvents() would determine the kind of event, but then call
UpdateBuffer() in either case, and UpdateBuffer() would then have to
figure that out again to dispatch to HandleBufferAttach() or
HandleDrawableConfig(). Pretty pointless.
This is defaulted off as it has potentially large memory costs for a modest
performance gain. Ideally we will improve DRM performance to the point where
this optimization is not worth the memory cost in any case, or find some
middle ground in caching only limited numbers of certain buffers. For now,
this provides a modest 4% improvement in openarena on GM965 and 10% in openarena
on GM945.
Instead of passing in a fixed struct, the loader now passes in a list
of __DRIextension structs, to advertise the functionality it can provide
to the driver. Each extension is individually versioned and can be
extended or phased out as the interface develops.
Right now the DRI2 screen constructor takes 3 different versions:
DRI, DDX and DRM. This is mostly useless, though:
DRI: The DRI driver doesn't actually care about the DRI protocol,
it only talks to the loader, which in turn speaks DRI protocol. Thus,
the DRI protocol version is of not interest to the DRI driver, but it
needs to know what functionality the loader provides. At this point
that's reflected in the __DRIinterfaceMethods struct and the
internal_version integer.
DDX: The DDX version number is essentially used to track extensions
to the SAREA. With DRI2 the SAREA consists of a number of versioned,
self-describing blocks, so the DDX version is no longer interesting.
DRM: We have the fd, lets just ask the kernel ourselves.
The DriverAPI is internal to the DRI drivers and GetDrawableMSC
obsoletes GetMSC. Also, since the DRI driver interface has not yet
been released, just drop the getMSC function from the DRI interface
instead using the ABI preserving version mechanism.
Finally, using void pointer privates in the DRI interface is not allowed,
always pass the actual types around (__DRIdrawable in this case) to
enhance type safety and readability of the code.
The screen wide info such as pitch and cpp are obsoleted by the FBO
changes, so clean up the last few references to those, except for
setting up the legacy screen regions.
Putting the bufmgr in the screen is not thread-safe since the emit_reloc
changes. It also led to a significant performance hit from pthread usage
for the attempted thread-safety (up to 12% of a cpu spent on refcounting
protection in single-threaded 965). The motivation had been to allow
multi-context bufmgr sharing in classic mode, but it wasn't worth the cost.
This was replaced in previous releases of xserver/dri/libGL by reporting the
damage to the frontbuffer so that the server and driver could handle it
appropriately.
