[PATCH 4/4] miext/damage: Only wrap into the GC ops chain if there's a listener

[Aaron Plattner]

On 12/13/2011 02:31 PM, Adam Jackson wrote:
> Before:
> 40000000 trep @   0.0009 msec (1148346.9/sec): PutImage 10x10 square
> 60000000 trep @   0.0005 msec (2091666.1/sec): ShmPutImage 10x10 square
>
> After:
> 40000000 trep @   0.0008 msec (1191807.5/sec): PutImage 10x10 square
> 60000000 trep @   0.0005 msec (2180983.0/sec): ShmPutImage 10x10 square
>
> Signed-off-by: Adam Jackson<ajax at redhat.com>
> ---
>   miext/damage/damage.c |    6 +++++-
>   1 files changed, 5 insertions(+), 1 deletions(-)
>
> diff --git a/miext/damage/damage.c b/miext/damage/damage.c
> index d791211..dd4026b 100644
> --- a/miext/damage/damage.c
> +++ b/miext/damage/damage.c
> @@ -437,9 +437,13 @@ damageValidateGC(GCPtr         pGC,
>   		 unsigned long changes,
>   		 DrawablePtr   pDrawable)
>   {
> +    drawableDamage(pDrawable);
>       DAMAGE_GC_FUNC_PROLOGUE (pGC);
>       (*pGC->funcs->ValidateGC)(pGC, changes, pDrawable);
> -    pGCPriv->ops = pGC->ops;  /* just so it's not NULL */
> +    if (pDamage)
> +	pGCPriv->ops = pGC->ops;  /* just so it's not NULL */
> +    else
> +	pGCPriv->ops = NULL;
>       DAMAGE_GC_FUNC_EPILOGUE (pGC);
>   }

I think this needs to be accompanied by a change to DamageRegister (or 
miDamageRegister) to bump the drawable's serial number, or else creating 
a Damage object on a drawable won't cause GCs that are already validated 
against it to have the damage ops hooked in.

-- Aaron