}}

}}

}}

> I've noticed that vector creation time increases as the number of
> vectors created increases. Below is a dramatic illustration. This
> example was performed using BLT 2.4x with Tcl 8.3.2 on Windows NT.
> % time { for {set i 0} {$i< 2000} {incr i} {
>   blt::vector create #auto
> }}
> 4607000 microseconds per iteration
> % time { for {set i 0} {$i< 2000} {incr i} {
>   blt::vector create #auto
> }}
> 15372000 microseconds per iteration
> % time { for {set i 0} {$i< 2000} {incr i} {
>   blt::vector create #auto
> }}
> 27729000 microseconds per iteration
> Could this be caused by the vector creation command doing a linear
> search for the existence of the vector name? If so, maybe a hash table
> of vector names could remedy this.
> This latency is a real issue I'm facing where I could have over 5000
> vectors being created at a given time.

> > I've noticed that vector creation time increases as the number of
> > vectors created increases. Below is a dramatic illustration. This
> > example was performed using BLT 2.4x with Tcl 8.3.2 on Windows NT.

> > % time { for {set i 0} {$i< 2000} {incr i} {
> >   blt::vector create #auto
> > }}
> > 4607000 microseconds per iteration
> > % time { for {set i 0} {$i< 2000} {incr i} {
> >   blt::vector create #auto
> > }}
> > 15372000 microseconds per iteration
> > % time { for {set i 0} {$i< 2000} {incr i} {
> >   blt::vector create #auto
> > }}
> > 27729000 microseconds per iteration

> > Could this be caused by the vector creation command doing a linear
> > search for the existence of the vector name? If so, maybe a hash table
> > of vector names could remedy this.

> > This latency is a real issue I'm facing where I could have over 5000
> > vectors being created at a given time.

> Your diagnosis is exactly right.  There's a lot of (redundant)
> checking going on for a unique vector name.  I've fixed this
> so that vector generation appears linear.

>     % time { for {set i 0} {$i< 2000} {incr i} {
>        blt::vector create #auto
>     }}

>     58738 microseconds per iteration
>     46543 microseconds per iteration
>     42922 microseconds per iteration
>     44836 microseconds per iteration
>     42191 microseconds per iteration
>     45373 microseconds per iteration
>     57235 microseconds per iteration
>     53460 microseconds per iteration
>     42213 microseconds per iteration
>     43422 microseconds per iteration
>     45275 microseconds per iteration
>     43782 microseconds per iteration
>     43708 microseconds per iteration
>     41264 microseconds per iteration

> I can send you a patch if need something right away.  This bug affects
> only "#auto" vector name generation.  Therefore, if you make up your
> own vector name, you won't see this slowdown.

>     % time { for {set i 0} {$i< 2000} {incr i} {
>   blt::vector create v$i
>     }}
>     37720 microseconds per iteration
>     56042 microseconds per iteration
>     55467 microseconds per iteration
>     45022 microseconds per iteration
>     45199 microseconds per iteration
>     44782 microseconds per iteration
>     46710 microseconds per iteration
>     44679 microseconds per iteration
>     46323 microseconds per iteration
>     44841 microseconds per iteration
>     44291 microseconds per iteration

> Thanks for the bug report and the diagnosis.  I really appreciate it.

> --gah