send q VRf-Timeslicing_Userfunctions ww vrf kennedy_d PDereux@aol.com
from: Greg Goebel / HP-MXD
gvg@lvld.hp.com / 970-679-3030 / FAX 970-679-5971
to: P-E Dereux
date: Monday, 05 May 1997 1029 MDT
> From: PDereux@aol.com
> To: hpvxd_xc@hpislsup.lvld.hp.com
>
> Hye !
>
> Some comments about point 5 (objects running simultaneously in VEE 4.00)
> and 1 question about Vee 4.0 :
>
> I've not yet tried Vee 4.00, but what I can tell some about Vee 3.21 and
> multithreads.
> In Vee 3.21, if you have several threads running simultaneously, and each
> calling the same user function at the same time, these function calls will be
> executed sequentially, on call after this other. And I hope it's unchanged in
> Vee 4.00.
> IS IT STILL TRUE IN VEE 4.0???
Yes, it is still true, though only if you call the *same* UserFunction. They
are not reentrant.
However, if you are executing *different* UserFunctions, they *will*
timeslice. This was not true in older versions of VEE.
This turns out to affect a few people in a negative fashion. We are likely
to incorporate a flag in a future version of VEE that allows you to select
timeslicing or "atomic" operation.
> Note it's very usefull for "real time" features : if this function (and
> others ...)
> reads / writes a data, you could imagine the mess if all the function calls
> try to read /write the same data in the "same time" ...
> Hope this will help.
>
> P-E Dereux
> E S Lab
> Bell Helicopter Textron Canada
If you have more questions, let us know.
[<>] regards -- gvg
from: Greg Goebel / HP-MXD
gvg@lvld.hp.com / 970-679-3030 / FAX 970-679-5971
to: P-E Dereux
date: Monday, 05 May 1997 1029 MDT
> From: PDereux@aol.com
> To: hpvxd_xc@hpislsup.lvld.hp.com
>
> Hye !
>
> Some comments about point 5 (objects running simultaneously in VEE 4.00)
> and 1 question about Vee 4.0 :
>
> I've not yet tried Vee 4.00, but what I can tell some about Vee 3.21 and
> multithreads.
> In Vee 3.21, if you have several threads running simultaneously, and each
> calling the same user function at the same time, these function calls will be
> executed sequentially, on call after this other. And I hope it's unchanged in
> Vee 4.00.
> IS IT STILL TRUE IN VEE 4.0???
Yes, it is still true, though only if you call the *same* UserFunction. They
are not reentrant.
However, if you are executing *different* UserFunctions, they *will*
timeslice. This was not true in older versions of VEE.
This turns out to affect a few people in a negative fashion. We are likely
to incorporate a flag in a future version of VEE that allows you to select
timeslicing or "atomic" operation.
> Note it's very usefull for "real time" features : if this function (and
> others ...)
> reads / writes a data, you could imagine the mess if all the function calls
> try to read /write the same data in the "same time" ...
> Hope this will help.
>
> P-E Dereux
> E S Lab
> Bell Helicopter Textron Canada
If you have more questions, let us know.
[<>] regards -- gvg
--- On Mon, 5 May 1997 10:38:39 -0600 Greg Goebel <gvg@hpislsup.lvld.hp.com> wrote:
> send q VRf-Timeslicing_Userfunctions ww vrf kennedy_d PDereux@aol.com
>
> from: Greg Goebel / HP-MXD
> gvg@lvld.hp.com / 970-679-3030 / FAX 970-679-5971
> to: P-E Dereux
> date: Monday, 05 May 1997 1029 MDT
>
> > From: PDereux@aol.com
> > To: hpvxd_xc@hpislsup.lvld.hp.com
> >
> > Hye !
> >
> > Some comments about point 5 (objects running simultaneously in VEE 4.00)
> > and 1 question about Vee 4.0 :
> >
> > I've not yet tried Vee 4.00, but what I can tell some about Vee 3.21 and
> > multithreads.
> > In Vee 3.21, if you have several threads running simultaneously, and each
> > calling the same user function at the same time, these function calls will be
> > executed sequentially, on call after this other. And I hope it's unchanged in
> > Vee 4.00.
> > IS IT STILL TRUE IN VEE 4.0???
>
> Yes, it is still true, though only if you call the *same* UserFunction. They
> are not reentrant.
>
> However, if you are executing *different* UserFunctions, they *will*
> timeslice. This was not true in older versions of VEE.
>
> This turns out to affect a few people in a negative fashion. We are likely
> to incorporate a flag in a future version of VEE that allows you to select
> timeslicing or "atomic" operation.
>
> > Note it's very usefull for "real time" features : if this function (and
> > others ...)
> > reads / writes a data, you could imagine the mess if all the function calls
> > try to read /write the same data in the "same time" ...
> > Hope this will help.
> >
> > P-E Dereux
> > E S Lab
> > Bell Helicopter Textron Canada
>
> If you have more questions, let us know.
>
> [<>] regards -- gvg
---------------End of Original Message-----------------
Greg,
I cannot get timeslicing to work using VEE 4.0 for multiple user functions or user objects as shown in the
example program I sent to the forum last week. It did work for user objects under 3.21. I expected it to
work for both functions and objects under 4.0. Any ideas?
--------------------------------------------------------
Name: Tom Sanders
E-mail: toms@symca.com (Tom Sanders)
Date: 05/05/97
Time: 09:49:08
--------------------------------------------------------