[vtkusers] VTK in a multi-threaded program

[Richard Whitehead]

Seb,
Many thanks for the reply.  I don't think that what you suggest can
necessarily be safe, because Update might create temporary objects and that
involves the singleton garbage collector.

The correct solution is for the garbage collector to be thread-safe. This
would only involve some mutex locking, but I don't feel confident to
attempt it, even if I had time (I'm now under a lot of time pressure).
Many thanks,

Richard


On 24 March 2014 14:56, Sebastien Jourdain
<sebastien.jourdain at kitware.com>wrote:

> Another approach could be that the creation and the linkage with the UI is
> going through the single UI thread, but you rely on another thread to
> execute the actual pipeline by calling Update() on the mapper. Although, do
> not connect that pipeline yet to the render window until that working
> thread is done.
>
> Just my 2 cents,
>
> Seb
>
>
>
> On Mon, Mar 24, 2014 at 8:32 AM, Aashish Chaudhary <
> aashish.chaudhary at kitware.com> wrote:
>
>> Hi Richard,
>>
>> On Mon, Mar 24, 2014 at 10:25 AM, Richard Whitehead <
>> richard.whitehead at vivosight.com> wrote:
>>
>>> David,
>>> Unfortunately I am now in a really bad place.  I have some long-winded
>>> calculations to do and then visualise, which I want to do in a background
>>> thread.  This is for a commercial application and hanging the GUI is
>>> completely unacceptable.  I have now invested several man-months into VTK
>>> and I have to decide whether to drop it.  I think the only sensible thing I
>>> can do is to get rid of VTK from my calculations and only use it for
>>> visualisation.
>>>
>>
>> FYI, we have successfully used VTK in a multi-threaded environment for
>> our VisGUI application framework (
>> http://www.kitware.com/source/home/post/84) specifically dealing with
>> computations. Rendering was done single threaded though. The trick involved
>> writing our own thread safe version of vtkSmartPointer (I believe you are
>> doing something similar).
>>
>> - Aashish
>>
>>
>>
>>>  Many thanks,
>>> Richard
>>>
>>>
>>>
>>> On 24 March 2014 12:29, David Cole <dlrdave at aol.com> wrote:
>>>
>>>> You are definitely not going crazy. The really, really rather foul
>>>> thing, that frustrates me all the time, is when I must do some VTK
>>>> operation which takes significant time (on the order of seconds or minutes,
>>>> rather than the typical fraction of a second) ... and then it makes the GUI
>>>> completely unresponsive until the operation is done.
>>>>
>>>> I spend rather a lot of my time making sure that everything I do that's
>>>> VTK-based is at interactive speeds as much as possible to absolutely
>>>> minimize the user pain associated with this.
>>>>
>>>> Pushing long operations completely into a separate non-GUI thread would
>>>> be absolutely fantastic. I look forward to the day when such a thing
>>>> becomes possible.
>>>>
>>>>
>>>> :-)
>>>> D
>>>>
>>>>
>>>
>>>
>>> --
>>>
>>> Richard Whitehead *-* Senior Imaging Engineer
>>>
>>> *Michelson Diagnostics Ltd*
>>>
>>> *M:* +44 (0)7905 955276   *T:* +44 (0)20 8308 1695
>>>
>>> *E: *richard.whitehead at vivosight.com   *W:* www.vivosight.com
>>>
>>>
>>> <http://www.vivosight.com/>
>>>
>>>
>>> Michelson Diagnostics Ltd, 1 Grays Farm Production Village, Grays Farm
>>> Road, Orpington, Kent  BR5 3BD, UK
>>>
>>> Registered Office: 3 Shearwater, Maidstone, ME16 0DW.     Registered in
>>> England No. 5732681
>>>
>>> _______________________________________________
>>> Powered by www.kitware.com
>>>
>>> Visit other Kitware open-source projects at
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>>
>>
>> --
>> | Aashish Chaudhary
>> | R&D Engineer
>> | Kitware Inc.
>> | www.kitware.com
>>
>> _______________________________________________
>> Powered by www.kitware.com
>>
>> Visit other Kitware open-source projects at
>> http://www.kitware.com/opensource/opensource.html
>>
>> Please keep messages on-topic and check the VTK FAQ at:
>> http://www.vtk.org/Wiki/VTK_FAQ
>>
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>>
>


-- 

Richard Whitehead *-* Senior Imaging Engineer

*Michelson Diagnostics Ltd*

*M:* +44 (0)7905 955276   *T:* +44 (0)20 8308 1695

*E: *richard.whitehead at vivosight.com   *W:* www.vivosight.com


<http://www.vivosight.com/>


Michelson Diagnostics Ltd, 1 Grays Farm Production Village, Grays Farm
Road, Orpington, Kent  BR5 3BD, UK

Registered Office: 3 Shearwater, Maidstone, ME16 0DW.     Registered in
England No. 5732681
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