[Imstk-developers] high-speed thread in iMSTK

[Dzenan Zukic]

Each mesh could have its own mutex, which needs to be obtained by the
thread which wants to write it. Or if a thread can do something else, use
trylock and come back later to the mesh which was already locked.

Regards

Dženan Zukić, PhD, Senior R&D Engineer, Kitware (Carrboro, N.C.)

On Thu, Jun 22, 2017 at 3:45 PM, Milef, Nicholas Boris <milefn at rpi.edu>
wrote:

> Ok, after talking to Zhaohui and profiling, it appears to be a thread
> synchronization issue (which is why it only shows up in debug mode).
>
> This is the problem:
> The render thread reads the mesh data. If the transform hasn't been
> applied, it gets applied.
> The physics thread writes the mesh data. If the transform hasn't been
> applied, it gets applied.
>
> The problem is that the render thread continually modifies the data as
> it's reading it. Meanwhile, the physics thread is setting data very quickly
> (or vice-versa, depending who wins the race condition). We saw earlier that
> the physics thread was less than 1 FPS, but now the render thread is less
> than 1 FPS. We don't synchronize between threads (which is another
> problem), so this is what's causing this.
>
> Any ideas on how to proceed?
> ------------------------------
> *From:* Imstk-developers [imstk-developers-bounces at imstk.org] on behalf
> of Dzenan Zukic [dzenan.zukic at kitware.com]
> *Sent:* Friday, June 09, 2017 11:53 AM
> *To:* Zhaohui Xia
>
> *Cc:* imstk-developers at imstk.org
> *Subject:* Re: [Imstk-developers] high-speed thread in iMSTK
>
> Hi Zhaohui,
>
> something like this
> <https://stackoverflow.com/questions/41264827/setting-optimization-settings-in-visual-studio-through-cmake>
> should work, you need to modify debug mode instead of release though.
>
> Regards
>
> Dženan Zukić, PhD, Senior R&D Engineer, Kitware (Carrboro, N.C.)
>
> On Fri, Jun 9, 2017 at 11:50 AM, Zhaohui Xia <unihui at gmail.com> wrote:
>
>> Hi Dzenan,
>>
>>
>>
>> Thanks for your advice. We need to set it for all the projects in the
>> solution, is this correct?
>>
>> Can we change it in the .CMakeList file to change the whole settings in
>> an easy way?
>>
>>
>>
>> Thanks,
>>
>> Zhaohui
>>
>> *From:* Dzenan Zukic [mailto:dzenan.zukic at kitware.com]
>> *Sent:* 2017年6月9日 8:57
>> *To:* Zhaohui Xia <unihui at gmail.com>
>> *Cc:* Andinet Enquobahrie <andinet.enqu at kitware.com>;
>> imstk-developers at imstk.org
>>
>> *Subject:* Re: [Imstk-developers] high-speed thread in iMSTK
>>
>>
>>
>> Hi Zhaohui,
>>
>>
>>
>> to enable a somewhat higher speed of debug mode, you can manually change
>> the compiler settings for individual projects, see this
>> <https://msdn.microsoft.com/en-us/library/8f8h5cxt.aspx> and this
>> <https://msdn.microsoft.com/en-us/library/k1ack8f1.aspx>. Enabling
>> optimizations increases difficulty of debugging, so you might enable more
>> optimizations for the Visual Studio projects you are not trying to debug,
>> and keep optimization disabled or at a low setting for the ones you are
>> modifying.
>>
>>
>>
>> Regards
>>
>>
>> Dženan Zukić, PhD, Senior R&D Engineer, Kitware (Carrboro, N.C.)
>>
>>
>>
>> On Thu, Jun 8, 2017 at 3:33 PM, Zhaohui Xia <unihui at gmail.com> wrote:
>>
>> Hi Andinet,
>>
>>
>>
>> I am afraid I made a mistake. The device thread is definitely a
>> high-speed thread. I figure out the issue, because I forget to close
>> something when I change the code in that thread.
>>
>>
>>
>> I think there is no performance bottlenecks currently in the main thread
>> under Release mode (60-70HZ), since the mesh size (1000 vertices) is not
>> very big now.
>>
>> But under Debug mode, the speed is too slow, it is just 0.16HZ for the
>> same mesh. Do we have any ways to improve it, e.g. changing some settings?
>> It would be very helpful for work if it can run faster.
>>
>>
>>
>> Thanks,
>>
>> Zhaohui
>>
>> *From:* Andinet Enquobahrie [mailto:andinet.enqu at kitware.com]
>> *Sent:* 2017年6月8日 13:29
>> *To:* Zhaohui Xia <unihui at gmail.com>
>> *Cc:* imstk-developers at imstk.org
>> *Subject:* Re: [Imstk-developers] high-speed thread in iMSTK
>>
>>
>>
>> Zhaohui
>>
>>
>>
>> Can you profile your code and let us know the key performance bottlenecks
>> in iMSTK?
>>
>>
>>
>> This is something Dr. Des is also interested. We will be exploring ways
>> of accelerating some of the modules.
>>
>>
>>
>> thanks
>>
>> Andinet
>>
>>
>>
>>
>>
>>
>>
>> On Thu, Jun 8, 2017 at 12:40 PM, Zhaohui Xia <unihui at gmail.com> wrote:
>>
>> Hi All,
>>
>>
>>
>> Do we have a high-speed thread (e.g. 1000HZ) in iMSTK? I tried different
>> modules e.g VRPNDeviceServer (device) and SceneMange (main thread), but the
>> maximum frame rates of them are 60-70HZ under Release mode.
>>
>> I also tried to set the Loopdelay to 0.001 or smaller (from my
>> understand, its default value is 0 should have the fastest speed, but it
>> also 60-70HZ).
>>
>>
>>
>> Thanks,
>>
>> Zhaohui
>>
>> ------------------------------------------------------------
>> -----------------------------------------------
>>
>> Zhaohui Xia, Ph.D.
>> Postdoctoral Research Associate, Center for Modeling, Simulation and
>> Imaging in Medicine (CeMSIM)
>> Rensselaer Polytechnic Institute
>>
>>
>> _______________________________________________
>> Imstk-developers mailing list
>> Imstk-developers at imstk.org
>> http://public.kitware.com/mailman/listinfo/imstk-developers
>>
>>
>>
>>
>>
>> --
>>
>> Andinet Enquobahrie, Ph.D., MBA
>> Director of Medical Computing
>> Kitware, Inc.
>>
>> http://www.kitware.com
>>
>> (919) 969-6990 x311 <%28919%29%20969-6990%20x311>
>>
>>
>>
>>
>>
>>
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>>
>>
>>
>
>
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