[vtk-developers] vtkMultiThreader Class Error in Output

[Jatin Parekh]

Hi Berk,
That worked.
Thanks for your quick reply!

Jatin Parekh

On Sun, Oct 12, 2014 at 6:43 PM, Berk Geveci <berk.geveci at kitware.com>
wrote:

> Check out the documentation of SetSingleMethod(), which reads:
>
> > Set the SingleMethod to f() and the UserData field of the ThreadInfo
> that is passed to it will be data.
> > This method (and all the methods passed to SetMultipleMethod) must be of
> type
> > vtkThreadFunctionType and must take a single argument of type void *.
>
> The argument passed to SetSingleMethod() is wrapped by the ThreadInfo
> struct and passed to the method. Something like:
>
> cout <<  ((vtkMultiThreader::ThreadInfo*)data)->UserData << endl
>
> should do the trick. Also see:
>
>
> http://www.vtk.org/doc/nightly/html/classvtkMultiThreader_1_1ThreadInfo.html
>
> Best,
> -berk
>
> On Sun, Oct 12, 2014 at 5:11 AM, Jatin Parekh <jatinparekh93 at gmail.com>
> wrote:
>
>> Hi!
>> I have a simple code as shown below. I am passing the same parameter to a
>> function via a normal function call and another via the vtkMultiThreader
>> SpawnThread. However, I am unable to get the expected output.
>>
>> *#include <iostream>*
>>
>> *#include <vtkMultiThreader.h>*
>>
>> *void *ThreadedFunction(void *data)*
>>
>> *{*
>>
>> *    std::cout << data << std::endl;*
>>
>> *}*
>>
>> *int main()*
>>
>> *{*
>>
>> *    vtkMultiThreader *threaded = vtkMultiThreader::New();*
>>
>> *    void *x = (void *)1;*
>>
>>
>>  *    std::cout << "Non Threaded function call:" << std::endl;*
>>
>> *    ThreadedFunction(x);*
>>
>>
>>  *    std::cout << "Now in threads:" << std::endl;*
>>
>> *    threaded->SpawnThread(ThreadedFunction, x);*
>>
>> *    return 0;*
>>
>> *}*
>>
>>
>> If I understand correctly, the output for both, the threaded function call as well as non threaded function call should be the same.
>>
>> But it gives me the following output:
>>
>> *Non Threaded function call:*
>>
>> *0x1*
>>
>> *Now in threads:*
>>
>> *0x10a89d0*
>>
>>
>> SO, the non-threaded function call displays the correct value whereas the MultiThreader call displays some different value.
>>
>> I don't get the reason why the 2 function calls give different outputs. Are they supposed to be different? If yes, then can someone please explain why it is supposed to be so?
>>
>> If no, then any ideas/hints on where I could possibly be making an error?
>>
>>
>> Thanks!
>>
>> Jatin Parekh
>>
>>
>> _______________________________________________
>> Powered by www.kitware.com
>>
>> Visit other Kitware open-source projects at
>> http://www.kitware.com/opensource/opensource.html
>>
>> Follow this link to subscribe/unsubscribe:
>> http://public.kitware.com/mailman/listinfo/vtk-developers
>>
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtk-developers/attachments/20141012/858b8c82/attachment-0002.html>