[Qgis-developer] Fwd: Threads in sextante

Victor Olaya volayaf at gmail.com
Tue May 29 03:02:57 PDT 2012


it all goes perfect :-)

> Note that iterating parameter values are not yet supported. Am looking
> into it, not sure if sextante or the backends make any assumptions
> about the order of iteration (that is, I have to use 1 thread or
> multiple synced threads) or if I can just run them in parallel.

The iterating execution could be run in paralell, asumming that
several threads can open the same layer at the same time. the layer to
be iterated is converted in n layers, each on containing just one
feature, but if the algorithm uses other layers, they are used all the
same for all the executions. I guess that opening some kind of formats
might block the file, which might cause other threads to fail.

Unless we are completely sure that all file formats (or data sources,
more generally speaking) can be accesed simultaneously and
independently by several threads (which I am no sure, and I think that
might not be like that), it is better to execute the processes on
after the other, just like calling several algorithms as it happens in
the modeler or the batch processing interface.

Regards, and keep the good work going :-)

> Thanks & regards,
> Camilo

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