[GRASS-dev] ParallelModuleQueue freezes...

[Stefan Blumentrath]

Thanks, Markus.

Seems that the ParallelModuleQueue itself works if it is fed with Module objects, but not if MultiModule objects are put into the queue...

So, I believe I am struggling with the same issue as Luca:
https://github.com/OSGeo/grass-addons/pull/523#issue-629160914

Can it be that returns of the MuliModule should be different? If I understand the source code [1]  correctly, Module returns "self" (a Module object) while MultiModule returns "None". Can that be the root cause?

Any help is much appreciated...

Cheers
Stefan

1: https://grass.osgeo.org/grass79/manuals/libpython/_modules/pygrass/modules/interface/module.html#MultiModule

-----Original Message-----
From: Markus Neteler <neteler at osgeo.org> 
Sent: tirsdag 25. mai 2021 20:17
To: Stefan Blumentrath <Stefan.Blumentrath at nina.no>
Cc: GRASS developers list <grass-dev at lists.osgeo.org>
Subject: Re: [GRASS-dev] ParallelModuleQueue freezes...

Hi Stefan,

On Tue, May 25, 2021 at 2:33 PM Stefan Blumentrath <Stefan.Blumentrath at nina.no> wrote:
>
> Dear devs,
>
>
>
> Currently, I am trying to run a combination of ParallelModuleQueue and MultiModule as described here in GRASS 7.8:
>
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgras
> s.osgeo.org%2Fgrass79%2Fmanuals%2Flibpython%2Fpygrass.modules.interfac
> e.html%3Fhighlight%3Dparallel%2520module%2520qu%23pygrass.modules.inte
> rface.module.ParallelModuleQueue&data=04%7C01%7C%7C61c3f8df57d44d9
> 0905108d91fa9435d%7C6cef373021314901831055b3abf02c73%7C0%7C0%7C6375756
> 34109191335%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
> IiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=PC64zLohfEqbxUcNfX4U
> hHHNf5VIgRO7x0o%2FbiYHyU4%3D&reserved=0
>
> It seems - in contrast to the documentation - also the finish_= parameter needs to be set to True for the modules to run.
>
> However, after finishing the queue, the script stalls and does not seem to get over queue.wait().
>
> Just to be clear, also the code from the doc does not seem to work for 
> me...

While I have no direct recommendation you may want to check the working code here, in the addons:
- t.rast.mosaic
- t.sentinel.import
- t.sentinel.mask
- t.rast.resample

See: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fsearch%3Fq%3Dorg%253Amundialis%2BParallelModuleQueue%26type%3Dcode&data=04%7C01%7C%7C61c3f8df57d44d90905108d91fa9435d%7C6cef373021314901831055b3abf02c73%7C0%7C0%7C637575634109191335%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=tbzIS%2FhRmi6hWOAuieoNxubEN73Q8MDmfqHK0wyy7eE%3D&reserved=0

Best,
Markus