r.mapcalculator in a loop generates C++ runtime error

[lobelius]

Hello. I'm employing r.mapcalculator in a QGIS console loop as per the following line. The script works just fine. However, from time to time, subprocess sh.exe raises a Windows C++ Runtime popup error R6016, which stops the loop as long as user doesn't click the ok button (attached an example taken from internet). The loop itself just freezes up, but doesn't terminate.

import processing

for i in range (0,1000): processing.runalg('​grass:r.mapcalculator',img1,img2,None,None,None,None,'A*B','-180,180,-90,90',0.25,imgout)

Any clues?

[lobelius]

runtime error

[marisn]

This is not a GRASS GIS bug but a QGIS one. There is a limit of 60 threads/processes that can use MSVCRT and this loop most likely hits limit before unloading happens. Upgrading MSVCRT or fixing QGIS code are the only two options.

More in KB 126709: ​https://support.microsoft.com/en-us/help/126709/prb-error-on-win32s-r6016---not-enough-space-for-thread-data